Device and method for reducing moving noise of fetus-voice meter probe

Abstract

The invention discloses a device and a method for reducing moving noise of a fetus-voice meter probe. The device for reducing the moving noise of the fetus-voice meter probe comprises an ultrasonic transmitting module, an ultrasonic receiving module and at least one three-axis sensor which are fixedly arranged on the fetus-voice meter probe, the fetus-voice meter further comprises a modulation-demodulation module, a band-pass filtering module, a control processing module and a sound playing module. The three-axis sensor monitors the motion condition of the fetus-voice meter probe in real time. The control processing module is combined with the band-pass filtering module and the three-axis sensor to transmit signals to carry out corresponding filtering and noise reduction processing and generate final digital signals; and the sound playing module converts the final digital signal into audio information for playing operation. The motion condition of the fetus-voice meter probe is monitored in real time through the three-axis sensor, then filtering and noise reduction operation is conducted through the control processing module, and the problem that monitoring is affected by noise generated when an existing fetus-voice meter probe moves is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fetal heart rate monitor noise reduction, and in particular to a device and method for reducing the noise of a fetal heart rate monitor probe movement. Background Art

[0002] Fetal heart rate and fetal heart sounds are important indicators for fetal health monitoring. Both of them can reflect the heart function of the fetus and are closely related to the oxygen supply status of the fetus and the entanglement of the umbilical cord. At present, the existing methods for detecting fetal heart rate and fetal heart sounds usually use ultrasonic Doppler fetal heart rate monitors. Ultrasonic Doppler fetal heart rate monitors actively emit ultrasonic waves to act on the fetal heart, use the Doppler effect of ultrasonic waves to obtain fetal heart beat information, calculate the fetal heart rate and monitor fetal heart sounds after signal processing. In traditional fetal heart monitoring, when the fetal heart rate monitor probe moves on the pregnant woman's abdomen, it will produce more obvious noise, which will seriously affect the clarity and accuracy of the fetal heart sound; this noise not only interferes with the doctor and the pregnant woman's monitoring of the fetal heart sound, but also may cover up important health information, leading to misdiagnosis or missed diagnosis; therefore, a device and method for reducing the noise of the fetal heart rate monitor probe movement is provided to solve the above problems. Summary of the invention

[0003] One of the purposes of the present invention is to provide a device and method for reducing the noise of a fetal heart rate monitor probe when it moves, so as to solve the problem that the noise generated by the existing fetal heart rate monitor probe when it moves affects monitoring.

[0004] The device and method for reducing the noise of the fetal heart rate monitor probe movement of the present invention can be realized by the following technical solutions:

[0005] The present invention provides a device for reducing the moving noise of a fetal heart rate monitor probe, comprising an ultrasonic transmitting module, which is fixedly arranged on the fetal heart rate monitor probe, and the ultrasonic transmitting module transmits an ultrasonic signal; an ultrasonic receiving module, which is fixedly arranged on the fetal heart rate monitor probe, and the ultrasonic receiving module receives an ultrasonic reflection signal; a modulation and demodulation module, which mixes the amplified ultrasonic reflection signal with the local oscillation signal emitted by the ultrasonic transmitting module; a bandpass filtering module, which filters the mixed high-frequency local oscillation signal and allows low-frequency signals to pass; at least one three-axis sensor, which is fixedly arranged on the fetal heart rate monitor probe, and the three-axis sensor monitors the movement status of the fetal heart rate monitor probe in real time; a control processing module, which performs corresponding filtering and noise reduction processing on the signals transmitted by the bandpass filtering module and the three-axis sensor and generates a final digital signal; and a sound playing module, which converts the final digital signal processed by the control processing module into audio information for playing.

[0006] In one embodiment, the ultrasonic transmitting module includes a high-frequency vibration circuit, a power amplifier and an ultrasonic transmitting chip; the high-frequency vibration circuit can generate a high-frequency signal; the power amplifier amplifies the generated high-frequency signal, and the amplified high-frequency signal drives the ultrasonic transmitting chip to form an ultrasonic beam.

[0007] In one embodiment, the modem module mixes the received ultrasonic transmission signal with the local oscillator signal transmitted by the ultrasonic transmission module to generate two frequency components: one is a signal with twice the local oscillator frequency, and the other is a Doppler frequency deviation signal; the bandpass filter module filters out the signal with twice the local oscillator frequency and only allows the Doppler frequency deviation signal, which contains relevant information about the fetal heartbeat.

