JPH08322841A - Ultrasonic doppler rheometer - Google Patents

Abstract

PURPOSE: To embody a calculating and plotting method of high noise resistance in a Doppler rheometer capable of calculating or plotting the max. blood flow velocity, etc., from a Doppler spectrum. CONSTITUTION: A frequency analyzer 15 calculates the Doppler spectrum. The noise components exclusive of blood flow information in the sections and states of the blood flow in the living body to be detected and the signal processing system of a device are included in the resulted Doppler spectrum. The max. blood flow velocity, etc., are calculated in a trace calculating means 18 from the Doppler spectrum. At this time, the max. blood flow velocity is calculated by providing the trace calculating means 18 with >=2 kinds of thresholds, by which the calculation of the high noise resistance is embodied and the more accurate max. blood flow velocity is calculated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic Doppler blood flow meter for measuring blood flow velocity in a living body.

[0002]

2. Description of the Related Art In ultrasonic Doppler blood flow measurement, which is widely used in ultrasonic diagnosis of biological circulatory organs, the function of automatically calculating and tracing the maximum blood flow velocity etc. is actively used in various diagnosis. It is being appreciated. At this time, in order to obtain an accurate trace when the noise component on the spectrum is high, various parameters such as gain have to be finely adjusted.

The basic principle of the conventional example will be described below with reference to FIG. In FIG. 4, reference numeral 1 is an ultrasonic probe that receives reflected ultrasonic waves from the subject through the ultrasonic transducer and converts them into electrical signals, and 2 is a drive pulse to the ultrasonic transducer of the ultrasonic probe 1. A transmission scanning circuit 3 for supplying supplies a reception processing circuit for amplifying a reception signal from the ultrasonic transducer of the ultrasonic probe 1, and a reference numeral 4 for an echo signal obtained from the inside of a living body by transmitting and receiving ultrasonic waves. Quadrature detection means for quadrature detection, 5 is a frequency analyzer for performing frequency analysis on the quadrature detection signal, and 6 is DSC for scanning conversion of the Doppler spectrum from the frequency analyzer 5.
A part 7, a trace synthesizing means for synthesizing the trace information with the Doppler spectrum, 8 a trace calculating means including threshold processing for calculating the maximum blood flow velocity and the like from the Doppler spectrum information, and 9 a trace calculating means 8 A trace drawing means 10 for sweeping information in time and drawing a trace is a display unit for displaying a trace showing a Doppler spectrum and a blood flow velocity.

The operation of the above arrangement will be described below. The drive pulse generated by the transmission scanning circuit 2 is applied to the ultrasonic transducer of the ultrasonic probe 1, converted into ultrasonic waves, and transmitted to the subject. The ultrasonic waves reflected from the subject are converted into electric signals by the ultrasonic transducer of the ultrasonic probe 1 and sent to the reception processing circuit 3. The reception signal is processed by the reception processing circuit 3 and then detected by the quadrature detection means 4 to obtain a quadrature detection signal. The two orthogonal signals are frequency-analyzed by the frequency analyzer 5 by complex operation, and the DSC unit 6 scan-converts them to obtain a Doppler spectrum indicating blood flow velocity information. On the other hand, the maximum blood flow velocity or the like is calculated from the Doppler spectrum information from the frequency analyzer 5 in the trace calculating means 8 including threshold processing by the method shown in FIG. When calculating the maximum blood flow velocity, a certain threshold is set on the luminance of the Doppler spectrum, and the maximum velocity of the velocity having the luminance exceeding the threshold is calculated as the maximum blood flow velocity. The maximum blood flow velocity information is swept in time, and trace drawing is performed by the trace drawing means 9. The trace information and the Doppler spectrum information from the DSC unit 6 are combined by the trace combining means 7 and displayed on the display unit 10.

[0005]

However, in the above-described conventional ultrasonic Doppler blood flow meter, when the maximum blood flow velocity is calculated by the trace calculating means, an accurate trace is obtained when the noise component on the spectrum is high. In order to do so, it is necessary to finely adjust various parameters such as the gain. When calculating the maximum blood flow velocity with one threshold value as shown in FIG. I could not trace.

