CN114767091A - Vital sign detection method and device with light reflector - Google Patents
Vital sign detection method and device with light reflector Download PDFInfo
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- A—HUMAN NECESSITIES
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- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
- A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
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- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/0002—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network
- A61B5/0015—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network characterised by features of the telemetry system
- A61B5/0017—Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network characterised by features of the telemetry system transmitting optical signals
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- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/02—Detecting, measuring or recording pulse, heart rate, blood pressure or blood flow; Combined pulse/heart-rate/blood pressure determination; Evaluating a cardiovascular condition not otherwise provided for, e.g. using combinations of techniques provided for in this group with electrocardiography or electroauscultation; Heart catheters for measuring blood pressure
- A61B5/0205—Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
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- A61B5/024—Detecting, measuring or recording pulse rate or heart rate
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Abstract
The invention relates to a vital sign detection method and device with a light reflector, belongs to the technical field of vital sign parameter monitoring, and aims to solve the problems of shortening the length of a sensing optical fiber of an existing microbend optical fiber BCG sensor, reducing the measurement error caused by the fluctuation of the output power of a light source of the existing microbend optical fiber BCG sensor and the like. The method comprises the following steps: generating light by a light source; light enters the optical path circulator through the first port and then enters the optical fiber sensor through the second port; under the condition that BCG signals act on the optical fiber sensor, light entering the optical fiber sensor reaches the light reflecting mirror; the light reaching the light reflector is reflected back to the optical fiber sensor and returns to the optical circuit circulator; receiving a first optical signal returned to the optical path circulator through a third port of the optical path circulator and converting the first optical signal into a first electrical signal; vital sign information is obtained from the first electrical signal. The light reflector is used to make the light wave pass through the sensing fiber twice, and the length of the sensing fiber is shortened by one time under the same sensitivity.
Description
Technical Field
The invention relates to the technical field of vital sign parameter monitoring, in particular to a vital sign detection method and device with a light reflector.
Background
The medical vital signs refer to indications for judging the severity and criticality of a patient, and the four vital signs include respiration, pulse, body temperature and blood pressure. At present, the vital sign sensing technology mainly comprises a photoplethysmography (PPG), an Electrocardiogram (ECG), a Ballistocardiogram (BCG) and the like. The PPG and ECG signals generally need to be directly contacted with the skin, electrodes are adhered to the body, patient compliance is poor, and long-term monitoring of vital sign parameters of a patient is difficult. Most of BCG signal monitoring does not need to be in direct contact with skin, the sensor is embedded into the mattress and the cushion, and the patient lies down or sits down to obtain vital sign information such as heart rate, respiratory rate and sleep quality, so that physiological burden on the patient is avoided, and the BCG signal monitoring device has wide attention in recent years.
The detection method of BCG signal mainly includes piezoelectric sensing method and optical fiber sensing method. The piezoelectric sensing method senses BCG signals through a piezoelectric film, is easily interfered by external environment and only can detect dynamic force; the optical fiber sensing method senses BCG signals through optical fibers, and has the advantages of electromagnetic interference resistance, good safety, capability of detecting tiny static force and dynamic force and the like. According to different modulation modes of optical signals, the optical fiber BCG sensor can be divided into a BCG sensor based on microbending optical fibers, a BCG sensor based on optical fiber gratings and a BCG sensor based on optical fiber interferometers, wherein the BCG sensor based on the microbending optical fibers has the advantages of simple structure, low cost and the like. The structure of a conventional microbend fiber-based vital sign monitoring device is shown in fig. 1, and when a BCG signal acts on a microbend fiber sensor composed of a sensing fiber and a grid structure, the sensing fiber is microbend, part of energy enters a fiber cladding to generate light intensity loss, and the BCG signal can be obtained by detecting the output light intensity of the microbend fiber sensor. However, the conventional microbend fiber-based vital sign monitoring device requires a long sensing fiber length and a serpentine routing for high sensitivity of the system, and the output power fluctuation of the light source can cause measurement errors.
