CN118680530A - A system and method for optical fiber detection - Google Patents

Abstract

The present application provides a system and method for optical fiber detection, which can be applied to vital signs detection scenarios, especially dynamic vital signs detection scenarios. The system includes a sensing optical path, a conversion module and a processing module, wherein the sensing optical path is used to receive an optical signal, a first vibration signal generated by the user due to breathing and heartbeat, and a second vibration signal existing in the detection environment, and divide the optical signal into a first optical signal, a second optical signal and a reference optical signal, and generate a third optical signal according to the first optical signal, the first vibration signal and the reference optical signal, and generate a fourth optical signal according to the second optical signal, the second vibration signal and the reference optical signal. The conversion module and the processing module generate the user's vital signs signal according to the third optical signal and the fourth optical signal. In the system disclosed in the present application, two signals share a reference signal, thereby eliminating environmental noise in the detection process and effectively improving the quality of signal acquisition.

Description

A system and method for optical fiber detection

Technical Field

The present application relates to the field of optical measurement, and more particularly, to a system and method for optical fiber detection.

Background Art

With the rapid development of the healthcare industry, vital signs detection technology has been widely popularized. Vital signs detection technology mainly detects human breathing, heart rate and other vital signs, thereby helping people to achieve real-time physical status detection and analysis.

Currently, the commonly used vital signs detection technologies in the industry mainly include electrocardiogram (ECG), photoplethysmography (PPG) and ballistocardiography (BCG). Among them, ECG and PPG both use lasers to detect the changes in light energy caused by the expansion and contraction of human capillaries, and can only detect human heart rate signals. In addition, ECG and PPG must be close to human skin, and their application scenarios are limited. BCG can use the vibrations generated by the expansion and contraction of the human aorta and breathing to achieve heart rate and breathing detection at the same time. It has received widespread attention in the industry and quickly became a research hotspot.

However, existing BCG detection technology is extremely susceptible to external interference and environmental noise (human activities, external vibrations), and is limited to measuring vital sign signals under static conditions, and cannot be applied to more complex scenarios.

Summary of the invention

The present application provides a system and method for optical fiber detection, which helps to suppress the influence of external interference on the detection process and improve the signal-to-noise ratio.

In the first aspect, a system for optical fiber detection is provided. The system includes a sensing optical path, a conversion module and a processing module. Among them: the light source is used to generate an optical signal; the sensing optical path is used to receive the optical signal, the first vibration signal generated by the user and the second vibration signal existing in the detection environment, divide the optical signal into a first optical signal, a second optical signal and a reference optical signal, generate a third optical signal according to the first optical signal, the first vibration signal and the reference optical signal, and generate a fourth optical signal according to the second optical signal, the second vibration signal and the reference optical signal. The conversion module is used to receive the third optical signal and convert the third optical signal into a first digital signal, and receive the fourth optical signal and convert the fourth optical signal into a second digital signal; the processing module is used to receive the first digital signal and the second digital signal, and demodulate the first digital signal and the second digital signal to obtain the user's vital sign signal.

In the system disclosed in the present application, two signals share a reference signal, thereby eliminating environmental noise during the detection process and effectively improving the quality of signal acquisition.

In combination with the first aspect, in some implementations of the first aspect, the sensing optical path includes a first coupler, a second coupler, a third coupler, a first optical fiber, and a second optical fiber, and the first optical fiber and the second optical fiber are arranged at different positions. The first coupler is used to receive an optical signal, and after dividing the optical signal into a first optical signal, a reference optical signal, and a second optical signal, the first optical signal is transmitted to the first optical fiber, the second optical signal is transmitted to the second optical fiber, and the reference optical signal is transmitted to the second coupler and the third coupler. The first optical fiber is used to receive a first vibration signal generated by a user, and the second optical fiber is used to receive a second vibration signal existing in the detection environment. The second coupler is used to receive a reference optical signal, a first optical signal, and a first vibration signal, and couples the reference optical signal, the first optical signal, and the first vibration signal into a third optical signal. The third coupler is used to receive a reference optical signal, a second optical signal, and a second vibration signal, and couples the reference optical signal, the second optical signal, and the second vibration signal into a fourth optical signal. In this way, by arranging two sensing optical fibers at different positions, one sensing optical fiber is used to receive a vibration signal generated by the user due to breathing and heartbeat, and the other sensing optical fiber is used to receive environmental noise, so that the environmental noise in the detection process can be eliminated, and the quality of signal acquisition can be effectively improved.

