JPS63317130A - Arterial sclerosis degree diagnostic apparatus using intravascular ultrasonic transducer - Google Patents

Abstract

PURPOSE:To perform the measurement of blood pressure and the calculation of the modulus of elasticity of a blood vessel with good accuracy by an intravascular method, by integrally forming a blood pressure sensor and an ultrasonic vibrator part at the leading end part of a catheter. CONSTITUTION:An intravascular ultrasonic transducer 12 consists of the catheter 22 inserted in a blood vessel 21, the vibrator support member 24 protruding from the guide passage 23 in the catheter 22, the ultrasonic vibrator part 25 mounted to said support member 24, the guide 26 of the support member 24 mounted to the leading end of the support member 24, the blood pressure measuring sensor 27 provided to the leading end of the catheter 22 and the strain pressure gauge 28 formed to the rear end of the catheter 22. The support mechanism part 31 for closely bringing the ultrasonic vibrator part 25 into contact with the inner surface of the wall 29 of the blood vessel 21 is formed to the support member 24.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an intravascular ultrasound system that can measure various quantities necessary for determining the vascular elastic modulus, etc., which is an index of arteriosclerosis degree, from within the blood vessel at the same location in the blood vessel. It is related to the arteriosclerosis diagnostic system BQT using a transducer.

[Prior art] +) J arteriosclerosis progresses with age from a young age, and reaches the stage where it does not cause various diseases; however, quantitative diagnostic technology regarding the degree of arteriosclerosis has not yet been established. Zu, early IIn
%,: A method has been developed that can determine the degree of progression of arteriosclerosis, and it is extremely important to develop a device that can accurately measure the degree of arteriosclerosis.

The most accurate evaluation method for the degree of arteriosclerosis is based on the stiffness of blood vessels, that is, the modulus of blood vessel elasticity, and a scaled modulus of blood vessel elasticity has been proposed so far. For non-extracted blood vessels in living organisms, the basic measurement method is to measure the rate of change in blood vessel diameter in response to pulsatile intravascular pressure changes (pulsatile pulses). As the disease progresses, the pulsatile diameter change decreases even if the pulse pressure remains the same, and it is possible to detect hardening changes. Among various vascular elastic moduli, the following vascular elastic modulus is frequently used to evaluate the degree of arteriosclerosis of non-extracted blood vessels. One is the pressure elastic modulus [p, where the pulse pressure is ΔP1, the blood vessel diameter is 1], and the pulsatile diameter change is ΔP.
and J, Ep-ΔP/(ΔI)/D”) ・・・・・・
Defined in (1). The pressure elasticity t'l modulus Ep is an elastic modulus that exists not only in the material hardness of the blood vessel wall but also in the wall, and the material hardness of the blood vessel itself cannot be evaluated.

To evaluate this, it is necessary to further measure the thickness of the blood vessel wall and obtain Young's modulus. If the All Doug ratio is known, it can be clarified whether the sclerotic changes due to arteriosclerosis are caused by qualitative changes or wall thickness.

Incremental elastic modulus has conventionally been proposed as the vascular elastic modulus that gives such a vascular wall Young's modulus. inc has good accuracy with wall thickness h as Einc = Ep ・C1-a”)/(2h/D
)−(2). Here, σ is Poisson's ratio and the blood vessel wall is 0.5.

BACKGROUND ART Conventionally, a method has been reported in which a tube diameter and a pulsatile diameter change ΔD are measured using ultrasonic waves for the purpose of determining the pressure elastic modulus. This method is an excellent method that non-invasively measures blood vessel diameter and pulsatile diameter change by injecting ultrasound waves from the body surface, but it requires pulse pressure information Δ to determine the elastic modulus.
P is a substitute for the value measured in the upper arm using a cuff-type sphygmomanometer, and is different from the pulse pressure at the site where arteriosclerosis is measured, such as the aorta. I had no choice. In addition, in the non-invasive method from the body surface, the lungs in the thorax and intestinal gas in the abdomen become obstacles to ultrasound propagation, severely limiting the measurable area in deep blood vessels such as the aorta. In general, the frequency of the ultrasound that can be used cannot be high due to attenuation in tissues, and therefore the resolution is poor, and the thickness of the blood vessel wall can be measured by resolving the ultrasound echoes from the inner and outer walls of the blood vessel. Therefore, it has been difficult to obtain the incremental elastic modulus of equation (2), which is more advanced diagnostic information regarding the degree of arteriosclerosis.

On the other hand, in order to solve the above-mentioned problems, the present inventors have already reported for the first time an attempt to perform measurement from within a blood vessel, although it is invasive. In this report, a small-sized ultrasonic transducer shown in FIG. 19 that can be inserted into a blood vessel was prototyped.

In this conventional example, a catheter 2 is inserted into a blood vessel wall 1, a transducer support mechanism 3 is protruded from the catheter 2 in a bent state, and an ultrasonic transducer section 4 attached to the tip of the transducer support B14f43 is inserted into the blood vessel wall 1. The measurement is performed using ultrasonic waves when U is in contact with the wall 1.

