CN113576515A

CN113576515A - Digital stethoscope

Info

Publication number: CN113576515A
Application number: CN202110662810.3A
Authority: CN
Inventors: 张晓隆
Original assignee: Second Affiliated Hospital and Yuying Childrens Hospital of Wenzhou Medical University
Current assignee: Second Affiliated Hospital and Yuying Childrens Hospital of Wenzhou Medical University
Priority date: 2021-06-15
Filing date: 2021-06-15
Publication date: 2021-11-02

Abstract

The invention provides a digital stethoscope, which comprises a sound sensor, an analog-to-digital converter, a controller, an audio codec and a playing component, wherein the sound sensor, the analog-to-digital converter, the controller, the audio codec and the playing component are connected in sequence; the acoustic sensor acquires a human heart sound signal and converts the human heart sound signal into an analog electrical signal; the analog-to-digital converter converts the analog electric signal into a digital electric signal; the controller carries out filtering and denoising processing on the digital electric signal to form a heart sound signal waveform, and after the qualification of the heart sound signal waveform is judged, the heart sound signal waveform and the judgment result are combined into an auscultation result represented by the digital signal; the audio codec converts the auscultation result represented by the digital signal into an analog audio signal; the playing component plays the analog audio signal. The invention can not only objectively judge and display auscultation results, but also realize remote real-time monitoring.

Description

Digital stethoscope

Technical Field

The invention relates to the technical field of clinical medical treatment, in particular to a digital stethoscope.

Background

Human physiological signals are important indexes for clinical diagnosis of diseases, and when the monitored value is greatly different from the normal range, pathological changes are likely to exist. Therefore, it is necessary to monitor physiological signals of the human body.

Currently, a stethoscope, a physiological signal monitoring device commonly used for diagnosing diseases by monitoring acoustic signals of the thoracic cavity of a human body, is mainly composed of a stethoscope head, a listening rubber tube and earplugs. The stethoscope converts sound into mechanical vibration after a film on the surface of the stethoscope head is contacted with a human body, and then the mechanical vibration is transmitted to two ears of a doctor through a closed rubber tube, so that the sound in the human body can be clearly heard.

However, although the existing stethoscope is simple in structure principle and convenient to use, auscultation results depend on the clinical experience of doctors, cannot be objectively judged and displayed, has high requirements on the surrounding diagnosis and treatment environment, and cannot realize long-distance real-time monitoring due to the limitation of connecting pieces.

Therefore, there is a need for a digital stethoscope that can not only objectively determine and display auscultation results, but also realize remote real-time monitoring.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide a digital stethoscope, which not only can objectively determine and display auscultation results, but also can realize remote real-time monitoring.

In order to solve the above technical problem, an embodiment of the present invention provides a digital stethoscope, including a sound sensor, an analog-to-digital converter, a controller, an audio codec, and a playing component, which are connected in sequence; wherein the content of the first and second substances,

the acoustic sensor is used for acquiring a human heart sound signal and converting the human heart sound signal into an analog electric signal;

the analog-to-digital converter is used for converting the analog electric signal into a digital electric signal;

the controller is used for forming a heart sound signal waveform after the digital electric signal is subjected to filtering and denoising processing, judging the qualification of the heart sound signal waveform, and further combining the heart sound signal waveform and the judgment result into an auscultation result represented by a digital signal;

the audio codec is used for converting the auscultation result represented by the digital signal into an analog audio signal;

the playing component is used for playing the analog audio signal.

Wherein, still include: an amplifier and/or a filtering noise reducer; the amplifier is arranged between the audio codec and the playing component and is used for amplifying the analog audio signal; the filtering noise reducer is arranged between the audio codec and the playing component and is used for filtering and denoising the simulated audio signal.

The amplifier comprises a passive high-pass filter circuit, an amplification chip AD8226 and a four-order voltage-controlled Sallen-Key structure type band-pass filter which are sequentially connected; wherein the content of the first and second substances,

the passive high-pass filter circuit is composed of a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2;

the band-pass filter with the four-order voltage-controlled Sallen-Key structure is formed by connecting two filters with the model number of AD823A in series.