In combination with the first aspect, in certain implementations of the first aspect, the sensing optical path further includes a fourth coupler. The fourth coupler is used to divide the reference optical signal into the first reference optical signal and the second reference optical signal in equal proportion, and transmit the divided signals to the second coupler and the third coupler, respectively. The second coupler is specifically used to receive the first reference optical signal, the first optical signal, and the first vibration signal, and couple the first reference optical signal, the first optical signal, and the first vibration signal into the third optical signal. The third coupler is specifically used to receive the second reference optical signal, the second optical signal, and the second vibration signal, and couple the second reference optical signal, the second optical signal, and the second vibration signal into the fourth optical signal.

In combination with the first aspect, in some implementations of the first aspect, the sensing optical path further includes a third optical fiber, and the third optical fiber is used to transmit the reference optical signal from the first coupler to the fourth coupler.

In combination with the first aspect, in some implementations of the first aspect, the third optical fiber is disposed at the same position as the first optical fiber, or the third optical fiber is disposed at the same position as the second optical fiber.

In combination with the first aspect, in some implementations of the first aspect, the first optical fiber is a single-mode optical fiber, a few-mode optical fiber, a multi-mode optical fiber, or a hollow-core optical fiber. Correspondingly, the second optical fiber and the third optical fiber may also be single-mode optical fiber, a few-mode optical fiber, a multi-mode optical fiber, or a hollow-core optical fiber.

In combination with the first aspect, in some other implementations of the first aspect, the third optical fiber and the first optical fiber belong to different cores in the same multi-core optical fiber, or the third optical fiber and the second optical fiber belong to different cores in the same multi-core optical fiber.

In combination with the first aspect, in some implementations of the first aspect, the second coupler is connected to the fourth coupler via a fourth optical fiber, and the length of the first optical fiber is the sum of the lengths of the third optical fiber and the fourth optical fiber. In this way, the measurement accuracy can be guaranteed.

In combination with the first aspect, in certain implementations of the first aspect, the conversion module includes a first conversion module and a second conversion module, the first conversion module is used to receive a third optical signal and convert the third optical signal into a first digital signal; the second conversion module is used to receive a fourth optical signal and convert the fourth optical signal into a second digital signal.

In combination with the first aspect, in certain implementations of the first aspect, the first conversion module includes a photodetector and a digital-to-analog converter, the photodetector is used to receive a third optical signal and convert the third optical signal into a first electrical signal, and the digital-to-analog converter is used to receive the first electrical signal and convert the first electrical signal into a first digital signal. Correspondingly, the second conversion module may also include a photodetector and a digital-to-analog converter, the photodetector is used to receive a fourth optical signal and convert the fourth optical signal into a second electrical signal; the digital-to-analog converter is used to receive a second electrical signal and convert the second electrical signal into a second digital signal.

In combination with the first aspect, in other implementations of the first aspect, the number of the third optical signals is M, the number of the photodetectors is M, the number of the first electrical signals is M, the number of the digital-to-analog converters is M, M is a positive integer, and the third optical signal corresponds to the photodetectors, the first electrical signals, and the digital-to-analog converters one-to-one. Correspondingly, the number of the fourth optical signals is N, the number of the photodetectors is N, the number of the second electrical signals is N, the number of the digital-to-analog converters is N, N is a positive integer, and the fourth optical signal corresponds to the photodetectors, the second electrical signals, and the digital-to-analog converters one-to-one.

