JPH0535331Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an ultrasonic microscope device that applies ultrasonic waves to a sample and converts the reflected sound waves into electrical signals to two-dimensionally image the fine structure of the sample.

[Prior Art] A conventionally used ultrasonic microscope device has a configuration as shown in FIG. , one electrode 12 is fixed to the planarly polished upper surface of an acoustic propagation member 14 made of sapphire or the like. The lower end of the acoustic propagation body 14 has a diameter of approximately 0.1 mmφ to 1.0 mmφ.
A concave hemispherical hole is formed, thereby forming an acoustic lens 16.

A sample stand 18 is arranged below the acoustic propagation body 14, and a sample 20 to be observed is placed on the sample stand 18 directly below the acoustic lens 16. A medium 22 such as water is filled in between.

Furthermore, a pulse 10 is applied to the electroacoustic transducer thin film 10.
A pulse oscillator 24 is provided for applying 0 to generate the plane ultrasound 102. The planar ultrasonic wave 102 generated from the electroacoustic transducer thin film 10 by the operation of the pulse oscillator 24 propagates through the acoustic propagation body 14 and reaches the acoustic lens 16. 1100m/s) and the sound speed of the water medium (1500m/s).
Sample 2
It is focused on the zero plane. Sample 20
The ultrasonic waves irradiated on the surface are reflected there and are transferred to sample 2.
Reflected ultrasound 104 of strength or weakness depending on the elastic properties of
Then it returns to the acoustic lens 16.

The reflected ultrasonic wave 104 then travels in the opposite direction through the acoustic propagation body 14 and is converted into a high frequency signal 106 when it reaches the electroacoustic conversion thin film 10.

This high frequency signal 106 is received by the receiver 26,
Here, the signal is detected by a diode and converted into a video signal 108, which is used as an input signal for the CRT display 28. Also, this CRT display 2
In order to display a two-dimensional image of the sample 20 at 8, the sample stage 18 is two-dimensionally scanned in the X-Y plane by the driving device 30 and the connecting rod 31.

In the ultrasonic microscope apparatus configured as described above, when the sample stage 18 is two-dimensionally scanned within the X-Y plane by the drive device 30, the intensity of the reflected ultrasonic waves 104 on the surface of the sample 20 as the sample 20 is scanned changes. is displayed two-dimensionally on 28 CRT displays.

By the way, when using such a device to observe a sample such as a living tissue or cell whose elastic properties are highly temperature dependent, the temperature of the sample is changed and the physical properties of the sample change at each temperature. It becomes necessary to observe the However, when the temperature of the sample changes, the temperature of the medium 22 through which the ultrasonic waves pass also changes, and the rate at which the ultrasonic waves are absorbed in the medium 22 changes accordingly. For example, when water is used as the medium 22, the second
As shown in the figure, as the temperature of the water rises above room temperature, the propagation speed of the ultrasonic waves increases somewhat, but the proportion of ultrasonic waves absorbed in the water decreases significantly, and the strength of the signal of the reflected ultrasonic waves 104 decreases. It is understood that the extent varies with temperature. In addition, changes in the measurement system of the apparatus, such as changes in the distance between the sample 20 and the acoustic lens 16 due to expansion or contraction of the acoustic lens 16 or the sample stage 18, cause changes in the output of the ultrasonic waves reflected by the sample 20 due to temperature changes. be. Therefore, it is necessary to correct the error in the reflected signal due to changes in the absorption rate of the ultrasonic wave 104 in the medium 22 at each temperature and the error in the reflected signal due to temperature changes in the measurement system of the device. It is impossible to observe changes in properties. However, due to the difficulty of implementing this, it has not been done using conventional ultrasonic microscope equipment, and it is possible to arbitrarily change the temperature of the sample 20 and observe changes in the physical properties of the sample 20 at each temperature. Nakatsuta.

[Purpose of the invention] The present invention was devised in view of the shortcomings of the prior art, and its purpose is to analyze biological tissues for which it is necessary to observe changes in physical properties at various temperatures.
The object of the present invention is to provide an ultrasonic microscope device that is effective for samples such as cells.

[Configuration of the device] In order to achieve this objective, the present invention includes a conventional ultrasonic microscope device that includes a heat-absorbing and heat-generating portion near the sample for heating or cooling the sample, and detecting the temperature of the sample. A temperature sensor is provided for inputting a detection signal from the temperature sensor to control the amount of heat absorbed by the heat absorption and heat absorption section in order to input a detection signal from the temperature sensor to maintain the sample at a certain arbitrary temperature. A means is provided to automatically correct errors in the reflected signal due to changes in the absorption rate of ultrasound in the medium due to changes in the temperature of the medium due to heat absorption and absorption from the sample along with the sample, as well as errors in the reflected signal due to the measurement system of the device. It is characterized by

[Embodiments of the invention] Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

In FIG. 3, a sample stage 34 on which a sample 32 is placed is fixed, and an electroacoustic transducer 36a and an acoustic lens 3
A transducer 36 consisting of an acoustic propagating body 36b having a shape 6c is connected to the scanning unit 4 via a connecting rod 38.
0, and the transducer 36 is two-dimensionally scanned within the XY plane by the operation of the scanning section 40.

A heat-absorbing or heat-absorbing section, for example, a thermoelement 42 is disposed below the sample stage 34, and the thermoelement 42 absorbs or generates heat on its surface 42a using a current supplied from a power source 44.

