JPS61111423A - Device for measuring intensity of ultrasonic output - Google Patents

Abstract

PURPOSE:To remove the measuring error of the intensity of an ultrasonic output by providing a water level mechanism to the upper part of a pressure receiving plate, and detecting the posture of the pressure receiving plate by the water level mechanism to adjust the pressure receiving plate so that an ultrasonic wave is made vertically incident. CONSTITUTION:The pressure receiving plate 21 can be sunk into a vessel 1 so that the pressure receiving surface 23 of the plate 21 is rectangular to the gravity direction by adjusting the length of a suspension wire 30 so that an air bubble 27 is positioned on the center of the pressure receiving plate 21 and fixing the pressure receiving plate 21. Under said status, an ultrasonic wave is radiated from an ultrasonic probe 15 on the basis of a driving signal supplied from an ultrasonic diagnostic device and made vertically incident upon the inside position of the suspension wire fixing part on the pressure receiving surface 23 of the plate 21. The intensity of the ultrasonic output is found out as the change of weight by a balance. Namely, the intensity of the ultrasonic output is amplified by a weight measuring amplifier and recorded on a recorder.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic output intensity measuring device for measuring the ultrasonic output intensity emitted from an ultrasonic probe of an ultrasonic diagnostic apparatus.

2. Description of the Related Art Structures of Conventional Examples and Their Problems In recent years, the role of ultrasonic diagnostic methods has become important in various fields of medicine, and the prevalence of ultrasonic diagnostic apparatuses has accordingly increased. The reason for this is that it is safer and easier to use than X-ray diagnostic equipment. Under these circumstances, research has recently been conducted on the effects of ultrasound on the human body, and in connection with this research, devices for measuring the intensity of ultrasound output have been developed. At present, methods for measuring ultrasonic output intensity are basically divided into four types: (1) mechanical method, (2) electrical method, (3) caloric method, and (4) optical method. Among them, (1) the measurement method using a balance, which is one of the mechanical methods, is capable of measuring low ultrasonic output of several tens of μW to several tens of mW, and is relatively easy to measure directly from weight changes. Since it is possible to obtain absolute output, it is generally used for ultrasonic output intensity measurement in the field of ultrasonic diagnostic equipment.

In a conventional ultrasonic output intensity measuring device using a balance, a liquid 2 such as water is contained in a container 1, as shown in FIG. On the other hand, in the balance 3, the central part of the rod-shaped body 4 is supported by a fulcrum, hooks 67 are provided on both sides, a plate 8 is suspended from the hook 6 on one side, and a weight 9 is placed on the plate 8. ing. A pressure receiving plate 10 is suspended by a hanging line 11 from a hook 7 on the opposite side of the weight 9 in this balance 3, and this pressure receiving plate 1
0 is submerged in the liquid 2 in the container 1.

A weight measuring amplifier 12 and a recorder 13 are connected in sequence to the fulcrum 5 of the balance 3 as measuring means.

Then, ultrasonic waves are emitted from the ultrasonic probe 15 in response to a drive signal applied from the ultrasonic diagnostic device 14, and the ultrasonic waves are transmitted to the pressure receiving plate (sound absorbing plate) 10 from the transparent part 1a at the lower part of the container 1.
corresponds to By the way, radiation pressure caused by ultrasound includes Rayleigh radiation pressure and Langevin radiation pressure, which are commonly used in ultrasound diagnostic equipment.

The radiation pressure that appears under these conditions is the latter Langevin radiation pressure. This radiation pressure F is equal to the energy density E of the ultrasonic waves at the front surface of the pressure receiving plate 1o receiving the radiation pressure, and finally the ultrasonic output intensity W is expressed by the following equation.

