JPH08322809A - Taction sensor - Google Patents

Abstract

PURPOSE: To provide a hardness sensor with which the information on the change in hardness with a wide rage of the surfaces of a measuring object is obtainable rapidly with relatively good accuracy. CONSTITUTION: This taction sensor consists of a probe 1 for the taction sensor including at least one ultrasonic oscillators and having a contact part for measurement to be brought into contact with vital tissues and a detecting circuit 22 for detecting the change in the resonance characteristics of the ultrasonic vibrator transducers when the contact part for measurement is brought into contact with the vital tissues and converting this change to the information on the hardness of the vital tissues. The regions where the ultrasonic oscillators act on the surface of the vital tissue sections with which the contact part for measurement comes into contact are made two-dimensional.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tactile sensor which is brought into contact with an object such as a living body to detect the hardness at the contact portion.

[0002]

2. Description of the Related Art As a conventional technology of this kind of tactile sensor,
First, there is a hardness sensor disclosed in Japanese Patent Laid-Open No. 2-290529. This hardness sensor is provided with a piezoelectric element on a vibration plate that contacts an object, and this piezoelectric element has an oscillation circuit and
A detection circuit for detecting a change in the resonance frequency that occurs when the object is touched is connected, and the hardness of the object is measured by the output from the detection circuit.

In Japanese Patent Publication No. 40-27236, a flexibility measuring device is proposed. This device converts electrical energy from an ultrasonic oscillator into ultrasonic vibration energy through a piezoelectric element and applies this ultrasonic vibration energy to a metal needle, while changing the mechanical load due to ultrasonic vibration at the tip of the metal needle. Is taken out as a change in acoustic impedance in the piezoelectric element, and the flexibility of an object with which the tip of the metal needle hits is measured.

[0004]

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 within a wide surface. Also, when trying to obtain hardness information in a plane with a spread using such a measuring device, it is necessary to move the sensing part including the piezoelectric vibrator by hand. The pressing force on the object fluctuates greatly. If the amount of pressing force greatly changes, the hardness of the pressed portion naturally changes, and it becomes difficult to obtain information under the same condition.

Furthermore, in particular, when the target object is a living body, there are many soft tissues by nature, and it is practically difficult to perform strict measurement, that is, movement of the piezoelectric element within a wide range by uniform pressing. It requires considerable skill to move the tip of the sensor 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.

The present invention has been made in view of the above problems, and an object thereof is to obtain information on the change in hardness over a wide range of surfaces of an object to be measured in a short time and relatively accurately. It is to provide a hardness sensor capable of

[0007]

The present invention provides a tactile sensor probe including at least one or more ultrasonic transducers and having a measuring contact portion for contacting the living tissue, and the measuring contact portion for the living tissue. Detecting means for detecting the change in the resonance characteristic of the ultrasonic transducer when contacted with the ultrasonic transducer and using it as the information of the hardness of the biological tissue, It is a tactile sensor characterized in that the tactile sensor is equipped with a driving means for making a region on which a sound wave oscillator acts two-dimensionally. By scanning the ultrasonic transducer with a means capable of two-dimensionally scanning, it is possible to measure a change in resonance characteristic over a wide range.

[0008]

【Example】

<First Embodiment> A first embodiment of the present invention will be described with reference to FIGS. (Purpose) The purpose of this example is mainly to obtain information on the change in hardness over a wide range of surfaces in a short time, and to insert it into a body cavity in a minimally invasive state to the human body. The point is to make direct contact with them so that information on hardness changes can be obtained. (Structure) FIG. 1 shows an outline of a tactile sensor system. This 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 includes a distal end portion 3 that comes 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 gripping part 7 required for operation, and a cable 8 for exchanging signals with the probe control part 2 is connected to the gripping part 7 of the probe 1. The sensor unit 1 having the ultrasonic transducer 9 housed in the side surface of the tip 3 of the probe 1
0 is provided. A signal line 11 is connected to the ultrasonic transducer 9.