[Problems to be Solved by the Invention] The above-mentioned conventional example could not be practical in terms of measurement accuracy, noise countermeasures, stability, etc., as described below. jl Namely: 1) Blood pressure measurement had to be done by other means as well as non-invasive methods, and for the reasons mentioned above, the measurement accuracy lacked reliability.

2) In addition, if blood pressure was to be measured within a blood vessel, it would be necessary to incise two blood vessels in order to insert both the ultrasound and blood pressure transducers into the blood vessel, making it difficult for this method to be widely used as a clinical testing method. Not only is it difficult to align the ultrasonic transducer and the blood pressure transducer,
As expected, the measured viscosity had to decrease.

3) Ultrasonic waves are emitted not only in front of the transducer but also in the rear, and unnecessary reflected echoes from the rear become noise in the measurement signal, making it inevitable that measurement often becomes impossible.

4) Since the vibrator was attached to the tip of the support mechanism, the support of the vibrator to the blood vessel wall was unstable, and the operator had to constantly adjust the measurement. At the curved portion of the blood vessel, the vibrator was in close contact with the wall, making measurement impossible.

As described above, even with the intravascular method, the conventional method described above cannot withstand practical measurement, and there is a situation in which a modification is desired.

The present invention has been made in view of the above-mentioned points, and therefore provides an artery using an ultrasound transducer in a curved tube, which eliminates the above-mentioned drawbacks and enables accurate measurement of blood pressure and calculation of vascular elastic modulus by intravascular method. The purpose of this invention is to provide a hardening degree diagnostic device.

[Means and effects for solving the problems] The present invention includes a blood pressure sensor for measuring pulse pressure on the distal end side of a catheter that can be inserted into a blood vessel, and a support mechanism that protrudes from the catheter. It is highly reliable and has a good S/N ratio by integrally forming the ultrasonic transducer part that is in close contact and can detect blood vessel diameter, pulsating diameter change, and blood vessel wall thickness using ultrasound. This allows us to measure the pressure elastic modulus and incremental elastic modulus, which are indicators of the degree of arteriosclerosis.

[Example] Hereinafter, the present invention will be specifically described with reference to the drawings.

1 to 10 relate to a first embodiment of the present invention, FIG. 1 shows a strain gauge pressure gauge having an ultrasonic transducer in a curved pipe in the first embodiment, and FIG. 2 shows an ultrasonic vibration 3 shows the overall structure of the first embodiment, FIG. 1 shows the structure of the ultrasonic microscale crystal 1, and FIG. 5 shows an explanatory diagram of the operation of FIG. 4. , Fig. 6 shows an explanatory diagram of the tracking mechanism, Fig. 7 shows an example of measuring the pipe diameter and the diameter change, Fig. 8 shows the structure of the sensor for surface pressure measurement, and Fig. 9 shows the structure of the surface pressure measurement sensor. An example of an ultrasonic echo signal obtained by applying 1:1 to a dog's blood vessel is shown, and FIG. 10 shows pressure elastic modulus, etc. obtained by applying measurement data measured for a dog's blood vessel.

As shown in FIG. 3, the arteriosclerosis degree diagnostic device 11 (using the curved tube ultrasonic transducer of the first embodiment) is an intravascular ultrasonic transducer that is elongated so that it can be inserted into a blood vessel. user 12 and this curved tube ultrasonic transducer 1
Based on the output signals from step 2, the pulse pressure ΔP, blood vessel diameter D1 beat V diameter change ΔD, and wall thickness are output to evaluate the degree of arteriosclerosis 1)+
It consists of a pulse visualization degree calculation section 13.

The (intravascular ultrasound) transducer 12 includes, as shown in FIG. 1, a catheter 22 inserted into a blood vessel 21, a transducer support member 24 projected from a guide path 23h of the catheter 22, An ultrasonic transducer section 25 attached to this (vibrator) support member 24, a guide 26 of the support member 24 attached to the tip of this support member 24, and a blood pressure sensor installed at the tip of the catheter 22. It consists of a measurement sensor 27 and a strain gauge pressure h128 formed at the rear end of this catheter 22. In addition, in FIG. 1, the sensor 27 shows a portion at the tip side of the communication hole communicating with the strain gauge pressure gauge 28 where the blood pressure at a3 is measured.

The support member 24 has a curved tip with a chevron-shaped bend, and an ultrasonic transducer section 25 is attached to the top of the chevron-shaped portion. A support mechanism portion 31 is formed that is brought into close contact with the inner surface of the wall 29. In this support member 24, at least the support mechanism portion 31 on the distal end side is formed of an alloy wire that exhibits superelastic properties. As this alloy wire, for example, a 0.3 m diameter nickel titanium alloy wire can be used.

Furthermore, the length of the support mechanism section 31 is approximately 50all! It is.

