JP2714059B2 - Ultrasonic Doppler device - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to an ultrasonic Doppler device capable of measuring a flow rate of a fluid using the Doppler effect of an ultrasonic wave.

(Prior Art) The applicant of the present invention has previously filed a patent application for an ultrasonic Doppler apparatus which enables measurement of a backflow jet flow rate by a color Doppler flow mapping method without measuring a cross-sectional area of a backflow jet of blood, for example. Provided as No. 63-110171. The apparatus comprises a first flow rate calculating means for calculating a flow velocity of a fluid based on an ultrasonic transmission / reception result at a first measurement point set at a discharge port on a displayed color Doppler image, and a fluid ejection from the first measurement point. A second flow rate calculating means for similarly calculating a flow rate of the fluid at a second measurement point set at an arbitrary position separated in the direction;
And a distance calculating means for calculating the distance between the second measurement points, and a flow rate calculating means for calculating the ejection flow rate of the fluid based on each of the calculated data.

(Problems to be solved by the invention) By the way, in such an ultrasonic Doppler device, the first
Since it is necessary to calculate the ejection flow rate after calculating three data of the flow velocity at the measurement point, the flow velocity at the second measurement point, and the distance between the first and second measurement points, the measurement takes time. There's a problem.

The present invention has been made in view of the above problems, and has as its object to provide an ultrasonic Doppler device capable of performing measurement in a short time.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a method of measuring the flow velocity of a fluid at a measurement point set at a jet port position on a color Doppler image based on the result of ultrasonic transmission / reception. Flow velocity calculating means for calculating, a distance calculating means for calculating a distance from the jet port to a position showing a value substantially equal to the flow velocity in the fluid jetting direction, and jetting of the fluid based on a calculation result of each of the arithmetic means. Flow rate calculating means for calculating the flow rate.

Flow velocity V _n of the fluid, such as blood ejected from (created for) spout is maintained approximately equal value to the distance L from ejection ports. By pre-calculate these flow rates V _n and the distance L thus, to calculate the fluid flow rate based on these two data. This reduces the types of data to be calculated in advance, so that measurement can be performed in a short time.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an ultrasonic Doppler apparatus according to the present invention, wherein an input unit 1 comprises a measuring point setting means 2 and a coefficient (α).
The setting means 3 is shown. The measurement point setting means 2 sets the measurement point N at the position of the ejection port (for example, the valve port of the heart) on the color Doppler image displayed on the display unit 9 as described later.

For example when the free turbulent jets is blood from the valve port of the heart is ejected from the ejection port at a flow rate V _N, a distance L in the spout as shown in FIG. 8 is the fluid surrounding the blood has been ejected An unmixed area, the so-called laminar core, remains in the center of the jet. Within this Raminakoa velocity is kept at a value equal to approximately V _n, the flow velocity V _L at the distance L can be represented by the following equation.

V _L = V _N (1−α) (1) where α: coefficient (for example, 0.1 is set) Further, assuming that the shape of the injection port is a circle and the diameter thereof is D, the following equation is established. .

L = 6.8D (2) As a method of measuring L satisfying the expression (1),
On the displayed color Doppler image, a region showing a flow velocity of _VL or more can be displayed in a specific color, and the distance between the specific color region and the ejection port can be measured using a distance marker. As another method, the measurement can be performed by gradually moving the measurement sample position P from the ejection port in the ejection direction as shown by an arrow as shown in FIG. 4 and stopping at the position _VL .

The coefficient setting means 3 sets the coefficient α in the equation (1), and can set a value of, for example, about 0.1. As these measurement point setting means 2 and coefficient setting means 3, a trackball, a mouse or the like provided on an operation panel (not shown) can be used.

The blood flow imaging unit 4 uses the ultrasonic Doppler method and the pulse reflection method together, so that a blood flow image and a tomographic image (B-mode image) are displayed on the same screen based on echo information obtained by one ultrasonic probe. Is displayed.