In the probe 1, the outer diameters of the tip portion 3, the elastic bending portion 4, and the insertion tube 5 which are connected in series are substantially the same, and these portions, as shown in FIG. It can be inserted into the body cavity through the tube 12.
The tip portion 3 and the elastic bending portion 4 are rotatably fixed to the insertion tube 5 via the bearing portion 13. The insertion tube 5 is fixed to the case 14 of the drive unit 6.

A rotary drive source 16 to which a drive force transmission shaft 15 is connected is arranged in the case 14. Driving force transmission shaft 1
5 is inserted into 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 arranged in the driving force transmission shaft 15. The distal end portion 3 and the elastic bending portion 4 are operated by the rotary drive source 16 via the drive force transmission shaft 15 to rotate about the insertion tube 5, that is, the sensor portion 10 serves as a measurement contact portion. A driving means is provided which two-dimensionally smoothes the region where the ultrasonic transducer 9 acts on the surface of the living tissue that comes into contact.

In the drive unit 6, an encoder 17 for obtaining rotation information of the drive force transmission shaft 15 and a slip ring 1 for relaying an electric signal with the sensor unit 10 through a signal line 11.
8 are provided.

On the other hand, the probe control unit 2 in this system is roughly divided into the following. That is, an ultrasonic drive unit 21 for sending an ultrasonic drive signal to the sensor unit 10 housed in the tip portion 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 counting unit 22 or the hardness of the living tissue part corresponding thereto, and the tip portion 3
And a scanning control unit 24 that controls the rotary drive source 16 to perform scanning. (Operation / Effect) When this probe 1 is used, 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 punctured in the body cavity wall 25 in advance, and the elastic bending portion 4 is bent. The distal end portion 3 is made substantially perpendicular to the insertion tube 5, and the sensor portion 10 is brought into contact with the surface of the living tissue part 26 in the body cavity. When the rotational force of the rotary 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 indicated by arrows around the insertion tube 5 while maintaining the bent state. Rotate as shown. That is,
Due to the elasticity of the elastic bending portion 4, the tip portion 3 has its sensor portion 10
The sensor unit 10 scans the surface of the biological tissue portion 26 in an annular shape by moving the surface of the biological tissue portion 26 while always contacting the surface of the biological tissue portion 26. The resonance frequency detected by the sensor unit 10 at this time is measured by the frequency counting unit 22. Generally, the frequency change has a characteristic that the softer the material, the greater the amount of change with respect to the frequency in the air. Therefore, the hardness of the body tissue portion corresponding to the change in the frequency is measured.

That is, the sensor section 10 serves as a measurement contact section, and the sensor section 10 is driven so as to two-dimensionally smooth the area on the surface of the living tissue with which the ultrasonic transducer 9 acts. As a result, information on the change in hardness can be obtained over a wide range of biological tissue parts. Further, it is possible to associate the hardness information by the encoder 17 with the information on the position sequentially operated, and in this way, the hardness information on each position over a wide range can be individually obtained.

Further, since the probe 1 can be inserted through the outer tube 12 such as a trocar, it is less invasive to the subject, and yet the tip portion 3 is bent with respect to the insertion tube 5 in the body cavity. Since the tip 3 can be rotated,
Even in comparison with the outer diameter of the outer tube 12, a wide range of hardness can be efficiently measured. Furthermore, by inserting it into the body cavity, it becomes possible to apply the sensor unit 10 more directly to the target site. In addition, the elastic bending portion 4 constantly urges the sensor portion 10 at an appropriate pressure, and the contact pressure becomes stable, so that the hardness measurement accuracy can be improved. <Second Embodiment> A second embodiment of the present invention will be described with reference to FIG. (Purpose) The purpose of this embodiment is mainly to provide a low-cost system in which information on hardness change over a wide range of surfaces can be obtained relatively accurately in a short time with a simple configuration. It is in. (Structure) The probe 30 of this embodiment includes a housing 31. An elastic film body 32 made of, for example, silicon rubber is stretched over the front opening of the housing 31. Inside the housing 31, the ultrasonic transducer 33 and the vibration propagating body 3 are provided.
A sensor unit portion 36 that is unitized from 4 is provided. The vibration propagating body 34 has a tip portion 37 formed in a conical shape with a slightly rounded tip. Housing 3
1, a ball screw 38 is arranged in parallel with the surface of the film body 32, and a ball screw 3 is provided on one side of the housing 31.
8 is provided with a stepping motor 39. The rotation information of the ball screw 38 by the stepping motor 39 is obtained by the encoder 40.