In combination with the first aspect, in certain implementations of the first aspect, the control module includes at least one of a digital signal processor (DSP), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a central processing unit (CPU), or a microcontroller unit (MCU).

In combination with the first aspect, in some implementations of the first aspect, the system may further include a light source, which may be a semiconductor fiber laser, for generating an optical signal.

In a second aspect, a method for optical fiber detection is provided. The method is performed by the optical fiber detection system described in the first aspect, and the method includes: receiving an optical signal, dividing the optical signal into a first optical signal, a reference optical signal, and a third optical signal, receiving a first vibration signal generated by a user and a second vibration signal existing in a detection environment; dividing the reference optical signal into a first reference optical signal and a second reference optical signal in equal proportion; generating a third optical signal according to the first optical signal, the first vibration signal, and the first reference optical signal, generating a fourth optical signal according to the second optical signal, the second vibration signal, and the second reference optical signal; and generating a vital sign signal of the user according to the third optical signal and the fourth optical signal.

In the system disclosed in the present application, two signals share a reference signal, thereby eliminating environmental noise during the detection process and effectively improving the quality of signal acquisition.

In combination with the second aspect, in certain implementations of the second aspect, a user's vital sign signal is generated based on the third optical signal and the fourth optical signal, including: converting the third optical signal into a first electrical signal, and converting the first electrical signal into a first digital signal; converting the fourth optical signal into a second electrical signal, and converting the second electrical signal into a second digital signal; and demodulating the first digital signal and the second digital signal to obtain the user's vital sign signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure of a first optical fiber detection system provided in an embodiment of the present application.

FIG. 2 is a schematic diagram of the structure of a second optical fiber detection system provided in an embodiment of the present application.

FIG3 is a schematic diagram of the structure of a third optical fiber detection system provided in an embodiment of the present application.

FIG. 4 is a specific example of a conversion module provided in an embodiment of the present application.

FIG. 5 is another specific example of the conversion module provided in an embodiment of the present application.

FIG6 is a schematic diagram of the structure of a fourth optical fiber detection system provided in an embodiment of the present application.

FIG. 7 is a flow chart of the optical fiber detection method provided in an embodiment of the present application.

DETAILED DESCRIPTION

The technical solution in this application will be described below in conjunction with the accompanying drawings.

The terms used in the following embodiments are only for the purpose of describing specific embodiments, and are not intended to be used as limitations on the present application. As used in the specification and the appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context. It should also be understood that in the following embodiments of the present application, "at least one", "one or more" refer to one, two or more. The term "and/or" is used to describe the association relationship of associated objects, indicating that three relationships may exist; for example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character "/" generally indicates that the objects associated before and after are in an "or" relationship.

References to "one embodiment" or "some embodiments" etc. described in this specification mean that a particular feature, structure or characteristic described in conjunction with the embodiment is included in one or more embodiments of the present application. Thus, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

With the rapid development of the healthcare industry, vital signs detection technology has been widely popularized. Vital signs detection technology mainly detects human breathing, heart rate and other vital signs, thereby helping people to achieve real-time physical status detection and analysis.

Currently, the commonly used vital signs detection technologies in the industry mainly include ECG, PPG and BCG. Among them, ECG and PPG both use lasers to detect the changes in light energy caused by the expansion and contraction of human capillaries, and can only detect human heart rate signals. In addition, ECG and PPG must be close to human skin, and their application scenarios are limited. BCG can use the vibrations generated by the expansion and contraction of the human aorta and breathing to achieve heart rate and breathing detection at the same time. It has received widespread attention in the industry and quickly became a research hotspot.

