JPS618035A - Ultrasonic doppler diagnostic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an ultrasonic Doppler diagnostic device.1 In particular, in a device that measures the flow velocity of blood flow etc. using the Doppler effect, The present invention relates to an ultrasonic Doppler diagnostic device that can accurately set the incident angle of a sound beam.

[Technology background]

In recent years, arterial vascular diseases such as cerebral thrombosis and myocardial infarction have rapidly increased.
It has been discovered that mechanical factors such as blood pressure acting on the blood vessel wall play a major role in triggering this phenomenon.In order to analyze such mechanical effects, various blood flow needles have been developed, and blood flow velocity has been developed. measurements are being taken. A Doppler blood flow meter using ultrasound is known as such a blood flow needle. The ultrasonic Doppler diagnostic device, which measures blood velocity using the ultrasonic Doppler effect, irradiates an object moving at a speed like a blood cell with ultrasonic waves of frequency fO, and observes the reflected anti-wave resistance. At this time, the frequency fs has a predetermined relationship with fo due to the Doppler effect, and the total frequency deviation amount Δr is expressed as rS−fO. Blood flow is measured from such a Doppler shift amount.

[Conventional technology and problems]

A conventional embodiment of the above-mentioned ultrasonic Doppler diagnostic apparatus is shown in FIG. Fig. 5 shows an example of an ultrasound probe of an ultrasound Doppler diagnostic device; 1 indicates an ultrasound probe;
An ultrasonic transducer 2 is provided within the ultrasonic probe. 3 is the skin of the body.

4 is a blood vessel in which blood flows in the direction indicated by the arrow.

Ultrasonic waves are emitted from the ultrasonic transducer and irradiated in a direction forming an angle θ with the axial direction Y-Y of the ultrasonic probe 1. Since this irradiation angle 9 affects the frequency deviation amount Δf, in the conventional configuration, the angle between the tip surface 1a of the ultrasonic probe 1 and the mounting surface of the ultrasonic transducer 2 is fixed.

Flatten the tip surface 1a of the ultrasound probe 1 and flatten the skin surface 3a.
By standing the ultrasound probe 1 vertically parallel to the angle θ, it is assumed that the ultrasound beam 4 intersects the blood vessel at a known angle θ.

However, in this configuration, the blood flow direction A is the skin surface 3a of the body.
Since it is based on the assumption that the direction of blood flow is parallel to the body surface, it has a drawback that the measurement error of the frequency deviation amount Δf increases when the body surface and the blood flow direction are not parallel.

[Purpose of the invention]

The present invention has been made to address the above-mentioned drawbacks, and is an ultrasonic Doppler diagnosis having an angle detection means for accurately maintaining the angle formed between the irradiation direction of an ultrasound beam irradiated for blood flow measurement and the direction of blood flow. The purpose is to provide a device.

[Structure of the invention]

According to the present invention, this purpose is to provide an apparatus for measuring blood flow by irradiating ultrasound into blood vessels and observing frequencies shifted by the Doppler effect, in which a transducer for blood flow velocity measurement is installed in an ultrasound probe. Equipped.

The ultrasonic probe includes an angle detection transducer that can maintain an ultrasonic beam direction at a constant angle with respect to the ultrasonic beam direction of the blood flow velocity measurement transducer. This is achieved by providing an ultrasonic Doppler diagnostic device characterized in that a user is connected to a Doppler frequency analysis circuit for angle detection.

[Embodiments of the invention]

An embodiment of the present invention will be described in detail below with reference to FIGS. 1 to 4.

Fig. 1 is a system diagram for explaining the ultrasonic probe of the ultrasonic Doppler diagnostic device of the present invention and its operating principle, and Figs. 2 to 4 show the angle of the ultrasonic probe and the output waveforms of each frequency analysis circuit. 5 is an explanatory diagram showing the relationship between the two, and the same parts as those in the conventional example shown in FIG. 5 will be explained using the same reference numerals.

In FIG. 1, reference numeral 1 denotes an ultrasonic probe, and an ultrasonic transducer 5 for angle detection is attached to the horizontal surface 1a at the tip of the ultrasonic probe, and the probe axis Y
An ultrasonic transducer 2 for blood flow velocity measurement is attached to the tip of the probe so as to form a predetermined angle θ with -Y. 3 is the skin of the body.

4 is a blood vessel in which blood flows in direction B.

The ultrasound beams 5a and 2a from the image sound wave transducer 5.2 are irradiated so as to intersect with the direction B, which is the blood flow direction, with an angular difference of θ. The ultrasonic transducer 5 for angle detection is connected to a Doppler frequency analysis circuit 6 for angle detection.