The unitized sensor unit portion 36 is supported by a ball screw 38, and is movable in the horizontal direction in the drawing, that is, the direction along the surface of the film body 32, by the rotation of the ball screw 38. In other words, the driving means is provided which two-dimensionally smoothes the region where the ultrasonic transducer acts on the surface of the living tissue. The tip portion 37 of the vibration propagating body 34 of the sensor unit portion 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 with respect to 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 section 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 unit 36, a frequency count unit for measuring the resonance frequency detected by the sensor unit unit 36, and a frequency count unit for measuring the resonance frequency. And a stepping motor 39 as a rotation driving source for scanning the sensor unit 36.
A scanning control unit and the like for controlling the are provided. The rotation information of the ball screw 38 obtained by the encoder 40 is also transmitted to the probe control unit. (Operation / Effect) When the probe 30 of this embodiment is used, the membrane 32 is applied to the surface of the living tissue part 44 in advance as shown in FIG. Then, a command is given to the probe controller to drive the stepping motor 39, and the ball screw 38
Is rotated to move the sensor unit portion 36 along the film body 32. Vibration propagating body 3 in the sensor unit section 36
The tip portion 37 of 4 moves so as to be in smooth contact with the inner surface of the film body 32, is pressed against the surface of the living tissue part 44 through the film body 32, and linearly moves to perform two-dimensional scanning. This provides information on hardness changes over a wide range. Furthermore, it is possible to associate the hardness information with the position information by the encoder 40, and in this way, the hardness information at each position over a wide range can be individually obtained.

According to this embodiment, since the hardness information is obtained by mechanically scanning a single ultrasonic transducer, it is not necessary to correct the individual difference of the ultrasonic transducer. . Therefore, the accuracy in measuring the frequency change is good.

Further, since the wiring is small and the structure is simple, an inexpensive probe can be realized. Further, the circuit in the probe control unit is also simplified, so that the system is inexpensive. In addition, since the film body is stretched over the housing that is molded according to the horizontal scanning width, by applying this probe to the test object, it is possible to uniformly press within the scanning range. It is possible and the measurement accuracy is improved.

The probe of this embodiment can be used in measuring the hardness of the living tissue in the body cavity by being constructed in a relatively small size so as to be introduced into the body cavity for use. <Third Embodiment> A third embodiment of the present invention will be described with reference to FIG. (Purpose) The purpose of this embodiment is to provide a system in which hardness change information can be obtained over a wide range of surfaces in a short period of time with a simple configuration, and with relatively high accuracy. It is to be able to provide a probe that is difficult to do. (Structure) The probe 50 of this embodiment includes a housing 51. An elastic film body 52 made of, for example, silicon rubber is stretched on the front opening of the housing 51. Inside the housing 51, the ultrasonic transducer 53 and the vibration propagating body 5 are provided.
Sensor unit part 5 of the same configuration unitized from 4
A plurality of 6 are arranged side by side and fixedly arranged. The tip portion 57 of the vibration propagating body 54 of the sensor unit portion 56 is formed in a conical shape with a slightly rounded tip. The plurality of sensor unit portions 56 are arranged in a line so that the tip 57 of the vibration propagating body 54 contacts the inner surface of the film body 52, and are arranged in parallel and in close contact with each other. That is,
A region where the ultrasonic transducer 53 acts on the surface of the living tissue constitutes a driving means for smoothing the region two-dimensionally.

