CN210144637U

CN210144637U - Vital sign parameter monitoring device based on four-cone optical fiber interferometer

Info

Publication number: CN210144637U
Application number: CN201920128570.7U
Authority: CN
Inventors: 陈智浩; 陈亚杰; 陈伟娟
Original assignee: Quanzhou Normal University
Current assignee: Fujian Yingyu Technology Co ltd
Priority date: 2019-01-25
Filing date: 2019-01-25
Publication date: 2020-03-17
Anticipated expiration: 2029-01-25

Abstract

The utility model provides a vital sign parameter monitoring devices based on four awl optical fiber interferometer, a serial communication port, include and connect gradually through transmission optical fiber: the device comprises a light source, a four-cone sensing optical fiber, a photoelectric detector and an upper computer connected with the photoelectric detector. Compared with other interference type optical fiber vital sign parameter monitoring systems, the system has the advantages that: the reference arm and the interference arm are not separated, so that the influence of the environment on the reference arm is avoided. For the four-cone sensing optical fiber sensing, the optical fiber sensing. Meanwhile, the device has the advantages of simple structure, simple and convenient process steps, easiness in preparation, good product stability, long service life and the like, can realize real-time measurement, achieves the purpose of continuously measuring vital sign parameters of a human body, and can be used as a coherent light source and an incoherent light source.

Description

Vital sign parameter monitoring device based on four-cone optical fiber interferometer

Technical Field

The utility model belongs to the technical field of vital sign parameter real-time supervision, especially, relate to a vital sign parameter monitoring devices based on four awl optical fiber interferometer.

Background

In recent years, the incidence of cardiovascular and cerebrovascular diseases is continuously increased, the effect of preventing the cardiovascular and cerebrovascular diseases can be achieved by carrying out real-time online detection on vital sign parameters of a human body, the vital sign parameter monitoring equipment is roughly divided into invasive type and non-invasive type, the invasive vital sign parameter monitoring equipment needs to be tightly connected with the skin of a person to be detected, and the monitoring equipment is not suitable for long-term monitoring. The non-invasive vital sign monitoring equipment has the technical advantages that the vital sign parameters of a person to be detected can be measured without directly contacting the skin of the person to be detected. However, most of the devices are electronic sensing monitoring devices, are greatly influenced by electromagnetic interference, and are not suitable for CT and nuclear magnetic resonance examination. The optical fiber sensor is free from electromagnetic interference, so that the optical fiber-based vital sign parameter sensor has certain advantages when being used in hospitals and even families. US6498652B1 proposes monitoring vital sign parameters using a fiber optic interferometer, which in embodiments includes a variety of fiber optic interferometers. Chinese patent also proposes the use of mach-zehnder interference principles to monitor vital sign parameters (chinese patent CN 206342462U). These fiber optic interferometers all have a sensing arm and a reference arm, so that the reference arm is not affected by the external environment, and the difficulty and cost of sensor packaging are increased.

SUMMERY OF THE UTILITY MODEL

Not enough to prior art exists, the utility model discloses a to the improvement of fiber optic interferometer, make it need not to keep apart sensing arm and reference arm, obtain simple structure, low cost, the high vital sign parameter monitoring devices of sensitivity. In the scheme of the utility model, the fibre core and the cladding of the four-cone sensing optical fiber of adoption both as the reference arm, also as the sensing arm. When human body vibration perturbation is applied to the four-cone sensing optical fiber, the interference phase difference, the light intensity in the optical fiber core and the cladding synchronously change, and the output light intensity changes along with the change. By demodulating the output light intensity, the information of body vibration, such as respiration, heartbeat, body movement and the like, can be restored. The utility model discloses specifically adopt following technical scheme:

the utility model provides a vital sign parameter monitoring devices based on four awl optical fiber interferometer which characterized in that includes and connects gradually through transmission optical fiber: the device comprises a light source, a four-cone sensing optical fiber, a photoelectric detector and an upper computer connected with the photoelectric detector.

Preferably, the light source is an FP or DFB or VECEL light source or a white light source.

Preferably, the first transmission optical fiber is respectively connected with the output end of the light source and the input end of the four-cone sensing optical fiber; the second transmission optical fiber is respectively connected with the output end of the four-cone sensing optical fiber and the input end of the photoelectric detector.

Preferably, the first and second transmission fibers are single mode fibers.

Preferably, the four-taper sensing fiber has a core and a cladding, including two taper waists.

Preferably, the four-cone sensing fiber is made by tapering a single-mode fiber with the length of 50cm and the inner and outer core diameters of 9/125 um; the diameter of the conical waist is 50-70 microns, and the distance between the two conical waists is larger than 1 cm.

Preferably, the four-cone sensing fiber is made by drawing a cone by using a multimode fiber.

The utility model discloses and other interference type optic fibre vital sign parameter monitoring systems advantage lies in compared to preferred scheme thereof: the reference arm and the interference arm are not separated, so that the influence of the environment on the reference arm is avoided. For the four-cone sensing optical fiber sensing, the optical fiber sensing. Meanwhile, the device has the advantages of simple structure, simple and convenient process steps, easiness in preparation, good product stability, long service life and the like, can realize real-time measurement, achieves the purpose of continuously measuring vital sign parameters of a human body, and can be used as a coherent light source and an incoherent light source.

Drawings

The invention will be described in further detail with reference to the following drawings and detailed description:

fig. 1 is a schematic view of the overall structure of an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a four-cone sensing optical fiber according to an embodiment of the present invention;

FIG. 3 is a schematic view of the working principle of the embodiment of the present invention;

FIG. 4 is a diagram illustrating the results of an embodiment of the present invention;

in the figure: 11-a light source; 12-a first transmission fiber; 13-a four-taper sensing fiber; 14-a second transmission fiber; 15-a photodetector; 16-an upper computer; 131-a first cone waist; 132-second cone waist; 31-spectrum before drift; 32-shifted spectrum.

