JPH07303657A - Pulse ultrasonic therapy device - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a pulse ultrasonic therapy apparatus in which a sample volume once set is at the same position with respect to a focus. [Structure] The present invention comprises a therapeutic ultrasonic wave generation source 1, a transducer, a transmission / reception system 4, and a sample volume setting section 7.
And a sample-hold circuit 6 _c and an FF for frequency-analyzing the Doppler signal cut out by the sample-hold circuit 6 _c
T6 _f , a sensor 10 for detecting the relative position of the transducer with respect to the therapeutic ultrasonic wave generation source 1, and a sensor 1
The displacement amount of the transducer with respect to the therapeutic ultrasonic wave generation source 1 is calculated based on the detection result of 0, and the timing of the range gate applied by the sample hold circuit 6 _c to the Doppler signal from the mixer 6 _a is calculated based on the displacement amount. And gate control means 9 and 13 for changing the relative position of the sample volume with respect to the focus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to pulse ultrasonic treatment for converging pulse-like ultrasonic waves for treatment to form a focal point and treat (crush) an object to be treated such as a stone placed at the focal point with its impact force. Regarding the device.

[0002]

2. Description of the Related Art A calculus breaking device is a typical example of this type of pulse ultrasonic therapy device. The calculus breaking device arranges a plurality of high-power transducers in a spherical shell shape on a frame and focuses ultrasonic waves repeatedly emitted in a pulse shape from each high-power transducer according to the curvature of the spherical shell to form a focal point. , The stones placed at this focal point are repeatedly crushed by applying an impact force.

An opening is formed in the center of the frame, and a cylindrical probe is inserted into the opening rotatably and axially along the axial direction. For example, a sector scan type transducer array is attached to the tip of the probe. Some transducer arrays are connected to a frequency analysis circuit (for example, a fast Fourier transform circuit) for calculating the velocity distribution of blood flow at a certain observation point (sample volume) via a transmission / reception circuit. For example, if you adjust the sample volume to the stone,
Since the calculus moves back and forth according to the repetition period of the ultrasonic pulse, the velocity distribution near the calculus can be obtained in time series. Since the weight of the calculus changes before and after crushing, the velocity distribution changes before and after crushing. This makes it possible to confirm the therapeutic effect of stones.

However, the calculus breaking device has the following problems. It is difficult for a patient to maintain a constant posture for a long time, and the focus once focused on the patient deviates from the stone every time the posture is changed. In this case, the frame must be moved to refocus the stone. As the frame moves, the probe tip (transducer) may move away from the patient-to-surface, and to reduce the resulting ultrasound loss, the probe tip may be pulled out of the frame or inserted further deeper to reduce probe loss. It is necessary to contact the transducer) to the patient-to-surface. As a result,
The probe is displaced from the state in which the sample volume is set with respect to the frame, and the relative positional relationship between the sample volume and the focus changes. Therefore, the sample volume must be reset to its original position each time the probe is moved with respect to the frame, which is very troublesome and slows down patient throughput.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object thereof is to automatically move a sample volume once set even when a probe is moved with respect to a frame. It is an object of the present invention to provide a pulse ultrasonic therapy device whose relative position with respect to a focal point does not change.

[0006]

A pulse ultrasonic therapeutic apparatus according to the present invention focuses a pulsed therapeutic ultrasonic wave on a predetermined position to form a focal point, and treats an object to be treated placed at the focal point. A therapeutic ultrasonic wave generating means, a transducer for transmitting and receiving ultrasonic waves, and driving the transducer according to a predetermined repetition frequency to repeatedly transmit the ultrasonic waves from the transducer, and to transmit the ultrasonic waves via the transducer. Transmitting and receiving means for repeatedly receiving reflected waves, means for setting a sample volume at an arbitrary position with respect to the treated body, detecting means for phase-detecting the output from the transmitting and receiving means to detect a Doppler signal, and Gate means for applying a range gate to the Doppler signal from the detection means to cut out the Doppler signal in the sample volume; Frequency analysis means for obtaining the velocity distribution of the blood flow in the sample volume by frequency-analyzing the Doppler signal cut out by the operating means, means for displaying the velocity distribution by the frequency analysis means in time series, and the therapeutic A sensor for detecting the relative position of the transducer with respect to the ultrasonic wave generating means, and the therapeutic use of the transducer based on the detection result of the sensor when the position of the transducer is displaced with respect to the therapeutic ultrasonic wave generating means. The displacement amount with respect to the ultrasonic wave generating means is calculated, and the timing of the range gate applied to the output from the detecting means by the gate means is changed based on the displacement amount to change the relative position of the sample volume with respect to the focus. Gate control means for maintaining the positional relationship.