Disclosure of Invention
In view of the above analysis, embodiments of the present invention are directed to a method and an apparatus for vital sign detection with a light reflector, so as to shorten the length of the sensing fiber of the conventional microbending fiber BCG sensor and reduce the measurement error caused by the fluctuation of the output power of the light source of the conventional microbending fiber BCG sensor.
In one aspect, an embodiment of the present invention provides a method for detecting vital signs with an optical mirror, including: generating light by a light source; the first beam of light enters the optical path circulator through the first port and then enters the optical fiber sensor through the second port; under the condition that BCG signals act on the optical fiber sensor, light reaches the light reflecting mirror after passing through the optical fiber sensor; the light reaching the light reflector is reflected back to the optical fiber sensor and returns to the optical path circulator; receiving a first optical signal returned to the optical path circulator through a third port of the optical path circulator and converting the first optical signal into a first electrical signal; and obtaining BCG information according to the first electric signal so as to obtain vital sign information.
The beneficial effects of the above technical scheme are as follows: the invention utilizes the light reflector to enable the light wave to pass through the sensing optical fiber twice, and compared with the traditional vital sign microbending optical fiber sensing system, the length of the sensing optical fiber can be shortened by one time under the condition of the same sensitivity, thereby optimizing the performance of the vital sign detection device.
Based on the further improvement of the method, the light reflector makes the light pass through the sensing optical fiber twice in sequence so as to shorten the length of the sensing optical fiber in the optical fiber sensor under the condition of the same sensitivity, wherein the light reflector comprises an optical fiber coated total reflector or an optical fiber ring reflector.
Based on a further improvement of the above method, a feedback control loop is connected between the light source and the optical circuit circulator to stabilize the output power of the light source, wherein stabilizing the output power of the light source comprises: splitting the light into the first beam of light and a second beam of light; receiving the second beam of light by a first photodetector and converting the second beam of light into a second electrical signal; and adjusting the voltage or the current loaded on the light source in real time according to the second electric signal to keep the light power output by the light source stable.
In another aspect, an embodiment of the invention provides a vital signs detection device with an optical mirror, comprising: a light source for generating light; the optical path circulator is used for enabling a first beam of light to enter the optical path circulator through a first port and then enter the optical fiber sensor through a second port; in the optical fiber sensor, when BCG signals act on the optical fiber sensor, light passes through the optical fiber sensor and then reaches the light reflector; the light reflector is used for reflecting the light reaching the light reflector back to the optical fiber sensor and returning the light to the optical path circulator; the second photoelectric detector is used for receiving the first optical signal returned to the optical path circulator through the third port and converting the first optical signal into a first electric signal; and a signal demodulation detection module for obtaining the vital sign information according to the first electric signal.
Based on the further improvement of the device, the light reflector makes light pass through the sensing optical fiber twice in sequence so as to shorten the length of the sensing optical fiber in the optical fiber sensor under the condition of the same sensitivity, wherein the light reflector is an optical fiber coated total reflector or an optical fiber ring reflector.
Based on the further improvement of the device, the vital sign detection device with the light reflector further comprises a feedback control loop which is connected between the light source and the light path circulating device and is used for stabilizing the output power of the light source.
Based on further improvement of the device, the feedback control loop comprises an optical fiber coupler, a first photoelectric detector and a light source driving module, wherein the optical fiber coupler is used for dividing the light into a first beam of light and a second beam of light; the first photoelectric detector is used for receiving the second beam of light and converting the second beam of light into a second electric signal; and the light source driving module is used for adjusting the voltage or the current loaded on the light source in real time according to the second electric signal so as to keep the light power output by the light source stable.
Based on the further improvement of the device, the optical path circulator is an optical fiber circulator or an MEMS spatial beam splitter.
Based on the further improvement of the device, the sensing optical fiber type in the optical fiber sensor comprises a multimode optical fiber, a polarization maintaining optical fiber or a single mode optical fiber.
