CN113037405B - Electronic noise and interference test system of ultrasonic diagnostic equipment - Google Patents
Electronic noise and interference test system of ultrasonic diagnostic equipment Download PDFInfo
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- CN113037405B CN113037405B CN202110136789.3A CN202110136789A CN113037405B CN 113037405 B CN113037405 B CN 113037405B CN 202110136789 A CN202110136789 A CN 202110136789A CN 113037405 B CN113037405 B CN 113037405B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
- H04B17/336—Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
- H04B17/345—Interference values
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Abstract
The invention discloses an electronic noise and interference test system of ultrasonic diagnostic equipment, which comprises a transmitting link and a receiving link, wherein the transmitting link is connected with the receiving link through a communication link; the transmitting link comprises a transmitting signal control unit, a transmitting circuit, a high-voltage switch and a probe array element; the receiving link comprises a transmitting/receiving change-over switch, an ultrasonic analog front end unit and a receiving signal control unit; the transmitting signal control unit controls the transmitting circuit to generate high-voltage pulse, the generated high-voltage pulse enters the probe array element after passing through the high-voltage switch, and the array element is excited by the high-voltage pulse to send out an ultrasonic signal; the ultrasonic signals are converted into electric signals through the probe array element conversion processing, the electric signals sequentially pass through the high-voltage switch and the transmitting/receiving conversion switch and then enter the ultrasonic simulation front-end unit to be processed, and the processed signals are input into the received signal control unit to be processed. The invention can help engineers to find and change design defects and improve image quality.
Description
Technical Field
The invention relates to the technical field of ultrasonic systems, in particular to an electronic noise and interference testing system of ultrasonic diagnostic equipment.
Background
Noise level is an important measure of ultrasound systems and is directly related to image quality. The system internal hardware noise influencing the ultrasonic image is divided into two types of substrate noise and interference, wherein the substrate noise mainly comprises electronic thermal noise and the like and is inherent noise of the system; the interference belongs to the problem of signal integrity, and mainly comprises signals of a power distribution system, a clock, power switch frequency and the like, wherein the signals are coupled into an ultrasonic echo signal through an analog signal link at the front end of the system, then are subjected to AD sampling and quantization, and finally become important factors influencing the quality of the ultrasonic echo signal.
In the hardware design and test links of an ultrasonic system, a convenient and accurate test method for the noise level and the interference of a system substrate is not available, and subjective judgment can be only carried out through reflection on an image. In order to solve the problems, the invention provides a system capable of quantitatively detecting the substrate noise level of an ultrasonic system and whether a signal is mixed with strong interference, and aims to help engineers to find and modify design defects and improve image quality.
Disclosure of Invention
The invention aims to provide an electronic noise and interference test system of ultrasonic diagnostic equipment aiming at the defects of the prior art, which can help engineers to find and change design defects and improve image quality.
In order to achieve the purpose, the invention adopts the following technical scheme:
an electronic noise and interference test system of an ultrasonic diagnosis device comprises a transmitting link and a receiving link; the transmitting link comprises a transmitting signal control unit, a transmitting circuit, a high-voltage switch and a probe array element; the receiving link comprises a transmitting/receiving change-over switch, an ultrasonic analog front end unit and a receiving signal control unit;
the transmitting circuit is respectively connected with the transmitting signal control unit and the high-voltage switch, and the high-voltage switch is connected with the probe array element; the transmitting/receiving change-over switch is respectively connected with the high-voltage switch and the ultrasonic simulation front-end unit, and the receiving signal control unit is connected with the ultrasonic simulation front-end unit;
the transmitting signal control unit controls the transmitting circuit to generate high-voltage pulse, the generated high-voltage pulse enters the probe array element after passing through the high-voltage switch, and the array element is excited by the high-voltage pulse to send out an ultrasonic signal; the ultrasonic signals are converted into electric signals through the conversion processing of the array elements of the probe, the electric signals sequentially pass through the high-voltage switch and the transmitting/receiving conversion switch and then enter the ultrasonic simulation front-end unit for processing, and the processed signals are input to the received signal control unit for processing.
Further, the ultrasonic analog front end unit comprises an amplifier, a low-pass filter, an analog-to-digital converter (ADC) and a Time Gain Compensation (TGC); the low-pass filter is respectively connected with the amplifier and the analog-to-digital converter (ADC), and the Time Gain Compensation (TGC) is connected with the amplifier;
the entering into the ultrasonic simulation front-end unit for processing specifically comprises the following steps: and the electric signal is subjected to time gain compensation TGC and then enters an amplifier for amplification, and the amplified electric signal is converted into a digital signal through an analog-to-digital converter ADC.
