JPH05322731A - Method and device for sensing hardness of substance - Google Patents

Abstract

PURPOSE:To provide a new sensor which has a characteristic close to the human sense of touching, is easy to handle, and can easily be in small size. CONSTITUTION:A sensor part concerned 1 is composed of an objective touching vibrator 11 and a vibration sensing part 12 or an element 13 for sensing vibration, with which measuring is conducted on the change of the oscillation frequency in a self-excited oscillator circuit 2 in which the output signal of the sensing part 12 or sensing element 13 is amplified and fed forcedly back to the touching vibrator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting hardness of a substance using an objective contact oscillator and a detector used for the method.

[0002]

BACKGROUND OF THE INVENTION Today's medical technology has made significant progress, but tactile diagnosis remains an important method. For example, palpation is important for diagnosis in order to know prostatic hypertrophy, lumps, foreign bodies, skin health, and the like. It is also medically important to detect the hardness of a minute portion of soft tissue such as a living body as a value corresponding to the sense of touch. For this reason, research has been conducted to develop a sensor corresponding to the tactile sense using a pressure sensor, an optical sensor, or the like to make it useful for diagnosis, but it has not been put into practical use yet. In addition, quantitative realization of tactile sensation is desired not only in medicine but also in many fields.

[0003]

Therefore, in view of the above situation, the present application uses a method for detecting the hardness of a substance, which utilizes the fact that the objective contact vibrator changes the oscillation frequency due to the contact with the object. The invention of a detector is made and provided herein.

[0004]

In order to achieve the above-mentioned object, the present invention is constructed as follows. That is, the method for detecting the hardness of a substance according to the present invention relates to a self-excited oscillating circuit section configured by amplifying an output signal of a vibration detection unit provided in an objective contact vibrator and then forcibly feeding it back to the objective contact vibrator. The hardness of the substance is sensed by measuring the change in the oscillation frequency.

Further, the output signal may be taken out through a vibration detecting element attached to the objective contact vibrator. Next, a substance hardness detection apparatus according to the present invention is a self-excited oscillation circuit which is composed of a sensor section composed of an objective contact vibrator, and an output signal from the sensor section is amplified and forcibly fed back to the objective contact vibrator. And a measuring unit that measures the oscillation frequency of the self-excited oscillation circuit unit.

Furthermore, the sensor section may have a structure in which a vibration detecting element is attached to the objective contact vibrator to obtain an output signal. In the self-excited oscillation circuit unit, the self-excited oscillation circuit unit may be configured so as to be forcibly fed back through the phase shift circuit and the bandpass filter after being amplified by the radiation increasing circuit.

Further, a large number of these sensors are linearly arranged,
Alternatively, the system may be arranged in a plane to measure the hardness of a substance in a wide range at the same time.

Further, the contactor attached to the objective contact oscillator may be a system for measuring the hardness of a substance by appropriately changing the shape of the contactor into a spherical shape or a needle shape according to the purpose.

[0009]

EXAMPLES Examples of the present invention and measurement examples thereof will be described below in detail. Reference numeral 1 denotes a sensor unit, which includes an objective contact vibrator 11. The sensor unit 1 is attached to a fingertip of a hand, a grasped object (not shown), or the like. Here, as the objective contact oscillator 11, for example, a piezoelectric ceramic oscillator or a crystal oscillator is preferable, and the shape thereof is not limited, and the objective contact oscillator 11 is formed in an appropriate shape according to the shape of the grip portion to be attached. To be done.

Further, although the output signal may be directly taken out from the vibration detecting section 12 provided in the objective contact vibrator 11,
In order to further increase the sensitivity, the vibration detecting element 13 may be attached to the objective contact vibrator 11. The specific attachment means may be adhesive or the like as long as it is configured to transmit vibration. The vibration detecting element 13 may be, for example, a piezoelectric ceramic element, a piezoelectric acceleration pickup, a polymer piezoelectric film, or the like, and its shape is appropriately formed corresponding to the objective contact vibrator 11.

Reference numeral 2 denotes a self-excited oscillation circuit section, which amplifies an output signal from the vibration detecting section 12 provided in the objective contact vibrator 11 with an amplifier circuit 21, and the amplified signal is amplified by the objective contact vibrator 1.
The circuit is configured so as to perform forced feedback to be supplied to 1. With this configuration, the objective contact vibrator 11 and the amplifier circuit 21 are controlled by a circuit that vibrates the objective contact vibrator 11 by adjusting the amplification degree of the amplifier circuit 21, amplifies the output signal of the vibration detection unit 12, and then forcibly returns the amplified signal. Then, the oscillator circuit is configured to self-oscillate.

In the self-excited oscillation circuit section 2,
The output signal from the vibration detecting element 13 may be amplified by the amplifier circuit 21, and then passed through the phase shift circuit 22 and the bandpass filter circuit 23 to be forcibly fed back to the objective contact vibrator 11. As a result, the sensitivity and resolution of the sensor unit can be improved and the stability can be increased. Reference numeral 3 is a measuring unit, which is an amplifier circuit 21 and a vibration detecting unit 1.
It is composed of a frequency measuring circuit 31 connected between the two and a data processing circuit 32 connected to the frequency measuring circuit 31.