Based on a further improvement of the above device, the optical fiber sensor comprises: the sensing optical fiber, the grid structure, the upper flexible outer cover and the lower flexible outer cover are arranged on the lower portion of the sensing optical fiber; the upper flexible outer cover is arranged above the sensing optical fiber and is in contact with the upper surface of the sensing optical fiber; and the lower flexible outer cover is arranged below the grid structure and is in contact with the lower surface of the grid structure.
Based on the further improvement of the device, the vital sign detection device can be arranged in daily necessities, wherein the daily necessities comprise mattresses, cushions or pillows.
Compared with the prior art, the invention can realize at least one of the following beneficial effects:
1. compared with the traditional vital sign micro-bending optical fiber sensing system, the length of the sensing optical fiber in the vital sign detection device can be shortened by one time under the condition of the same sensitivity, so that the performance of the vital sign detection device is optimized.
2. Compared with the traditional vital sign microbending optical fiber sensing system, the embodiment of the invention introduces closed-loop feedback control to stabilize the output power of the light source, and can effectively inhibit the measurement error caused by the fluctuation of the output power of the light source, thereby optimizing the performance of the vital sign detection device.
In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
The drawings, in which like reference numerals refer to like parts throughout, are for the purpose of illustrating particular embodiments only and are not to be considered limiting of the invention.
Fig. 1 is a schematic structural diagram of a conventional vital sign microbend optical fiber sensing system.
Fig. 2 is a flow chart of a vital sign detection method with an optical mirror according to an embodiment of the invention.
Fig. 3 is a functional block diagram of a vital signs detection device with an optical mirror according to an embodiment of the invention.
Fig. 4 is a schematic structural view of a vital signs detection device with light mirrors according to a first embodiment of the invention.
Fig. 5 is a schematic structural view of a vital signs detection device with light mirrors according to a second embodiment of the invention.
Detailed Description
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.
In one embodiment of the invention, a method for vital sign detection with an optical mirror is disclosed. As shown in fig. 2, the vital signs detection method with optical mirror comprises: in step S202, light is generated by a light source (the light source herein is a width light source) and divided into first light and second light; in step S204, a first beam of light enters the optical circuit circulator through the first port, and then enters the optical fiber sensor (the optical fiber sensor herein is a microbend optical fiber sensor) through the second port; in step S206, in the case where the BCG signal is applied to the optical fiber sensor, the light reaches the light reflecting mirror after passing through the optical fiber sensor; in step S208, the light reaching the light reflector is reflected back to the optical fiber sensor and to the optical path circulator; in step S210, receiving a first optical signal returned to the optical path circulator via the third port of the optical path circulator and converting the first optical signal into a first electrical signal; and obtaining BCG information according to the first electrical signal in step S212, so that the vital sign information, specifically, the vital sign information includes heart rate, respiration rate, etc.
Compared with the prior art, the embodiment of the invention utilizes the light reflector to enable the light wave to pass through the sensing optical fiber twice, and compared with the traditional vital sign microbending optical fiber sensing system, the length of the sensing optical fiber in the vital sign detection device can be shortened by one time under the condition of the same sensitivity.
Hereinafter, a vital sign detection method with light mirrors according to an embodiment of the invention is described in detail with reference to fig. 2.
In step S202, light is generated by a light source, which is a broadband light source, and the light is split into first light and second light. In step S204, a first beam of light enters the optical circuit circulator through the first port, and then enters the optical fiber sensor (herein, the optical fiber sensor is a microbend optical fiber sensor) through the second port. In particular, the optical circuit circulator includes a first port, a second port, and a third port. In step S206, in the case where the BCG signal is applied to the optical fiber sensor, the light reaches the light reflecting mirror after passing through the optical fiber sensor. In step S208, the light reaching the light reflector is reflected back to the optical fiber sensor and to the optical path circulator. The light is made to pass through the optical fiber sensor twice by the light reflector to shorten the sensing optical fiber length in the optical fiber sensor under the same sensitivity condition. Specifically, the light reflector comprises a fiber coated total reflection mirror or a fiber ring reflector. In step S210, the first optical signal returned to the optical path circulator is received via the third port of the optical path circulator and converted into a first electrical signal. In step S212, BCG information is obtained from the first electrical signal, thereby obtaining vital sign information. Specifically, the vital sign information includes a heart rate, a respiration rate, and the like.