Further, the amplifier comprises a low noise amplifier LNA, a voltage control amplifier VCA and a programmable gain amplifier PGA, wherein the voltage control amplifier VCA is connected with the low noise amplifier LNA and the programmable gain amplifier PGA respectively, the programmable gain amplifier PGA is connected with the low pass filter, and the voltage control amplifier VCA is connected with the time gain compensation TGC.
Furthermore, the receiving link also comprises an AD data acquisition unit and a TGC analog voltage generation unit;
the AD data acquisition unit is connected with the analog-to-digital converter ADC and used for acquiring the number of AD data points;
the TGC analog voltage generation unit is connected with the time gain compensation TGC and is used for generating analog voltage.
Further, the inputting of the processed signal to the received signal control unit for processing includes performing beam forming and signal and image processing on the input signal.
Further, the low noise amplifier LNA and the programmable gain amplifier PGA are set to be the highest gears; the step of the voltage control amplifier VCA is set to 0dB.
Furthermore, the cut-off frequency point of the low-pass filter is the upper limit of the system bandwidth.
Further, the number of the AD data points collected by the AD data collecting unit is more than or equal to 1 thousand points.
Furthermore, the AD data acquisition unit is also used for performing full-point Fourier transform FFT on the number of the acquired AD data points.
Compared with the prior art, the system capable of quantitatively detecting the substrate noise level of the ultrasonic system and whether the signals are mixed with strong interference or not can help system testing and designers to conveniently and accurately analyze the noise performance of front-end hardware of the system, help the system testing and designers to identify whether the signals are pure and interfere with frequency points, improve design defects, improve the signal-to-noise ratio of the ultrasonic signals and further improve image quality.
Drawings
Fig. 1 is a structural diagram of an electronic noise and interference test system of an ultrasonic diagnostic apparatus according to an embodiment;
FIG. 2 is a frequency domain diagram of the background noise provided in the second embodiment;
fig. 3 is a schematic diagram of the frequency spectrum of the AD data mixed with strong interference of 0.8MHz in the signal provided in the third embodiment.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the features in the following embodiments and examples may be combined with each other without conflict.
The invention aims to provide an electronic noise and interference testing system of an ultrasonic diagnostic device aiming at the defects of the prior art.
Example one
The electronic noise and interference test system of the ultrasonic diagnostic equipment provided by the embodiment, as shown in fig. 1, includes a transmitting link and a receiving link; the transmitting link comprises a transmitting signal control unit 11, a transmitting circuit 12, a high-voltage switch 13 and a probe array element 14; the receiving chain comprises a transmitting/receiving conversion switch 15, an ultrasonic analog front end unit 16 and a receiving signal control unit 17.
The transmitting signal control unit 11 is connected with one end of a transmitting circuit 12, the other end of the transmitting circuit 12 is connected with one end of a high-voltage switch 13, the other end of the high-voltage switch 13 is connected with one end of a probe array element 14, and the other end of the probe array element 14 is grounded; the other end of the high-voltage switch is further connected with one end of a transmitting/receiving change-over switch 15, the other end of the transmitting/receiving change-over switch 15 is connected with an ultrasonic analog front-end unit 16, and the other end of the ultrasonic analog front-end unit 16 is connected with a received signal control unit 17.
In this embodiment, the receiving link further includes an AD data acquisition unit 18 and a TGC analog voltage generation unit 19.
The ultrasound analog front end 16 unit includes a low noise amplifier LNA, a voltage controlled amplifier (attenuator) VCA, a programmable gain amplifier PGA, a low pass filter, an analog to digital converter ADC, a time gain compensation TGC.
One end of a low noise amplifier LNA is connected with a transmitting/receiving conversion switch 15, the other end of the low noise amplifier LNA is connected with one end of a voltage control amplifier VCA, the other end of the voltage control amplifier VCA is connected with one end of a programmable gain amplifier PGA, the other end of the programmable gain amplifier PGA is connected with one end of a low-pass filter, the other end of the low-pass filter is connected with one end of an analog-to-digital converter ADC, and the other end of the analog-to-digital converter ADC is respectively connected with a receiving signal control unit 17 and an AD data acquisition unit 18; the TGC analog voltage generating unit 19 is connected to one end of the time gain compensation TGC, and the other end of the time gain compensation TGC is connected to the other end of the voltage control amplifier VCA.
The basic concept of the embodiment is as follows: the system noise and interference can be obtained by controlling the input ends of all parts in a signal path to be grounded and then collecting AD data of closed-loop signals for analysis. The background noise is mainly represented in the form of white noise, and randomly and only follows the statistical characteristics, and the power of each frequency component is uniformly distributed in the whole bandwidth, so that a horizontal line can be approximately drawn.
