TWM505286U - Fiber optics sensing device and monitoring system - Google Patents

Description

Fiber optic sensing device and monitoring system

This creation belongs to the technical field of fiber optic sensing devices, and more particularly to fiber optic sensing devices and monitoring systems using fiber optic sensing devices.

In recent years, with the development of fiber optic sensing device monitoring technology, fiber optic sensing devices can be used to detect human body breathing, heartbeat, sleep, etc., and have gradually been applied to the field of household items, such as baby pads, seat cushions and the like.

Taking a human body respiratory monitoring mattress with a fiber-optic sensing device as an example, the outer surface is a kit, and the fiber optic sensing device is arranged in the kit. The fiber-optic sensing device comprises an optical fiber and two upper and lower grids, and the grid is a layer material which is harder than the optical fiber. The optical fibers are arranged in parallel with each other in the grid to form a sensing area. Thus, when the human body is pressed against the mattress, as the human body breathes, the upper and lower layers of the grid are pressed against the optical fiber to cause different deformation of the optical fiber. When the fiber is bent, light decay occurs, and the light decay value is transmitted to the electronic component, and the mathematical data of the electronic component can be used to obtain information about the human body's breathing.

However, due to the defect that the optical fiber itself is easy to be broken or damaged, when the upper and lower meshes are easy to break the optical fiber and the optical fiber is arranged, the interval between adjacent optical fibers cannot be too small, and the bending curvature characteristic of the optical fiber itself is limited, and the interval is generally at least 20 mm. If it is too small, the fiber may be broken, and the excessive interval may cause the deformation of the fiber in some areas of the grid to be inconspicuous, affecting the light decay value. Therefore, there is an inductive blind zone, resulting in uneven sensitivity of the fiber sensing device, mass production. At the time, the sensitivity of each mass-produced fiber-optic sensing device cannot be unified, and the difference is large. In addition, there is still the problem that when the same pressure acts on different sensing points on the same grid, the sensitivity of different sensing points is large, which may cause the human body to change different postures on the sensing layer. The breathing changes cannot be measured, and the upper and lower meshes cannot be bent. If the mesh is bent, the fiber between the upper and lower meshes will be difficult to receive pressure from the sensing layer, thus reducing the sensitivity of the fiber sensing device. In addition, the upper and lower grids must have a certain thickness to make the fiber bend-induced, and the thickness cannot be adjusted according to different applications, resulting in limited application range.

In view of this, the present invention proposes a fiber-optic sensing device, which mainly comprises a base film, a first flexible film, a second flexible film, and an optical fiber. The base film has a first surface and a second surface; the first flexible film is disposed on the first surface of the base film, and defines a first interlayer together with the base film; the second flexible film is disposed on the base film a second surface, and a second interlayer is defined together with the base film; the optical fiber includes a first fiber portion and a second fiber portion, the first fiber portion is disposed in the first layer, and the first fiber portion is along the first layer The first direction extends. The second fiber portion is disposed in the second spacer, and the second fiber portion is interlaced with the first fiber portion in the projection direction without overlapping.

In another aspect of the present invention, the first optical fiber portion includes a plurality of first bending sections and a plurality of first straight sections, and the two ends of each of the first bending sections are respectively connected to the first straight section. Each of the first straight segments extends in a second direction substantially perpendicular to the first direction; the second fiber portion includes a plurality of second bent segments and a plurality of second straight segments, each of the second bent segments The two ends are respectively connected to the second straight section, and each of the second straight sections is extended along the second direction.

Another concept of the present invention is that the optical fiber sensing device further includes a third flexible film disposed on the first flexible film to define a third interlayer together with the first flexible film; the optical fiber further includes a The third fiber portion, the third fiber portion is disposed in the third layer in the first direction, and the first fiber portion, the second fiber portion and the third fiber portion do not overlap or are staggered in the projection direction.

Another concept of the present invention is the fiber optic sensing device, wherein the third fiber portion includes a plurality of third bending sections and a plurality of third straight sections, and the two ends of each of the third bending sections are respectively connected to the third straight line The segments, each of the third straight segments, extend in a second direction that is substantially perpendicular to the first direction.

Another concept of the present invention is that in the above fiber-optic sensing device, the curvature radii of the adjacent first bending sections are different from each other; the curvatures of the adjacent second bending sections are different from each other.