W=FXC=ΔmXgnXc Here, Δm is the balance 3 connected to the pressure receiving plate 10 with a hanging wire 11
is the weight change detected by , where gn is the standard gravitational acceleration and C is the sound velocity of the liquid 2 contained in the container 1. Conventionally, this liquid 2 is degassed water. Therefore, pressure receiving plate 1o
The ultrasonic output intensity received from the ultrasonic probe 15 can be directly determined as an absolute output using the balance 3 as a change in weight. This weight change is amplified by a weight measuring amplifier 12 and recorded on a recorder 13. Note that the weight 9 is used to balance the weight of the pressure receiving plate 1o before irradiating the pressure receiving plate 10 with ultrasonic waves.

By the way, the weight change handled by the ultrasonic output intensity measuring device using this balance method is, for example, when trying to measure an ultrasonic output intensity of 1 mW, water is used as the liquid 2 in the container 1, and the water temperature is 20"C (0 = When measuring at 1640 m/s), the weight change Δm is 66.8 μg, which is a very small value, and problems with the measurement conditions and equipment are important.Therefore, the above conventional ultrasonic output intensity measurement In order to reduce the reflection loss from the pressure plate 10 in the device and reduce measurement errors, the surface of the pressure plate 1o, which is submerged in the liquid 2 in the container 1 by the hanging wire 11, is placed at right angles to the direction of gravity. Moreover, the structure of the pressure receiving plate 10 and the ultrasonic probe 15
It is important that the ultrasonic radiation surface of the ultrasonic probe 1o is parallel to the ultrasonic wave emitting surface, that is, that the ultrasonic waves from the ultrasonic probe 16 are made perpendicularly incident on the pressure receiving plate 1o. However, the conventional ultrasonic output intensity measuring device described above does not have a means for adjusting the attitude of the pressure receiving plate 10 suspended from the balance 3 and a means for detecting the attitude state of the pressure receiving plate 10. Since the pressure receiving plate 10 and the pressure receiving plate 10 are fixed in an assembled state, they cannot be easily adjusted.

Purpose of the Invention The present invention detects the attitude of a pressure receiving plate and adjusts the attitude so that ultrasonic waves are incident in the vertical direction, thereby eliminating measurement errors in ultrasonic output intensity. The object of the present invention is to provide an ultrasonic output intensity measuring device.

Structure of the Invention In order to achieve this object, the present invention comprises a container containing a liquid, a balance with a weight suspended from one side, and a plurality of points on the outer periphery of the balance suspended from hanging lines on the other side. a pressure receiving plate, which is submerged in the liquid and irradiated with the ultrasonic waves to be measured; a fixing means for fixing the pressure receiving plate to each suspension wire in a position adjustable manner; It is equipped with an enclosed leveling mechanism and a measuring means for measuring the weight change obtained by irradiating the pressure plate with ultrasonic waves using the balance, and the leveling mechanism detects the attitude of the pressure plate and the ultrasonic waves are aligned in the vertical direction. The enemy is that it is constructed in such a way that it can be adjusted so that it is incident.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 2 to 4, the pressure receiving plate 21 is made of a material such as silicone rubber, which has low ultrasonic reflection loss (acoustic impedance is close to that of water) and has a high sound absorption effect, and is shaped like a disk. is formed. A circular leveling mechanism 22 is provided at the upper center of the pressure receiving plate 21, and a distance is provided so that the ultrasonic waves incident on the pressure receiving surface 23 are absorbed while reaching the leveling mechanism 22. The pressure receiving plate 2 is an example of the leveling mechanism 22.
A circular recess 24 is formed in the upper center of the pressure receiving plate 21, and a transparent sealing plate 25 is attached to the upper surface of the pressure receiving plate 21 to seal the recess 24. A liquid 26 such as the like is sealed with air bubbles 27 left behind. The pressure receiving plate 21 is arranged at a plurality of positions (
In the illustrated example, it is hung from the hook 7 of the balance at four locations.

That is, the upper end annular portion 29 of the suspension line 28 is hung on the hook 7, and the lower end of the suspension line 28 is branched into four suspension lines 3o.