When inserted into the blood vessel 21, the bent support mechanism part 31 causes the diameter of the blood vessel to increase by 5 degrees (as shown in FIG. The ultrasonic transducer part 25 attached to the 111th part of this mountain is in contact with one of the two inner surfaces, and the top side of the n-mountains is pressed against the other opposing inner surface. It is pressed tightly against the other wall.
The ultrasonic transducer unit 25 transmits ultrasonic waves to the inner blood side while being in close contact with the wall surface, or transmits ultrasonic waves to the blood side inside. Three waves of echoes can be received, (the operator has to constantly adjust them, and the distance to the force wall is inconsistent due to poor contact). , without any decrease in reliability). The high measurement of f−t′(
9.

By the way, FIG. 2 shows the structure of the ultrasonic transducer section 25 attached to the support member 24.

The ultrasonic transducer section 25 includes an ultrasonic transducer 33 formed into a substantially plate shape using a piezoelectric material such as lead zirconate ditanate.
An acoustic matching layer 34 is formed on the front surface of the ultrasonic transducer 33 (which transmits and receives ultrasonic waves), and is provided to efficiently transmit and receive ultrasonic waves. A rear ultrahigh wave is provided to emit ultrasonic pulses only at the transmitting/receiving surface 35 on which the 8-echo matching layer 34 is provided, and to receive echo waves to avoid mixing of unnecessary reflected liquid from the back side. Two signal wires 37 and 38 are connected to a suppressing member (for example, foamed plastic such as styrofoam) 36 and electrode models (not shown) on the front and back surfaces of the ultrasonic transducer 33, and these signal wires 37 .38, and consists of three mold members made of epoxy resin or the like and fixed with resin to the superelastic alloy wire forming the support mechanism section 31. The size of the vibrator section 25 is, for example, a width of 2.3 am, a length of 4.5 as+, and a thickness of 1.51 m.

[1] The signal line 38 on the back side of the sonic transducer section 33 is attached to a superelastic alloy wire with a conductive adhesive or the like to make it conductive.
This alloy wire is the ultrasonic transducer 33 (or ultrasonic transducer part 2
5) to send ultrasonic excitation pulses to the ultrasonic sensor 3.
It also serves as a signal transmission line for transmitting the echo signal received at 3 and subjected to piezoelectric conversion.

In addition, the ultrasonic transducer section 25 inserted into the blood vessel 21
The support mechanism 31 and guide 26 are coated with antithrombotic H material.

As shown in FIG. 3, the output of the blood pressure sensor 27 is input to the distortion amplifier 41, and the blood pressure ['! After amplifying the blood pressure signal outputted from the sensor 27, the A/D converter 42 converts it into a digital time signal. This A/D'' conversion signal is input to the pulse pressure calculating section 43, and the pulse pressure ΔP is calculated.

On the other hand, the output of the ultrasonic transducer section 25 is input to a zero-cross tracking type ultrasonic minute displacement meter 44 and a high-speed A/D converter 45, and the output of this high-speed A/D converter 45 is roughly sent to a wall thickness calculation section 46. It has been entered. This thick-walled pancreas exhibit 4
6 performs fast Fourier transform on the digital signal of the RF echo signal, and calculates the wave frequency on the obtained power spectrum.
is detected and the wall thickness is calculated.

In addition, the output j signal of the (zero cross tracking type) ultrasonic minute displacement meter 44 is passed through a low pass filter (abbreviated as LPF) 47 and a bypass filter (abbreviated as +-IPF) 48, and then outputted as A/l). The blood vessel elastic modulus is inputted to the blood vessel elastic modulus 49 and the tube diameter change calculation unit 51 via the converter 42,
The pipe diameter and the pipe diameter change ΔD are respectively calculated.

The output information of the pulse pressure calculation section 43, tube diameter change calculation section 51, and wall thickness calculation section 46, that is, pulse pressure ΔP, tube diameter D1 tube diameter change Δ
The P1 wall thickness is input to the vessel elastic modulus σ Exhibit 49, and the vessel elastic modulus Ep and incremental elastic modulus E, which are closely related to the degree of arteriosclerosis, are
inc is calculated.

Note that each of the calculation units described above is composed of a microprocessor.

By the way, the configuration of the ultrasonic minute displacement meter 44 is shown in FIG.

Ultrasonic vibration of the intravascular ultrasound transducer 12
The section 25 is connected to a transmitting/receiving circuit 61, and this transmitting/receiving circuit 6
The ultrasonic excitation pulse transmitted through the ultrasonic excitation pulse 1 generates an ultrasonic wave and emits it to the target region side, and the ultrasonic echo signal is captured and piezoelectrically converted into an electric signal (RF echo signal). to be transmitted.

This transmitting/receiving circuit 61 is connected to a transmitting clock generating circuit 62 that generates a transmitting clock for ultrasonic excitation, and is also connected to a zero cross detector 63 and a CRT monitor 64, and inputs an RF echo signal.