The filtering noise reducer comprises a first resistor R1, a second resistor R2, a third resistor R3, a feedback resistor R5, a current-limiting resistor R6, a feedback resistor R7, a first capacitor C1, a second capacitor C2, a filter capacitor C4, a filter capacitor C5, a first amplifier IC1 and a second amplifier IC 2; wherein the content of the first and second substances,

the output end of the audio codec is connected in series with the first resistor R1, and is filtered by a first capacitor C1 and a second capacitor C2 which are connected in parallel, and is correspondingly connected to two output ends of the first amplifier IC1 after being connected in parallel with a divider resistor formed by a second resistor R2 and a third resistor R3; the inverting input end of the first amplifier IC1 is connected to the output end of the first amplifier IC1 through the feedback resistor R5, and the non-inverting input end of the first amplifier IC1 is connected to the filter capacitor C4 and is also connected to the non-inverting input end of the second amplifier IC 2; the output end of the first amplifier IC1 is connected to the inverting input end of the second amplifier IC2 after being filtered by the third capacitor C3 and the current limiting resistor R6; the inverting input terminal of the second amplifier IC2 is connected to the output terminal of the second amplifier IC2 through the feedback resistor R7, and the output terminal of the second amplifier IC2 is connected to the playing component through the filter capacitor C5.

Wherein, still include: a display module; the display module is connected with the controller and used for displaying the auscultation result.

Wherein, still include: a wireless communication module; the wireless communication module is connected with the controller and used for reporting the auscultation result to a designated upper computer so as to realize online remote real-time monitoring of the upper computer.

The wireless communication module is one or a combination of a WIFI submodule, a 4G submodule, a 5G submodule, a Bluetooth submodule and a ZigBee submodule.

Wherein the playing component comprises a microphone and a loudspeaker.

Wherein the loudspeaker is a mono loudspeaker or a binaural loudspeaker.

The heart sound signal carries at least one of pulse information, SpO2 information, finger temperature, forehead temperature, stethoscope reading and otoscope reading.

The embodiment of the invention has the following beneficial effects:

1. the auscultation method comprises the steps of obtaining a human heart sound signal based on a sound sensor, converting the human heart sound signal into an analog electric signal, converting the analog electric signal into a digital electric signal through an analog-to-digital converter, sending the digital electric signal into a controller for filtering and denoising, forming a heart sound signal waveform, judging the qualification, obtaining an auscultation result represented by the digital signal by combining the heart sound signal waveform and the judgment result, further converting the heart sound signal waveform into an analog audio signal through an audio codec, sending the analog audio signal into a playing component for playing, and accordingly achieving objective judgment of the auscultation result without depending on experience judgment of medical staff;

2. the invention also displays auscultation results based on the display module, thereby realizing real-time display of the auscultation results;

3. the invention also reports auscultation results to a designated upper computer based on the wireless communication module so as to realize online remote real-time monitoring of the upper computer.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is within the scope of the present invention for those skilled in the art to obtain other drawings based on the drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a digital stethoscope according to an embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of the amplifying circuit of FIG. 1;

fig. 3 is a circuit connection diagram of the filtering noise reducer in fig. 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1, a digital stethoscope proposed in the embodiment of the present invention includes an acoustic sensor 1, an analog-to-digital converter 2, a controller 3, an audio codec 4 and a playing component 5, which are connected in sequence; wherein the content of the first and second substances,

the acoustic sensor 1 is used for acquiring a human heart sound signal and converting the human heart sound signal into an analog electric signal; the acoustic sensor 1 not only collects a heart sound signal, but also can carry at least one of pulse information, SpO2 information, finger temperature, forehead temperature, stethoscope reading and otoscope reading on the heart sound signal so as to facilitate remote analysis;

an analog-to-digital converter 2 for converting the analog electrical signal into a digital electrical signal;

the controller 3 is used for performing filtering and denoising processing on the digital electric signal to form a heart sound signal waveform, judging the qualification of the heart sound signal waveform, and further combining the heart sound signal waveform and the judgment result into an auscultation result represented by the digital signal; it should be noted that the qualification judgment of the heart sound signal waveform is realized by judging the positions of the upper and lower limits of the waveform in the specific process, for example, if the peak of the waveform exceeds the upper limit or the trough exceeds the lower limit, the heart sound signal waveform is determined to be unqualified; otherwise, if the wave crest and the wave trough of the waveform are positioned between the upper limit and the lower limit, the waveform of the heart sound signal is determined to be qualified;

an audio codec 4 for converting the auscultation result represented in the digital signal into an analog audio signal;

a playing component 5 for playing the analog audio signal; the playing component 4 includes a microphone and a speaker, and the speaker is a mono speaker or a binaural speaker.