The present invention solves such a conventional problem. In the calculation of the maximum blood flow velocity, even if the noise component on the Doppler spectrum is high, the accurate maximum blood flow velocity trace calculation is performed. It is an object of the present invention to provide an ultrasonic Doppler blood flow meter capable of performing the above.

[0007]

In order to achieve the above-mentioned object, the present invention provides the trace computing means with two or more kinds of threshold values.

[0008]

Therefore, according to the present invention, by providing two or more kinds of thresholds in the trace calculating means, accurate maximum blood flow velocity trace calculation can be performed even when the noise component on the spectrum is high.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of an embodiment of the present invention. In FIG. 1, 11 is an ultrasonic probe, 12 is a transmission scanning circuit, 13 is a reception processing circuit, 14 is a quadrature detection means,
Reference numeral 15 is a frequency analyzer, 16 is a DSC unit, 17 is a trace synthesizing unit, 18 is a trace calculating unit including two or more types of threshold processing, 19 is a trace drawing unit, and 20 is a display unit. The basic principle of ultrasonic Doppler blood flow is the same as that of the conventional example shown in FIG. 4, and the difference is due to the processing method of the trace calculation means 18.

With respect to the above configuration, the operation of the trace computing means 18 will be described in detail. Two types of threshold values 1 and 2 on the brightness of the Doppler spectrum are provided as shown in FIG. The threshold value 1 is the same value as the conventional example, and the threshold value 2 is larger than the threshold value 1. First, V0, which is the maximum speed having a brightness exceeding the threshold value 2, is obtained.
Next, between V0 and the maximum velocity value V1 of the flow velocity display, the minimum blood velocity of the velocity having the brightness exceeding the threshold value 1 is obtained as the final maximum blood velocity. As described above, an accurate maximum blood flow velocity trace as shown in FIG. 3 can be obtained. Two or more thresholds may be provided.

[0011]

As described above, according to the present invention,
By providing two or more types of threshold values in the trace calculation means, accurate maximum blood flow velocity trace calculation can be performed even when the noise component on the Doppler spectrum is high.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an ultrasonic Doppler blood flow meter according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a Doppler maximum blood flow velocity trace calculation method in one embodiment of the present invention.

FIG. 3 is a Doppler maximum blood flow velocity trace screen diagram in one embodiment of the present invention.

FIG. 4 is a schematic block diagram of an ultrasonic Doppler blood flow meter in a conventional example.

FIG. 5 is a schematic diagram of a Doppler maximum blood flow velocity trace calculation method in a conventional example.

FIG. 6 is a Doppler maximum blood flow velocity trace screen diagram in a conventional example.

[Explanation of symbols]

 Reference Signs List 11 ultrasonic probe 12 transmission scanning circuit 13 reception processing circuit 14 quadrature detection means 15 frequency analyzer 16 DSC section 17 trace synthesis means 18 trace calculation means 19 trace drawing means 20 display section

Claims (2)

[Claims] 1. A quadrature detecting means for quadrature detecting an echo signal obtained from the inside of a living body by transmitting and receiving ultrasonic waves, a frequency analyzer for frequency-analyzing two orthogonal signals by a complex operation, and a frequency analyzer. An ultrasonic Doppler blood flow meter comprising a trace calculation means for calculating the maximum blood flow velocity and the like with two or more kinds of threshold values and a means for outputting image information and trace information to a display section. 2. A quadrature detection means for quadrature detection of an echo signal obtained from the inside of a living body by transmitting and receiving ultrasonic waves, a frequency analyzer for frequency-analyzing two orthogonal signals by a complex operation, and a frequency analyzer. The DSC section that scan-converts the obtained information, the trace calculating means that calculates the maximum blood flow velocity and the like from the information from the frequency analyzer by two or more types of threshold values, and the maximum blood flow velocity and the like are swept in time. An ultrasonic Doppler blood flow meter comprising: a trace drawing means for drawing a trace by a trace and a trace synthesizing means for synthesizing the information from the DSC section and the trace information from the trace drawing means and outputting it to the display section.