The output of the 1o cross detector 63 is the gate circuit 65.
and is manually operated by the tracking controller 66.

Further, the output of the transmission clock generating circuit 62 is applied to the terminals 1 to 1 of the control flop 67, and outputs the 7-lip flop 67 in synchronization with the transmission L1 clock. The output of the gate circuit 65 is applied to the reset terminal of this Noritsubu flop 67 GJ%, and is reset by the output of the gate circuit 65.

The output of the flip knob 67 is input to an integrating circuit 68, and the integrated output of the integrating circuit 68 is input to a ripple hold circuit 69 where it is number-held. The outputs of these six sample and hold circuits are input to a 200 l-1z low pass filter (20011Z LPF) 71, and the output that has passed through this 200Hz LPF 71 is 0.
1Hz LPF72 and 0.1l-1z I-IPF7
3 will be done manually.

The above-mentioned tracking control 1''-566 is connected to the tracking counter 74, and this tracking counter 74
is connected to the initial set circuit 75.

This ultrasonic minute displacement meter 44 includes a transmission clock generation circuit 6
2 generates a transmission clock and transmits/receives the circuit (31
Then, an excitation pulse is applied to the ultrasonic transducer section 25 to output an ultrasonic wave pulse as shown by the dotted line J in FIG. 5(A). At the same time, the flip-flop 67 is set by the transmission clock of the transmission clock generation circuit 62 as shown in FIG. It is integrated.

By the way, the ultrasonic pulse generated by the application of the excitation required pulse is transmitted to the ultrasonic transducer 33 of the ultrasonic transducer section 25.
From there, it is sent out through the transmitting/receiving surface 35 toward the blood side in the blood vessel that is in close contact with the transmitting/receiving surface 35. A part of the ultrasound waves propagated through the blood is reflected by the inner surface of the blood vessel wall 29, and a part is also reflected by the outer surface of the blood 11 wall.
Work: 1 - Shin; jLJV 1, UV2/
+CXfl? '< Return to him11i1jfJ1 child 33. Engineering: 1-Ie UV1. UV2 is amplified by the transmitting/receiving circuit 61 and displayed on the monitor 64 (four waveforms shown in FIG. 5(A)). However, the echo signal UVI on the inner surface of the blood vessel wall is recognized on the Teshini 6/I, and the position is indicated by the controller forming the initial set circuit 75, and the timing to open the gate is set in the tracking counter. do. This gate sets the card king controller 6G so that the gate opens at the time when the transmission clock is generated and the echo pulse on the inner surface of the blood vessel wall returns from C. The above echo signal LJV1. UV2 is zero cross detector 6
3, a pulse is generated at the point where the echo signals Uv1 and UV2 pyrocross as shown in FIG. 5(B). The gate circuit 65 is operated by the tracking controller 66 to open the gate as shown in FIG. 5(C), passes through the pyrocross (detector) output on the inner surface of the blood vessel wall, and resets the flip 70 knob 67.

Note that when the blood vessel wall moves due to pulsation, the listening time of the gate changes as will be described later, and the gate circuit 65 is controlled by the tracking controller 66 so that the zero cross signal of the inner surface of the blood vessel wall is always input to the flip-flop 67. Ru. The output waveform of the flip-flop 67 shown in FIG.
It has a time span that is twice as long.

The output of the flip 70 knob 67 is integrated into a voltage by an integrating circuit 68, and its peak value is sampled and held by a sample hold circuit 69 as shown in FIG. 5(F), and corresponds to the diameter of the blood vessel. converted to voltage. after that,
For example, unnecessary noise on the high frequency side is removed using 200H7LPF71, and then, for example, 0. I Hz LPF72 extracts the DC component and produces a signal equivalent to the average lightness of blood vessels? At the same time, a signal corresponding to the variation ΔD, that is, the change in blood vessel diameter due to pulsation, can be obtained from the 01 and HHPF73.

Note that the sample hold circuit 69 and the integration circuit 68 are reset by the transmission clock.

Furthermore, when opening and closing the gate using the gate circuit 65 described in 7L, the ultrasonic pulses emitted from the ultrasonic transducer 33 actually return various pulses through the matching layer 34, blood vessels, etc. This prevents the flip-flop 67 from being repited by these various pulses, making it possible to eliminate blood vessel diameter with high reliability.

In addition, in order to eliminate the diameter of the blood vessel, the space between the back surface of the ultrasonic transducer 33 and the 1111N tube wall can be corrected by setting the flip 70 knob based on the transmission clock earlier by this space. It is also possible to correct the blood vessel diameter in this way to obtain a more accurate blood vessel diameter.

FIG. 6 is an explanatory diagram showing the tracking mechanism.