[0007]

According to the pulse ultrasonic therapy apparatus of the present invention,
After setting the sample volume once, even if the position of the transducer is displaced with respect to the therapeutic ultrasonic wave generating means, the gate means is based on the displacement amount of the transducer with respect to the therapeutic ultrasonic wave generating means, with respect to the output from the detecting means. The timing of the applied range gate is changed to maintain the relative position of the sample volume with respect to the focus. Therefore, the operator is freed from the trouble of resetting the sample volume, the time for resetting the sample volume is shortened, and the patient throughput is improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the pulse ultrasonic therapeutic apparatus according to the present invention will be described below with reference to the drawings. Here, a calculus breaking device, which is a typical example of the pulse ultrasonic therapy device, will be described as an example.

FIG. 1 is a block diagram of the present embodiment. In FIG. 1, reference numeral 1 denotes _a therapeutic ultrasonic wave generation source in which a plurality of high-power transducers 1 ₁ to 1 _n for emitting therapeutic ultrasonic waves are mounted on the inner surface of an umbrella-shaped frame 1 _a . A high output pulser 2 is connected to the plurality of high output oscillators 1 ₁ to 1 _n . The pulsar 2 charges the voltage of the high-voltage DC power source with a capacitor, and discharges this charge to a plurality of high-power transducers 1 ₁ to 1 _n all at once via a transistor and a resonance circuit,
Pulsed therapeutic ultrasonic waves are repeatedly generated from the plurality of high-power transducers 1 ₁ to 1 _n until the treatment is completed. The therapeutic ultrasonic waves emitted from each high-power transducer 1 ₁ to 1 _n are in the frame 1
_A focus F is formed at a predetermined position determined by the curvature of the umbrella shape of a, and a focus F is formed there. The stone as the object to be treated, which is set at the focal point F, is treated (crushed) by its impact force.
The plurality of high-power transducers 1 ₁ to 1 _n may be arranged in a plane. In this case, the therapeutic ultrasonic waves emitted from the high-power transducers 1 ₁ to 1 _n may be focused by changing the timing of discharging the charged electric charge in the high-power transducers 1 ₁ to 1 _n. The therapeutic ultrasonic waves emitted from each of the high-power transducers 1 ₁ to 1 _n may be focused by disposing an acoustic lens on the ultrasonic radiation side of the plurality of high-power transducers 1 ₁ to 1 _n .

[0010] The central portion of the frame 1 _a is cut out, there the probe 3 of cylindrical shape is inserted freely movably and axially rotate in the axial direction. A plurality of transducers are arranged in parallel at the tip of the probe 3. A transmission / reception system 4 is connected to the probe 3. The transmission and reception system 4 includes a pulsar 4 _a to transmit the driving ultrasonically at a constant repetition period according to a repetition frequency (rate frequency) f _r of the transducer of a given probe 3, for example, a sector scan.
Reflected wave reflected by the patient's body are received by each transducer, the received signals are sent to the adder 4 _c through the preamplifier 4 _b. The adder 4 _c gives different delay times to these received signals and adds them, that is, gives reception directivity. The detector 4 _d detects the envelope of the output of the adder 4 _c and generates B-mode image data. The digital scan converter (DSC) 4 _e temporarily holds data to be displayed such as B-mode image data and outputs it to the monitor 5 for display.

Reference numeral 6 is a so-called 1-point Doppler processing system, which is a frequency analysis processing system for obtaining the velocity distribution of a moving body within a certain observation range (hereinafter referred to as "sample volume"). The output signal of the adder 4 _c is sent to the mixer 6 _a , where it is multiplied by a reference signal having the center frequency f ₀ of the transmitted ultrasonic wave from a transmission circuit (not shown), whereby the Doppler shift f _d and (2 · f A Doppler signal having a frequency component of ₀ + f _d ) is obtained. The high frequency component (2 · f ₀ + f _d ) of this Doppler signal is passed through the low pass filter (LPF) 6
Removed with _b . Thus the Doppler signal of only the frequency components of the Doppler shift f _d is obtained. Next, a sample hold circuit (S / H) is applied to the output of the low pass filter 6 _b.
At 6 _c , the range gate is applied at a timing corresponding to the depth of the sample volume, and the Doppler signal only in the sample volume is cut out. Since this Doppler signal includes unnecessary frequency components and sweetpotato clutter components from a portion of the organ wall that is slower than blood flow, these clutter components are extracted from the Doppler signal by a high-pass filter (HPF) 6 _d. To remove. The Doppler signal from which the clutter component has been removed is A
It is sent to the fast Fourier transform circuit (FFT) 6 _f as a frequency analysis circuit via the / D converter 6 _e , where the frequency is analyzed in real time, and the velocity distribution in the sample volume is obtained. This velocity distribution is displayed in time series in real time on the monitor 5 via the digital scan converter 4 _e .