The signal supply to the ultrasonic transducer 53 is guided to the probe control section as described above via the cable section 58. Each sensor unit unit 56 is provided in the probe control unit.
An ultrasonic drive unit for sending an ultrasonic drive signal to
A frequency counting unit that measures the resonance frequency detected by each sensor unit unit 56, a display unit that displays the frequency change measured by the frequency counting unit, and the like are provided. The ultrasonic drive units may be built in as many as the ultrasonic transducers 53, or the number of drive units may be reduced from the number of the ultrasonic transducers 53 by using a drive signal switching circuit. (Operation / Effect) When the probe 50 of this embodiment is used, the film body 52 is applied to the surface of the living tissue site. Then, a command is given to the probe controller to drive the ultrasonic transducer 53 of each sensor unit 56, and the resonance frequency detected by each sensor unit 56 is measured. Information on the change in hardness can be obtained from the difference in the resonance frequency. The sensor unit portions 56 are two-dimensionally arranged in a line, and therefore, information on the hardness change over a wide range can be obtained. Further, the hardness information of each position corresponding to each sensor unit portion 56 can be individually obtained over a wide range.

Since the ultrasonic transducers 53 of the plurality of sensor unit portions 56 can be driven almost simultaneously, the measurement can be performed in a very short time. Therefore, there are few time restrictions on the subject. Since the housing 51 and the film body 52 have a certain area, uniform pressing can be obtained, and the hardness measurement accuracy is improved. Since the probe 50 itself has no mechanically moving element, once assembled, it is unlikely to break down. <Fourth Embodiment> A fourth embodiment of the present invention will be described with reference to FIGS. (Purpose) The purpose of this embodiment is to provide a system that can obtain information on hardness change over a wide range of surfaces in a relatively short time and with relatively high accuracy. (Structure) The probe 60 of this embodiment includes a drum 63 rotatable with respect to a main body 62 having a handle 61.
The drum 63 has a slip ring 64. Drum 6
3 also has an elastic cylindrical film body 66 made of, for example, silicon rubber, attached to a part of the cylindrical housing 65,
A plurality of sensor unit parts 67 are radially arranged in this. Similar to the third embodiment, the sensor unit portion 67 has the same configuration in which the ultrasonic transducer 68 and the vibration propagating body 69 are unitized.
The tip portion 70 of 9 is directed to the outside so as to contact the inner surface of the film body 66. The drum 63 has a plurality of sensor unit parts 67.
By incorporating the above, the driving means is configured to two-dimensionally smooth the region where the ultrasonic transducer 68 acts on the surface of the living tissue. The plurality of sensor unit parts 67 are arranged at equal intervals radially around the rotation center of the drum 63. However, in order to increase the number of the sensor unit parts 67 and arrange them densely, the center side base parts thereof are adjacent to each other. The side portions 71 are narrowed and tightly butted.

The cable portion 72 connected to the ultrasonic transducer 68 is bundled toward the cylindrical center of the drum 63, as shown in FIG.
Is connected to the slip ring 64, and is electrically connected to the cable portion 72 inserted in the handle 61. The cable portion 72 is led out from the end surface of the handle 61 and is connected to the probe control portion as described above.

Each sensor unit 6 is provided in the probe controller.
7, an ultrasonic drive unit for sending an ultrasonic drive signal, a frequency count unit for measuring the resonance frequency detected by each sensor unit 67, and a display for displaying the frequency change measured by this frequency count unit. Units and the like are provided. The ultrasonic drive units may be built in as many as the ultrasonic transducers 68, or the number of drive units may be less than the number of sensor unit sections 67 by using a drive signal switching circuit. (Operation / Effect) When using the probe 60 of this embodiment, the drum 63 is applied to the surface of the living tissue part and rolled. Then, the ultrasonic transducer 68 of each sensor unit 67 is driven, and the resonance frequency detected by each sensor unit 67 is measured. Information on the change in hardness can be obtained from the difference in the resonance frequency. The respective sensor unit parts 67 are radially arranged on the rotating drum 63, and by applying the sensor unit parts 67 to the surface of the living tissue part and rolling it, information on the hardness change over a wide range can be obtained. Further, the hardness information at each position corresponding to each sensor unit portion 67 can be obtained over a wide range.

