JPH06197893A - Ultrasonic wave transmissive inspection device - Google Patents

Abstract

PURPOSE:To surely remove air bubbles and air layers sticking to an ultrasonic transducer dipped in matching liquid or the outer surface of an object to be examined in a short time. CONSTITUTION:A water stream inducing means (air bubble removing means) composed of water flow holes 8a, 8b and a pump 9 and an air bubble and air layer detecting part 18 are arranged on the bottom of a measuring tank 1 in which an object 3 to be examined, and transducers 4, 5 which are opposed to each other with the object 3 being located therebetween, and matching liquid (water) are stored. Further, the pump 9 is driven by an air bubble/air layer removing instruction signal from a detecting part 18 so as to jet water sucked through the water stream hole 8a is jetted from the water stream holes 8b, 8c so as to remove air-bubbles or an air layer sticking to the outer surfaces of the transducers 4, 5 and the outer surface of the object 3 to be examined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an apparatus applied to the field of clarifying the difference between substances by measuring the amount of attenuation of ultrasonic waves in the substance, and is particularly used for the diagnosis of osteoporosis in the living body. The present invention relates to an ultrasonic attenuation measuring device or a bone mineral quantifying device.

[0002]

2. Description of the Related Art Osteoporosis is a condition in which the density of bone tissue decreases due to calcium deficiency or the like.
There has already been proposed a method of quantitatively measuring the characteristics (bone mineral density, stiffness, etc.) of bone by measuring the velocity (sonic velocity) and attenuation of ultrasonic waves in the bone. Such an ultrasonic examination is usually performed on the heel of thin soft tissue. A conventional device for measuring bone characteristics (called an ultrasonic bone mineral quantification device) uses a container (measuring tank) in which an ultrasonic wave generator and an ultrasonic wave detector are attached to face each other. To do. The ultrasonic generator and ultrasonic detector
An ultrasonic transducer, which is generally called an ultrasonic transducer, capable of generating and detecting ultrasonic waves with one unit is used.

In the measuring tank, put a foot so that the heel may block the ultrasonic wave generation / detection device, and further, for the purpose of matching when the ultrasonic wave is incident on the heel (that is, reflected by the surface of the heel). Water as a matching solution (to minimize ultrasonic waves). When an ultrasonic wave is emitted from the generator in that state, the ultrasonic wave propagates and is attenuated when passing through the calcaneus at a speed according to the amount of bone mineral. Therefore, by measuring the arrival time, velocity, or attenuation of the ultrasonic waves with the detector, it is possible to measure the amount corresponding to the amount of bone mineral in the calcaneus, which is the subject.

Since the matching liquid is kept at the same level as that of the subject (around 37 ° C.), bubbles or air layers are easily formed on the ultrasonic transducer and the surface of the subject. When such bubbles and air layers are present on the transducer surface, the acoustic impedance changes and the output intensity,
Furthermore, the frequency distribution of the output pulse changes greatly. Further, if air bubbles or air layers are present on the surface of the subject, ultrasonic waves are scattered and reflected, resulting in overmeasurement of ultrasonic wave attenuation.

Therefore, in order to improve the measurement accuracy,
In order to reduce the attenuation of ultrasonic waves other than the absorption of ultrasonic waves by the subject as much as possible, air bubbles and air layers on the ultrasonic transmission path (particularly the surfaces of the subject and the transducer) must be removed as much as possible. At present, the removal of air bubbles and air layers formed on the surface of the transducer and the subject is performed by manually wiping the surface of the subject and the transducer with the examiner's own hand, air bubbles, or
This is done by waiting for the air layer to dissolve in the matching liquid, or by circulating and degassing the matching liquid.

[0006]

However, in the above-mentioned first method, air bubbles and
There are various uncertain factors, such as having to confirm the presence or absence of an air layer, and the possibility that air may be mixed and adhered by the hands of the examiner. In addition, in the second and third methods, it takes time to completely remove the air bubbles and air layers, so that not only the inspection time becomes long and the subject is burdened, but also the inspection efficiency decreases. There was a problem.

In view of the above, the present invention provides an ultrasonic transmission inspection apparatus capable of reliably removing bubbles and air layers attached to or formed on the surface of a transducer or the surface of a subject in a short time. The purpose is to do.

[0008]

In order to achieve the above object, the present invention provides a means for removing an ultrasonic transducer and air bubbles or air layers adhering to the surface of a subject. It is characterized by that. As the removing means, an ultrasonic transducer, a water jet mechanism for spraying water (matching liquid) on the surface of the subject, an ultrasonic transducer, and a wiper mechanism for wiping the surface of the subject, and an ultrasonic wave A vibration mechanism that gives a slight vibration to the converter or the subject can be used.

A second aspect of the present invention is a bubble or a bubble on the surface of the ultrasonic transducer together with a means for removing an air layer.
It is characterized in that a bubble detecting means for detecting the presence or absence of an air layer is provided. As the air bubble detecting means, the transducer itself is provided with its function, and the presence or absence of air bubbles and air bubbles on the surface of the transducer is automatically detected from the attenuation of the ultrasonic wave in the state where the subject is not placed between the transducers.

