JP2000081385A - Tactile sensor probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tactile sensor probe for making thin an insertion part. SOLUTION: A sensor element 15 by a piezoelectric vibrator where a sensor surface is exposed is provided at the tip side part of a flexible insertion part 2, a self-excitation oscillation circuit 20 that is located at the rear side of and near the sensor element 15 and is turned into an integrated circuit is provided in the insertion part 2, the self-excitation oscillation circuit 20 is mounted to a flexible substrate 23 the flexible substrate 23 allows the self-excitation circuit 20 to be divided into a plurality of circuit parts and circuit parts 21 and 22 to be dispersed and mounted and at the same time, allows them to be arranged inside the insertion part 2, and the width of the flexible substrate 23 between the dispersed circuit parts 21 and 22 is smaller than the circuit parts 21 and 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tactile sensor probe for detecting a tactile sensation (reaction) when it comes into contact with an object having viscoelastic properties.

[0002]

2. Description of the Related Art In recent years, surgery and diagnosis in a body cavity using an endoscope have been expanding, and tactile information as well as visual information is important for proper diagnosis and treatment in a body cavity. .
The tactile sensation here is a perception due to a reaction when coming into contact with an object having viscoelastic properties.

Conventionally, a tactile sensor for detecting the viscoelastic characteristics of an object as mechanical impedance has been proposed (Japanese Patent Laid-Open No. Hei 8-261915). This conventional tactile sensor is configured as a probe that detects the mechanical impedance of an object having viscoelastic properties from the output signal of a self-excited oscillation circuit composed of a piezoelectric vibrator, and a piezoelectric vibrator and an equivalent circuit of the piezoelectric vibrator. A transmitting circuit using a constant is assembled to the housing.

[0004]

[Problems to be Solved by the Invention]
By the way, as a characteristic of the vibration type sensor using the Colpitts circuit, a sensor driving circuit must be provided near the sensor piezoelectric vibrator. However, in the conventional tactile sensor, since the sensor driving circuit is configured by individual single electronic components, each electronic component is bulky,
The size of the circuit part was considerably large. For this reason, it has been difficult to reduce the diameter and size of the tactile sensor probe. In addition, since the size of the circuit is increased, it is difficult to reduce the diameter of the endoscope so that it can be used by being inserted into a narrow passage such as a channel formed on the endoscope. It is particularly difficult to provide a sensor probe having a flexible insertion portion so that it can be inserted.

(Object) The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to reduce the diameter of an insertion portion and to make the insertion portion flexible if necessary. It is also possible to provide a tactile sensor probe.

[0006]

(Means) The present invention is provided with a tactile sensor for detecting the mechanical impedance of an object having viscoelastic characteristics by the output signal of a self-excited oscillation circuit composed of a piezoelectric vibrator. In the tactile sensor probe, a flexible insertion portion, a piezoelectric vibrator provided at a tip side portion of the insertion portion, and a self-excited oscillation provided at a rear side of the piezoelectric vibrator inside the insertion portion. A circuit, and a flexible substrate connected to the distal end portion of the insertion portion, on which the self-excited oscillation circuit is formed, wherein the self-excited oscillation circuit is divided into a plurality of integrated circuit circuits. It is characterized in that each of the circuit sections is dispersed and arranged on a portion of the flexible substrate located inside the insertion section.

(Function) In the above structure, the circuit for driving the sensor is integrated and miniaturized, and the circuit is divided into a plurality of parts and provided separately on a flexible substrate so that the hard part does not become long. Thereby, the tactile sensor probe can be made thinner and more flexible. This allows the tactile sensor probe to be used, for example, by inserting it into a channel of a flexible endoscope.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. Figure 1 shows the first
1 shows the entire tactile sensor probe 1 according to the embodiment.
The tactile sensor probe 1 has a long flexible insertion portion 2,
A grip 3 is attached to a base end of the insertion section 2. An energizing cable 4 is led out from the rear end of the grip 3, and a connector 5 is provided at an extending end of the energizing cable 4.