By rolling the drum 63 while holding the handle 61, the hardness is two-dimensionally measured without pressing the single sensor unit portion 67 into a point contact and always holding the object with a wide surface including the housing 65. Since the measurement can be performed and the drum 63 is rolled, the pressing pressure is less likely to vary, and the information on the change in hardness can be obtained accurately. <Modification> In the third and fourth embodiments described above, the sensor unit parts are arranged in a line, but the sensor unit parts may be arranged in a plurality of lines. With this configuration, a large number of sensor unit parts can be opposed to the measurement site at one time, and thus a wide range can be measured in a shorter time.

Another example of the tactile sensor system will be described with reference to FIGS. 7 and 8. (Structure) FIG. 7 shows a schematic structure of a tactile sensor system according to this example, which is provided with a tactile sensor probe 82 and a probe control unit 83 which are introduced into a body cavity through the endoscope 81. ing.

The tactile sensor probe 82 has a long and flexible insertion portion 84, and the tip portion 85 of the insertion portion 84.
The sensor unit portion as shown in FIG. That is, the cylindrical ultrasonic transducer 8 is attached to the tip portion 85.
6 is provided coaxially with respect to the long axis of the insertion portion 84, and the ultrasonic transducer 86 is coaxially covered with a tip cover 87 in a close contact state. The outer peripheral side surface of the tip cover 87 forms a contact portion 88 for contacting, for example, a tubular organ. The cylindrical ultrasonic transducer 86 is polarized so as to vibrate in the radial direction x with respect to its central axis as shown in FIG. 8B. Then, the ultrasonic transducer 86 and the contact portion 88 are integrally united 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 inside of 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 an oscillating operation is provided at the hand of the tactile sensor probe 82. The operator can arbitrarily operate the operation switch 92.

The probe control section 83 is provided with an oscillating circuit 93 which oscillates a signal for vibrating the ultrasonic transducer 86 at the resonance frequency. A frequency detection circuit 94 and a voltage detection circuit 95 are connected to the oscillation circuit 93, and constitute a means for monitoring a change in resonance frequency and a change in mechanical impedance. (Operation) When the hardness of the luminal organ is measured using this tactile sensor system to identify the position of the lesion, the operation is performed as follows. First, the tactile sensor probe 8 is inserted through the channel of the endoscope 81 that is previously inserted into the body cavity.
2 is guided and the tip portion 85 of the tactile sensor probe 82 is inserted into the luminal organ 98 of the patient 97 under the observation of the endoscope 81. FIG. 8A shows the state.

Then, the contact portion 88 of the tip portion 85 is moved inside the organ 98 while contacting the inner surface of the tubular organ 98. Here, when the operator 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 the signal from the oscillation circuit 93. The mechanical impedance changes according to the hardness of the organ 98 due to the contact of the contact portion 88 with the organ 98, and the resonance frequency of the contact portion 88 changes, but the resonance frequency of the resonance frequency changes because the oscillation circuit 93 performs self-excited oscillation. It is possible to oscillate following changes. The change in the resonance frequency at this time is monitored by the frequency detection circuit 94, and the change in voltage is monitored by the voltage detection circuit 95, and the information on at least one of them can be obtained as the change information on the hardness of the organ 98. For example, the position of the lesioned part 99 localized under the mucous membrane of the organ 98 can be identified by the hardness change information. (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. Lesions such as tumors 9
It is possible to exert excellent operability for judging the presence of the No. 9 element.

An example of the tactile sensor system will be described with reference to FIGS. 9 and 10. (Structure) FIG. 9 shows a schematic structure of the tactile sensor system according to this example.
Tactile sensor probe 10 introduced into body cavity through
2 and the probe control unit 103. Apart from this, a rigid endoscope 105 to be introduced into the body cavity through the trocar outer tube 104 is prepared.