[0008] In one embodiment, when the three-axis sensor detects the movement of the fetal heart rate monitor probe, the three-axis sensor generates accelerations in the X, Y, and Z directions, which are respectively denoted as a and x 、a y 、a z , the acceleration in the moving direction is the vector sum a of the accelerations of the three axes:

[0009]

[0010] When the fetal heart rate monitor probe starts to move from rest, its moving speed is:

[0011] v i (t) = ∫a i (t)dt

[0012] Its displacement is:

[0013] s i (t) = ∫v i (t)dt

[0014] The speed and displacement of the fetal heart rate monitor probe can be calculated through the acceleration of the fetal heart rate monitor probe.

[0015] In one embodiment, the three-axis sensor is fixed on a circuit board or a shell in a fetal heart rate monitor probe.

[0016] In one embodiment, the control processing module includes an analog-to-digital converter, and the Doppler frequency deviation signal of the bandpass filtering module is sampled by the analog-to-digital converter to convert the analog signal into a digital signal.

[0017] In one embodiment, the control processing module calculates the intensity of movement of the fetal heart rate monitor probe based on the acceleration, velocity and displacement information detected by the three-axis sensor when the fetal heart rate monitor probe moves, and performs corresponding noise reduction processing on the Doppler frequency deviation signal according to the movement intensity of the fetal heart rate monitor probe.

[0018] In one embodiment, the control processing module further includes an adaptive filter, and the adaptive filter dynamically adjusts its parameters according to the noise characteristics generated by the movement of the fetal heart rate monitor probe.

[0019] In one embodiment, the sound playback module includes a speaker or an earphone interface, which can automatically adjust the gain.

[0020] The present invention provides a method for reducing the moving noise of a fetal heart rate monitor probe, which is applied to any of the above-mentioned devices for reducing the moving noise of a fetal heart rate monitor probe, and specifically comprises the following steps:

[0021] S1, the ultrasonic transmitting module transmits an ultrasonic signal;

[0022] S2, the ultrasonic receiving module receives the reflected ultrasonic signal;

[0023] S3, the modulation and demodulation module mixes the ultrasonic reflection signal received by the ultrasonic receiving module with the local oscillation signal transmitted by the ultrasonic transmitting module to generate a high-frequency local oscillation signal and a low-frequency Doppler frequency deviation signal;

[0024] S4, the bandpass filter module performs filtering operation on the high-frequency local oscillator signal, and transmits the low-frequency Doppler frequency deviation signal to the control processing module for analysis and calculation processing; at the same time, the three-axis sensor monitors the movement of the fetal heart rate monitor probe in real time, and transmits the monitoring signal to the control processing module for analysis and calculation processing;

[0025] S5, the control processing module combines the transmission signals of the bandpass filter module and the three-axis sensor to perform corresponding filtering and noise reduction processing and generate a final digital signal, and then converts the digital signal into audio information through the sound playing module to play the fetal heart sound.

[0026] Compared with the prior art, the device and method for reducing the noise of the fetal heart rate monitor probe movement of the present invention have the following beneficial effects:

[0027] The present invention discloses a device and method for reducing the moving noise of a fetal heart rate monitor probe. The device and method mix an ultrasonic reflection signal and a local oscillator signal emitted by an ultrasonic transmission module through a modulation and demodulation module to generate a high-frequency local oscillator signal and a low-frequency Doppler frequency deviation signal. The bandpass filter module performs a filtering operation on the high-frequency local oscillator signal, and transmits the low-frequency Doppler frequency deviation signal to a control processing module for analysis and calculation processing. At the same time, a three-axis sensor monitors the movement of the fetal heart rate monitor probe in real time, and transmits the monitoring signal to the control processing module for analysis and calculation processing. The control processing module performs corresponding filtering and noise reduction processing on the transmission signal of the bandpass filter module and the three-axis sensor and generates a final digital signal, and then converts the digital signal into audio information through a sound playback module to play the fetal heart sound, thereby largely solving the problem that the noise generated by the existing fetal heart rate monitor probe when moving affects the monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a connection schematic diagram of a device for reducing the noise of a fetal heart rate monitor probe movement according to the present invention;

[0030] Figure 2 A flow chart of a method for reducing the noise of a fetal heart rate monitor probe movement according to the present invention.