The interference is different from random noise, and is often represented as spectral lines of fixed frequency points in a noise spectrum, and the spectral lines regularly appear and have amplitude values obviously higher than a substrate. Interference tends to appear in the frequency domain as multiple harmonics due to its periodicity in the time domain, and energy decreases as the number of harmonics increases. In addition, the interference of different frequencies is relatively independent and is independently represented on the spectral line. Therefore, the interference source can be found by identifying the fundamental frequency. And (4) positioning an interference path, namely, spinning and cocoon stripping are required, and the signal path is gradually divided, so that an interference coupling mode is finally obtained.
The specific implementation scheme of the embodiment is as follows:
in a transmitting link, a transmitting signal control unit 11 controls a transmitting circuit 12 to generate high-voltage pulses according to a scanning sequence, the generated high-voltage pulses pass through a high-voltage switch 13 and then enter a probe array element 14, and the array element is excited by the high-voltage pulses to send out ultrasonic signals;
in a receiving link, an ultrasonic signal sent out is converted into an electric signal through a probe array element 14, the electric signal sequentially passes through a high-voltage switch 13 and a transmitting/receiving conversion switch 15 and then enters an ultrasonic analog front-end unit 16 for processing, specifically, the electric signal is sampled and quantized by an analog-to-digital converter (ADC) after being subjected to Time Gain Compensation (TGC) and then is converted into a digital signal, and then the signal is sent to a received signal control unit 17 for beam forming and signal and image processing.
Due to layout, grounding, etc., the noise or interference performance of each part or each channel in the system may be inconsistent. Therefore, in the testing link, firstly, single-channel emission and reception need to be controlled, and the noise level of each channel is measured in a traversing manner; and secondly, the signal link can be processed in a segmented mode and divided into an ATGC link, a transmitting link and a receiving link so as to clarify an interference path and a noise source.
The environment and conditions for testing by using the test system of the embodiment are as follows:
environment: during noise test, the system needs to be tested under the conditions of complete components and complete mechanical structure of the system, the relative cleanness of the surrounding electromagnetic environment is ensured as much as possible, and the test result is prevented from being influenced by external environment interference.
Conditions are as follows:
1. when each channel is subjected to noise test, the corresponding physical channel is grounded through a 50 ohm resistor at the probe connecting end;
2. in order to prevent the damage of the chip at the front end of the ultrasonic simulation caused by the reverse injection of the strong current of the high-voltage transmitting circuit into the receiving link after the channel is grounded, at the moment, the digital signals of the transmitting waveform need to be controlled to be all zero level, namely, the transmitting module is set to work normally but no high-voltage transmitting waveform is output.
3. In order to obtain the noise level under the broadband condition as much as possible, the link gain and the filter of the ultrasonic analog front end should be set as follows:
the LNA and the PGA are both set to be the highest gears; VCA is set to 0dB and does not change over time, so that system link signal gain is maximized;
the low pass filter cutoff frequency is typically chosen as the upper limit of the system bandwidth.
4. When single channel noise level is analyzed, the high-voltage switches only opening corresponding channels need to be controlled, and the high-voltage switches connected with other channels are all closed, so that signal crosstalk is avoided.
5. When the AD data of the corresponding channel is collected, in order to obtain sufficient frequency domain information as far as possible and avoid a strong barrier effect, the data sampling rate should be set to be high, and the number of the AD data collection points should not be too small, and generally can be set to be more than 1 thousand points.
6. Because the ultrasonic system transmitting chain, the receiving chain and the TGC analog voltage generating circuit mainly use analog electronic devices and are highly sensitive areas of noise coupling, 50-ohm resistance grounding treatment can be respectively carried out at positions (1), (2) and (3) according to the marks in figure 1, and each module is independently opened and respectively analyzed so as to judge the coupling path of interference.
7. The AD data analysis method comprises the following steps: and performing full-point Fourier transform (FFT) on the acquired AD data, and judging the quantitative analysis of the noise level according to the Root Mean Square (RMS) value of the AD time domain signal.
Compared with the prior art, the system for quantitatively detecting whether the substrate noise level and the signals of the ultrasonic system are mixed with strong interference or not can help system testing and designers to conveniently and accurately analyze the noise performance of front-end hardware of the system, help the system to identify whether the signals are pure and interfere with frequency points, improve design defects, improve the signal-to-noise ratio of the ultrasonic signals and further improve image quality.
Example two
The difference between the electronic noise and interference test system of the ultrasonic diagnostic equipment provided by the embodiment and the first embodiment is that:
this example illustrates the results of specific tests.
When the test system of the first embodiment is used to test the substrate noise level of the ultrasonic hardware system, the result is shown in fig. 2, and it can be analyzed from fig. 2 that the substrate noise of the system is at a-10 dB level.
