JPH05228148A - Ultrasonic transmission inspecting system - Google Patents

Abstract

PURPOSE:To enable measurement with high accuracy with the inspection device ade quate for diagnosis of the osteoporosis, etc., by providing ultrasonic generators and ultrasonic detectors on the opposite inside walls of a measurement chamber contg. a testee body and providing a liquid enclosing body for fixing the testee body by expansion between the respective inside walls and the testee body. CONSTITUTION:The porous body (liquid enclosing body) 41 is provided on the inner side of a frame 40 of the ultrasonic device for ultrasonic quantitative determination of the osteosalt and an ultrasonic matching liquid is filled therein to closely enclose the circumference of, for example, the heel, which is a part of the testee body, by which a measuring section 10 is constituted. A matching liquid injecting/discharging section 11 is controlled by a control section 15 in accordance with the output of a pressure sensor 43 provided in the porous body 41, by which the pressure of the matching liquid in the porous body 41 is regulated. The testee body is thereby fixed closely to the measuring section 10. Ultrasonic waves are passed through the heel bone in this state by the ultrasonic pair transducers, 46a, 46b, provided on the inside walls on both sides of the frame 40. The velocity and attenuation quantity of the ultrasonic waves in the heel bone are measured and the quantity corresponding to the osteosalt quantity is calculated in accordance with the result of the measurement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic transmission inspection device or an ultrasonic bone mineral quantification device used for diagnosis of osteoporosis.

[0002]

2. Description of the Related Art Osteoporosis is a condition in which the density of bone tissue decreases due to lack of calcium, etc., but for the purpose of diagnosis, ultrasonic waves are passed through the bone to determine the speed (sound velocity) and attenuation of the ultrasonic waves in the bone. A method of quantitatively measuring the characteristics of bone (bone mineral density, stiffness, etc.) by measuring the above has been devised. Such ultrasonography is usually performed on the heel of a thin soft tissue foot.

A conventional device for measuring the characteristics of bone (called an ultrasonic bone mineral quantification device) is a container (measuring tank) in which an ultrasonic generator and an ultrasonic detector are mounted on the inner wall so as to face each other. ) Is used. For the ultrasonic generator and the ultrasonic detector, a device called an ultrasonic transducer that can generate and detect ultrasonic waves with one unit is usually used. In this measuring tank, put your feet so that the heel may block the ultrasonic wave generation / detection device, and also for matching when the ultrasonic wave is incident on the heel (that is, the ultrasonic waves reflected on the surface of the heel should be Add water as a matching liquid (so that the sound waves are as low as possible). When an ultrasonic wave is emitted from the generator in that state, the ultrasonic wave propagates at a speed corresponding to the amount of bone mineral and is attenuated when passing through the calcaneus. Therefore, the amount corresponding to the amount of bone mineral in the calcaneus, which is the subject, can be measured by measuring the velocity or the amount of attenuation of the ultrasonic wave with the detector.

[0004]

Even if the surroundings of the subject are filled with the ultrasonic matching liquid so that the reflection of the ultrasonic waves on the surface of the subject (calcaneus) is minimized, some of the ultrasonic waves are still exposed. Although reflected on the surface of the sample, this amount of reflection changes depending on the angle between the propagation direction of the ultrasonic wave and the surface of the sample. Further, if the inclination of the subject with respect to the ultrasonic wave propagation direction changes, the ultrasonic wave propagation distances in the subject will differ even if the subject has the same size. from these things,
In order to perform an ultrasonic transmission examination with good reproducibility, it is desirable that the orientation of the subject be always constant with respect to the ultrasonic wave propagation direction.

The present invention has been made to solve such a problem, and an object of the present invention is to fix an object so as to always have a fixed positional relationship with respect to an ultrasonic wave propagation direction. By so doing, the reproducibility of the ultrasonic transmission inspection is assured, and the ultrasonic transmission inspection device capable of performing accurate measurement is provided.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an ultrasonic wave for inspecting the characteristics of an object by measuring the speed and attenuation of the ultrasonic wave passing through the object. In the transmission inspection apparatus, a) a measurement tank in which the subject is placed, b) an ultrasonic generator and an ultrasonic detector provided on the inner walls of the two measurement tanks facing each other with the subject in between, and c) at least the above It is characterized in that it is provided between the inner wall of the two surfaces and the subject, and is provided with a liquid package for expanding and fixing the subject by injecting an ultrasonic matching liquid into the inside.