[0031] Markings in the figure: 11, ultrasonic transmitting module; 12, ultrasonic receiving module; 13, modulation and demodulation module; 14, bandpass filtering module; 15, three-axis sensor; 16, control processing module; 17, sound playing module. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figure 1 As shown in the figure, a device for reducing the moving noise of a fetal heart rate monitor probe of the present invention mainly comprises an ultrasonic transmitting module 11, an ultrasonic receiving module 12, a modulation and demodulation module 13, a bandpass filtering module 14, at least one three-axis sensor 15, a control processing module 16 and a sound playing module 17; the ultrasonic transmitting module 11 and the ultrasonic receiving module 12 are respectively fixedly arranged on the fetal heart rate monitor probe, and the ultrasonic transmitting module 11 transmits ultrasonic signals to the abdomen of a pregnant woman, and these ultrasonic signals will generate ultrasonic reflection signals after encountering the fetal heart or other reflection objects, and the ultrasonic reflection signals will be used to detect the heartbeat of the fetus; the ultrasonic receiving module 12 receives the ultrasonic reflection signals, and transmits the ultrasonic reflection signals to the modulation and demodulation module 13 after amplifying them. The modulation module 13 and the local oscillator signal emitted by the ultrasonic transmitting module 11 are mixed; the bandpass filtering module 14 filters the mixed high-frequency signal and allows the low-frequency signal to pass, and the low-frequency signal passed is transmitted to the control processing module 16; at least one three-axis sensor 15 is fixedly arranged on the fetal heart rate monitor probe, which actually monitors the movement status of the fetal heart rate monitor probe in real time, and transmits the movement signal related to the fetal heart rate monitor probe to the control processing module 16; the control processing module 16 combines the signals transmitted by the bandpass filtering module 14 and the three-axis sensor 15 to perform corresponding filtering and noise reduction processing and generate a final digital signal; the sound playing module 17 converts the final digital signal processed by the control processing module 16 into audio information for playing operation.

[0035] Among them, the ultrasonic transmitting module 11 includes a high-frequency vibration circuit, a power amplifier and an ultrasonic transmitting chip; the high-frequency vibration circuit can generate a high-frequency signal of 1MHz to 5MHz; the power amplifier amplifies the generated high-frequency signal, and the amplified high-frequency signal drives the ultrasonic transmitting chip to form an ultrasonic beam, which is then transmitted to the pregnant woman's abdomen. These ultrasonic signals will generate ultrasonic reflection signals after encountering the fetal heart or other reflectors, and the ultrasonic reflection signals will be used to detect the fetal heartbeat.

[0036] Among them, the ultrasonic receiving module 12 includes an ultrasonic receiving chip and a power amplifier; the ultrasonic signal emitted by the ultrasonic transmitting module 11 will be received by the ultrasonic receiving chip after being reflected by the fetal heart or other reflective objects; the signal received by the ultrasonic receiving chip is usually very weak and needs to be amplified by a power amplifier for subsequent processing and analysis; the amplified ultrasonic reflection signal will be sent to the modem module 13 for further processing.

[0037] The modulation and demodulation module 13 mixes the received amplified ultrasonic transmission signal with the local oscillator signal transmitted by the ultrasonic transmission module 11, that is, multiplies the two. This mixing process will generate two frequency components: one is a twice local oscillator frequency signal, and the other is a Doppler frequency deviation signal.

[0038] Assume that the local oscillator signal emitted by the ultrasonic transmitting module 11 is sinωt, and the frequency deviation frequency generated by the fetal heartbeat movement is ω s , then the received ultrasonic signal containing Doppler frequency deviation is sin(ω+ω s )t, and multiplying the two gives:

[0039]

[0040] It can be seen from the above formula that after the received signal with Doppler frequency deviation is multiplied by the transmitted local oscillator signal, a signal with twice the local oscillator frequency and a signal with only Doppler frequency deviation are obtained. The local oscillator signal frequency is very high, while the Doppler frequency deviation signal is only a few hundred Hz. After the generated signal with twice the local oscillator frequency and the signal with Doppler frequency deviation pass through the bandpass filter module 14, the bandpass filter module 14 can filter out the signal with twice the local oscillator frequency, leaving only the Doppler frequency deviation signal:

[0041]

[0042] The Doppler frequency deviation signal contains relevant information about the fetal heart beat.