The tactile sensor probe 102 is provided with a long rigid insertion portion 106, and a sensor unit portion as shown in FIG. 10 is incorporated in the tip end portion 107 of the insertion portion 106. That is, the cylindrical ultrasonic transducer 108 is provided on the tip portion 107 in a state of being coaxially arranged 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 tip portion 107. Further, the ultrasonic vibrator 108 has a vibration angle conversion element 109 also serving as a tactile contact portion at its tip.
The vibration angle conversion element 109 internally reflects the vibration received from the ultrasonic vibrator 108 and converts the vibration direction obliquely forward with a specific angle with respect to the central axis direction x. The tip portion of the vibration angle conversion element 109 projects from the hole 112 of the cover 111, and the tip portion thereof forms a slightly rounded contact portion 113.

The signal line 11 is connected to the electrode of the ultrasonic transducer 108.
4 are connected. The signal line 114 is connected to the insertion section 106.
After being guided to the hand side through the inside of the probe, it is connected to the probe control unit 103 through the signal cable 115. Further, an operation switch 116 for operating the oscillation operation is provided at the hand of the tactile sensor probe 102. The operator can arbitrarily operate the operation switch 116.

The probe control unit 103 is provided with an oscillating circuit 93 which oscillates a signal for vibrating the ultrasonic oscillator 108 at the resonance frequency. A frequency detection circuit 94 and a voltage detection circuit 95 are connected to the oscillation circuit 93, and constitute a means for monitoring changes in resonance frequency and changes in mechanical impedance. (Operation) When the hardness of the abdominal organ is measured by using this tactile sensor system to identify the position of the lesion, the procedure is as follows. The tactile sensor probe 102 is inserted into the abdominal cavity through the trocar mantle 101, and the rigid endoscope 1
Under the observation of 05, the vibration angle conversion element 1 protruding obliquely
The contact portion 113 at the tip of 09 is moved on the surface of the organ 121 while contacting 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 having the contact portion 113 and the ultrasonic vibrator 108 are the oscillation circuit 93.
The vibration from the resonance frequency is integrally generated by the signal from the. The tip of the contact portion 113 has a tactile sensor probe 102.
It vibrates by projecting diagonally forward with respect to the axis of. Therefore, the organ 1 obliquely in front of the tactile sensor probe 102
21 can be easily approached. By the self-excited oscillation, the ultrasonic vibrator 108 and the vibration angle conversion element 109 integrally vibrate at the resonance frequency. Further, as shown in FIG. 10, in the contact portion 113, longitudinal vibration in the x direction perpendicular to the contact surface is performed. The contact of the contact portion 113 with the organ 121 changes the mechanical impedance 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-excited oscillation. It oscillates following changes in the resonance frequency. The change in the resonance frequency is monitored by the frequency change detection circuit 94,
Further, the voltage change is monitored by the voltage detection circuit 95, and at least one of them can be obtained as the change information of the hardness of the organ 121. By the change in hardness, for example, the position of the lesion 122 localized inside the organ 121 can be identified. (Effect) Organ 1 diagonally ahead of the tactile sensor probe 102
Since the hardness can be measured with respect to 21, the operability thereof can be improved.

An example of the tactile sensor probe will be described with reference to FIGS. 11 and 12. (Structure) In the tactile sensor probe 131 in this example, thin film-like energy confinement type vibrators 133 are arranged on both upper and lower side surfaces near the tip of the body cavity insertion portion 132. The number of the energy confinement type vibrators 133 may be one or more, and the energy confinement type vibrators 133 may be formed as one tubular shape.

The energy confinement vibrator 133 vibrates in the film thickness direction, but is attached so as to vibrate in the direction perpendicular to the axis of the tactile sensor probe 131, and serves as a contact portion 134 to the outside. It is airtightly covered with a resin film such as polyurethane or silicon.