However, the existing BCG detection technology is extremely susceptible to external interference and environmental noise (body movement, external vibration), and the external noise has a wide frequency band. Some signals fall into the BCG frequency band and are difficult to filter out directly through the filter, resulting in failure in measuring vital sign parameters. Therefore, it is limited to measuring vital sign signals under static conditions, such as lying down, sitting still, and standing, and cannot be widely used in more complex scenarios, such as car seats.

Based on this, the present application proposes a system and method for optical fiber detection, which helps to suppress the impact of external interference on the detection process and improve the signal-to-noise ratio. It can be applied to a variety of complex scenarios. For example, it may be used in scenarios such as cushions, mattresses, and fabrics (such as clothes) to realize smart cushions, mattresses, and wearable devices for user vital signs monitoring.

FIG1 shows a schematic structural diagram of a first optical fiber detection system provided in an embodiment of the present application.

As shown in FIG1 , the system 100 includes a sensing optical circuit 110, a conversion module 120 and a processing module 130. The sensing optical circuit 110 is used to receive an optical signal, a first vibration signal generated by the user's heartbeat and breathing, and a second vibration signal existing in the detection environment, and divide the optical signal into a first optical signal, a second optical signal and a reference optical signal, and generate a third optical signal according to the first optical signal, the first vibration signal and the reference optical signal, and generate a fourth optical signal according to the second optical signal, the second vibration signal and the reference optical signal. The conversion module 120 is used to receive the third optical signal and convert the third optical signal into a first digital signal, and to receive the fourth optical signal and convert the fourth optical signal into a second digital signal. The processing module 130 is used to receive the first digital signal and the second digital signal, and to demodulate the first digital signal and the second digital signal to obtain the user's vital sign signal.

Optionally, the system 100 may further include a light source, which may be a semiconductor fiber laser with an operating wavelength of 1550 nm, for generating an optical signal.

Optionally, the optical signal may be divided into the first optical signal, the reference optical signal, and the second optical signal in equal proportions or in other ways, which is not limited in the present application.

In the system disclosed in the present application, two signals share a reference signal, thereby eliminating environmental noise during the detection process and effectively improving the quality of signal acquisition.

FIG2 shows a schematic diagram of the structure of the second optical fiber detection system provided in an embodiment of the present application. FIG2 shows a specific structure of a sensing optical path 110. As shown in FIG2, the sensing optical path 110 includes a first coupler 111, a second coupler 112, a third coupler 113, a first optical fiber 115, and a second optical fiber 116. Among them, the first optical fiber 115 and the second optical fiber 116 are arranged at different positions relative to the user. For example, the first optical fiber 115 can be arranged at a place close to the user or close to the user, and the second optical fiber 116 can be arranged at a place far from the user. The first coupler 111 is used to receive an optical signal, and after dividing the optical signal into a first optical signal, a reference optical signal, and a second optical signal, the first optical signal is transmitted to the first optical fiber 115, the second optical signal is transmitted to the second optical fiber 116, and the reference optical signal is transmitted to the second coupler 112 and the third coupler 113. The first optical fiber 115 is used to receive a first vibration signal generated by the user, and the second optical fiber 116 is used to receive a second vibration signal existing in the detection environment. The second coupler 112 is used to receive the reference optical signal, the first optical signal and the first vibration signal, and couple the reference optical signal, the first optical signal and the first vibration signal into a third optical signal. The third coupler 113 is used to receive the reference optical signal, the second optical signal and the second vibration signal, and couple the reference optical signal, the second optical signal and the second vibration signal into a fourth optical signal.

Optionally, the system 100 may also include multiple conversion modules, such as a first conversion module 121 and a second conversion module 122. The first conversion module 121 is used to receive the third optical signal and convert the third optical signal into a first digital signal. The second conversion module 122 is used to receive the fourth optical signal and convert the fourth optical signal into a second digital signal.

The system disclosed in the present application arranges two sensing optical fibers at different positions, one sensing optical fiber is used to receive vibration signals generated by the user's breathing and heartbeat, and the other sensing optical fiber is used to receive environmental noise, thereby eliminating environmental noise in the detection process and effectively improving the quality of signal acquisition.