The insertion section 2 has a diameter small enough to be inserted into a channel of an endoscope, for example, and has an outer diameter of, for example, φ2.5 mm. The length of the insertion portion 2 is, for example, 1,8.
00 mm, which is a length that allows the distal end portion to protrude from the distal end of the channel of the endoscope. Further, since the insertion portion 2 has flexibility, even if it is a flexible endoscope, it can be inserted through the channel. More specifically, the flexible tube 6 is formed by a portion of the flexible tube 6 forming substantially the entire length of the insertion portion 2 and a distal end portion 8 formed by a rigid housing 7 connected to the distal end of the flexible tube 6. I have. At the rear end of the housing 7, a cylindrical connecting portion 11 is integrally formed, and a flange portion 12 is formed at an intermediate outer periphery of the connecting portion 11. A flexible tube 6 is attached to the outer periphery of the connecting portion 11.
And the portion of the flexible tube 6 and the portion of the housing 7 of the distal end portion 8 are connected and fixed.

The flexible tube 6 has a structure in which a blade (metal cylindrical net) is sandwiched between the inside and outside of the resin by a resin. The thickness can be reduced, and a large space inside the flexible tube 6 can be secured. In addition, since the blade is used, the flexible tube 6 is resistant to crushing and has excellent torque followability.

A sensor element 15 is mounted on the tip 8. The housing 7 is made of an electrical insulator to connect wires to the sensor element 15 within the tip 8.
The housing 7 is particularly made of mica-based ceramics in order to ensure free cutting properties suitable for fine machining. As shown in FIG. 2, the lower end of the distal end portion 8 is cut off obliquely to form a sensor element mounting surface 17, and the sensor element mounting surface 17 is exposed with the sensor surface of the sensor element 15 exposed. It is installed. That is, the sensor element 15 is arranged slightly obliquely forward with respect to the longitudinal axis direction of the insertion section 2. For this reason, as will be described later with reference to FIG. 6, when used through the channel of the endoscope, the sensor surface of the sensor element 15 is easily brought into contact with the surface of the measurement target. Also, since the sensor element mounting surface 17 is formed by cutting off the front end portion 8 obliquely, the sensor element 1
5 can have a large area for mounting.

The sensor element 15 is configured as shown in FIG. That is, the sensor element 15 is a square made of piezoelectric ceramics and having a side of about 1.5 mm and a thickness of 0.12 mm. Circular electrodes 18a and 18b for confining energy are provided on both sides of the sensor element 15.
Are formed. By applying a voltage waveform between the electrodes 18a and 18b on both surfaces, the sensor element 15 oscillates by confining energy only in a portion between the electrode portions. That is, the change in the thickness of the sensor element 15 occurs only in the portion where the circular electrode 18 is formed,
The other parts are energy-trap type vibrators that do not vibrate.

The electrode 18a on the front side of the sensor element 15 passes through the side face of the sensor element 15 and the electrode 19a for wiring connection on the back side.
a. The back electrode 18b is connected to the back wiring connection electrode 19b. Therefore, on the back side of the sensor element 15, both the front and back electrodes 18a, 18b
The connection of the wiring from the tip 8 can be made.

The sensor element 15 resonates by an oscillation circuit 20 composed of a Colpitts circuit, which will be described later, and its resonance characteristics vary depending on the characteristics of an object with which the sensor element 15 is in contact. Therefore, by observing the change in the resonance frequency of the tactile sensor, the degree of hardness of the object with which the sensor element 15 is in contact can be distinguished.

The self-excited oscillation circuit 20 needs to be provided very close to the sensor element 15. For this reason, in the present embodiment, as shown in FIG. 2, the insertion portion 2 is located inside the vicinity of the distal end portion of the flexible tube 6 located on the distal end side. That is, the self-excited oscillation circuit 20 includes a plurality of circuit units 2
The plurality of circuit portions 21 and 22 are divided and arranged in the flexible tube 6.