The tracking gate opening period of the gate circuit 65 whose opening/closing is controlled by the tracking controller 66 has a time width corresponding to one cycle of the ultrahigh wave oscillation frequency (for example, 5M1iz), and this time width is as shown in FIG. First time as shown in a)! Tsu1 Kagawa II OII gate and for correction after 114 "
Divide into 3 parts: +1° gate and -1'° gate. Therefore, the gate position: S set at the zero cross point of -130 from the inner surface of the blood vessel wall is stored in the tracking counter 74 by counting the clock in synchronization with the T'e vibration repetition period 1υ1. Uru.

As shown by the arrow in FIG. 6(b), from the solid line to the line f1, the t# (ml) point of the echo signal due to the blood vessel wall is from the 110 If gate for initialization. Assuming that the phase shift has entered the region of "' + 1" goo! for correction, the tracking controller 66 corrects the phase shift (31
(Difference in count number compared to numerical value, etc.) is detected, and a count-up signal is output. This brings us to Trough 4: 74! The memorized "O" gate position n is moved by "' + 1" in the direction of the above arrow,
In other words, the number is updated to n as shown in FIG. 6(C).

In this way, the repetition of detection and gate displacement correction based on the detection results in repeated oscillation cycles! (same as +V) Since it is performed every several 100 μsec, for example, several tens of cm/
It is possible to follow a surface pipe wall carrying machine with a speed of up to 1 sec. While this tracking gate is listening, each of the above-mentioned τ
Koyamabe performs signal processing. In other words, a constant voltage rectangular wave corresponding to the distance α1 between the inner wall surfaces of the blood vessel is formed from the output of the flip-flop circuit 67, and then this rectangular wave is integrated by the integrating circuit G E3 C. The h1-minute voltage of (is converted to 1,1, which corresponds to the distance of the inner wall surface of the blood vessel. This (1,i C is an appropriate value, and the average voltage is The DC component per +n to the diameter and II'
It is separated into two AC components, one corresponding to the change in bamboo diameter. 7th
The figure shows the average 1 yen D of the abdominal aorta that was extracted in this example.
((a) in the same figure) and I+i fh diameter change ΔD (((a) in the same figure).
b)).

By the way, as shown in FIG. 8, there is a catheter tip-shaped pressure hole in the neck of the blood pressure measurement lever 27 on the front side of the lance durie 12, marked with L. Take 1 directly f=J
G-no is also fine. These form pressure sensors using strain gauges.

The pressure sensor 81 shown in FIG. 8(a) has a substantially cylindrical shape, and a pleated metal bellows 83 is installed on the inner 11 side of the outer cylinder 82 through the air gear 11 knob 82. The strain gauge 84 is used to measure the contraction at . In addition, a heat supply supplement 785 is provided to compensate for temperature dependence.

The pressure sensor 91 shown in FIG. The back sides of the silicon plates 94 and 94 are attached to each other with adhesive 95, and the bases of these silicon plates 94 and 94 are
- After the fixing member 96'c is fixed, the end of the cylinder 93 is also sealed with the plus book member 96, and the surface of the silicone plate 94 of -1 is exposed to exposure I'i to remove blood FT. It forms measurable daicephram.

Incidentally, each silicon plate 94 is provided with an electric wire (4i 97) and drawn out by a lead wire.

In the pressure sensor 101G shown in FIG.
03, and between its tips [fix silicone 1-dicephram 104 to 1 part with L4 resin 105, etc., and connect copper wire 1
It is designed to be able to pull out the hole at 0G. In addition, quartz tube 1
A Teflon tube 107 is installed in 1ll11 of 03.

The pressure sensor 111 shown in FIG. 0(d) is a stainless steel block 11 in which a side hole is provided near the leading end of a cylindrical member 112 such as a catheter, and a space is provided in a portion opposite to this side hole.
3, a die (/flame 114) is placed on the silicon plate, and the side facing the side hole is adhesively fixed with a silicone adhesive 115. There is 1 drawer on the side! J116 is the drawer 1
I'm being kicked.

The pressure hinge IJ-121 shown in FIG. 8(c) has a stainless steel case 123 at the tip of a cylindrical member 122 such as a catheter.
Install the side hole type pressure sensor 124 inside this stainless steel case 123, and install the silicone rubber diaphragm 125 on the pressure detection part of this pressure sensor 9-124.
Hard] - Fixed with poxy resin 126. Among the pressure sensors 81.91, 101, 111.121, those of the type that measure pressure on the side surface can measure the pressure more smoothly. This is less susceptible to the influence of dynamic pressure components of blood flow, and is advantageous for actual blood pressure measurements because excessive force is not applied when inserting it into a blood vessel.

According to the first embodiment having the above configuration, when the distal end side of the intravascular ultraviolet transducer 12 is inserted into the blood vessel 21, the first
As shown in FIG. 1, the ultrasonic transducer section 25 is intimately attached to the inner surface of the blood vessel wall 29 in the support mechanism section 31. In this case, the blood pressure measurement sensor 27 faces the vicinity of the ultrasonic transducer section 25,
Blood pressure near the ultrasound transducer section 225 can be measured.