The sample volume setting unit 7 is, for example, a mouse, and its movement is interlocked with the sample volume marker SVM displayed on the monitor 5 together with the B-mode image through the sample volume marker creating unit 8 and the sample volume marker SVM. Is set at an arbitrary position on the B-mode image (in the scan plane of the probe 3). The sample volume setting unit 7 can set the size of the sample volume in addition to setting the sample volume. The gate control unit 9 controls the distance of the sample volume from the transducer, that is, the depth of the sample volume and the timing of applying the range gate in the sample hold circuit 6 _c according to the azimuth direction. Twice this depth is the length of the reciprocal path of ultrasonic waves from the transducer to the sample volume, and by dividing the length of this reciprocal path by the ultrasonic wave propagation velocity in the living body, the timing of applying the range gate can be determined. Can be calculated. This timing means that the adder output is the sample hold circuit 6 _c after one ultrasonic wave transmission.
It is the length of time from the time when the first time was reached.

[0013] sensor 10 is a rotary decoder for example, is fixed to the frame 1 _a, to detect the relative position of the probe 3 to the frame 1 _a. Based on the detection result of the sensor 10, the relative position calculation unit 11 determines the relative position of the probe 3 with respect to the frame 1 _a of the therapeutic ultrasonic wave generation source 1, that is, the insertion depth (vertical position in the axial direction) and the axis of the probe 3. Calculate the rotation angle. Since the focus F is uniquely and directly determined with respect to the frame 1 _a , the focus marker creation unit 12 obtains the position of the focus F in the B-mode image based on the calculation result of the relative position calculation unit 11, and A focus marker FM is created at the position. The focus marker FM is displayed so as to be superimposed on the B-mode image on the monitor 5.

The displacement amount calculation unit 13 once focuses on the calculus F
The frame 1 _a is set so that the two coincide with each other, the probe 3 is inserted into the frame 1 _a so that the tip of the probe 3 contacts the surface of the patient at that position, and the sample volume is set at an arbitrary position. After that, the focus F is deviated from the calculus due to the change of the posture of the patient and the frame 1 _a is reset, and when the insertion depth of the probe 3 with respect to the frame 1 _a is changed, the sample volume is set. difference was the insertion depth relative to the frame 1 _a of the probe 3 when the, the insertion depth relative to the frame 1 _a of the probe 3 and reconfiguring the frame 1 _a, that is, calculates the amount of displacement. Based on this displacement amount, the gate control unit 9 changes the timing of applying the range gate in the sample hold circuit 6 _c . That is, since the length of the ultrasonic wave propagation path between the transducer and the sample volume when the sample volume is once set increases or decreases by twice the displacement amount, the range gate timing is twice the displacement amount. The distance can be slowed or accelerated by the time divided by the ultrasonic wave propagation speed in the living body.

Next, the operation of this embodiment will be described. In preparation for the start of treatment, the frame _1a is moved under the B-mode image reference, and the focus F is adjusted to the stone. At this time, the sample volume setting unit 7 is operated by the operator, and the sample volume is set at an arbitrary position while watching the sample volume marker SVM displayed together with the B mode image on the monitor 5 in conjunction with the movement of the sample volume setting unit 7. Is set. Here, for convenience of explanation, the following description will be made assuming that the sample volume is set at the focal point F.

When the treatment is started, a pulse voltage is repeatedly applied from the pulsar 2 to the plurality of high-power transducers 1 ₁ to 1 _n, and pulsed therapeutic ultrasonic waves are transmitted to the plurality of high-power transducers 1 _1.
Repetitively radiated from ~ 1 _n and focused at a position determined by the shape of the frame 1 _a to repeatedly form the focal point F. The calculus placed at the focal point F is repeatedly subjected to the impact force, and will eventually be crushed.

During treatment, the calculus undergoes reciprocating motion by intermittently receiving an impact force at the focal point F, and its weight changes before and after crushing. Therefore, the moving speed of the reciprocating motion changes before and after the crushing. The therapeutic effect can be confirmed by the change in the moving speed.