FIG3 shows a schematic diagram of the structure of the third fiber optic detection system provided in an embodiment of the present application. FIG3 shows another specific structure of the sensing optical path 110. Different from the sensing optical path in FIG2, in the system shown in FIG3, the sensing optical path 110 also includes a fourth coupler 117 and a third optical fiber 118. Among them, the third optical fiber 118 is used to transmit the reference optical signal from the first coupler 111 to the fourth coupler 117. The fourth coupler 117 is used to divide the reference optical signal into the first reference optical signal and the second reference optical signal in equal proportion, and transmit them to the second coupler 112 and the third coupler 113 respectively. The second coupler 112 is specifically used to receive the first reference optical signal, the first optical signal and the first vibration signal, and couple the first reference optical signal, the first optical signal and the first vibration signal into the third optical signal. The third coupler 113 is specifically used to receive the second reference optical signal, the second optical signal and the second vibration signal, and couple the second reference optical signal, the second optical signal and the second vibration signal into the fourth optical signal.

Optionally, the third optical fiber 118 is arranged at the same position as the first optical fiber 115, or the third optical fiber 118 is arranged at the same position as the second optical fiber 116. For example, the third optical fiber 118 and the first optical fiber 115 can be fixed on a substrate, and the substrate can be an acrylic board, cardboard, plastic board, rubber board, etc., which is not limited in the present application.

Optionally, the first optical fiber 115 may be a single-mode optical fiber, a few-mode optical fiber, a multi-mode optical fiber or a hollow-core optical fiber. Correspondingly, the second optical fiber 116 and the third optical fiber 118 may also be a single-mode optical fiber, a few-mode optical fiber, a multi-mode optical fiber or a hollow-core optical fiber.

Optionally, the second coupler 112 and the fourth coupler 117 are connected via a fourth optical fiber 119, and the length of the first optical fiber 115 is the sum of the lengths of the third optical fiber 118 and the fourth optical fiber 119. Correspondingly, the third coupler 113 and the fourth coupler 117 are connected via a fifth optical fiber, and the length of the second optical fiber 116 is the sum of the lengths of the third optical fiber 118 and the fifth optical fiber.

The system disclosed in the present application arranges two sensing optical fibers at different positions, one sensing optical fiber is used to receive vibration signals generated by the user's breathing and heartbeat, and the other sensing optical fiber is used to receive environmental noise, thereby eliminating environmental noise in the detection process and effectively improving the quality of signal acquisition.

FIG4 shows a specific example of a conversion module provided in an embodiment of the present application. As shown in FIG4, the conversion module 400 shown in FIG4 is a specific example of the conversion module 120 in FIG1 or the first conversion module 121 in FIG2 (and FIG3). The conversion module 400 may include a photodetector 410 and a digital-to-analog converter 420, the photodetector 410 is used to receive the third optical signal and convert the third optical signal into a first electrical signal, and the digital-to-analog converter 420 is used to receive the first electrical signal and convert the first electrical signal into a first digital signal.

Optionally, the conversion module 400 may also be a specific example of the second conversion module 122 in FIG. 2 (and FIG. 3). When the conversion module 400 is a specific example of the second conversion module 122 in FIG. 2 (and FIG. 3), the photodetector 410 is used to receive the fourth optical signal and convert the fourth optical signal into a second electrical signal; the digital-to-analog converter 420 is used to receive the second electrical signal and convert the second electrical signal into a second digital signal.