Since the support mechanism 31 transmits and receives ultrasonic waves while being in close contact with the blood vessel wall 29, it is possible to receive ultrasonic echo signals that allow highly accurate measurement of the tube diameter and the like. As a measurement example using this first embodiment, FIG. 9 shows echoes of a blood vessel wall measured in a dog's thoracic aorta.The echoes from the inner and outer walls of the blood vessel are divided into 1 parts to eliminate the influence of noise. It is measured without receiving it. Figure 10 [, L image thigh υ
A transducer was inserted into the aorta through the aorta, and the pulse pressure, pulsatile diameter change, tube diameter, and wall thickness were measured along the aorta, and the pressure elastic modulus and Young's modulus (J) were calculated. There is -C. Pressure elastic modulus of the aorta1. There was a noticeable increase in the distance from L chest 81S to the periphery, but no significant change was observed in the tube diameter to wall thickness ratio, and the increase in pressure elastic modulus toward the periphery was due to Young's modulus It is clear that this is due to an increase in the material hardness of the wall tissue itself, and arteriosclerosis degree diagnosis 1
We were able to demonstrate the practicality of the present invention when purchasing a GI. The main factors related to the measurement accuracy of blood vessel elastic properties are the pulsatile diameter change and the wall J', and at the used frequency of 5 M l-I z, the former is about 51. There were approximately 20 locations after lithography, and the minimum measurable thickness was 4J, approximately 0.3 ml.

As described above, according to the first embodiment, it is possible to obtain the pressure elastic modulus Ep, the incremental elastic modulus [inc, etc., which are highly accurate indicators of the degree of arteriosclerosis, and to make an accurate diagnosis. Become.

In addition, in the first embodiment, the ultrasonic minute displacement meter 44 uses a one-step tracking type to follow the timing of return from the inner surface of the blood vessel wall, and only in the vicinity of the timing
Since gate opening/closing control is performed so that ~ can be heard, it is possible to prevent measurement values from varying due to unnecessary noise signals and obtain highly reliable information.

, The characteristics and effects of the embodiment described in F are summarized as follows.

1) Since the blood pressure range and the transducer are configured as an integrated l-transducer, it is possible to simultaneously perform 81 measurements at the same location.
IIJ vein hardness is much more accurate than conventional methods.

2) Since the pulsatile diameter change waveform and the blood pressure waveform can be measured simultaneously, it is theoretically possible to measure not only the vascular elasticity but also the vascular viscosity.

3) The vibrator part is made of airbath using foamed plastic snacks.
Since it is a cking type, it is possible to remove the 111 signal from the rear, but it also prevents electric shock, and the S/N ratio is further improved.

4) By using a support mechanism with superelasticity and placing the transducer part in the center, not only can the transducer be brought into close contact with the blood vessel wall within the blood vessel, but also the ultrasonic beam can be applied to the blood vessel wall. It is possible to stably detect the vascular wall echo signal from within the blood vessel, which is necessary to measure the diameter of the C-plane tube and the pulsatile diameter change at 0=I°C vertically.

5) Non-invasive measurement methods from the body surface have a problem with attenuation of the ultrasonic intensity that reaches the blood vessels, so when measuring deep blood vessels, the ultrasonic frequency used must be low.High-resolution blood vessels Wall thickness measurements cannot be expected. On the other hand, in the present invention, which allows measurement from within the blood vessel, the ultrasonic propagation path is only through the blood within the blood vessel, and the propagation length is short, at most 20 IIllm, so the reduction is not an obstacle to measurement and the frequency is increased. Therefore, by using the transducer according to the present invention, it is also possible to measure the wall thickness of deep blood vessels.

6) Since the measurement accuracy of wall thickness and the minimum measurable thickness improve in proportion to the ultrasonic frequency used, it is possible to significantly improve these measurement performances by increasing the frequency.

FIG. 11 shows the distal end side of an intravascular angle multiplexing transducer in a second embodiment of the present invention.

In this second embodiment, the strain gauge pressure gauge 28 is not used in the first embodiment, and the blood pressure measurement sensor 27 is
For example, the one shown in FIG. 8(a) (that is, the code 8
1) It uses the et al. Incidentally, the one shown in FIG. 8(b) or 0) may also be used. The rest is the same as the first embodiment. Therefore, the effects are almost the same.

FIG. 12 shows the distal end side of an intravascular angular acoustic wave transducer according to a third embodiment of the present invention.

In this third embodiment (6L catheter 131 has an elastic support mechanism section formed by two support lines 132 and 133 protruding from both sides thereof. One end of each support 1!11132 and 133 is fixed to the tip of catheter 131. Therefore, the support line 132 which has a habit of bending on one side
An ultrasonic vibrating section 25 is attached to the central portion of the catheter 131, and the other end thereof is inserted into a hollow passage within the catheter 131 so that it can be protruded or retracted. Also, the other support line 13
The other end of the catheter 131 can be fixed to the centipede 131, or can be freely moved back and forth within the hollow passage of the catheter 131, similar to one of the support wires 132.

