JPH0221255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a real-time ultrasonic tomography/Doppler composite diagnostic apparatus.

Regarding the examination of hemodynamic function, especially cardiac blood flow, there is a method of obtaining the frequency distribution of Doppler signals (hereinafter referred to as blood flow pattern) using an ultrasonic pulsed Doppler blood flow meter, and also a method of obtaining the frequency distribution of the Doppler signal (hereinafter referred to as blood flow pattern) using an ultrasonic pulsed Doppler blood flow meter. M-mode echocardiogram (hereinafter referred to as
UCG) and high-speed scanning ultrasonic tomography equipment,
For example, methods for obtaining tomographic images using sector-type or linear-type electronic scanning ultrasound tomography apparatuses have been considered to be superior. Therefore, Fig. 1 A, B (A
is the sector method and B is the linear method),
The tomographic probe 1 and the Doppler probe 2 are connected by an arm 3, and the ultrasonic emission pulses of each are switched in chronological order. 2 and potentiometer 4.
A real-time ultrasonic tomography/Doppler composite diagnostic apparatus has been proposed that can simultaneously measure the tomographic image and measure the blood flow velocity at any point within the displayed tomographic image.

Furthermore, as shown in FIG. 2, an improved type has been proposed in which the tomographic probe 1 shown in FIG. 1 is also used as a Doppler probe 2. In Fig. 2, 5 is a control section, 6 is a transmitter/receiver section, 7 is a probe consisting of a large number of transducers arranged in a row, 8 is a Doppler detection section consisting of a mixing circuit and a sample circuit, and 9 is a Doppler sound A generating speaker, 10 a frequency-voltage conversion circuit comprising, for example, a zero crossing circuit, a frequency analysis circuit, etc., 11 a video mixer, 12 a sweep signal generating circuit for a CRT display device, and 13 a CRT display device. In the device shown in FIG. 2, a control unit 5 determines the direction of ultrasonic pulses emitted from a probe 7, a transmitting/receiving unit 6 generates a group of high-voltage pulses, and the pulses are sequentially supplied to the transducer of the probe 7. be done. As a result, ultrasonic pulses are sequentially emitted from the transducer of the probe 7 only in the determined specific direction. The reflected wave is then received by the probe 7 and converted into an electrical signal.
This electric signal (reflected signal) is amplified and phase-combined by the transmitting/receiving section 6, and is input to the image mixer 11 and the Doppler detecting section 8. In the Doppler detection section 8, the Doppler signal obtained by mixing the phase-combined reflected signal from the transmitting/receiving section 6 and the original oscillation carrier signal from the control section 5 is detected at an arbitrary depth by a control signal from the control section 5. Detected as a Doppler signal. The Doppler signal obtained here drives the speaker 9 to generate Doppler sound, and is converted into a blood flow pattern signal by the frequency-voltage conversion circuit 10.
1 is input. The video mixer 11 synchronizes and mixes the reflected signal from the transmitting/receiving section 6 and the blood flow pattern signal, and in this case, converts the signal into a UCG and a luminance modulation signal for the blood flow pattern. The reflected signal for tomographic images from section 6 and the Doppler sample position mark signal PM are mixed in synchronization, and this mixed signal is used as a brightness modulation signal for tomographic images to be switched on the CRT display device 13 in synchronization with the sweep switching signal. Sweep signal generation circuit 12 of CRT display device 13
As shown in FIG. 3 [A is a tomographic image, B is a Doppler sample position, C is a UCG, D is a blood flow pattern, and E is a distance marker], according to the control signal from the control unit 5. A sweep switching signal (U signal) for displaying "UCG+blood flow pattern" and a sweep switching signal (T signal) for tomographic image display are generated alternately.

As mentioned above, the conventional real-time ultrasonic tomography/Doppler composite diagnostic system displays the tomographic image (a) and the Doppler sample position (b) of blood flow, as shown in FIG. The UCG direction and blood flow pattern 2 (blood flow velocity in the beam direction of the ultrasound pulse) are displayed. Since it only displays the velocity, but not the true velocity vector in the blood flow direction and its absolute value, the conventional real-time ultrasonic tomography/Doppler combined diagnostic equipment cannot provide accurate diagnosis. It was hot.