FIG5 shows another specific example of the conversion module provided in an embodiment of the present application. As shown in FIG5 , the conversion module 500 shown in FIG5 is another specific example of the first conversion module 121 in FIG2 (and FIG3 ). The conversion module 500 may include a photodetector 511, a photodetector 512, a photodetector 513, a digital-to-analog converter 521, a digital-to-analog converter 522, and a digital-to-analog converter 523. Among them, the photodetector 511 is used to receive the third optical signal-1 and convert the third optical signal-1 into a first electrical signal-1, and the digital-to-analog converter 521 is used to receive the first electrical signal-1 and convert the first electrical signal into a first digital signal-1; the photodetector 512 is used to receive the third optical signal-2 and convert the third optical signal-2 into a first electrical signal-2, and the digital-to-analog converter 522 is used to receive the first electrical signal-2 and convert the first electrical signal into a first digital signal-2; the photodetector 513 is used to receive the third optical signal-3 and convert the third optical signal-3 into a first electrical signal-3, and the digital-to-analog converter 523 is used to receive the first electrical signal-3 and convert the first electrical signal into a first digital signal-3.

Optionally, the conversion module 500 may also be a specific example of the second conversion module 122 in FIG. 2 (and FIG. 3). When the conversion module 500 is a specific example of the second conversion module 122 in FIG. 2 (and FIG. 3), the photodetector 511 is used to receive the fourth optical signal-1 and convert the fourth optical signal into a second electrical signal-1, and the digital-to-analog converter 521 is used to receive the second electrical signal-1 and convert the second electrical signal-1 into a second digital signal-1; the photodetector 512 is used to receive the fourth optical signal-1 and convert the fourth optical signal into a second electrical signal-1, and the digital-to-analog converter 522 is used to receive the second electrical signal-1 and convert the second electrical signal-1 into a second digital signal-1; the photodetector 513 is used to receive the fourth optical signal-3 and convert the fourth optical signal into a second electrical signal-3, and the digital-to-analog converter 523 is used to receive the second electrical signal-3 and convert the second electrical signal-3 into a second digital signal-3.

It should be understood that the conversion module 500 includes three photodetectors and three digital-to-analog converters as an example only and should not be used as a limitation of the present application. In practical applications, the photodetectors and digital-to-analog converters can be used in combination according to the application scenario or the number of output signals of the front-stage coupler, and the number of photodetectors and digital-to-analog converters corresponds to the number of signals, and the present application does not limit the specific number.

In an embodiment of the present application, the control module includes at least one of a DSP, a CPLD, an FPGA, a CPU or an MCU. When the processor receives the specific demodulation process of the digital signal, it varies depending on the number of digital signals. For example, when the processor receives a first digital signal output by the third coupler and a second digital signal output by the fourth coupler (at this time, the conversion module can be shown in Figure 2), the processor receives two digital signals, and converts the two digital signals into a coupled signal x(t), and uses the Hilbert transform (such as the following formula 1) to extract the phase signal s(t), thereby realizing signal demodulation. For another example, when the processor receives three first digital signals output by the third coupler and three second digital signals output by the fourth coupler (at this time, the conversion module may be as shown in FIG3 ), the processor receives six digital signals, and uses 3*3 balanced demodulation to obtain two sensing signals x ₁ (t) and x ₂ (t), performs bandpass filtering on x ₁ (t) and x ₂ (t) to filter out signals outside the heartbeat frequency band, and performs fast Fourier transform (FFT) on the filtered signals to obtain x ₁ (f) and x ₂ (f), and x ₁ (f) satisfies the following formula 2, and x ₂ (f) satisfies the following formula 3. Further according to formula 4, we obtain right Perform inverse fast Fourier transform (IFFT) to obtain Thus, the user's vital sign signal is obtained. Where k is a system correction parameter, k satisfies the following formula 5, and f ₁ and f ₂ are the frequency band boundaries corresponding to the heart rate signal.

FIG6 shows a schematic diagram of the structure of the fourth fiber optic detection system provided in an embodiment of the present application. Compared with the system shown in FIG1 to FIG3, in the system 600 shown in FIG6, the multiple optical fibers can be different cores in the same multi-core optical fiber. As shown in FIG6, the first optical fiber 115, the second optical fiber 116 and the third optical fiber 118 can be different cores in the multi-core optical fiber 1101. In this way, the common mode noise in the multiple cores can be offset when the signal is coupled, which helps to improve the signal-to-noise ratio of the signal.