This energy confining oscillator 133 is shown in FIG.
It is configured as shown in FIG. That is, the electrodes 136 are formed on both surfaces of the arc-shaped thin plate 135 of piezoelectric element material such as ceramics.
The arc-shaped thin plate 135 is polarized in the film thickness direction. Further, the ultrasonic oscillator 133 and the contact portion 134 are integrated with each other 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 oscillator 133 can be formed using, for example, a semiconductor manufacturing technique.

Electrode 13 of energy confinement oscillator 133
A signal line 137 is connected to 6. This signal line 13
7 is connected to the probe controller as described above. Further, an operation switch (in the figure) for operating the oscillation operation is provided at the hand of the tactile sensor probe 131. The operator can operate the operation switch arbitrarily.

The probe control section is provided with an oscillation circuit for oscillating a signal for vibrating the energy confinement type oscillator 133 at the resonance frequency. A frequency detection circuit and a voltage detection circuit are connected to the oscillation circuit, and constitute a means for monitoring a change in resonance frequency and a change in mechanical impedance. (Operation) This tactile sensor probe 131 is inserted endoscopically into the tubular organ, and is moved inside the organ while the contact portion 134 is in contact with the inner surface of the organ. At this time, the operator operates the oscillation switch to operate the oscillation circuit. The ultrasonic vibrator 133 and the contact portion 134 integrally vibrate at the resonance frequency according to the signal from the oscillation circuit. The contact of the contact portion 134 with the organ changes the mechanical impedance according to the hardness of the organ,
Although the resonance frequency of No. 4 changes, the oscillation circuit performs self-excited oscillation, so that the oscillation can follow the change of the resonance frequency. The change in the resonance frequency is monitored by the frequency detection circuit, and the change in the voltage is monitored by the voltage detection circuit, and at least one of these can be obtained as the change information of the hardness of the organ. From this, it is possible to identify the position of a lesion localized under the mucosa of an organ, for example. (Effect) According to the tactile sensor probe 131 of this embodiment, since the hardness characteristic in the direction perpendicular to the insertion direction is measured as a change in frequency or voltage, it is possible to measure, for example, a tumor under the mucous membrane of a tubular organ. Excellent operability can be exhibited for determining the presence of a lesion. [Additional Notes] 1. A tactile sensor probe including at least one or more ultrasonic transducers and having a contact portion for measurement which is brought into contact with a biological tissue, and resonance characteristics of the ultrasonic transducer when the contact portion for measurement is brought into contact with the biological tissue. Detecting means for detecting the change in the body tissue and using it as the information of the hardness of the living tissue, and the region where the ultrasonic transducer acts on the surface of the living tissue contacting the measuring contact portion is two-dimensional. A tactile sensor comprising a driving means for tightening. 2. The tactile sensor according to Supplementary Note 1, wherein the driving unit includes a plurality of ultrasonic transducers and drives them at the same time. 3. The tactile sensor according to Item 1, wherein the driving unit includes a plurality of ultrasonic vibrators and electrically switches and drives the ultrasonic vibrators. 4. The tactile sensor as set forth in appendix 1, wherein the driving means mechanically scans one ultrasonic transducer. 5. The tactile sensor according to item 1, wherein the driving means mechanically scans a plurality of ultrasonic transducers. 6. The tactile sensor according to Supplementary Note 1, wherein the tactile sensor includes a plurality of ultrasonic vibrators, and the ultrasonic vibrators are linearly arranged. 7. The tactile sensor according to Supplementary Note 1, wherein the tactile sensor includes a plurality of ultrasonic transducers, and the ultrasonic transducers are arranged in a ring shape. 8. The tactile sensor according to Additional Note 1, comprising a plurality of ultrasonic transducers, 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 at the distal end side of the elastic bending portion is inserted in a bent state. The tactile sensor according to claim 1, wherein the tactile sensor is rotated around a central axis of the portion. 10. A tactile sensor probe including at least one or more ultrasonic transducers and having a contact portion for measurement that makes contact with biological tissue, and resonance characteristics of the ultrasonic transducer when the contact portion for measurement is brought into contact with biological tissue. In the tactile sensor equipped with a detection circuit for detecting the change of the body temperature and using it as the information of the hardness of the living tissue, the vibration direction of the ultrasonic vibration in the measuring section is not parallel to the central axis of the tactile sensor probe. A tactile sensor characterized by. 11. The tactile sensor according to Additional Note 10, wherein the ultrasonic transducer has a cylindrical shape and is polarized in the radial direction. 12. The tactile sensor according to Supplementary Note 10, wherein a vibration direction conversion member is arranged between the ultrasonic transducer and the measurement unit. 13. 11. The tactile sensor according to appendix 10, wherein the ultrasonic transducer is an energy confinement type transducer. 14. 14. The tactile sensor according to appendix 13, wherein the energy confinement type vibrator is attached to a side surface of a probe. (Problems with Conventional Examples of Supplementary Notes 10 to 14) A tactile sensor has been proposed which measures hardness of a biological tissue by bringing a probe that vibrates ultrasonically into contact with the biological tissue and detecting a change in resonance frequency of the probe. There is. Such a tactile sensor is used to measure the elasticity of the skin or to identify the position of a tumor localized under the mucosa in a body cavity by 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 bring the measurement object into contact with the axial direction of the probe. was there. For this reason, it is difficult to measure the tactile sensation of the living tissue existing laterally of the probe or diagonally forward, and there is a problem that operability is extremely poor.