[0007]

When performing the ultrasonic transmission inspection, after the subject is put in the measuring tank a, first, the ultrasonic matching liquid (for example, water) is injected into the liquid envelope c to expand the liquid envelope c. .. When the liquid envelope c is sufficiently expanded, the liquid envelope c fixes the subject from both sides in the measurement tank a, and makes the position and orientation of the subject in the measurement tank a substantially constant. After that, the ultrasonic wave transmission test with good reproducibility can be performed by measuring the sound velocity, the amount of transmission, etc. of the ultrasonic wave passing through the subject by the ultrasonic wave generator and the ultrasonic wave detector b.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the embodiments of the present invention, an ultrasonic permeation inspection device (ultrasonic bone mineral quantification device) that does not use a liquid envelope will be described with reference to FIGS. This device is shown in Figure 1.
As shown in FIG. 3, the measuring unit 10, the matching liquid injection / discharge unit 11, the matching liquid temperature control unit 12, the ultrasonic oscillation control unit 13, the ultrasonic measurement unit 14, the control unit 15, and the display unit 16 are included. The measuring unit 10 includes a measuring tank 20 in which a subject's foot (heel) is placed.
In addition, two pairs of ultrasonic transducers 21 and 22 provided to face the inner wall of the measuring tank 20 are included. Also,
The control unit 15 includes a matching degree control unit 17 for adjusting the matching degree between the matching liquid and the subject, a sound velocity / attenuation amount calculating unit 18 for calculating the sound velocity and the attenuation amount of ultrasonic waves, and the calculated values. The bone-mineral-equivalent amount conversion part 19 which converts into a bone-mineral equivalent amount is included. In each ultrasonic transducer pair 21, 22, the transducers 21a and 21b face each other,
Further, the transducers 22a and 22b face each other.

The bone mineral content is measured by the present ultrasonic bone mineral content measuring apparatus as follows. First, the heel of the subject is placed in the measurement tank 20 at a position where only one transducer pair 22 is blocked and the other transducer pair 21 is not blocked. Next, a matching liquid (for example, water) whose temperature is controlled to a predetermined temperature is injected from the matching liquid injecting / discharging portion 11 to the injection port 23
It is poured into the measuring tank 20 from. When the liquid level meter 25 provided on the inner wall of the measuring tank 20 detects that the liquid level in the measuring tank 20 has reached a predetermined level, the matching liquid injecting / discharging unit 1
1 stops the injection of the matching liquid. After that, after the state of the matching liquid is stabilized, the matching adjustment between the heel as the subject and the matching liquid is performed as follows.

First, as shown in FIG. 3 (a), the ultrasonic oscillation controller 13 has one transducer 22a (or 2) of the transducer pair 22 which is shielded by the heel.
The ultrasonic pulse is emitted from 2b) toward the heel. A part of this ultrasonic wave is reflected at the boundary between the matching liquid 26 and the heel 27, and the transducer 22a (or 2) that emitted the ultrasonic wave.
2b), the ultrasonic measurement unit 14 uses the same transducer 22a (or 22b) as the ultrasonic intensity.
To detect.

The reflectance of the ultrasonic waves at the boundary between the matching liquid and the subject generally changes with the temperature of the matching liquid, as shown in FIG. 2 (a) or (b). For example, FIG. 2 (a)
In the combination of the matching liquid of this type and the test object, the reflectance is the lowest when the temperature of the matching liquid is T3, and the amount of reflected ultrasonic waves regardless of whether the temperature of the matching liquid is lower or higher. Will increase. Further, in another combination of the matching liquid and the subject, as shown in FIG. 2B, the reflectance may simply increase or decrease in the adjustable temperature range.
Here, the adjustable temperature range is usually a temperature that a human body as a subject can tolerate.

In any case, the matching degree control unit 17 issues a command signal to the matching liquid temperature control unit 12 so as to change the temperature of the matching liquid, so that the matching liquid in the matching liquid injection / discharge unit 11 can be controlled. While the temperature is gradually changed, the matching liquid 26 whose temperature has changed is injected into the measuring tank 20 through the inlet 23 (at the same time, the matching liquid 26 in the measuring tank 20 is discharged from the outlet 24 by the same amount. To). In this way, the matching liquid 26
While changing the temperature, the matching degree control unit 17 detects the point where the reflectance becomes the lowest in a predetermined temperature range (between T1 and T2) while observing the ultrasonic intensity detected by the ultrasonic measurement unit 14. To do. In this way, the temperature at which the reflectance becomes the lowest (Fig. 2
After detecting the temperature T3 in (a) and the temperature T1 in FIG. 2 (b), the matching degree control unit 17 sends a command signal to the matching liquid temperature control unit 12 so as to set the temperature of the matching liquid 26 to that temperature. Out and inject the matching liquid 26 adjusted to the optimum temperature.
It is injected into the measuring tank 20 by the discharge part 11.