[0010]

When the matching liquid is put into the measuring tank or the subject is put into the measuring tank, bubbles are easily generated and adhered to the surface of the transducer and the subject, and an air layer is sometimes formed. Air bubbles and air layers adhering to both surfaces are removed by the air bubble removing means before the inspection is started. When a water flow is used for the removal, the water flow is emitted from the water flow generation hole provided on the inner wall of the measurement tank toward the transducer, the bubbles on the surface of the subject, and the air layer. As a result, air bubbles and air layers adhering to the surface are peeled off and float on the water surface.

If the air bubble and the air layer are not on the ultrasonic wave transmission path between the transducers, the influence (scattering and reflection) of the air bubble and the air layer on the measurement is eliminated, and the reliability of the ultrasonic absorption evaluation by the object is improved. . Further, by automatically detecting the air bubbles and the air layer on the transducer surface, it is possible to reduce the measurement error in each inspection due to air and improve the reproducibility.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an ultrasonic transducer, in which a water stream is blown onto the surface of a subject to remove air bubbles and air layers, the configuration of which will be described in relation to the operation.

Water, which is the matching liquid 2, is placed in the measuring tank 1. In order to confirm the presence or absence of air bubbles and air bubbles on the surfaces of the transducers (ultrasonic transducers) 4, 5, the transmittance of ultrasonic waves is measured without the object 3 being inspected. The ultrasonic wave is generated by the transducer 4 on the generation side and received by the transducer 5 on the detection side. The sound velocity / attenuation amount calculator 17 of the system controller 15 calculates the transmittance from the generated ultrasonic wave and the received ultrasonic wave, and the calculated transmittance is preset in the bubble / air layer detector 18. Is compared to a threshold.

If it is other than the threshold value, it is judged that there are bubbles and air layers on the surfaces of the transducers 4 and 5, and the bubble / air layer removal control unit 14 is instructed to remove the bubbles and air layers. The water flow is emitted by the pump 9 from the water flow hole 8a to the water flow hole 8b for a certain period of time (the water flow hole 8b is installed on the surfaces of the transducers 4 and 5 and the water flow hole 8c is installed so as to emit the water flow on the surface of the subject 3). .). For confirmation, the ultrasonic transmittance is measured again. The above operation is repeated until the threshold value is exceeded. In addition, this bubble, air layer removal operation,
Regardless of the presence or absence of air bubbles and air bubbles on the surfaces of the transducers 4 and 5, the inspection may always be performed before the start of inspection.

When the air bubbles and air layers on the surfaces of the transducers 4 and 5 are removed, the LED 6 is turned on, for example, indicating that the first stage measurement preparation is completed. The subject 3 is gently placed in a predetermined position between the transducers 4 and 5. When the subject 3 is placed at a predetermined position, the air bubble / air layer removal start switch 10 on the surface of the subject 3 is turned on, and the water flow is emitted from the water flow hole 8c for a certain period of time. Note that this operation may be performed at regular intervals when the inspection takes a long time.

The removal of air bubbles and air layers is performed by the automatic method as described above and the manual method by operating the air bubble and air layer removal switch 7 by the examiner (when the air bubble and air layer removal switch 7 is turned on, the transducer 4 , 5 and the surface of the subject 3 are fired). At a minimum, allow the examiner to operate manually. Also,
In addition to the water flow generation shown here, it is also conceivable that only the water flow holes facing the transducer and the surface of the subject are directed, and the direction of the water flow is changed by controlling the pump. For example, when a water stream is emitted to the transducer surface, water is sucked from the water stream hole directed to the subject surface, and the water stream is emitted from the water stream hole directed to the transducer surface. The opposite is true when a water stream is launched onto the surface of the subject. This method requires a switch to specify the direction of water flow. After the bubbles and the air layer are removed, the matching liquid control unit 13 controls the matching liquid 2 so as to keep it at a constant temperature, and the inspection is ready.

FIG. 2 shows an embodiment in which air bubbles and air layers are removed by using a wiper. After water, which is the matching liquid 2, is put into the measuring tank 1, air bubbles on the surfaces of the transducers 4 and 5 are removed.
The presence / absence of the air layer is carried out in the same procedure as in the case of the water flow in FIG. When the presence of air bubbles and air layers on the surfaces of the transducers 4 and 5 is confirmed, the air bubble and air layer removal control unit 14 receives an instruction to remove air bubbles and air layers, and the wiper drive unit 9a moves the wiper 8c along the surfaces of the transducers 4 and 5. Move it up and down for a certain time.