Further, a temperature sensor 46 for detecting the temperature of the sample 32 is arranged near the sample 32 on the sample stage 34, and a detection signal output from this temperature sensor 46 is input to a temperature controller 48.

The temperature controller 48 compares the preset temperature with the sample temperature detected by the temperature sensor 46, sends a signal proportional to the difference between the two to the power source 44, and the power source 44 responds to the signal. The thermoelement 42
The temperature of the sample 32 is maintained at the temperature set in the temperature controller 48 by controlling the amount of heat absorbed or the amount of heat generated.

In this way, when the sample 32 is kept at a required temperature by the temperature controller 48 and the pulse oscillator 50 is operated to send pulses 110 to the transducer 36, the transducer 36 outputs ultrasonic waves. This output ultrasonic wave passes through the medium 52 and passes through the sample 3.
2 and reflected from the sample 32
12, the high frequency signal 11 passes through the acoustic propagation body 36b and is transmitted to the electroacoustic transducer 36a of the transducer 36.
4, and this high frequency signal 114 is sent to the receiver 2.
6 is diode-detected and converted into a first video signal 116.

By the way, the ultrasonic wave 1 reflected from the sample 32
12 is a reflected signal obtained by converting the ultrasonic wave 112 by the transducer 36 because it is partially absorbed into the medium 52 when passing through the medium 52 based on the ultrasonic absorption rate at each temperature of the medium 52. That is, the high frequency signal 114 or the first video signal 116
is not a signal that faithfully reflects the elastic properties, which are the physical properties of the sample 32. In addition, as a measurement system of the apparatus, the acoustic lens 36c or the sample stage 34 expands and contracts in the thickness direction due to temperature changes, and the sample 3
There is an error in the reflected signal due to a change in the distance between the acoustic lens 2 and the acoustic lens 36c.

Therefore, the computer 54 is used as a means for automatically correcting errors in the reflected signal due to changes in absorption in the ultrasonic medium 52 due to temperature changes in the medium 52 and errors in the reflected signal due to the measurement system of the apparatus. The computer 54 calculates errors in the reflected signal due to changes in the absorption rate of the ultrasonic wave 112 due to various temperatures of the medium 52, and errors in the reflected signal due to changes in the measurement system of the apparatus such as the distance between the acoustic lens 36c and the sample 32 at each temperature. A program for correction is preset. The computer 54 receives set temperature data from the temperature controller 48 to set the temperature of the sample 32 to a certain arbitrary temperature, and also inputs data from the receiver 26 at that temperature including errors caused by the medium 52 and the measurement system of the device. When the first video signal 116, which is a reflected signal, is output, the computer 54 corrects the error from the first video signal 116 to accurately display the elastic properties of the sample 32, which are physical properties at the temperature. A reflected second video signal 118 is output, and the sample 32 is displayed on the CRT display 56 by the second video signal 118.
A two-dimensional image is displayed.

Although the thermoelement 42 made of a semiconductor is shown in the heat absorption/heat absorption portion in the above embodiment, the thermoelement 42 is not limited to this, and it is also possible to use other heat exchangers or the like.

With such a configuration, even when observing a sample such as a biological tissue or a cell whose elastic properties are highly dependent on temperature, it is possible to faithfully image the physical properties of the sample at each temperature.

[Effects of the invention] As explained above, according to the invention, the sample can be maintained at an arbitrary temperature, and errors in the reflected signal due to changes in the absorption rate of ultrasound in the medium due to changes in the temperature of the medium can be prevented. By providing a means to automatically correct errors in reflected signals due to temperature changes,
This has the effect of allowing faithful imaging of changes in physical properties of the sample due to various temperatures.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional ultrasonic microscope device, Fig. 2 is a graph showing temperature changes in the sound velocity and ultrasonic absorption coefficient of the medium (water), and Fig. 3 is a diagram showing a preferred embodiment of the present invention. FIG. 32...Sample, 36...Transducer, 3
6a...Electroacoustic conversion element, 36b...Acoustic propagation body, 36c...Acoustic lens, 42...Thermo element (heat absorption/heat absorption part), 46...Temperature sensor, 48
... Temperature controller, 52 ... Medium, 114 ... High frequency signal, 116 ... First video signal, 118 ...
...Second video signal.

Claims (1)

[Claims for Utility Model Registration] A transducer is formed by an acoustic lens having an electroacoustic conversion element at one end of the acoustic propagation body and a predetermined focus at the other end, and a predetermined sample is placed near the focal point of the acoustic lens. In an ultrasonic microscope apparatus that interposes a medium between the acoustic lens and the sample and images the sample using sound waves reflected by the sample of sound waves emitted from the acoustic lens into the medium, A heat absorption and heat absorption part and a temperature sensor are disposed in the temperature sensor, and a temperature controller is provided to input a detection signal from the temperature sensor and control the heat absorption and heat generation amount of the heat absorption and heat absorption part in order to bring the sample to a certain arbitrary temperature,
In addition, a means for automatically correcting errors in the ultrasonic reflected signal due to temperature changes in the medium and the measurement system of the apparatus is provided, and the state of the physical properties of the sample is determined by heating or cooling the sample to an arbitrary temperature. Ultrasonic microscope device that enables imaging.