A feedback control loop is connected between the light source and the optical circuit circulator to stabilize the output power of the light source. Specifically, stabilizing the output power of the light source includes: splitting the light into a first beam of light and a second beam of light; receiving the second beam of light through the first photoelectric detector and converting the second beam of light into a second electric signal; and adjusting the voltage or current loaded on the light source in real time according to the second electric signal to keep the light power output by the light source stable.
In one embodiment of the invention, a vital sign detection device having an optical mirror is disclosed. With reference to fig. 3 to 5, the vital signs detection device with light mirror comprises: the device comprises a light source 2, a light path circulator 5, an optical fiber sensor 6, a light reflector 7, a second photoelectric detector 8, a signal demodulation detection module 9 and a feedback control loop. Hereinafter, with reference to fig. 3 to 5, the respective components of the vital signs detection device with light mirror according to an embodiment of the invention will be described in detail.
The light source 2 is for generating light. The light source 2 is a light emitting diode or other low-cost light source.
The feedback control loop is connected between the light source and the light path circulator and is used for stabilizing the output power of the light source. The feedback control loop further comprises a fiber coupler 3, a first photodetector 4 and a light source driving module 1. The fiber coupler 3 is used to split the light into a first beam of light and a second beam of light. The first photoelectric detector 4 is used for receiving the second beam of light and converting the second beam of light into a second electric signal; and the light source driving module 1 is used for adjusting the voltage or the current loaded on the light source 2 in real time according to the second electric signal so as to keep the optical power output by the light source stable, specifically, when the detected light intensity is larger than a set value, the voltage or the current loaded on the light source is reduced, and when the detected light intensity is smaller than the set value, the voltage or the current loaded on the light source is increased.
The optical circuit circulator 5 includes a first port, a second port, and a third port. A first beam of light enters the optical circuit circulator 5 via the first port and then enters the optical fiber sensor 6 via the second port. The optical path circulator 5 is a fiber circulator or a MEMS spatial beam splitter.
In the case where the BCG signal 10 acts on the optical fiber sensor 6, light entering the optical fiber sensor 6 propagates forward to reach the light reflecting mirror 7. The sensing fiber type in the fiber sensor 6 includes a multimode fiber, a polarization maintaining fiber or a single mode fiber. The optical fiber sensor 6 is built in a daily product, wherein the daily product comprises a mattress, a cushion or a pillow. The fiber sensor 6 comprises a sensing fiber, a grid structure, an upper flexible housing and a lower flexible housing. Specifically, the lattice structure is laid under the sensing fiber, which is slightly bent in the case where the BCG signal 10 acts on the optical fiber sensor 6. The upper flexible housing is disposed over and in contact with the upper surface of the sensing optical fiber. The lower flexible housing is disposed below the lattice structure and in contact with the lower surface of the lattice structure.
The light reflector 7 is used to reflect the light that has reached the light reflector 7 back to the fiber sensor 6 and back to the optical path circulator 5. The light reflector 7 passes the light through the fiber sensor 6 twice in sequence to shorten the sensing fiber length in the fiber sensor 6 with the same sensitivity. Referring to fig. 4 and 5, the light reflector 7 is a fiber coated total reflection mirror or a fiber ring reflector. Specifically, the optical fiber coated total reflection mirror is an optical fiber device, and the coating is carried out on the section of the optical fiber to ensure that light is totally reflected. The fiber ring reflector consists of a 2 x 2 or 2 x 1 fiber coupler with a splitting ratio of 50: 50.