EXAMPLE III
The difference between the electronic noise and interference test system of the ultrasonic diagnostic equipment provided by the embodiment and the first embodiment is that:
this example illustrates the results of specific tests.
If the test system of the first embodiment is used to test whether the ultrasonic hardware system is mixed with the interference signal, the result is shown in fig. 3, and it can be analyzed from fig. 3 that strong interference noise is mixed into the front end of the system, and the frequency point appears with 0.8MHz as the frequency multiplication, and further the mixed interference fundamental frequency point can be analyzed to be 0.8MHz.
It is to be noted that the foregoing description is only exemplary of the invention and that the principles of the technology may be employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in some detail by the above embodiments, the invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the invention, and the scope of the invention is determined by the scope of the appended claims.
Claims (6)
1. An electronic noise and interference test system of an ultrasonic diagnosis device is characterized by comprising a transmitting link and a receiving link; the transmitting link comprises a transmitting signal control unit, a transmitting circuit, a high-voltage switch and a probe array element; the receiving link comprises a transmitting/receiving change-over switch, an ultrasonic analog front end unit and a receiving signal control unit;
the transmitting circuit is respectively connected with the transmitting signal control unit and the high-voltage switch, and the high-voltage switch is connected with the probe array element; the transmitting/receiving change-over switch is respectively connected with the high-voltage switch and the ultrasonic simulation front-end unit, and the receiving signal control unit is connected with the ultrasonic simulation front-end unit;
the ultrasonic analog front end unit comprises an amplifier, a low-pass filter, an analog-to-digital converter (ADC) and a Time Gain Compensation (TGC); the low-pass filter is respectively connected with the amplifier and the analog-to-digital converter (ADC), and the Time Gain Compensation (TGC) is connected with the amplifier;
the amplifier comprises a low noise amplifier LNA, a voltage control amplifier VCA and a programmable gain amplifier PGA, wherein the voltage control amplifier VCA is respectively connected with the low noise amplifier LNA and the programmable gain amplifier PGA, the programmable gain amplifier PGA is connected with the low-pass filter, and the voltage control amplifier VCA is connected with the time gain compensation TGC;
in a transmitting link, a transmitting signal control unit controls a transmitting circuit to generate high-voltage pulse according to a scanning sequence, the generated high-voltage pulse enters a probe array element after passing through a high-voltage switch, and the probe array element is excited by the high-voltage pulse to send out an ultrasonic signal; in a receiving link, an ultrasonic signal sent out is converted into an electric signal through conversion processing of an array element of a probe, the electric signal sequentially passes through a high-voltage switch and a transmitting/receiving conversion switch and then enters an ultrasonic analog front-end unit for processing, and the specific processing is sampling and quantizing by an analog-to-digital converter (ADC) after Time Gain Compensation (TGC) and then converting the signal into a digital signal; the digital signal is sent to a receiving signal control unit for beam forming and signal and image processing;
the entering into the ultrasonic simulation front-end unit for processing specifically comprises the following steps: the electric signal is subjected to time gain compensation TGC processing and then enters an amplifier for amplification processing, and the amplified electric signal is converted into a digital signal through an analog-to-digital converter ADC;
the signal and image processing procedure is as follows:
grounding input ends of all parts in a signal path through control, and acquiring AD data of a closed-loop signal for analysis; the analysis process is to apply Fast Fourier Transform (FFT) operation to obtain the frequency spectrum of the noise signal, and observe the base noise level, the frequency point of interference and the interference intensity from a spectrogram.
2. The electronic noise and interference test system of the ultrasonic diagnostic apparatus according to claim 1, wherein the receiving link further comprises an AD data acquisition unit, a TGC analog voltage generation unit;
the AD data acquisition unit is connected with the ADC and used for acquiring the number of AD data points;
the TGC analog voltage generation unit is connected with the time gain compensation TGC and is used for generating analog voltage.
3. The electronic noise and interference testing system of the ultrasonic diagnostic apparatus according to claim 1, wherein the low noise amplifier LNA and the programmable gain amplifier PGA are each set to the highest stage; the step of the voltage control amplifier VCA is set to 0dB.
4. The system for testing electronic noise and interference of ultrasonic diagnostic equipment according to claim 1, wherein the cut-off frequency point of the low-pass filter is the upper limit of the system bandwidth.
5. The system for testing electronic noise and interference of ultrasonic diagnostic equipment according to claim 2, wherein the number of the AD data points collected in the AD data collecting unit is 1 kilo point or more.
6. The system for testing electronic noise and interference of ultrasonic diagnostic equipment according to claim 2, wherein the AD data acquisition unit is further configured to perform a full-point fourier transform FFT on the number of acquired AD data points.
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