A pressure sensor 1) 134 for blood pressure measurement is attached to the catheter 131 near the position 1Iv7 opposite to the ultrasonic transducer section 25. As this hinge 134, the one shown in FIG. 8 can be used, or other known hinges can be used.

A signal transmission of $1135 is extracted from this sensor 1:34. Note that a superelastic alloy wire or the like may be used as the support wires 132 and 133.

FIG. 13 shows the distal end side of a vascular ultrasound transducer according to a fourth embodiment of the present invention. For example, a support line 143 formed of a superelastic alloy wire or other wire is attached to the surface on the blood pressure sensor 142 side.
The ultrasonic transducer portion 25 can be brought into close contact with the blood vessel wall 29 by protruding in a chevron or arc shape. In addition, support line 14
One end of the transducer 3 is fixed to the distal end of the catheter 141, and the other end protrudes through a hollow passage within the catheter 141 and is retracted to eliminate the chevron-shaped portion and make the distal end of the transducer easier to handle and remove.

FIG. 14 shows the distal end side of the intravascular ultrasound transducer according to the fifth embodiment of the present invention. In addition, a superelastic alloy wire 153 is passed through the catheter 151 to form a close support mechanism. Therefore, when this catheter 151 is inserted into a blood vessel,
Due to the superelastic alloy $1153, the distal end side of the catheter 151 is bent as in the 14th example, so that the ultrasonic transducer section 25 can be tightly shielded from the blood vessel wall 31.

Note that the ultrasonic transducer section 25 may be attached to the blood pressure sensor 152 side, and the blood pressure sensor 152 may be adjacent to the front or rear side.

FIG. 15 shows the distal end side of the +fn intraductal ultrasonic transducer in J3 according to the sixth embodiment of the present invention.

In this embodiment, a support mechanism is formed in a bent manner on the distal end side of the catheter 161. This support mechanism brings the ultrasonic transducer section 25 into close contact with the blood vessel wall 29. Note that the blood pressure sensor 162 is attached to the inner surface when bent.

FIG. 16 shows the distal end side of an intraluminal ultrasonic transducer according to a seventh embodiment of the present invention. In this embodiment, a blood pressure sensor 172 is attached near the distal end of a catheter 171. The ultrasonic transducer part 25, which has a supporting structure protruding from the surface and is not superelastic and is attached to the tip of the alloy wire 173, is tightly attached to the blood vessel wall 29. I try to make it 1.

FIG. 17 shows the eighth embodiment of the present invention with J34
J shows the tip side of the wave transducer.

This embodiment is the same as the above seventh embodiment,
The alloy wire 173 with the first section 25 at the tip is roughly extended to form a loop-shaped support mechanism section on the catheter 171 in the shape of R-1.

Note that both ends of the alloy wire 173 may be made to move forward and backward within the hollow passage of the force i-del 171, or only one end may be allowed to move forward and backward.

FIG. 18 shows the main part of the ninth embodiment of the present invention.

This example allows you to celebrate your wedding without using a catheter.
Channel 182 of 181 (in this case, a fiberscope) was used.

Fiberscope 1811; & , Fiberscope 1
An objective lens 183 is provided at the distal end of the image guide 181, and an image is formed on the distal end surface of the image guide 184, and the optical image is transmitted to the rear end surface on the proximal side for magnified observation through an eyepiece (not shown). Further, a light guide (4.1, not shown) is inserted through this scope 181 so that a target region within a field of view that can be imaged by the objective lens 183 can be illuminated.

By the way, this fiberscope 181 is provided with a channel 182 through which a mollusk or the like can be inserted, and an ultrasonic transducer section 25 is attached to the tip, and a superelastic alloy wire 185 forming a transdecoder is passed through the channel 182 to measure the diameter of blood vessels, etc. I am making it possible to measure it. Note that the alloy wire 185 exhibits superelastic t'l characteristics at least in the vicinity of the portion where the ultrasonic transducer section 25 is attached.
This is because it is formed.

The above-mentioned space 182 is used for blood pressure measurement, and is guided to the pressure H1 using a strain gauge shown in FIG. 1 to perform blood pressure measurement.

In addition, the space of the upper channel 182 was measured using a strain gauge.
Zeta pressure 5! The blood pressure sensor may be installed near the tip of the alloy wire 185 (for example, slightly behind the ultrasonic transducer section 25) without communicating with the wire.

In addition, the catheter has a P1" sensor, pco2゜pO
It is also possible to incorporate other sensors such as No. 2 to enable simultaneous measurement.

In each embodiment, the catheter may be an endoscope equipped with illumination means (eg, a light guide fiber) and a VA optical fiber.

Although the ultrasonic transducer section 25 is composed of a single ultrasonic transducer in each of the above embodiments, it may be composed of a plurality of ultrasonic transducers.