[0043] Among them, when the three-axis sensor 15 detects the movement of the fetal heart rate monitor probe, the three-axis sensor 15 can detect the acceleration of the fetal heart rate monitor probe in the three directions of X, Y, and Z in real time. These acceleration information can be used to calculate the movement speed and displacement of the fetal heart rate monitor probe; at the same time, when the fetal heart rate monitor probe is moving, the ultrasonic receiving module 12 will receive a strong ultrasonic Doppler echo, thereby forming a strong pseudo fetal heart sound signal. If these pseudo fetal heart sound signals are not processed and directly played out, they will produce strong noise, causing great interference to the monitoring of fetal heart sound. During the movement of the fetal heart rate monitor probe, the three-axis sensor 15 will generate acceleration in the three directions of X, Y, and Z, which are respectively recorded as a and z. x 、a y 、a z, the acceleration in the moving direction is the vector sum a of the accelerations of the three axes:

[0044]

[0045] When the fetal heart rate monitor probe starts to move from rest, its moving speed is:

[0046] v i (t) = ∫a i (t)dt

[0047] Its displacement is:

[0048] s i (t) = ∫v i (t)dt

[0049] That is, the acceleration of the fetal heart rate monitor probe can be used to calculate the speed and displacement of the fetal heart rate monitor probe. The greater the speed and displacement of the fetal heart rate monitor probe, the greater the noise signal intensity generated; the greater the noise generated by the movement of the fetal heart rate monitor probe, the greater the noise reduction amplitude of the output sound.

[0050] In this embodiment, the three-axis sensor 15 can be fixed on a circuit board inside the fetal heart rate monitor probe, or can be fixed on the shell of the fetal heart rate monitor probe, as long as the three-axis sensor 15 moves synchronously with the fetal heart rate monitor probe; the number of the three-axis sensor 15 can be one or more.

[0051] Among them, the control processing module 16 includes an analog-to-digital converter, and the Doppler frequency deviation signal of the bandpass filter module 14 is sampled by an analog-to-digital converter (ADC) to convert the analog signal into a digital signal, so as to perform filtering and noise reduction on the Doppler frequency deviation signal; at the same time, the control processing module 16 calculates the intensity of the movement of the fetal heart rate monitor probe based on the acceleration, velocity and displacement information detected by the three-axis sensor 15 when the fetal heart rate monitor probe moves; according to the movement intensity of the fetal heart rate monitor probe, the Doppler frequency deviation signal is subjected to corresponding noise reduction processing; the noise reduction processing can be achieved through an adaptive filter, which dynamically adjusts its parameters according to the noise characteristics generated by the movement of the fetal heart rate monitor probe to minimize the impact of noise on the fetal heart sound signal.

[0052] Among them, the sound playback module 17 includes a speaker or headphone interface, which can convert the processed digital signal into an audio signal for doctors and pregnant women to monitor; the sound playback module 17 can automatically adjust the gain to avoid excessive or insufficient sounds, provide clear and soft fetal heart sound signals, and minimize noise interference.

[0053] See also Figure 2 As shown, the specific steps of a method for reducing the movement noise of a fetal heart rate monitor probe of the present invention include:

[0054] S1, the ultrasonic transmitting module 11 transmits an ultrasonic signal;

[0055] S2, the ultrasonic receiving module 12 receives the reflected ultrasonic signal;

[0056] S3, the modulation and demodulation module 13 mixes the ultrasonic reflection signal received by the ultrasonic receiving module 12 and the local oscillation signal emitted by the ultrasonic transmitting module 11 to generate a high-frequency local oscillation signal and a low-frequency Doppler frequency deviation signal;

[0057] S4, the bandpass filter module 14 performs filtering operation on the high-frequency local oscillator signal, and transmits the low-frequency Doppler frequency deviation signal to the control processing module 16 for analysis and calculation processing; at the same time, the three-axis sensor 15 monitors the movement of the fetal heart rate monitor probe in real time, and transmits the monitoring signal to the control processing module 16 for analysis and calculation processing;

[0058] S5, the control processing module 16 performs corresponding filtering and noise reduction processing on the transmission signals of the bandpass filter module 14 and the three-axis sensor 15 and generates a final digital signal, and then converts the digital signal into audio information through the sound playing module 17 to play the fetal heart sound.

[0059] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A device for reducing the noise of a fetal heart rate monitor probe movement, characterized in that: include: An ultrasonic transmitting module, which is fixedly arranged on the fetal heart rate monitor probe, and transmits ultrasonic signals; An ultrasonic receiving module, which is fixedly arranged on the fetal heart rate monitor probe, and receives ultrasonic reflection signals; A modulation and demodulation module, which mixes the amplified ultrasonic reflection signal with the local oscillation signal emitted by the ultrasonic emission module; A bandpass filter module, which filters the mixed high-frequency local oscillator signal and allows the low-frequency signal to pass; At least one three-axis sensor, which is fixedly mounted on the fetal heart rate monitor probe, and the three-axis sensor monitors the movement of the fetal heart rate monitor probe in real time; A control processing module, which combines the signals transmitted by the bandpass filtering module and the three-axis sensor to perform corresponding filtering and noise reduction processing and generate a final digital signal; The sound playing module converts the final digital signal processed by the control processing module into audio information for playing operation.