Supplementary notes 10 to 14 provide a tactile sensor with good operability that can measure the tactile sensation of living tissue located in various directions regardless of the probe insertion direction 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 center axis of the probe, the ultrasonic waves in the measurement unit with respect to the biological tissue obliquely forward of the probe axis or on the side surface are not measured. Vibration can be easily input in the direction perpendicular to the surface of the living body, and a tactile sensor with good operability can be provided.

[0040]

As described above, according to the present invention, when hardness is measured by changing the frequency of ultrasonic waves, information on the change in hardness can be accurately measured in a wide range in a short time. can get.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an outline of a tactile sensor system according to a first embodiment.

FIG. 2 is an explanatory view of the usage state of the tactile sensor probe.

FIG. 3 is an explanatory diagram of a tactile sensor probe according to a second embodiment.

FIG. 4 is an explanatory diagram of a tactile sensor probe according to a third embodiment.

FIG. 5 is a perspective view of a tactile sensor probe according to a fourth embodiment.

FIG. 6 is a transverse sectional view of the tactile sensor probe.

FIG. 7 is an explanatory diagram showing an outline of a tactile sensor system.

FIG. 8 is an explanatory view of the tactile sensor probe.

FIG. 9 is an explanatory diagram showing an outline of another tactile sensor system.

FIG. 10 is an explanatory diagram of the tactile sensor probe of the same.

FIG. 11 is an explanatory diagram of another tactile sensor.

FIG. 12 is a perspective view of the energy confinement type vibrator.

[Explanation of symbols]

1 ... Tactile sensor probe, 2 ... Probe control unit, 3 ...
Tip part, 4 ... Elastic bending part, 5 ... Insertion tube, 6 ... Driving part, 9
... ultrasonic transducer, 10 ... sensor part, 11 ... signal line, 14
... case, 15 ... drive force transmission shaft, 16 ... rotary drive source, 1
7 ... Encoder, 18 ... Slip ring, 21 ... Ultrasonic drive unit, 22 ... Frequency counting unit, 24 ...
Scan control unit.

Claims (1)

[Claims] 1. A tactile sensor probe having at least one ultrasonic transducer and having a measuring contact portion for contacting with biological tissue, and ultrasonic waves when the measuring contact portion is brought into contact with biological tissue. A detection unit for detecting a change in the resonance characteristic of the oscillator and using it as information on the hardness of the biological tissue, and a region where the ultrasonic oscillator acts on the surface of the biological tissue in contact with the measurement contact portion is A tactile sensor characterized in that it is provided with a driving means that can be made two-dimensionally.