The circuit board in which the self-excited oscillation circuit 20 is incorporated uses a flexible board 23, and the longitudinal direction of the flexible board 23 is arranged parallel to the longitudinal axis of the insertion section 2. The self-excited oscillation circuit 20 is divided into two circuit portions 21 and 22 on the flexible substrate 23. Further, each of the circuit portions 21 and 22 is made of a hybrid IC constituted by a bare chip. Since the components of the hybrid IC are relatively hard, the self-excited oscillation circuit 20 is divided into a plurality of circuit portions 21 and 22 and the hard portions are dispersed and arranged, thereby providing flexibility. Was held.

Further, in order to provide more flexibility, a first separating portion for connecting the circuit portion 21 on the distal end side of the flexible substrate 23 to the distal end portion 8 on which the sensor element 15 is mounted. 24a is smaller in width than the circuit section 21. Similarly, the portion of the second separation portion 24b connecting the circuit portions 21 and 22 is narrower than the portion constituting the circuit portions 21 and 22. According to the above configuration, the hard distal end portion 8 and the two circuit portions 21 and 22 are dispersedly connected by the flexible separation portions 24a and 24b. Be flexible. In addition, the length of the circuit parts 21 and 22 is about 12 mm, and the length of the separation parts 24a and 24b is about 20 mm.

A Colpitts circuit 26 is provided in the first circuit section 21.
, And a buffer circuit 27 is provided in the second circuit unit 22 on the hand side. Experiments have shown that when the sensor element 15 and the Colpitts circuit 26 are separated from each other by 8 cm or more, the oscillation of the sensor element 15 may become unstable or stop. Therefore, in the configuration of the first embodiment, since the distance between the sensor element 15 and the Colpitts circuit 26 is set to about 3 cm (or less), stable oscillation is possible.

The first circuit portion 21 is connected to the sensor element 15 at the distal end portion 8 through a wiring 28 on the first separation portion 24a of the flexible substrate 23, and the circuit portions 21 and 22 are connected to the second separation portion 24b. Are connected through the wiring 29. Further, the second circuit section 22 is connected to a wiring 31 that is connected to the near side of the flexible substrate 23. Wiring 31
Passes through the insertion section 2 and the grip 3 and is connected to an energizing cable 4 for connection to a drive and measurement system described later.
Then, a drive and measurement system is connected through the power supply cable 4.

The wiring 31 is a multi-core wiring, for example, a three-core wiring, and each line is a ground line 34, a power supply line 35, and a signal line 36. Further, if the capacitance between these three lines fluctuates, an adverse effect such as an unstable output of the sensor element 15 is given. Therefore, each core is parallel to the longitudinal direction and the distance between the lines is constant. Uses ribbon-shaped wiring.

The surface of the flexible substrate 23 is connected to the distal end portion 8 so as to be substantially parallel to the sensor element mounting surface 17 so as not to be twisted. Since the sensor element mounting surface 17 is formed by cutting off the distal end portion 8 obliquely, it is actually slightly inclined with respect to the surface of the flexible substrate 23.

The reason why the surface of the flexible substrate 23 and the sensor element mounting surface 17 are arranged in a substantially parallel and non-twisting direction is to facilitate the bending of the insertion portion 2 in the direction of the sensor surface of the sensor element 15. is there. The self-excited oscillation circuit 20
The circuit board is made of a flexible board 23 and is easily curved toward its surface side. However, it is desired that the circuit board bend along the board surface as much as possible so as not to be twisted. As shown in FIG. 6, when the sensor element 15 is pressed against an object, the insertion section 2 of the tactile sensor probe 1 is curved in the normal direction of the sensor surface of the sensor element 15. By arranging the surface of the substrate 23 in substantially parallel, there is an effect that the flexible substrate 23 is curved along the surface.

As shown in FIG. 5, the connecting portion 11 has a groove 2 into which both ends of the flexible substrate 23 are fitted.
5 are formed, and the flexible substrate 2 is
3 are fitted into the sensor element mounting surface 17.
The flexible substrate 23 can be attached to the distal end portion 8 in a state substantially parallel to the above. In this manner, the flexible substrate 2 is connected to the connecting portion 11 for connecting the flexible substrate 23.
Since the positioning means for determining the connection direction of the flexible substrate 23 is provided, the assemblability of the flexible substrate 23 is improved.
Note that a slit groove or the like may be used instead of the groove 25.