2. The device for reducing the noise of a fetal heart rate monitor probe movement according to claim 1, characterized in that: The ultrasonic transmitting module includes a high-frequency vibration circuit, a power amplifier and an ultrasonic transmitting chip; the high-frequency vibration circuit can generate a high-frequency signal; the power amplifier amplifies the generated high-frequency signal, and the amplified high-frequency signal drives the ultrasonic transmitting chip to form an ultrasonic beam.

3. The device for reducing the noise of a fetal heart rate monitor probe movement according to claim 1, characterized in that: The modulation and demodulation module mixes the received ultrasonic transmission signal with the local oscillator signal transmitted by the ultrasonic transmission module to generate two frequency components: one is a signal with twice the local oscillator frequency, and the other is a Doppler frequency deviation signal; the bandpass filtering module filters out the signal with twice the local oscillator frequency and only allows the Doppler frequency deviation signal, which contains relevant information about the fetal heartbeat.

4. The device for reducing the noise of a fetal heart rate monitor probe movement according to claim 1, characterized in that: When the three-axis sensor detects the movement of the fetal heart rate monitor probe, the three-axis sensor will generate acceleration in the X, Y, and Z directions, which are respectively denoted as a x 、a y 、a z , the acceleration in the moving direction is the vector sum a of the accelerations of the three axes: When the fetal heart rate monitor probe starts to move from rest, its moving speed is: v i (t)=∫a i (t)dt Its displacement is: s i (t)=∫v i (t)dt The speed and displacement of the fetal heart rate monitor probe can be calculated through the acceleration of the fetal heart rate monitor probe.

5. The device for reducing the noise of the fetal heart rate monitor probe movement according to claim 4, characterized in that: The three-axis sensor is fixed on a circuit board or a shell in the fetal heart rate monitor probe.

6. The device for reducing the noise of a fetal heart rate monitor probe movement according to claim 1, characterized in that: The control processing module includes an analog-to-digital converter, and the Doppler frequency deviation signal of the bandpass filtering module is sampled by the analog-to-digital converter to convert the analog signal into a digital signal.

7. The device for reducing the noise of the fetal heart rate monitor probe movement according to claim 6, characterized in that: The control processing module calculates the intensity of the movement of the fetal heart rate monitor probe based on the acceleration, velocity and displacement information detected by the three-axis sensor when the fetal heart rate monitor probe moves, and performs corresponding noise reduction processing on the Doppler frequency deviation signal according to the movement intensity of the fetal heart rate monitor probe.

8. The device for reducing the noise of a fetal heart rate monitor probe movement according to claim 7, characterized in that: The control processing module also includes an adaptive filter, which dynamically adjusts its parameters according to the noise characteristics generated by the movement of the fetal heart rate monitor probe.

9. The device for reducing the noise of a fetal heart rate monitor probe movement according to claim 1, characterized in that: The sound playing module includes a speaker or an earphone interface, which can automatically adjust the gain.

10. A method for reducing the noise of a fetal heart rate monitor probe when it moves, which is applied to the device for reducing the noise of a fetal heart rate monitor probe when it moves according to any one of claims 1 to 9, characterized in that: The specific steps include: S1, the ultrasonic transmitting module transmits an ultrasonic signal; S2, the ultrasonic receiving module receives the reflected ultrasonic signal; S3, the modulation and demodulation module mixes the ultrasonic reflection signal received by the ultrasonic receiving module with the local oscillation signal transmitted by the ultrasonic transmitting module to generate a high-frequency local oscillation signal and a low-frequency Doppler frequency deviation signal; S4, the bandpass filter module performs filtering operation on the high-frequency local oscillator signal, and transmits the low-frequency Doppler frequency deviation signal to the control processing module for analysis and calculation processing; at the same time, the three-axis sensor monitors the movement of the fetal heart rate monitor probe in real time, and transmits the monitoring signal to the control processing module for analysis and calculation processing; S5, the control processing module combines the transmission signals of the bandpass filter module and the three-axis sensor to perform corresponding filtering and noise reduction processing and generate a final digital signal, and then converts the digital signal into audio information through the sound playing module to play the fetal heart sound.

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