It should be noted that, instead of adjusting the temperature of the matching liquid outside the measuring tank 20 (matching liquid injecting / discharging portion 11) as described above, a temperature sensor, a heater and a cooler are provided in the measuring tank 20 for measurement. The temperature of the matching liquid may be directly controlled in the tank 20. Further, in order to change the matching degree between the matching liquid and the subject, the temperature of the matching liquid is changed in the above example, but the matching degree of the matching liquid is changed by changing the mixing ratio of the two liquids having different acoustic impedances. May be changed. For example, water (acoustic impedance z ≈
It is also possible to use a mixture of 1.5 × 10 ⁶ kg / m ² ) and glycerin (z≈2.5 × 10 ⁶ kg / m ² ) as the matching solution, and change the mixing ratio of both when adjusting the matching. it can.

After the matching degree between the matching liquid and the subject (heel) is optimized as described above, quantitative measurement of bone mineral is started.
The control unit 15 first measures the velocity vw of the ultrasonic waves in the water and the attenuation amount rw (per unit distance) by the transducer pair 21 having no heel. First, the ultrasonic oscillation control unit 13 emits an ultrasonic pulse from one transducer 21a and the other transducer 21b.
Then, the ultrasonic measuring unit 14 receives the time tw during that period.
To measure. Since the distance L between the two transducers 21a and 21b is known, the velocity vw of the ultrasonic waves in the water under the present conditions can be obtained as vw = L / tw. Further, the attenuation amount rw is obtained by measuring the intensity of the ultrasonic wave detected by the transducer 21b on the receiving side by the ultrasonic wave measuring unit 14 and comparing this with the intensity of the ultrasonic wave generated by the transducer 21a on the generating side. be able to. These are the control unit 15
The sound velocity / attenuation amount calculation unit 18 therein calculates.

On the other hand, the thickness of the heel 27 is measured by the transducer pair 22 with the heel 27 interposed. Figure 3
As shown in (a), each transducer 22a, 22a
An ultrasonic pulse is emitted from b, and the ultrasonic wave reflected by the surface of the heel 27 and returning is emitted from the transducer 22.
a, 22b itself detects. The ultrasonic measurement unit 14 measures the times t1 and t2 from the emission of the ultrasonic pulse to the detection for each of the transducers 22a and 22b. Based on the measured values t1 and t2, the control unit 15 determines the distances L1 and L2 between the transducers 22a and 22b and the surface of the heel 27.
Is calculated as L1 = vw · t1 / 2 and L2 = vw · t2 / 2. Further, the thickness Lb of the heel 27 is calculated as Lb = L-L1-L2.

Finally, the ultrasonic wave velocity vb and the attenuation amount rb in the calcaneus are measured by the transducer pair 22 in which the heel 27 is also interposed. That is, one transducer 22a emits an ultrasonic pulse, and the other transducer 22b detects it (or vice versa), and measures the time twb and the intensity of the detected ultrasonic wave during that period. From this measured value, the ultrasonic velocity vb in the calcaneus can be calculated as vb = Lb / (Lb / vw + Δt) Δt = twb−tw. Alternatively, as shown in FIG. 3B, it can be calculated as vb = Lb / (tw-t1 / 2-t2 / 2). Further, the attenuation amount rb of the ultrasonic wave in the calcaneus can also be calculated by substituting the detected ultrasonic intensity value into a predetermined formula. The value of the thickness Lb of the calcaneus is also required in the calculation of the attenuation amount, but by substituting the value Lb calculated as described above, it is possible to measure the attenuation amount with good reproducibility. Based on the velocity or the attenuation amount of the ultrasonic wave calculated in this way, the bone mineral content equivalent conversion unit 19 calculates the bone mineral equivalent amount, and the result is displayed on the display unit 16.

Next, according to the embodiment of the present invention, instead of immersing the subject (heel) in the matching liquid, an expandable and contractible liquid envelope (bolus) containing the matching liquid is used. An ultrasonic bone mineral quantification device capable of matching and fixing a subject will be described. As shown in FIG. 4, in the measurement unit 10 of the ultrasonic bone mineral quantification device of the present embodiment, a bolus 41 is provided inside the frame 40, and the interior of the bolus 41 is filled with a matching liquid to surround the heel 27 that is the subject. It is surrounded by matching liquid without any gaps. Therefore, the control unit 15 and the matching liquid injecting / discharging unit 11 according to the present embodiment monitor the pressure sensor 43 provided in the bolus 41 and adjust the pressure of the matching liquid in the bolus 41 to be constant. The matching liquid is injected / discharged from 44 and the discharge port 45. This allows the bolus 41
Will always fix the heel 27 with a constant pressure, prevent movement of the heel 27 during measurement, perform accurate bone mineral quantitative measurement, and guarantee reproducibility of measurement.