Based on the detection result of the sensor 10, the relative position calculation unit 11 calculates the insertion depth of the probe 3 into the frame 1 _a of the therapeutic ultrasonic wave generation source 1. The gate control unit 9 calculates the timing for applying the range gate in the sample hold circuit 6 _c based on the insertion depth and the distance from the transducer to the sample volume. FIG. 2A is a diagram showing the positional relationship between the sample volume SV ₀ , the focus F and the probe 3 immediately after the start of treatment, and FIGS. 3A and 3B are the samples in the positional relationship of FIG. 2A. It is a figure which shows the timing which applies a range gate to the Doppler signal in the hold circuit _6c along a time axis.
3A and 3B, at time t ₀ , the adder output is the sample hold circuit 6 _c after one ultrasonic wave transmission.
Is the first time to reach. Here, when the distance from the transducer at the tip of the probe 3 to the sample volume SV ₀ is D ₀ and the ultrasonic wave propagation speed in the living body is C,
The time TW from t ₀ to t ₁ when the range gate is applied is
It is calculated by the following equation (1).

TW = 2 · D ₀ / C (1) At this timing, in the sample hold circuit 6 _c , the range gate is applied to the Doppler signal that has passed from the adder 4 _c to the mixer 6 _a and the low pass filter 6 _b. Is multiplied, and the Doppler signal only in the sample volume SV ₀ is cut out. The Doppler signal has its clutter component removed by the high-pass filter 6 _d . The Doppler signal with the clutter component removed is
It is sent to the fast Fourier transformer 6 _f via the A / D converter 6 _e , where frequency analysis is performed in real time, and the velocity distribution in the sample volume SV ₀ is obtained. The velocity distribution over the digital scan converter 4 _e monitor 5
Are displayed in real time in chronological order.

During the treatment, for example, the patient's posture may change, and the focus F once aligned may deviate from the calculus. In this case, it is necessary to properly move the frame 1 _a up, down, left and right to adjust the focus F to the calculus. Furthermore, it is necessary to contact with the patient body surface the tip of the transducer of the probe 3 moves in the axial direction of the probe 3 to the frame 1 _a in accordance with the movement of the frame 1 _a. The relative position between the probe 3 and the frame 1 _a changes,
The sample volume SV ₀ once set is out of focus F.

FIG. 2B is a diagram showing the positional relationship among the sample volume SV ₁ , the focus F and the probe 3 after the sample volume SV ₀ which is out of focus F is automatically reset. FIGS. 2C and 2D are views showing the timing of applying the range gate to the Doppler signal in the sample hold circuit 6 _c in the positional relationship of FIG. 2B along the time axis. In addition, in FIGS. 3C and 3D, the time t ₀ is
Similar to (a) and (b), it shows the time when the adder output first reaches the sample hold circuit 6 _c after one ultrasonic wave transmission.

The displacement amount calculation unit 13 uses the detection signal from the sensor 10, the sample volume SV ₀ is holds the insertion depth relative to the frame 1 _a of the probe 3 when it is set, and the insertion depth, the difference between the insertion depth relative to the frame 1 _a of the probe 3 which is re-set in accordance with the change of the patient's posture, i.e. to calculate the amount of displacement. Based on this displacement amount, the gate control unit 9 causes the frame 1 of the probe 3 to
The sample hold circuit 6 _c before the insertion depth with respect to _a is changed, the timing for applying the range gate is changed by Δt, and the sample volume SV ₀ out of focus F is
Change to the sample volume SV ₁ that matches the focus F.
The amount of displacement, the distance D ₀ between the tip of the transducer of the probe 3 to the sample volume SV _0, equal to the difference between the distance D ₁ of the from the tip of the transducer of the probe 3 to the sample volume SV _1. Δt is calculated according to the following equation (2).

Δt = 2 · (D ₀ −D ₁ ) / C (2) Therefore, even if the positional relationship between the probe 3 and the frame 1 _a changes after the sample volume is once set, The position of the sample volume is automatically changed,
The positional relationship between the sample volume and the focus does not change. This frees the operator from the trouble of resetting the sample volume. It also reduces the time to reset the sample volume and improves patient throughput. It is needless to say that the present invention is not limited to the above-described embodiments and can be variously modified and implemented without departing from the gist thereof.