After this, as in the case of the water flow, the bubbles,
Check for the presence of an air layer, and if there is any, wiper 8
Repeat removal with c. When the removal of the air bubbles and the air layer on the transducer surface is completed, the removal is indicated, for example, the LED 6 is turned on. After that, the subject 3 is gently put in a predetermined position, and the subject 3 is placed in a predetermined position, whereby the switch 10 for starting the removal of bubbles and air layers on the surface of the subject is turned on and the surface of the subject 3 is removed. The wiper 8d for removing bubbles and air layers moves up and down on the surface of the subject 3 for a certain period of time. After that, the matching liquid 2 is controlled to be kept at a constant temperature as in the case of the water flow, and the inspection is ready. Wiper 8c, 8d
May have a structure such as a brush-shaped one or a rubber-shaped one which can be replaced according to the situation.

FIG. 3 shows an embodiment in which air bubbles and air layers are removed by using vibration, and the entire flow follows the flow shown in the flow chart of FIG. 4 as in the case of the water flow and wiper embodiments. Therefore, description will be given from the point where bubbles and air layers are confirmed on the transducer surface. When the presence of air bubbles and air layers is confirmed on the surfaces of the transducers 4 and 5, the air bubble and air layer removal control unit 14 receives an instruction to remove air bubbles and air layers, and causes the vibration controllers 8 to vibrate the transducers 4 and 5 themselves. Air bubbles and air layers are thereby torn off.

As in the embodiment shown in FIGS.
Repeat until no air layer is present. The removal of the air bubbles and air layer on the surface of the subject 3 after this can also be done by placing the subject 3 in a predetermined position by the air bubble / air layer removal switch 10 as well as the subject table / air bubble removal switch, as in the embodiment using the water flow and the wiper. When turned on, the subject table 10 vibrates for a certain period of time, causing the subject 3 to vibrate. As a result, air bubbles and air layers attached to the subject are removed. After that, the matching liquid 2 is kept at a constant temperature and is ready for inspection.

The removal of the air bubbles and air layer on the surface of the transducer and the subject can be done by water flow, wiper or vibration, but the removing means used for the transducer and the subject can be changed and combined. At this time, it is important to select the optimum air bubble and air layer removing means for each transducer and subject. The inspection is performed as follows after the subject 3 is placed at a predetermined position and air bubbles and air layers are removed. The procedure will be briefly described below.

The ultrasonic oscillation control unit 12 emits an ultrasonic pulse from the transducer 4 on the generation side, the transducer 5 on the detection side receives it, and the ultrasonic measuring unit 11 measures the time between them. From this time and the distance between the transducers, the speed of sound / attenuation calculation section 17 calculates the speed of sound. Furthermore, the ultrasonic measurement unit 11 measures the intensity of the ultrasonic wave received by the transducer 5 on the detection side, and the ultrasonic attenuation amount is calculated by the ultrasonic velocity / attenuation amount calculation unit from the ultrasonic intensity emitted by the transducer 4 on the generation side. It is calculated.

The sound velocity and the attenuation amount calculated in this way are converted into the bone mineral amount in the bone mineral amount equivalent conversion unit 16, and the result is output to the display unit 19. Degassed water may be used as the matching liquid in the measurement.

[0024]

According to the present invention, the transducer, the air bubbles on the surface of the subject, and the air layer, which cause the attenuation of the ultrasonic waves other than the subject and cause the deterioration of the inspection accuracy, can be reliably performed in a short time. It can be removed and accurate measurement can be performed. Further, the automatic detection function of air bubbles and air layers on the surface of the transducer makes it possible to eliminate the influence of variations in the presence / absence of air bubbles and air layers for each examiner on the inspection.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 4 is a flowchart for explaining an operation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Measuring tank 2 ... Matching liquid 3 ... Specimen 4, 5 ... Transducer (ultrasonic transducer) 8 ... Vibration controller 8a, 8b ... Water flow hole 8c, 8d ... Wiper 9 ... Pump 9
a: wiper drive unit 10: subject table and subject bubble, air layer removal switch 11 ... ultrasonic measurement unit 12 ... ultrasonic control unit 13 ... matching liquid control unit 14 ... bubble / air layer removal control unit 15 ... system control Part 16 ... Bone mineral content equivalent conversion part 17 ... Sound velocity / attenuation calculation part 18 ... Bubble / air amount detection part 19 ... Display part

Claims (2)

[Claims] 1. At least a pair of ultrasonic transducers, one of which is an ultrasonic wave generator and the other of which acts as an ultrasonic wave detector, are arranged in opposition to each other in a measurement tank in which a subject and a matching liquid are placed. In the ultrasonic transmission inspection device for inspecting the ultrasonic transmission characteristics of the subject by measuring the ultrasonic waves transmitted through the subject, the ultrasonic transducer and the air bubbles or air layers adhering to the surface of the subject are measured. An ultrasonic transmission inspection apparatus, characterized in that a means for removing the ultrasonic wave is provided. 2. The ultrasonic transmission inspection apparatus according to claim 1, further comprising bubble detection means for detecting the presence or absence of bubbles and an air layer on the surface of the ultrasonic transducer. Inspection device.