In an embodiment of the present invention, the digital stethoscope further includes: an amplifier 6 and/or a filtering noise reducer 7; the amplifier 6 is arranged between the audio codec 4 and the playing component 5, and is used for amplifying an analog audio signal; the filtering noise reducer 7 is disposed between the audio codec 4 and the playing component 5, and is configured to filter and denoise the analog audio signal. It should be noted that if both the amplifier 6 and the filter noise reducer 7 are included, they may be connected in series, and it is preferable that the filter noise reducer 7 is connected in series at the output of the amplifier 6.

It can be understood that, among the acoustic sensor 1, the analog-to-digital converter 2, and the controller 3, a corresponding amplifier 6 may also be provided, which may be designed specifically with reference to practical applications and will not be described herein again.

In one embodiment, as shown in fig. 2, the amplifier 5 includes a passive high-pass filter circuit, an amplifying chip AD8226, and a band-pass filter of a fourth-order voltage-controlled Sallen-Key structure type, which are connected in sequence; wherein the content of the first and second substances,

Namely, the amplification chip AD8226 is selected to amplify the digital heart sound signal, and the signal gain is set to 495; the capacitors C1 and C2 isolate direct-current differential mode voltage in output signals of the sensor chip, meanwhile, the resistors R1 and R2 and the capacitors C1 and C2 form a passive high-pass filter, and first heart sounds and second heart sounds with main frequencies distributed at 20 Hz-600 Hz are collected according to the characteristics of the heart sounds. An AD823A filter is selected to build a common four-order voltage-controlled Sallen-Key structure type band-pass filter, the bandwidth is 20 Hz-1 kHz, and the gain in a pass band is zero.

In one embodiment, as shown in fig. 3, the filtering noise reducer 7 includes a first resistor R1, a second resistor R2, a third resistor R3, a feedback resistor R5, a current limiting resistor R6, a feedback resistor R7, a first capacitor C1, a second capacitor C2, a filtering capacitor C4, a filtering capacitor C5, a first amplifier IC1, and a second amplifier IC 2; wherein the content of the first and second substances,

the output end of the audio codec 4 is connected in series with a first resistor R1, and is filtered by a first capacitor C1 and a second capacitor C2 which are connected in parallel, and is respectively and correspondingly connected to two output ends of the first amplifier IC1 after a divider resistor formed by connecting a second resistor R2 and a third resistor R3 in parallel; the inverting input end of the first amplifier IC1 is connected with the output end of the first amplifier IC1 through a feedback resistor R5, and the non-inverting input end of the first amplifier IC1 is connected with the filter capacitor C4 and is also connected with the non-inverting input end of the second amplifier IC 2; the output end of the first amplifier IC1 is filtered by a third capacitor C3 and is connected to the inverting input end of the second amplifier IC2 after passing through a current limiting resistor R6; the inverting input terminal of the second amplifier IC2 is connected to the output terminal of the second amplifier IC2 through the feedback resistor R7, and the output terminal of the second amplifier IC2 is connected to the playing component 5 through the filter capacitor C5.

In an embodiment of the present invention, the digital stethoscope further includes: a display module 8; the display module 8 is connected to the controller 3 and is configured to display an auscultation result, so as to display the auscultation result in real time.

In an embodiment of the present invention, the digital stethoscope further includes: a wireless communication module 9; the wireless communication module 9 is connected to the controller 3, and is configured to report an auscultation result to a designated upper computer (not shown) so as to implement online remote real-time monitoring by the upper computer. The wireless communication module 9 is one or a combination of a WIFI sub-module, a 4G sub-module, a 5G sub-module, a bluetooth sub-module and a ZigBee sub-module.