In the measurement system described above, the contactor 14 attached to the objective contact vibrator 11 is appropriately formed into a spherical shape or a needle shape according to the purpose.

[0014]

Since the embodiment of the present application is configured as described above,
First, the oscillation frequency of the self-excited oscillation circuit unit 2 before the objective contact vibrator 11 contacts an object is measured. Next, when the object 4 comes into contact with the objective contact vibrator 11, the oscillation frequency of the self-excited oscillation circuit unit 2 changes. Therefore, the oscillation frequency at this time is measured, and the change amount of the oscillation frequency before and after the contact is measured. If you ask,
You can know the hardness of a substance.

By analyzing the series of measurement data by the data processing circuit, the hardness of the substance can be detected in real time. FIG. 3 is a graph showing the measurement results of frequency changes performed using the above device. When the sensor unit is brought into contact with a prostate model composed of gelatin and hard rubber balls (t1), the oscillation frequency changes depending on the hardness of the object. Since the amount of frequency change before and after the contact corresponds to the hardness of the substance, the hardness of gelatin alone becomes extremely soft as shown in FIG. However, when the sensor is moved onto the rubber ball representing the prostate model, the frequency change amount decreases due to the hardness of the rubber, and the hardness increases.

[0016]

[Effect] Since the present invention is configured as described above,
It has the following effects. Since the hardness of the substance is sensed by utilizing the change in the oscillation frequency of the self-excited oscillation, it is possible to obtain the characteristics close to the tactile sensation of a person with high sensitivity and excellent resolution. Since the sensor unit including the objective contact vibrator is easily miniaturized, it can be attached to a fingertip or the like to detect the hardness of a foreign body or soft tissue in a living body with the same sensation as by palpation. The hardness of a minute portion such as a cell can be detected by making the contactor attached to the objective contact vibrator into an extremely thin needle shape. By inserting the above needle-shaped contactor into an extremely thin cylinder and inserting it into a soft tissue such as a living body, the hardness of the substance in contact with the tip of the contactor can be detected. Since self-excited oscillation is used, it is not necessary to adjust the oscillator to search for the oscillation frequency each time the contacted substance changes, and the handling is extremely easy and real-time measurement is possible. INDUSTRIAL APPLICABILITY Since the present invention has an easy interface with a computer, high-speed data processing enables real-time processing, and can be applied not only in the medical field but also in various fields such as robotics and food engineering. is there.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention.

FIG. 2 is a schematic perspective explanatory view showing another embodiment of the present invention.

FIG. 3 is a schematic perspective view showing an embodiment of a sensor section contactor.

FIG. 4 is a schematic perspective view showing an embodiment of a sensor section contactor.

FIG. 5 is a schematic perspective view showing an embodiment of contact with a sensor unit.

FIG. 6 is a graph showing the measurement results of the example of the present invention.

[Explanation of symbols]

 1 Sensor Section 2 Self-Excited Oscillation Section 3 Measurement Section 4 Material 11 Objective Contact Oscillator 12 Vibration Detection Section 13 Vibration Detection Element 14 Contact Element 15 Tube 21 Amplification Circuit 22 Phase Shift Circuit 23 Bandpass Filter Circuit 31 Frequency Measurement Circuit 32 Data Processing circuit

Claims (7)

[Claims] 1. A self-excited oscillation circuit section formed by amplifying an output signal of a vibration detection section (12) provided in an objective contact vibrator (11) and then forcibly feeding it back to the object contact vibrator (11). A hardness detection method characterized in that the hardness of a substance is sensed by measuring a change in oscillation frequency in (2). 2. The method for detecting the hardness of a substance according to claim 1, wherein an output signal is taken out through a vibration detecting element (13) attached to the objective contact vibrator (11). 3. A sensor section (1) consisting of an objective contact vibrator (11), and a self-excited apparatus for amplifying an output signal from the sensor section (1) and forcibly feeding it back to the objective contact vibrator (11). An apparatus for detecting hardness of a substance, comprising an oscillation circuit section (2) and a measuring section (3) for measuring an oscillation frequency of the self-excited oscillation circuit section (2). 4. A sensor section (1) comprising an objective contact vibrator (11) to which a vibration detecting element (13) is attached.
And an output signal from the vibration detecting element (13) is amplified by an amplifier circuit (21), and then the objective contact vibrator (1) is passed through a phase shift circuit (21) and a bandpass filter circuit (23).
1) a self-excited oscillation circuit section (2) forcibly fed back, and a measuring section (3) for measuring the oscillation frequency of the self-excited oscillation circuit section (2). Detection device. 5. A hardness detector for a substance, which uses the measurement system according to any one of claims 1 to 4 and is a linear array system using a large number of sensors or an area sensor system. 6. A contactor (1) is attached to the objective contact vibrator (11).
4) is attached, and the contactor (14) is formed into a spherical shape or a needle shape, and the material hardness detecting device according to claim 1 to 5. 7. A material hardness detecting device using the measuring system according to claim 1, wherein the contactor (14) is needle-shaped, and a cylindrical cover is attached to the contactor (14).