[0024]

As described above, the present invention focuses the pulsed therapeutic ultrasonic waves on a predetermined position to form a focal point, and treats the body to be treated placed at the focal point. Generating means, a transducer for transmitting and receiving ultrasonic waves, and driving the transducer according to a predetermined repetition frequency to repeatedly transmit ultrasonic waves from the transducer, and repeatedly receive reflected waves of the ultrasonic waves via the transducer. Transmitting / receiving means, means for setting a sample volume at an arbitrary position with respect to the body to be treated, detecting means for phase-detecting the output from the transmitting / receiving means to detect a Doppler signal, and Doppler from the detecting means. A gate means for applying a range gate to the signal to cut out the Doppler signal in the sample volume, and a gate means for cutting out with the gate means. Frequency analysis means for frequency-analyzing the Doppler signal to obtain the velocity distribution of the blood flow in the sample volume, means for displaying the velocity distribution by the frequency analysis means in time series, and the transducer for the therapeutic ultrasonic wave generation means. And a displacement amount of the transducer with respect to the therapeutic ultrasonic wave generating means based on the detection result of the sensor when the position of the transducer is displaced with respect to the therapeutic ultrasonic wave generating means. Gate control for maintaining the relative positional relationship of the sample volume with respect to the focus by changing the timing of the range gate applied to the output from the detection means by the gate means based on the displacement amount. And a pulsed ultrasonic treatment device.

According to the present invention, even if the position of the transducer is displaced with respect to the therapeutic ultrasonic wave generating means after the sample volume is once set, the gate is based on the displacement amount of the transducer with respect to the therapeutic ultrasonic wave generating means. It is possible to provide a pulse ultrasonic therapy apparatus in which the timing of the range gate applied by the means to the Doppler signal output from the detection means is changed, and the relative positional relationship of the sample volume with respect to the focus is maintained. This frees the operator from the trouble of resetting the sample volume, and
The time to reset the sample volume is reduced and patient throughput is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment according to the present invention.

FIG. 2 is a diagram showing a positional relationship among a sample volume, a focal point, and a probe.

FIG. 3 is a diagram showing a timing of applying a range gate to a Doppler signal in the sample hold circuit of FIG. 1 along a time axis.

[Explanation of symbols]

1 ... therapeutic ultrasonic wave generation source, 2 ... pulser, 3 ... probe,
4 ... Transmission / reception system, 5 ... Monitor, 6 ... 1 point Doppler system,
7 ... Sample volume setting unit, 8 ... Sample volume marker creating unit, 9 ... Gate control unit, 10 ... Sensor, 11 ...
Relative position calculation unit, 12 ... Focus marker creation unit, 13
… Displacement calculation section.

Claims (3)

[Claims] 1. An ultrasonic wave is transmitted to and received from a therapeutic ultrasonic wave generating means for focusing a pulsed therapeutic ultrasonic wave at a predetermined position to form a focal point and treating an object to be treated installed at the focal point. A transducer, a transmitting / receiving unit that drives the transducer according to a predetermined repetition frequency to repeatedly transmit ultrasonic waves from the transducer, and repeatedly receives reflected waves of the ultrasonic waves via the transducer; A means for setting a sample volume at an arbitrary position, a detecting means for phase-detecting the output from the transmitting / receiving means to detect a Doppler signal, and a sample for applying a range gate to the Doppler signal from the detecting means. Gate means for cutting out the Doppler signal in the volume and frequency analysis of the Doppler signal cut out by the gate means Frequency analysis means for obtaining the velocity distribution of blood flow in the sample volume, means for displaying the velocity distribution by the frequency analysis means in time series, and the relative position of the transducer with respect to the therapeutic ultrasonic wave generation means. A sensor for detecting, and when the position of the transducer is displaced with respect to the therapeutic ultrasonic wave generating means, the displacement amount of the transducer with respect to the therapeutic ultrasonic wave generating means is calculated based on the detection result of the sensor, and the displacement is Gate control means for changing the timing of the range gate applied to the output from the detection means by the gate means based on the amount to maintain the relative positional relationship of the sample volume with respect to the focus. A pulsed ultrasonic treatment device. 2. The gate control means sets the displacement amount to 2
2. The pulse ultrasonic therapeutic apparatus according to claim 1, wherein the timing of the range gate applied to the output from the detecting means is changed based on the result of dividing the multiplied value by the ultrasonic wave propagation velocity. 3. The therapeutic ultrasonic wave generating means comprises an umbrella-shaped frame, a plurality of transducers arranged on an inner surface of the frame, and a pulser for driving the plurality of transducers to emit ultrasonic waves. The pulse ultrasonic therapy device according to claim 1.