Detailed Description

In order to make the features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail as follows:

as shown in fig. 1, the apparatus of the present embodiment includes: including connecting gradually through transmission fiber: the device comprises a light source 11, a four-cone sensing optical fiber 13, a photoelectric detector 15 and an upper computer 16 connected with the photoelectric detector 15. The upper computer 16 is generally a PC or a smart phone, and carries a vital sign parameter extraction and analysis algorithm module, and the extraction and algorithm module adopts the existing vital sign parameter extraction and analysis algorithm in the prior art except for extracting heartbeat information by using FFT higher harmonics, so that the details are not repeated herein.

Specifically, in the present embodiment, the light source 11 is an FP or DFB or VECEL light source 11 or a white light source 11.

The first transmission optical fiber 12 is respectively connected with the output end of the light source 11 and the input end of the four-cone sensing optical fiber 13; the second transmission optical fiber 14 is respectively connected with the output end of the four-cone sensing optical fiber 13 and the input end of the photoelectric detector 15.

The first and

second transmission fibers

12, 14 are single mode fibers.

Specifically, the four-taper sensing fiber 13 is made by tapering according to the following method:

step A1: intercepting a structure with the length of 50cm and the inner and outer core diameters of 9/125um to form a common single mode fiber by a fiber core and a cladding;

step A2: forming the four-cone sensing optical fiber 13 with a four-cone structure including two cone waists as shown in fig. 2 by using a tapering method, such as melting and drawing by using a carbon dioxide laser; the diameter of the waist is 50-70 microns, and the distance between the two waist is more than 1 cm.

Similarly, the four-taper sensing fiber 13 can also be made by multimode fiber tapering.

In this embodiment, the photodetector 15 may be connected to the host computer 16 through wireless transmission such as bluetooth, so as to ensure the portability of the whole device. The vital sign parameter extraction and analysis algorithm module in the upper computer 16 is used for processing the original signal output by the photoelectric detector 15 and then obtaining vital sign parameter information.

The specific working method and principle of the embodiment are as follows:

as shown in fig. 3, in the initial state, the operating wavelength of the (laser) light source 11 is λ, and the output power of the four-taper sensing fiber 13 is P; when incident light propagates at the first taper waist 131 of the four-taper sensing fiber 13, the core mode is split into a fundamental mode and a high-order mode, both of which are transmitted in the fiber and then accumulate phase shift; the fundamental and high order modes recombine, interfere, at the second waist 132; assuming that only two modes co-propagate, when the two fields combine and produce a wavelength dependent intensity interference, resulting in a pre-drift spectrum 31, the interference output of the four-taper sensing fiber 13 can be expressed as:

；

；

wherein

Which is indicative of the intensity of the interference signal,

、

the intensities of a fiber core fundamental mode and a lowest-order cladding mode of the four-cone sensing fiber 13 are respectively;

、

effective refractive indexes of a fiber core fundamental mode and a lowest-order cladding mode of the four-cone sensing fiber 13 are respectively set; l is the distance between two conical waists of the optical fiber;

the refractive index and the device length can be changed due to the disturbance of the body movement, the respiration and the heartbeat of the human body, the spectrum of the four-cone sensing optical fiber 13 is shifted to form a shifted spectrum 32, and the light intensity at the working wavelength is changed; at the moment, the output power of the four-cone sensing fiber 13 is changed from P to

(ii) a As shown in fig. 4, the upper computer 16 can obtain the vital sign parameter information by analyzing the signals collected by the photodetector 15, and because the heartbeat fundamental frequency signal is seriously interfered, the heartbeat information is extracted by FFT higher harmonics.

If the multi-mode optical fiber is adopted to manufacture the interferometer, the working principle of the interferometer belongs to multi-beam interference, and the result is similar.

The present invention is not limited to the above-mentioned preferred embodiments, and other various forms of the four-cone fiber optic interferometer based vital sign parameter monitoring device can be obtained by anyone who can benefit from the teaching of the present invention.

Claims

1. The utility model provides a vital sign parameter monitoring devices based on four awl optical fiber interferometer which characterized in that includes and connects gradually through transmission optical fiber: the device comprises a light source, a four-cone sensing optical fiber, a photoelectric detector and an upper computer connected with the photoelectric detector; the first transmission optical fiber is respectively connected with the output end of the light source and the input end of the four-cone sensing optical fiber; the second transmission optical fiber is respectively connected with the output end of the four-cone sensing optical fiber and the input end of the photoelectric detector.

2. The four-cone fiber optic interferometer-based vital sign parameter monitoring device of claim 1, wherein: the light source is an FP or DFB or VECEL light source or a white light source.

3. The four-cone fiber optic interferometer-based vital sign parameter monitoring device of claim 1, wherein: the first transmission fiber and the second transmission fiber are single mode fibers.

4. The four-cone fiber optic interferometer-based vital sign parameter monitoring device of claim 1, wherein: the four-cone sensing optical fiber is provided with a fiber core and a cladding, and comprises two cone waists.

5. The four-cone fiber interferometer-based vital sign parameter monitoring device of claim 4, wherein: the four-cone sensing optical fiber is made by tapering a single-mode optical fiber with the length of 50cm and the inner and outer core diameters of 9/125 um; the diameter of the conical waist is 50-70 microns, and the distance between the two conical waists is larger than 1 cm.

6. The four-cone fiber optic interferometer-based vital sign parameter monitoring device of claim 1, wherein: the four-cone sensing optical fiber is made by drawing a cone by adopting a multimode optical fiber.