As shown in FIG. 1, when the tactile sensor probe 1 is inserted through the channel of the endoscope, the orientation of the sensor surface of the sensor element 15 at the distal end 8 can be recognized at the base side of the insertion section 2. Is provided with an index 32.

FIG. 4 shows a drive and measurement system in which the tactile sensor probe 1 is connected via the energizing cable 4. The energizing cable 4 extending from the tactile sensor probe 1 is connected to the repeater 41 by the connector 5. A DC power supply 42, a high-frequency amplifier 43, and a frequency counter 44 are connected to the repeater 41. The frequency counter 44 is connected to a personal computer (small computer terminal) 45, and a monitor 46 for displaying the output of the tactile sensor is connected to the personal computer 45.

The tactile sensor probe 1 and each device (DC power supply 42, high frequency amplifier 43, frequency counter 44) are connected via a repeater 41. The DC power supply 42 supplies electricity for driving the sensor element 15 and the oscillation circuit 20,
The high-frequency amplifier 43 amplifies the waveform signal output from the sensor element 15, and the signal amplified by the high-frequency amplifier 43 is sent to a frequency counter 44 to detect the frequency of the sensor output signal. The information from the frequency counter 44 is sent to the personal computer 45 for processing, and is imaged so that the operator can recognize the change in the frequency of the sensor output. By observing the monitor 46 connected to the personal computer 45, the operator can see the frequency change of the sensor element 15 as an image. Specifically, the frequency change of the sensor element 15 is displayed on the monitor 46 in the form of a bar graph. When the object is hard, the displayed bar is long, and when the object is soft, the bar is short.

FIG. 6 shows an actual use state of the tactile sensor probe 1 and shows a situation when the tip 8 of the tactile sensor probe 1 is pressed against the object 51. While operating the tactile sensor probe 1 protruding from the channel of the flexible endoscope 52 with the endoscope 52, the tip 8 of the tactile sensor probe 1 is pressed against the surface of the target object 51 so as to be measured. At the time of measurement, the entire surface (sensor surface) of the circular electrode of the sensor element 15 is made to hit the surface of the object 51.

According to the above configuration, the tactile sensor probe 1 having the thin and flexible insertion portion 2 can be obtained because the circuit portions 21 and 22 are integrated circuits and are arranged separately on the flexible substrate 23. .

(Modification) The portion of the housing 7 constituting the distal end portion 8 of the insertion portion 2 is not limited to a ceramic material, but may be made of another material such as plastic as long as it has good workability and is an insulator. good. The distal end portion 8 is divided into two parts, the mounting portion of the sensor element 15 on the distal end side is made of ceramic, and the side connected to the tube 6 on the rear side is made of another durable material such as stainless steel. May be used. The sensor element 15 may not be arranged obliquely at the distal end portion 8 but may be arranged at the cylindrical end face.

The length of the insertion portion 2 is not limited to 1,800 mm, but may be 1,500 mm depending on the length of the endoscope used together.
It may be up to 2,000 mm. Further, the tube 6 of the insertion portion 2 is not a shape in which a metal cylindrical mesh is sandwiched between resins, but may be a normal resin tube. Further, the display of the sensor output may be an XY graph of the horizontal axis time and the vertical axis frequency instead of the bar graph, or both the bar graph and the XY graph may be displayed.

<Supplementary Notes> In a tactile sensor probe equipped with a tactile sensor for detecting a mechanical impedance of an object having a viscoelastic characteristic by an output signal of a self-excited oscillation circuit composed of a piezoelectric vibrator, a flexible insertion portion, and a tip side portion of the insertion portion A self-excited oscillation circuit connected to a tip portion of the insertion portion, and a self-excited oscillation circuit provided at a rear side of the piezoelectric vibrator inside the insertion portion. And a flexible substrate on which the self-excited oscillation circuit is divided into a plurality of integrated circuit circuits, and each circuit section is located inside the insertion section. A tactile sensor probe, wherein the tactile sensor probe is dispersedly arranged on the flexible substrate.