The second photodetector 8 is configured to receive the first optical signal returned to the optical circuit circulator 5 via the second output port and convert the first optical signal into a first electrical signal.
The signal demodulation detection module 9 is configured to obtain BCG information according to the first electrical signal, so that the vital sign information includes, specifically, heart rate, respiratory rate, and the like. And acquiring a BCG signal according to the electric signal, and extracting vital sign information such as heart rate, respiratory rate and the like from the BCG signal. Method of extracting heart rate and respiration rate from BCG signal: the heart rate of an adult is between 0.50Hz and 3.00Hz, the respiratory rate is between 0.16Hz and 0.50Hz, and other noise is suppressed by using a band-pass filter, so that heart rate or respiratory rate information is acquired. The first electric signal is voltage, the voltage represents the size of the BCG signal, and the respiration rate and the heart rate are extracted from the BCG signal.
Hereinafter, a vital sign detection device with an optical mirror according to an embodiment of the invention will be described in detail by way of a specific example with reference to fig. 3 to 5.
Referring to fig. 3, the invention provides a vital sign detection device with a light reflector, which comprises a light source driving module 1, a light source 2, an optical fiber coupler 3, a first photoelectric detector 4, a light path circulating device 5, a microbend optical fiber sensor 6, a light reflector 7, a second photoelectric detector 8, a signal demodulation detection module 9 and a BCG signal 10; the microbend optical fiber sensor 6 is composed of sensing optical fibers and a grid structure.
The light source driving module 1, the light source 2, the optical fiber coupler 3 and the first photoelectric detector 4 are connected to form a closed loop; the light source driving module 1 is connected with the light source 2; the light source 2 is connected with the optical fiber coupler 3; the optical fiber coupler 3 is connected with the first photoelectric detector 4; the first photoelectric detector 4 is connected with the light source driving module 1; the optical path circulator 5 has three ports which are respectively connected with the optical fiber coupler 3, the second photoelectric detector 8 and the microbend optical fiber sensor 6; the microbend optical fiber sensor 6 is connected with the light reflector 7; the second photoelectric detector 8 is connected with the signal demodulation detection module 9; the BCG signal 10 acts on the microbend fibre sensor 6.
Hereinafter, with reference to fig. 3 to 5, the principle of the vital signs detection device with light mirror according to an embodiment of the invention is described in detail.
Referring to fig. 3, light emitted from the light source 2 is divided into two beams of light (the ratio is from 1:99 to 50:50, the signal of the closed loop feedback end is small) by the optical fiber coupler 3, one beam of light is received by the first detector 4 and then converted into an electrical signal, and the light source driving module 1 adjusts the voltage or current loaded on the light source 2 in real time according to the electrical signal, so that the optical power output by the light source 2 is kept stable (when the detected light intensity is greater than the set value, the voltage or current loaded on the light source is reduced, and when the detected light intensity is smaller than the set value, the voltage or current loaded on the light source is increased). Another beam of light branched from the optical fiber coupler 3 enters the optical path circulator 5, enters the microbend optical fiber sensor 6 after being output from the optical path circulator 5, reaches the light reflector 7 after being output from the microbend optical fiber sensor 6, is reflected back to the microbend optical fiber sensor 6 by the light reflector 7, returns to the optical path circulator 5, finally reaches the second photoelectric detector 8 to convert optical signals into electric signals, and the electric signals pass through the signal demodulation and detection module 9 to obtain vital sign information such as heart rate and respiratory rate. In the working principle process, the light waves pass through the sensing optical fiber twice, and compared with a traditional vital sign microbend optical fiber sensing system, the length of the sensing optical fiber in the vital sign detection device can be shortened by one time under the condition of the same sensitivity.
In an exemplary embodiment of the invention, two structures of vital sign detection devices with optical reflectors are provided, namely a vital sign detection device with an optical fiber coated total reflector and a vital sign detection device with an optical fiber ring reflector.