The present invention has been made to eliminate the above-mentioned drawbacks, and its purpose is to automatically display the beam direction of the ultrasound pulse, its Doppler sample position, and the velocity vector amount in the blood flow direction. Real-time ultrasonic tomography system that enables accurate diagnosis
To provide a Doppler complex diagnostic device.

Furthermore, the present invention provides a method for determining the beam direction of the ultrasound pulse, its Doppler sample position, and velocity vector amount in the blood flow direction from an ultrasound diagnostic image, a blood flow pattern,
The object of the present invention is to provide a real-time ultrasonic tomography/Doppler composite diagnostic device that can be easily associated with UCG and improve diagnostic efficiency.

The present invention will be explained in detail below along with the principle and examples.

(1) Principle of the present invention Figure 4 is a diagram for explaining the principle of the present invention, where SF is an ultrasonic probe, SF ₁ and SF ₂ are transmitted ultrasonic pulse beams, and ν is a blood flow. The velocity is the deflection angle, O is the center line, and θ is the angle in the blood flow direction with respect to the center line O.

In Fig. 4, the ultrasound probe SF is divided into two parts, which are connected alternately to the Doppler blood flow meter, and the transmission frequencies of the ultrasound pulse beams SF ₁ and SF ₂ are set to f ₀ and the respective transmission frequencies are set to f ₀ . If the measured values of the change in reception frequency are Δf ₁ and Δf ₂ , the following equation (1) holds true.

From formula (1) From formula (2) From equation (3), tanθ=sinθ/cosθ=(Δf ₁ −Δf ₂ )cos/(Δ
f ₁ + Δf ₂ ) sin...(4) From equation (4) above, the deflection angle is a preset value, and by measuring the changes Δf ₁ and Δf ₂ between the transmitting frequency f ₀ and the receiving frequency, It can be seen that the angle θ of the flow direction, the vector of the blood flow velocity ν, and their absolute values can be detected and displayed.

(2) Embodiment of the present invention FIG. 5 is a block diagram showing the structure of an embodiment of the present invention based on the above principle. In the figure, 20 is an ultrasonic probe, which is composed of a plurality of transducers 20A to 20F (not shown). The output of each vibrator 20A to 20F is connected to a transmitting/receiving circuit 21A to 21F, respectively.
The outputs of F are sent to delay circuits 22A to 22F, respectively.
It is connected to the. Each delay circuit 22A to 22F
The output of is connected to adders 23A and 23B,
The output of the adder 23A is sent to the first ultrasonic pulse Doppler blood flow meter (hereinafter simply referred to as the blood flow meter) CH ₁ , and the output of the adder 23B is sent to the second ultrasonic pulse Doppler blood flow meter (hereinafter simply referred to as the blood flow meter) CH _2. sent to. At the same time, the outputs of the adders 23A and 23B are sent to the adder 24 and added together, detected by the detector 25, and input to the video amplifier 26. The output of the video amplifier 26 is input as a tomographic image signal to the Z-axis of a display device 27 such as a CRT, and the tomographic image is displayed on the CRT.

FIG. 6 is a diagram showing a specific configuration of the blood flow meters CH ₁ and CH ₂ , the angle θ, and the velocity ν calculating section, in which 28A to 28D are mixers, 29A to 29
D is a sample hold circuit, 30A to 30D are low-pass filters, and 31A and 31B are frequency detection circuits, which detect the frequency change of the aforementioned transmitted ultrasonic pulse beam and received ultrasonic pulse beam, that is, the Doppler frequencies Δf ₁ and Δf ₂ . It is for the purpose of 32 is an arithmetic circuit, which satisfies the equation (4) above.
The value of tanθ is determined, and the angle θ is determined from this value. 33 is blood flow velocity ν=Δf ₁ +Δf ₂ /4f ₀ cosθco
It is an arithmetic circuit for calculating s×C, and 34 is a display circuit.

Next, the operation of the ultrasonic pulse Doppler blood flow meter of this embodiment will be explained.