The jet flow rate calculation unit 5 calculates the flow velocity and flow rate of the blood flow, and includes a flow rate calculation means 5a, a distance calculation means 5b, and a flow rate calculation means 5c as shown in FIG. Flow rate calculation means 5a is to calculate the flow velocity V _N of the blood at the measurement point N set by the measurement point setting unit 2. The distance calculation means 5b calculates the distance L that satisfies the expression (1). Further, the flow rate calculating means 5c is provided with each of the calculating means 5a, 5
The ejection flow rate Q of the blood flow is calculated based on each data V _N , L calculated in b. The ejection flow rate Q can be calculated according to the following equation.

Here, the algorithm of the flow velocity calculating means 5a and the distance calculating means 5b will be described.

In FIG. 4, a B-mode image and a blood flow distribution diagram of the subject (for example, the heart) are formed based on the reception echo of the ultrasonic wave transmitted from the probe 11, and the blood flow distribution is displayed on the B-mode image (black and white). An image (color), that is, a color Doppler image is superimposed. When the color Doppler image measurement point on N is set, the flow rate computation unit 5a calculates a flow velocity V _N at the measuring points N according to the following equation.

Here, fd _n: Doppler shift frequency C: propagation velocity of the ultrasonic wave in a living body (sound velocity) f _0: ultrasonic center frequency theta _n: the angle of the straight line and the scanning line from the measuring point to the distance L direction also, The distance calculation means 5b displays the flow velocity region equal to or higher than _VL in a specific color on the color Doppler image as described above, and measures the distance between the color region and the ejection port using a distance marker.

The blood flow imaging unit 4 and the jet flow calculation unit 5 are CP
It is connected to the U bus 7. Blood flow imaging unit 4
The blood flow information and the calculation result of the jet flow rate calculation unit 5 obtained by the above are transferred to the display control unit 8 via the CPU bus 7, and are transferred to the display unit 9 such as a CRT display under the control of the display control unit 8. Is displayed. A CPU (Central Processing Unit) 6 controls the operation of the entire apparatus of the present embodiment.

Next, a detailed configuration of the blood flow imaging unit 4 in FIG. 1 will be described with reference to FIG. Reference numeral 11 denotes an ultrasonic probe for transmitting / receiving ultrasonic pulses to / from a subject, and 12 denotes an analog section of a sector electronic scanning device, which includes a preamplifier 13, a pulser 14, and an oscillator.
15, a delay line 16, an adder 17, and a detector 18. 19 is a DSC (digital scan converter), 20 is a color processing circuit, 35 is a control circuit, 29
Is a marker generation unit.

One of the signals output from the adder 17 is a detector 18,
The data is sent to the DSC 19 via the line 37, and is used to display a tomographic image (monochrome B-mode image). The other is sent below line 39 and serves to display a blood flow image. line
The signal added from 39 is split into two, mixers 24a and 24b, respectively.
Is added to Each mixer 24a, 24b has a 90 ° transfer device 25
The reference signal f _S from the oscillator 15 is added each to have a 90 ° phase difference by the. As a result, the low pal filter 26a,
The Doppler shift frequency component fd and the (2fs + fd) signal are input to 26b, and high-frequency components are removed by the low-pass filters 26a and 26b, so that only the Doppler shift frequency component fd is obtained.
This is the phase detection output signal for calculating the blood flow distribution image formed and flow rate V _N.

The phase detection output contains not only blood flow information but also unnecessary reflected signals (called clutter) from slow-moving objects such as the heart wall. The phase detection output is MTI (Moving Target Indicat
ion) calculation unit 27.

The MTI operation unit 27 includes an A / D converter, a plurality of line memories, an MTI filter, an autocorrelator, an average speed operation unit, a dispersion operation unit, and a power operation unit.

The value calculated for each point is DSC19
After the data is interpolated, the color processing circuit 20
Is converted into color information. For example, the flow approaching the probe 11 is converted to reddish, and the flow away from the probe 11 is converted to blued.

The marker generating section 29 generates information for forming a marker indicated at the measurement point N setting position by the measurement point setting means 2 in the input section 1 in FIG. Superimposed on top.
The measurement point setting information is transmitted to the jet flow rate calculation unit 5 via the control circuit 35.