Further, a plurality of ultrasonic transducer sections 25 may be provided. However, more detailed data may be obtained using highly accurate information or a different frequency.

Note that the zero-cross tracking ultrasonic minute eave displacement meter may be configured with an ultrasonic vibrator from outside the body.

[Effects of the Invention] As described above, according to the present invention, the ultrasonic transducer used to measure the diameter of the blood vessel and the blood pressure measurement sensor V are both inserted into the blood vessel to measure the degree of arteriosclerosis. The pressure elastic modulus and Young's modulus, which are indicators, can be determined with high accuracy.

[Brief explanation of drawings]

1 to 10 relate to a first embodiment of the present invention, FIG. 1 is a side view showing an intravascular sonic transducer in the first embodiment, and FIG. 2 is a configuration of an ultrasonic transducer section. Figure 3 is a block diagram showing the configuration of the first embodiment, and Figure 4 shows the configuration of the bald O cross tracking type ultrasonic minute displacement meter! The lock diagram, Fig. 5 is a timing chart diagram for explaining the operation of Fig. 4, and Fig. 6 is a timing chart for explaining the operation of Fig. 4.
The figure is an explanatory diagram of the zero-cross tracking type gate opening/closing mechanism.
The figure is a measurement graph of tube diameter and tube diameter change, FIG. 8 is a structural diagram showing the structure of various blood pressure sensors υ, and FIG. 9 is a waveform diagram showing the ultrasonic echo signal obtained by the first embodiment. FIG. 10 is a measurement graph showing the pressure elastic modulus, etc. measured by the first embodiment, and FIG. 11 is a measurement graph showing the pressure elastic modulus, etc., measured by the first embodiment. The tip side is shown 1
A cross-sectional view, FIG.
Figure 3 shows the distal side of the intravascular 8-wave transducer according to the fourth embodiment of the present invention. Figure 15 shows the distal side of the 8-wave I transducer. 1 shows the distal side of the vascular ultrasound transducer according to the seventh embodiment of the present invention.
17 is a 1" cross-sectional view showing the distal end side of the 11-wave intravascular transducer according to the eighth embodiment of the present invention; FIG.
FIG. 18 is a sectional view showing the tip *11; side of the intravascular sound wave transducer in the ninth embodiment of the present invention, -]19
The figure is a configuration diagram showing the tip side of a conventional example. 11... Arteriosclerosis degree diagnosis l1yi device 12... Intravascular ultrasound & waves] Lance γ Cori 13...
Arteriosclerosis electric wire exhibition - 21... Blood vessel 22... Catheter 24... Support member 25... Ultrasonic adult part 2G... Guide 27... Blood pressure measurement tip 29... Blood vessel wall 31 ... Support h); Support part Fig. 4 Fig. 5 Fig. 6 Fig. 77 Ushihi UP Fig. 7 (b) Fig. 8 (C) 123 +24 Fig. 9 TIME (JJsec) Fig. 11 Fig. 12 Fig. 13 Figure 142 +43 Figure 14 Figure 17 Old figure Figure 19 Procedure Ne City j] 3-HjH voluntary) January 26, 1985 1, Indication of the case 1988 Patent Application No. 155173
No. 2, title of the invention: Vascular problems & wave transduction] -!
3.Relationship with the review case for correction in the diagnosis of arteriosclerosis using the 3rd aspect of the application Trial Representative: Satoshi Shimoyama, Department 4, Agent Address: 7-4-4 Nishi-Shinjuku, Shinjuku-ku, Tokyo Drawings “Figures 8 and 10” 1. Line 7 of page 3 of the specification “… is ΔP・
``...'' should be corrected to ``... is ΔD...''. 2. Delete "Incremental wall Young's modulus... has been proposed" from lines 17 to 19 on page 3 of the specification. 3. In the 8th line of page 13 of AkiratIA Harm, "...Change ΔP..." is corrected to "...Change ΔD...". 8th (a) (C) +23 124

Claims (1)

[Claims] 1. Can be inserted into a blood vessel and transmits and receives ultrasonic waves to determine the diameter of the blood vessel,
An intravascular ultrasound system characterized by forming an intravascular ultrasound transducer that integrates an ultrasound transducer section for detecting pulsatile diameter changes and blood vessel wall thickness, and a blood pressure sensor section for detecting pulse pressure. Arteriosclerosis diagnostic device using a sound wave transducer. 2. The arteriosclerosis degree diagnostic apparatus using an intravascular ultrasonic transducer according to claim 1, wherein the ultrasonic transducer section is closely supported on the inner surface of the blood vessel wall by a transducer support mechanism. 3. The ultrasonic transducer section and the blood pressure sensor section are characterized in that their output signals are input to an arteriosclerosis degree calculation device section, and pressure elastic modulus and incremental elastic modulus, which are indicators of arteriosclerosis degree, are calculated. An arteriosclerosis degree diagnostic device using the intravascular ultrasound transducer according to claim 1.