2. 2. The tactile sensor probe according to claim 1, wherein a width of the flexible board between the circuit portions is smaller than that of the circuit portion. 3. 2. The tactile sensor probe according to claim 1, wherein a distal end surface of a distal end portion of the insertion section is formed substantially obliquely, and the piezoelectric vibrator is disposed on the distal end surface.

4. 2. The tactile sensor probe according to claim 1, wherein the sensor surface and the surface of the flexible substrate are arranged substantially in parallel. 5. 2. The tactile sensor probe according to claim 1, wherein a connecting portion of the distal end portion for connecting the flexible substrate is provided with positioning means such as a slit or a groove for positioning an orientation of connecting the flexible substrate.

6. The tactile sensor probe according to claim 1, wherein a multi-core wiring is connected to a rear end of the flexible substrate,
A ribbon-shaped wiring in which each core of the wiring is parallel to the longitudinal direction. 7. 2. The tactile sensor probe according to claim 1, wherein an index is provided on an outer surface of a rear end portion of the insertion portion so as to indicate a relative orientation of the piezoelectric vibrator with respect to a sensor surface. 8. 2. The tactile sensor probe according to claim 1, wherein the insertion portion includes a first resin tube, a metal cylindrical mesh provided on an outer surface of the resin tube, and a second resin mesh provided on an outer surface of the metal cylindrical mesh. Wherein the first resin tube, the metal cylindrical mesh, and the second resin tube are integrally formed. 9. 2. The tactile sensor probe according to claim 1, wherein the distal end of the insertion portion is made of an electrically insulating and free-cutting mica ceramic.

[0035]

As described above, according to the present invention, a small-diameter and flexible tactile sensor probe can be manufactured, so that the probe can be used, for example, by inserting it into a channel of a flexible endoscope for digestive organs. There is also an effect that you can also.

[Brief description of the drawings]

FIG. 1 is an overall view of a tactile sensor probe according to a first embodiment.

FIG. 2A is a side view of a portion near a distal end of an insertion portion of the tactile sensor probe, and FIG. 2B is a longitudinal sectional view of a portion near a distal end of the insertion portion of the tactile sensor probe. .

3A and 3B are diagrams illustrating a configuration of a sensor element of the tactile sensor probe, wherein FIG. 3A is a rear view, FIG. 3B is a side view, and FIG. 3C is a front view.

FIG. 4 is a system explanatory diagram showing the tactile sensor probe and its peripheral devices.

FIG. 5 is an enlarged perspective view showing a connection portion between a tip portion of the tactile sensor probe and a circuit board.

FIG. 6 is an explanatory diagram of a state when the tactile sensor probe is pressed against an object.

[Explanation of symbols]

1 ... tactile sensor probe, 2 ... insertion part, 3 ... grip,
6 ... flexible tube, 7 ... housing, 8 ... tip, 1
5 sensor element, 20 self-excited oscillation circuit, 21, 22 circuit part, 23 flexible substrate, 24a first separation part, 24b second separation part, 26 Colpitts circuit, 2
7 ... Buffer circuit 27

Continued on front page F term (reference) 2G047 AC13 BA04 BB04 BC13 CA01 EA15 4C061 AA00 BB00 CC00 DD03 FF21 FF24 FF35 FF43 FF50 GG15 HH51 HH60 JJ12 JJ17

Claims (1)

[Claims] 1. A tactile sensor probe equipped with a tactile sensor for detecting a mechanical impedance of an object having a viscoelastic characteristic by an output signal of a self-excited oscillation circuit composed of a piezoelectric vibrator, comprising: a flexible insertion portion; A piezoelectric vibrator provided at a tip side portion of the portion, a self-excited oscillation circuit provided at a rear side of the piezoelectric vibrator inside the insertion portion, and connected to a tip portion of the insertion portion; A flexible substrate on which the self-excited oscillation circuit is formed, wherein the self-excited oscillation circuit is configured to be divided into a plurality of integrated circuit parts, and each of the circuit parts is the insertion part. A tactile sensor probe, wherein the tactile sensor probe is dispersedly arranged on a portion of the flexible substrate located inside the tactile sensor probe.