 Next, the operation of the present embodiment will be described.

Ultrasonic waves are transmitted and received by the sector electronic scanning analog section 12 under the control of the control circuit 35 in FIG. 3, and a B-mode image and a blood flow distribution image of the subject are formed. It is displayed on the display unit 9 under control.

The operator sets the measurement point N and the coefficient α on this display image (color Doppler image) by operating the input unit 1.
Based on this, the flow velocity is calculated by the flow velocity calculating means 5a according to the equation (4).
V _N is calculated, and (1) is calculated by the distance calculation means 5b.
A distance L satisfying the expression is calculated. Next, the calculated data V _N and L are input to the flow rate calculating means 5c, and the measurement point N, that is, the jet flow rate Q is obtained based on the equation (3). The flow velocity V _N , the distance L, and the ejection flow rate Q thus obtained are numerically displayed on the display screen of the display section 9 under the control of the display control section 8 as shown in FIG.

According to the present embodiment, it is possible to determine the ejection flow rate of the blood flow without measuring the cross-sectional area of the backflow port / valve port of the valve regurgitation / short-circuit flow / stenosis flow. Moreover 2 data of the distance L to the position that retain substantially equal to the flow velocity V _N of the flow velocity V _N and the measurement point in the measurement point set in advance calculated
Since only the type is required, the ejection flow rate can be calculated with a small amount of data, so that the measurement can be performed in a short time.

By setting the repetition frequency fr of the pulse for controlling the transmission and reception of the ultrasonic pulse higher than that of the commonly used (a) as shown in FIG. 6 (b), the flow velocity to be calculated which is limited by the sampling theorem You can increase the value of V _N
Since the return of the so-called blood flow pattern is alleviated, a blood flow image that is easy to observe can be obtained. Also, as shown in FIG. 7, a transmitting probe 11a and a receiving probe 11b are independently provided as the ultrasonic probe 11, and the application of the continuous wave Doppler method eliminates the influence of the return by the application of the continuous wave Doppler method. Measurement can be performed. Therefore, these are particularly advantageous when obtaining high-speed blood flow information,
The measurement system of the jet velocity can be improved.

[Effects of the Invention] As described above, according to the present invention, the ejection flow rate can be measured only by calculating in advance two types of data of the flow rate at the ejection port and the distance to a position substantially equal to the flow rate. Can be easily measured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the ultrasonic Doppler apparatus of the present invention, FIG. 2 is a block diagram showing a configuration of a main part of FIG. 1, and FIG. 3 is a configuration of another main part of FIG. FIG. 4 is a display example illustrating an example of a distance calculation method in the present embodiment. FIG. 5 is a display example illustrating each calculation data obtained by the present embodiment. (B) is a signal waveform diagram illustrating another embodiment of the present invention, FIG. 7 is a schematic diagram illustrating another embodiment of the present invention, and FIG. 8 is a description of a free turbulent jet in the background of the present invention. FIG. 2 ... Measurement point setting means, 3 ... Coefficient setting means, 4 ... Blood flow imaging unit, 5 ... Jet flow rate calculation unit, 5a ... Flow velocity calculation means, 5b ... Distance calculation means, 5c ... Flow rate calculation means.

Claims (2)

(57) [Claims] 1. An ultrasonic Doppler apparatus for obtaining a color Doppler image based on an ejection port and a reception echo of an ultrasonic wave transmitted toward a fluid ejected from the ejection port, the ejection port on the color Doppler image. A flow velocity calculating means for calculating the flow velocity of the fluid at the measurement point set at the position from the ultrasonic transmission / reception result, and a distance from the jet port to a position showing a value substantially equal to the flow velocity in the fluid jetting direction. An ultrasonic Doppler apparatus comprising: a distance calculating means; and a flow rate calculating means for calculating a flow rate of ejected fluid based on a calculation result of each of the calculating means. 2. The ultrasonic Doppler device according to claim 1, wherein said fluid is blood.