The ultrasonic transducer 2 for blood flow velocity measurement is connected to a Doppler frequency analysis circuit 7 for blood flow velocity measurement.

To explain the operation of the above configuration, the present invention uses the fact that the reflected waves from red blood cells of an ultrasound beam incident perpendicularly to the direction of blood flow in a blood vessel do not cause a Doppler shift. In order to accurately maintain the angle of the ultrasonic beam of the ultrasonic transducer for speed measurement, a Doppler frequency analysis circuit for angle detection uses the reflected wave of the ultrasonic beam 5a emitted from the ultrasonic transducer for angle detection 5. The angle at which the frequency deviation amount Δf becomes zero with respect to time t, as shown in FIG. 2 (al).

That is, the ultrasonic probe 1 is moved so that the ultrasonic beam 5a is at an angle perpendicular to the blood vessel direction B as shown in FIG.
Adjust the angle. If the ultrasonic probe 1 is held at this angle and the ultrasonic transducer 2 for blood velocity measurement directs the ultrasonic beam toward the blood vessel 4, the output of the Doppler frequency analysis circuit 7 for blood velocity measurement will be vertical. The frequency deviation amount Δr is on the axis.

If time t is plotted on the horizontal axis, blood flow analysis can be performed accurately at an angle of θ with respect to the normal to blood flow direction B, so Figure 2 fb
Δf as shown in l can be obtained.

Fig. 3 ia) -FC+ and Fig. 4 ta+ -fe) Doppler frequency analysis circuit 6 for angle detection when the ultrasonic beam for angle detection is irradiated at an incorrect angle with respect to the normal to the blood flow direction B. Figure 3 is a diagram showing the relationship between Δf and t similar to Figures 2(a) and 2(b) of the Doppler frequency analysis circuit 7 for measuring blood flow velocity. FIG. 3 (C
The output waveform of the frequency deviation amount Δf in the case of 1 is shown in FIGS. 4(al) and 4(b). This is the output waveform of the frequency deviation amount Δf in the case of FIG. 4(e) in which the ultrasonic beam 2a for measuring the blood flow velocity is irradiated and crossed perpendicularly to the blood flow direction B of the blood vessel 4.

From these, as shown in FIG. 1, the point where the frequency shift amount decreases to zero may be determined and the ultrasonic probe 1 may be fixed.

〔Effect of the invention〕

Since the present invention is constructed as described above, by finding the angular position at which the reflected wave of the ultrasonic beam 5a for angle detection becomes zero, it is possible to accurately set the angle of the ultrasonic beam for blood flow velocity measurement with respect to the blood vessel. It has the characteristic of being able to detect the shift frequency with high precision and measure blood flow velocity.

[Brief explanation of the drawing]

Fig. 1 is a system diagram for explaining the ultrasonic probe of the present invention and its operating principle, and Fig. 2 fa1. fbl is the output waveform diagram of the Doppler frequency analysis circuit for angle detection and the Doppler frequency analysis circuit for blood flow velocity measurement of the embodiment shown in Fig. 1, and Fig. 3 +a+
, , (bl, (C1 and Fig. 4(at, (bl,
(cl is the output waveform diagram of the Doppler frequency analysis circuit for angle detection at various angles of the ultrasound probe and the Doppler frequency analysis circuit for blood flow velocity measurement, and Figure 5 is the output waveform diagram of the ultrasound probe of the conventional ultrasound Doppler diagnostic device. 2. Ultrasonic probe, 2. Ultrasonic transducer for measuring blood flow velocity, 3. Skin,
4... Blood vessel, 2a, 5a... Ultrasonic beam, 5... Ultrasonic transducer for angle detection, 6... Doppler frequency analysis circuit for angle detection, 7... For blood flow velocity measurement Doppler frequency analysis circuit. Patent Applicant Fujitsu Ltd. Representative Patent Attorney Hiroshi Matsuoka Figure 2, f Figure 3 Mf -10t f -1chi↑

Claims (1)

[Claims] In a device that measures blood flow by irradiating a blood vessel with ultrasound and observing the frequency shifted by the Doppler effect, the ultrasonic probe is equipped with a transducer for measuring blood flow velocity, and the transducer for measuring blood flow velocity is The ultrasonic probe has an angle detection transducer that can maintain the ultrasonic beam direction at a constant angle with the ultrasonic beam direction,
An ultrasonic Doppler diagnostic device characterized in that the angle detection transducer is connected to an angle detection Doppler frequency analysis circuit.