Optionally, after extending from the multi-core optical fiber 1101, the first optical fiber 115 and the second optical fiber 116 should be arranged at different positions to obtain different vibration signals.

Optionally, the system 600 may further include a light source 150 for generating an optical signal and transmitting the optical signal to the first coupler 111 .

Fig. 7 shows a schematic flow chart of the optical fiber detection method provided in an embodiment of the present application. The method 700 can be executed by any one of the above systems 100 to 300 or the system 600, and systems composed of various combinations thereof.

S710, receiving an optical signal, and dividing the optical signal into a first optical signal, a reference optical signal, and a third optical signal.

Specifically, after the optical signal is divided into a first optical signal, a reference optical signal and a third optical signal, they are transmitted to a first optical fiber, a third optical fiber and a second optical fiber respectively, wherein the first optical fiber and the second optical fiber are arranged at different positions.

Optionally, the optical signal may be divided into the first optical signal, the reference optical signal, and the second optical signal in equal proportions or in other ways, which is not limited in the present application.

Optionally, the first optical fiber may be arranged at a position in close contact with the user, and the second optical fiber may be arranged at a position farther away from the user, such as under a seat, under a mattress, etc.

S720, receiving a first vibration signal generated by a user and a second vibration signal existing in a detection environment.

Specifically, a first vibration signal generated by the user's breathing and heartbeat is received through the first optical fiber, and a second vibration signal existing in the detection environment is received through the second optical fiber.

S730, dividing the reference optical signal into a first reference optical signal and a second reference optical signal in equal proportion.

S740, generating a third optical signal according to the first optical signal, the first vibration signal and the first reference optical signal, and generating a fourth optical signal according to the second optical signal, the second vibration signal and the second reference optical signal.

S750: Generate a vital sign signal of the user according to the third optical signal and the fourth optical signal.

The user's vital sign signals include but are not limited to the user's breathing and heartbeat signals.

The method disclosed in the present application arranges two sensing optical fibers at different positions, one sensing optical fiber is used to receive the vibration signal generated by the user's breathing and heartbeat, and the other sensing optical fiber is used to receive the environmental noise. The two signals share a reference signal, thereby eliminating the environmental noise in the detection process and effectively improving the quality of signal acquisition.

In the embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (14)

1.A system for fiber optic inspection, comprising:

The sensing optical path is used for receiving an optical signal, a first vibration signal generated by a user and a second vibration signal existing in a detection environment, dividing the optical signal into a first optical signal, a second optical signal and a reference optical signal, generating a third optical signal according to the first optical signal, the first vibration signal and the reference optical signal, and generating a fourth optical signal according to the second optical signal, the second vibration signal and the reference optical signal;

The conversion module is used for receiving the third optical signal, converting the third optical signal into a first digital signal, receiving the fourth optical signal and converting the fourth optical signal into a second digital signal;

And the processing module is used for receiving the first digital signal and the second digital signal, and demodulating the first digital signal and the second digital signal to obtain vital sign signals of the user.

2. The system of claim 1, wherein the sensing optical path comprises a first coupler, a second coupler, a third coupler, a first optical fiber, and a second optical fiber, the first optical fiber and the second optical fiber being disposed at different locations,

The first coupler is configured to receive the optical signal, divide the optical signal into a first optical signal, a reference optical signal, and a second optical signal, transmit the first optical signal to the first optical fiber, transmit the second optical signal to the second optical fiber, transmit the reference optical signal to the second coupler and the third coupler,

The first optical fiber is used for receiving a first vibration signal generated by a user,

The second optical fiber is used for receiving a second vibration signal existing in the detection environment,

The second coupler is configured to receive the reference optical signal, the first optical signal, and the first vibration signal, couple the reference optical signal, the first optical signal, and the first vibration signal into the third optical signal,

The third coupler is configured to receive the reference optical signal, the second optical signal, and the second vibration signal, and couple the reference optical signal, the second optical signal, and the second vibration signal into the fourth optical signal.