A first embodiment of the invention provides a vital signs detection device with a light reflector. With reference to fig. 4, the vital signs detection device with light mirror comprises: the device comprises a light source, a light source driving module, an optical fiber coupler, a first photoelectric detector, an optical fiber circulator, a second photoelectric detector, a sensing optical fiber, a grid structure, an optical fiber coating total reflector and a signal demodulation and detection module. The parameters of the device in the vital signs detection apparatus with light mirrors can be set as:
light source: light emitting diodes are used, with a wavelength of 1550nm, 1310nm or 850nm, or other low power, low cost light sources.
The optical fiber coupler: can adopt 1×2 fiber coupler or 2×2, wherein the coupling output intensity of one end of the optical fiber coupler is 1 to 50 percent.
A sensing optical fiber: adopting multimode fiber, single mode fiber or polarization maintaining fiber; a grid structure is laid below the sensor, the grid is composed of interwoven fibers, and the sensing fibers and the grid structure form a microbend fiber sensor; the sensing optical fiber and the two sides of the grid structure are flexible outer covers which are made of silica gel.
Optical fiber coating holophote: the working wavelength is 1550nm, 1310nm or 850nm, and the insertion loss is low.
The signal demodulation detection module: the method can be used for extracting vital sign information such as heart rate and respiratory rate.
A second embodiment of the invention provides a vital signs detection device having a light reflector. Referring to fig. 5, a vital signs detection device with optical mirror comprises: the device comprises a light source, a light source driving module, an optical fiber coupler, a first photoelectric detector, an optical fiber circulator, a second photoelectric detector, a sensing optical fiber, a grid structure, an optical fiber ring reflector and a signal demodulation and detection module. In a specific implementation, parameters of devices in the vital sign monitoring apparatus may be set as:
light source: light emitting diodes with wavelength of 1550nm, 1310nm or 850nm, or other low power, low cost light sources are used.
The optical fiber coupler: can adopt 1×2 fiber coupler or 2×2, wherein the coupling output intensity of one end of the optical fiber coupler is 1 to 50 percent.
Sensing an optical fiber: adopting multimode fiber, single mode fiber or polarization maintaining fiber; a grid structure is laid below the sensor, the grid is composed of interwoven fibers, and the sensing fibers and the grid structure form a microbend fiber sensor; the sensing optical fiber and the two sides of the grid structure are flexible outer covers which are made of silica gel.
A fiber ring reflector: the optical fiber is multimode fiber, single mode fiber or polarization maintaining fiber with a splitting ratio of 1: 50×2 or 2×2, and 2, a fiber coupler.
The signal demodulation detection module: the method can be used for extracting vital sign information such as heart rate and respiratory rate.
In summary, the present invention provides a vital signs detector with a light reflector. Compared with the traditional vital sign microbend optical fiber sensing system, the optical reflector is utilized to enable light waves to pass through the sensing optical fiber twice, and the length of the sensing optical fiber can be shortened by one time under the condition of the same sensitivity; the invention introduces closed-loop feedback control to stabilize the output power of the light source, and can effectively inhibit the measurement error caused by the fluctuation of the output power of the light source.
Those skilled in the art will appreciate that all or part of the flow of the method implementing the above embodiments may be implemented by a computer program, which is stored in a computer readable storage medium, to instruct related hardware. The computer readable storage medium is a magnetic disk, an optical disk, a read-only memory or a random access memory.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (10)
1. A method of vital sign detection having a light reflector, comprising:
generating light by a light source;
the first beam of light enters the optical path circulator through the first port and then enters the optical fiber sensor through the second port;
under the condition that BCG signals act on the optical fiber sensor, light reaches the light reflecting mirror after passing through the optical fiber sensor;
the light reaching the light reflector is reflected back to the optical fiber sensor and returns to the optical path circulator;
receiving a first optical signal returned to the optical path circulator through a third port of the optical path circulator and converting the first optical signal into a first electrical signal; and
and obtaining vital sign information according to the first electric signal.