In FIGS. 5 and 6, the ultrasonic probe 2
When the upper half oscillators 20A to 20C and the lower half oscillators 20D to 20F of 0 are operated alternately,
Each of the received ultrasonic pulse beams is transmitted through the transmitting/receiving circuits 21A to 21F and the delay circuit 2 shown in FIG.
2A to 22F, and are alternately input to blood flow meters CH ₁ and CH ₂ via adder circuits 23A and 23B. The signal input to blood flow meter CH ₁ is a received wave with a frequency (f ₀ + Δf ₁ ) that includes the Doppler frequency K, and the signal input to blood flow meter CH ₂ includes the Doppler frequency Δf ₂ . This is a received wave of frequency (f ₀ +Δf ₂ ). These received waves cos2π(f ₀ +Δf ₁ )t, cos2π
(f ₀ +Δf ₂ )t and the reference wave signals cos2πf ₀ t and sin2πf ₀ t having phases different from each other by 90° are sent to the mixer 28A of blood flow meters CH ₁ and CH ₂ as shown in FIG.
~ 28D, mixed here, and input to frequency detection circuits 31A, 31B via sample and hold circuits 29A to 29D and low pass filters 30A to 30D. By these frequency detection circuits 31A and 31B, the Doppler frequency Δf ₁ ,
Δf ₂ is detected and input to the arithmetic circuit 32 to determine the angle θ. This angle θ is sent to the display circuit 34 and also input to the arithmetic circuit 33 to determine the blood flow velocity ν. This blood flow velocity ν and angle θ
is input to the Z-axis of the display device 27 via the display circuit 34, and as shown in FIG. is displayed, and the absolute value of the vector of blood flow velocity in the blood flow direction is displayed on the blood flow pattern.

As explained above, according to the present invention, there is an ultrasonic probe that is divided into two parts and each has the same transmission frequency f ₀ , and a change in the receiving frequency received by each of the two divided ultrasound probes. The measured value Δf ₁ ,
A measuring means for measuring Δf ₂ and each of the measured values Δf ₁ ,
Since it is equipped with a calculation means for calculating the angle θ of the blood flow direction with respect to the center line of the ultrasound probe, the velocity vector of the blood flow, or the absolute value of the velocity vector from Δf ₂ , based on this calculation means The blood flow velocity vector and its absolute value with respect to the beam direction of the ultrasound pulse can be automatically displayed. Therefore, the beam direction of the ultrasound pulse,
Since the Doppler sample position and velocity vector amount in the blood flow direction are compared with the tomographic image, blood flow pattern, and UCG, accurate diagnosis is possible.

Further, by displaying the velocity vector and its absolute value in a superimposed manner on an ultrasonic diagnostic image, blood flow pattern, or UCG, the efficiency of diagnosis can be improved by immediately correlating them with each of these images.

[Brief explanation of drawings]

FIGS. 1A, B and 2 are diagrams showing an example of a real-time ultrasonic tomography/Doppler composite diagnostic device,
FIG. 3 is a diagram showing a screen displayed on a CRT display device of a conventional device, FIG. 4 is a diagram for explaining the principle of the present invention, and FIG. 5 is a diagram showing the configuration of an embodiment of the present invention. FIG. 6 is a block diagram showing the configuration of the first and second ultrasonic pulse Doppler blood flow meters and the angle θ and velocity ν calculation unit of the present invention, and FIG. CRT according to the embodiment shown in the figure
FIG. 3 is a diagram showing a screen displayed on a display device. 20...Ultrasonic probe, 21A-21F...Transmission/reception circuit, 22A-22F...Delay circuit, 23
A, 23B, 24...adder, 25...detector,
26... Video amplifier, 27... Display device, 28
A to 28D... mixer, 29A to 29D... sample hold circuit, 30A to 30D... low pass filter, 31A, 31B... frequency detection circuit,
32, 33...Arithmetic circuit, 34...Display circuit.

Claims (1)

[Claims] 1. A real-time ultrasonic tomogram that has the function of simultaneously measuring the blood flow velocity at a predetermined position in the displayed tomogram, M-mode echocardiogram, or blood flow pattern, and superimposing the blood flow measurement point on the tomogram. - In a Doppler complex diagnostic device, an ultrasound probe that is divided into two and each having the same transmission frequency f ₀ , and a measured value Δf of the change in reception frequency received by each of the two divisions of the ultrasound probe are ₁ , _Δf2
and a measuring means for measuring the measured values Δf ₁ and Δf _{2 .}
a calculation means for calculating the angle θ of the blood flow direction with respect to the center line of the ultrasound probe, the velocity vector of the blood flow, or the absolute value of the velocity vector; and the blood flow direction calculated by the calculation means. , a velocity vector in the blood flow direction, and a display means for superimposing and displaying the absolute value of the velocity vector on the tomographic image, M-mode echocardiogram, or blood flow pattern. Composite diagnostic device.