3. The system of claim 2, wherein the sensing optical path further comprises a fourth coupler,

The fourth coupler is used for equally dividing the reference optical signal into a first reference optical signal and a second reference optical signal, transmitting the first reference optical signal and the second reference optical signal to the second coupler and the third coupler respectively,

The second coupler is specifically configured to receive the first reference optical signal, the first optical signal, and the first vibration signal, couple the first reference optical signal, the first optical signal, and the first vibration signal to the third optical signal,

The third coupler is specifically configured to receive the second reference optical signal, the second optical signal, and the second vibration signal, and couple the second reference optical signal, the second optical signal, and the second vibration signal to the fourth optical signal.

4. A system according to claim 2 or 3, wherein the sensing optical path further comprises a third optical fiber for transmitting the reference optical signal from the first coupler to the fourth coupler.

5. The system of claim 4, wherein the third optical fiber is co-located with the first optical fiber, or

The third optical fiber and the second optical fiber are arranged at the same position.

6. The system of claim 4, wherein the third optical fiber and the first optical fiber belong to different cores in a same multi-core optical fiber, or

The third optical fiber and the second optical fiber belong to different fiber cores in the same multi-core optical fiber.

7. The system of any one of claims 1 to 6, wherein the second coupler and the fourth coupler are connected by a fourth optical fiber, and wherein the length of the first optical fiber is the sum of the lengths of the third optical fiber and the fourth optical fiber.

8. The system of any one of claims 1 to 7, wherein the conversion module comprises a first conversion module and a second conversion module,

The first conversion module is used for receiving the third optical signal and converting the third optical signal into a first digital signal;

the second conversion module is configured to receive the fourth optical signal and convert the fourth optical signal into a second digital signal.

9. The system of claim 8, wherein the first conversion module comprises a photodetector and a digital to analog converter,

The photoelectric detector is used for receiving the third optical signal and converting the third optical signal into a first electric signal;

The digital-to-analog converter is used for receiving the first electric signal and converting the first electric signal into the first digital signal.

10. The system of claim 9, wherein the number of third optical signals is M, the number of photodetectors is M, the number of first electrical signals is M, the number of digital-to-analog converters is M, the M is a positive integer,

The third optical signal corresponds to the photodetector, the first electrical signal and the digital-to-analog converter one by one.

11. The system of any one of claims 1 to 10, the processing module comprising at least one of a digital signal processor DSP, a complex programmable logic device CPLD, a field programmable gate array FPGA, a central processing unit CPU, or a micro control unit MCU.

12. The system according to any one of claims 1 to 11, further comprising a light source,

The light source is used for generating the optical signal.

13. A method of optical fiber inspection, comprising:

receiving an optical signal, dividing the optical signal into a first optical signal, a second optical signal and a reference optical signal,

A first vibration signal generated by a user and a second vibration signal present in the detection environment are received,

Equally dividing the reference optical signal into a first reference optical signal and a second reference optical signal;

Generating a third optical signal according to the first optical signal, the first vibration signal and the first reference optical signal, and generating a fourth optical signal according to the second optical signal, the second vibration signal and the second reference optical signal;

and generating vital sign signals of the user according to the third optical signal and the fourth optical signal.

14. The method of claim 13, wherein the generating the vital sign signal of the user from the third optical signal and the fourth optical signal comprises:

converting the third optical signal into a first electrical signal, and converting the first electrical signal into a first digital signal;

Converting the fourth optical signal into a second electrical signal, and converting the second electrical signal into a second digital signal;

and demodulating the first digital signal and the second digital signal to obtain vital sign signals of the user.