2. The method according to claim 1, wherein the light reflector comprises a total reflection mirror coated with an optical fiber or a ring mirror, and wherein the light reflector passes the optical fiber sensor twice in sequence through the optical reflector to shorten the sensing fiber length of the optical fiber sensor with the same sensitivity.
3. The method for vital sign detection with optical reflector of claim 1, wherein a feedback control loop is connected between the light source and the optical circuit circulator to stabilize the output power of the light source, wherein stabilizing the output power of the light source comprises:
splitting the light into the first beam of light and a second beam of light;
receiving the second beam of light by a first photodetector and converting the second beam of light into a second electrical signal; and
and adjusting the voltage or the current loaded on the light source in real time according to the second electric signal to keep the light power output by the light source stable.
4. A vital sign detection device having a light reflector, comprising:
a light source for generating light;
the optical path circulator is used for enabling a first beam of light to enter the optical path circulator through a first port and then enter the optical fiber sensor through a second port;
in the optical fiber sensor, when BCG signals act on the optical fiber sensor, light reaches the light reflector after passing through the optical fiber sensor;
the light reflector is used for reflecting the light reaching the light reflector back to the optical fiber sensor and returning the light to the optical path circulator;
the second photoelectric detector is used for receiving the first optical signal returned to the optical path circulator through the third port and converting the first optical signal into a first electric signal; and
and the signal demodulation and detection module is used for obtaining the vital sign information according to the first electric signal.
5. The vital sign detection device according to claim 4, wherein the light reflector is a fiber coated total reflector or a fiber ring reflector that directs light through the fiber sensor twice in sequence to shorten the sensing fiber length in the fiber sensor with the same sensitivity.
6. The vital sign detection device with optical reflector of claim 4, further comprising a feedback control loop connected between the light source and the optical circuit circulator for stabilizing the output power of the light source.
7. Vital signs detection device with light reflection mirror according to claim 6, wherein the feedback control loop comprises a fiber coupler, a first photo detector and a light source driving module, wherein,
the optical fiber coupler is used for dividing the light into a first beam of light and a second beam of light;
the first photoelectric detector is used for receiving the second beam of light and converting the second beam of light into a second electric signal; and
and the light source driving module is used for adjusting the voltage or the current loaded on the light source in real time according to the second electric signal so as to keep the optical power output by the light source stable.
8. The vital sign detection device with optical reflector of claim 4, wherein the optical circuit circulator is a fiber optic circulator or a MEMS spatial beam splitter.
9. Vital sign detection device according to claim 5, wherein the type of sensing fiber in the fiber sensor comprises a multimode fiber, a polarization maintaining fiber or a single mode fiber.
10. The vital sign detection device with light reflector of claim 9, wherein the fiber optic sensor comprises: the sensing optical fiber, the grid structure, the upper flexible outer cover and the lower flexible outer cover, wherein,
the grid structure is laid below the sensing optical fiber;
the upper flexible outer cover is arranged above the sensing optical fiber and is in contact with the upper surface of the sensing optical fiber; and
the lower flexible outer cover is arranged below the grid structure and is in contact with the lower surface of the grid structure.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115444407A (en) * | 2022-09-02 | 2022-12-09 | 嘉兴学院 | Physiological information monitoring device based on optical fiber sound wave sensing |
| CN115444406A (en) * | 2022-09-02 | 2022-12-09 | 嘉兴学院 | Intensity modulation type optical fiber vital sign monitoring device |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115444407A (en) * | 2022-09-02 | 2022-12-09 | 嘉兴学院 | Physiological information monitoring device based on optical fiber sound wave sensing |
| CN115444406A (en) * | 2022-09-02 | 2022-12-09 | 嘉兴学院 | Intensity modulation type optical fiber vital sign monitoring device |
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