It can be understood that the digital stethoscope is hand-held, integrated and portable, the components except the display module 8 are integrated on the circuit board and fixedly arranged in the shell, and the display module 8 (i.e. the display screen) is arranged in the center of the front surface of the shell; the display module 8 includes a display unit and an input unit, wherein the input unit is a key or a touch screen for inputting a control command to the controller 3. Once the collected heart sound signals are converted into analog voltage signals, the digital signals that control the analog-to-digital conversion are directly output through an audio jack after being digital-to-analog converted by the audio codec 4, and can be played back on a computer or a digital stethoscope. Meanwhile, the collected heart sound signals can be converted into digital signals, and then stored in the stethoscope or a removable non-volatile (NV) memory, such as an EEPROM or a flash memory, and can be played back through a speaker of the stethoscope when needed, and can also be transmitted to a computer for further analysis.

In an embodiment of the invention, the host computer is further capable of being coupled to a remote server and has at least one of an internet connection and a cellular connection. Wherein the content of the first and second substances,

and the remote server receives the heart sound signal waveform data from the upper computer. The remote server may also provide the professional with encrypted information from a preset database and stored heart sound signal oscillogram data. The remote server may access a preset database and initiate a mobile alert to the professional when an anomaly is found.

The remote server also includes a software program for the user to remotely conference with the professional, wherein the sensor data is submitted to the professional. The software program displays the user's corresponding sensor data.

The user can clearly see the waveform diagram of the heart sound signal on the app software, for example, the first heart sound is S1, the second heart sound is S2, the peak value of the normal human heart sound signal waveform S1 is significantly higher than that of S2, and the sound signals of S3 and S4 are weak. The interval between S1 and S2 is systolic, and the interval between S2 and the next S1 is diastolic. The time interval ratio is about 1: 2.

The embodiment of the invention has the following beneficial effects:

It should be noted that, in the above system embodiment, each included unit is only divided according to functional logic, but is not limited to the above division as long as the corresponding function can be implemented; in addition, specific names of the functional units are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present invention.

It will be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiments may be implemented by relevant hardware instructed by a program, and the program may be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A digital stethoscope is characterized by comprising a sound sensor, an analog-to-digital converter, a controller, an audio codec and a playing component which are connected in sequence; wherein the content of the first and second substances,

the playing component is used for playing the analog audio signal.

2. The digital stethoscope of claim 1, further comprising: an amplifier and/or a filtering noise reducer; the amplifier is arranged between the audio codec and the playing component and is used for amplifying the analog audio signal; the filtering noise reducer is arranged between the audio codec and the playing component and is used for filtering and denoising the simulated audio signal.

3. The digital stethoscope according to claim 2, wherein said amplifier comprises a passive high-pass filter circuit, an amplifying chip AD8226 and a band-pass filter of the fourth-order voltage-controlled Sallen-Key structure type connected in series; wherein the content of the first and second substances,

4. The digital stethoscope of claim 2, wherein said filtering noise reducer comprises a first resistor R1, a second resistor R2, a third resistor R3, a feedback resistor R5, a current limiting resistor R6, a feedback resistor R7, a first capacitor C1, a second capacitor C2, a filter capacitor C4, a filter capacitor C5, a first amplifier IC1, and a second amplifier IC 2; wherein the content of the first and second substances,

5. The digital stethoscope according to any one of claims 1-4, further comprising: a display module; the display module is connected with the controller and used for displaying the auscultation result.

6. The digital stethoscope of claim 5, further comprising: a wireless communication module; the wireless communication module is connected with the controller and used for reporting the auscultation result to a designated upper computer so as to realize online remote real-time monitoring of the upper computer.

7. The digital stethoscope according to claim 6, wherein said wireless communication module is one or more of a WIFI sub-module, a 4G sub-module, a 5G sub-module, a Bluetooth sub-module, and a ZigBee sub-module.

8. The digital stethoscope of claim 7, wherein said playback component comprises a microphone and a speaker.

9. The digital stethoscope of claim 8, wherein said speaker is a mono speaker or a binaural speaker.

10. The digital stethoscope of claim 9, wherein said heart sound signals carry at least one of pulse information, SpO2 information, finger temperature, forehead temperature, stethoscope readings, and otoscope readings.