On the other hand, fixing means are provided at four locations on the outer periphery of the pressure receiving plate 21 to adjust the position of the suspension wire 3o. That-
For example, a 4" hole 3° 7" 5 is formed in the pressure receiving plate 21 in parallel with the 14 circumference WE axis 'B' through which a hanging wire is inserted, and a fixing screw 32 as a fixing member can be moved back and forth in the direction perpendicular to the axis of this hole 31. It is screwed in.

Therefore, by inserting the hanging wire 3o into the hole 31 and advancing the fixing screw 32, the hanging wire 30 can be pressed and fixed against the inner wall of the hole 31. On the contrary, the fixing screw 32
By retreating, the hanging wire 30 can be completely released. The other configurations are similar to those shown in FIG. 1 of the conventional example.

Next, the operation of the above embodiment will be explained. The length of the hanging wire 30 is adjusted so that the air bubble 27 is located at the center of the pressure receiving plate 21, and the pressure receiving plate 21 is fixed so that the pressure receiving surface 23 of the pressure receiving plate 21 is perpendicular to the direction of gravity. 1
It can be sunk inside. In this state, the ultrasound diagnostic device 1
Added from 4. Ultrasonic waves are emitted from the ultrasonic probe 16 in response to the drive signal, and the ultrasonic waves strike the pressure receiving surface 23 of the pressure receiving plate 21 at the inner position of the hanging wire fixing portion in the vertical direction. Then, this ultrasonic output intensity is expressed as a weight change on the balance 3.
Find it by That is, this weight change is caused by the weight measurement amplifier 1
2 and recorded on the recorder 13. In the above embodiment, the screw 3 is used as a means for fixing the hanging wire 3o.
2 is used, but instead of the screw 32, the hanging wire 3o can be fixed by being crimped onto the inner wall of the hole 31 using a lever spring. Further, the leveling mechanism 22 may be formed separately from the pressure receiving plate 21 and attached to the pressure receiving plate 21.

Effects of the Invention As is clear from the above explanation, according to the present invention, the outer circumferential portion of the pressure plate is suspended from the opposite side of the balance from the weight at a plurality of locations by means of suspension lines so that the position can be adjusted, and the pressure plate is submerged in the liquid of the container. The pressure receiving plate is irradiated with ultrasonic waves to be measured, and the weight change due to this irradiation is measured by the above-mentioned balance. At this time, a leveling mechanism is provided on the top of the pressure receiving plate, and this leveling mechanism allows the pressure receiving plate to be adjusted in all its postures. It is possible to detect and adjust the ultrasonic waves to be incident in the vertical direction. Therefore, measurement errors in the ultrasonic output intensity can be eliminated.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of a conventional ultrasonic output intensity measuring device, FIGS. 2 to 4 show an embodiment of the pressure receiving plate used in the ultrasonic output intensity measuring device of the present invention, and FIG. is a plan view,
Figure 3 is a partially cutaway side view, 1... Container, 2...
...liquid, 3...balance, 12...
Weight measurement amplifier, 13...Recorder, 14...
... Ultrasonic diagnostic device, 16 ... Ultrasonic probe, 21 ... Pressure receiving plate, 22 ... Leveling mechanism, 26 ... Liquid, 27...Bubble, 28
．． 30... Hanging wire, 31... Hole for inserting the hanging wire, 32... Fixing screw. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3

Claims (2)

[Claims] (1) A container containing a liquid, a balance with a weight suspended on one side, and multiple points on the outer periphery of the balance suspended from hanging wires on the other side, which are submerged in the liquid and used for measurement. a pressure receiving plate to which ultrasonic waves to be applied are irradiated; a fixing means for fixing the pressure receiving plate to each suspension line in a position adjustable manner; a leveling mechanism provided on the upper part of the pressure receiving plate and containing air bubbles; An ultrasonic output intensity measuring device comprising: measuring means for measuring weight change obtained by irradiating ultrasonic waves using the balance. (2) The ultrasonic output intensity measuring device according to claim 1, wherein the fixing means comprises a hole for passing a hanging wire formed in the pressure receiving plate and a hanging wire fixing member provided in the pressure receiving plate.