After fixing the heel 27 in this manner, the matching degree control unit 17 changes the temperature of the matching liquid in the bolus 41 to change the temperature between the heel 27 and the bolus 41 as in the case described above. The temperature of the matching liquid that provides the best matching is detected (in this embodiment, the temperature sensor 42 provided in the bolus 41 is used), and the matching liquid in the bolus 41 is heated to that temperature or After cooling, measure. That is, ultrasonic waves are passed through the calcaneus by the ultrasonic transducer pairs 46a (ultrasonic wave generator) and 46b (ultrasonic wave detector) provided on the inner walls on both sides of the frame 40 via the heel 27, The velocity and attenuation of the ultrasonic wave are measured (FIG. 5 (a)). Note that, as shown in FIG. 5B, the ultrasonic wave in the matching liquid has the velocity and the attenuation amount expanded by expanding the bolus 41 without sandwiching the heel 27 and the transducer pair 46.
The measurement can be performed by using only the matching liquid in the bolus 41 between a and 46b.

Also in this embodiment, as shown in FIG. 6 (a), the transducer pairs 46a, 46b, 47a, 47 are respectively placed at the places where the heel is not interposed and at the places where the heel is interposed.
It is also possible to arrange b so that the measurement can be completed once. Further, as shown in FIG. 6B, the bolus 41 may be provided only on both sides 48 and 49 of the heel 27. Alternatively, conversely, boluses may be provided on the front and back to completely fix the heel 27 (foot) from all sides. In addition,
As a material of the bolus 41, a rubber film which is rich in elasticity by itself, or a plastic film having a small amount of expansion and contraction may be used. In this case, use a bolus with a sufficiently large internal volume so that the space between the ultrasonic generator and ultrasonic detector is filled with the ultrasonic matching liquid in the bolus when the bolus is fully expanded. Good.

In each of the above embodiments, the ultrasonic bone mineral quantifying device using the calcaneus as the subject has been exemplified. However, the present invention is not limited to bone, but the one using soft tissue as the subject, such as an ultrasonic transmission measuring device in general. Can be applied.

[0021]

According to the ultrasonic transmission inspection apparatus of the present invention,
Since the subject is fixed by the liquid envelope, the subject is always placed at a substantially constant position with respect to the ultrasonic generator and the ultrasonic detector. Therefore, the reproducibility of the measurement is guaranteed, and the bone mineral content (equivalent amount) and the like can be measured more accurately. Further, since the ultrasonic matching liquid (water or the like) does not come into direct contact with the subject (foot or the like), the subject does not get wet and the inspection becomes easier.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an ultrasonic bone mineral quantification device that does not use a liquid envelope.

FIG. 2 is a graph showing the relationship between the temperature of the matching liquid and the ultrasonic reflectance of the boundary between the matching liquid and the subject.

FIG. 3 is a cross-sectional view of a state in which a heel, which is a subject, is placed in the measurement tank.

FIG. 4 is a configuration diagram including a perspective view and a block diagram of an ultrasonic bone mineral quantification device having a measurement unit using a liquid envelope (bolus) that is an embodiment of the present invention.

FIG. 5 is a plan view of the measurement unit when the ultrasonic measurement is performed by fixing the heel with a bolus (a) and when the ultrasonic measurement is performed only by the bolus (b).

FIG. 6 is a plan view showing a modified example of a measurement unit using a bolus.

[Explanation of symbols]

10 ... Measuring unit 12 ... Matching liquid temperature control unit 17 ... Matching degree control unit 26 ... Matching liquid 27 ... Heel (subject) 40 ... Measuring tank 41 ... Bolus (liquid package) 44 ... Ultrasonic matching liquid injection port 45 ... Ultrasonic matching liquid discharge ports 46a, 47a ... Ultrasonic wave generators 46b, 47b
... Ultrasonic detector

Claims (1)

[Claims] 1. An ultrasonic transmission inspection apparatus for inspecting the characteristics of an object by measuring the velocity, attenuation, etc. of the ultrasonic wave passing through the object, wherein: a) a measuring tank in which the object is put; ) An ultrasonic wave generator and an ultrasonic wave detector provided on the inner walls of the measurement tank facing each other with the subject in between, and c) at least between the inner wall of the two faces and the subject, and the ultrasonic wave inside. An ultrasonic transmission inspection apparatus, comprising: a liquid envelope that expands by injecting a matching liquid and fixes the subject.