Another concept of the present invention is that in the above fiber-optic sensing device, the plurality of first straight line segments are spaced apart from each other in the first direction, and the plurality of first straight line segments are spaced apart from each other in the first direction.

Another concept of the present invention is that in the above fiber-optic sensing device, the lengths of the plurality of first straight line segments are not equal in length, and the lengths of the plurality of second straight line segments are not equal in length.

Another concept of the present invention is that in the above fiber optic sensing device, the length of the plurality of first straight line segments decreases or increases in a first direction; the length of the plurality of second straight line segments decreases or increases in a first direction.

In another aspect of the present invention, the first optical fiber portion includes a plurality of first bending sections and a plurality of first straight sections, and the two ends of each of the first bending sections are respectively connected to the first straight section. Each of the first straight segments extends in a second direction substantially perpendicular to the first direction; the second fiber portion includes a plurality of second bent segments and a plurality of second straight segments, each of the second bent segments The two ends are respectively connected to the second straight line section, and the ends of the second straight line sections are extended along the first direction.

The present invention also proposes a monitoring system comprising the above-described fiber optic sensing device, light source, light detecting element and processing circuit. A light source is coupled to the entrance end of the optical fiber for generating a light in the optical fiber. The light detecting component is connected to the exit end of the optical fiber for detecting a light decay value when the light propagates through the optical fiber to generate a light decay signal. The processing circuit is coupled to the light detecting element to generate a physiological activity parameter based on the light decay signal.

In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

It should be noted that when a component is referred to as being "fixed to" or "set to" another component, it can be directly on the other component or possibly at the same time. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or the central component may be present at the same time. The left, right, upper, lower, and the like orientations in this embodiment are merely relative concepts or reference to the normal use state of the product, and should not be considered as limiting.

Referring to FIG. 1 to FIG. 3, the optical fiber sensing device 10 of the first embodiment includes a base film 11, a first flexible film 12, a second flexible film 13, and a first optical fiber portion 14a and a second optical fiber. The fiber 14 of the portion 14b. The base film 11 has two surfaces. The first flexible film 12 is disposed on one surface of the base film 11 and defines a first barrier layer 19a together with the base film 11. The second flexible film 13 is disposed on the other surface of the base film 11 and defines a second barrier layer 19b together with the base film 11. The first fiber portion 14a is disposed in the first interlayer 19a, and the first fiber portion 14a extends in a first direction. The first direction referred to herein is equivalent to left to right or right to left in the drawing. The direction. The second fiber portion 14b is disposed in the second barrier layer 19b. In the present embodiment, the second fiber portion 14b also extends in the first direction, in the projection direction (corresponding to the normal direction of the base film 11). Upper second fiber portion 14b does not overlap with first fiber portion 14a but may be staggered. That is to say, the second fiber portion 14b and the first fiber portion 14a have only intersections in the projection direction, and no overlap of the line segments occurs.

It should be noted that the materials of the base film 11, the first flexible film 12 and the second flexible film 13 are soft materials, and the soft material may be silicone or woven fabric. The base film 11, the first flexible film 12 and the second flexible film 13 are deformable when subjected to pressure. The first flexible film 12 and the second flexible film 13 can function as a reference light signal that does not interfere with the original light source when it is not under pressure. In addition, the base film 11, the first flexible film 12 and the second flexible film 13 may also be a polyethylene film. The material not only has a flexible protective effect, but also has moisture resistance, low moisture permeability, and can be ensured. Dryness of the first fiber portion 14a and the second fiber portion 14b.

As shown in Fig. 1, a light fade signal is generated when the first fiber portion 14a is axially deformed, that is, a region where the first fiber portion 14a and the second fiber portion 14b are disposed will form the fiber sensing region 90. Therefore, it can be determined whether the optical fiber sensing region 90 is deformed by an external force by detecting the optical attenuation signal generated by the first optical fiber portion 14a or the second optical fiber portion 14b. Therefore, when the human body causes the optical fiber sensing device 10 to deform due to breathing, heartbeat or other physiological activities, the physiological activity of the human body can be detected by detecting the light decay signal generated by the first optical fiber portion 14a and/or the second optical fiber portion 14b. .

Since the first barrier layer 19a and the second barrier layer 19b are separated by the at least one base film 11 to separate the first flexible film 12 from the second flexible film 13, the structure of the entire fiber sensing device 10 can be layered. . For example, a base film 11 may be additionally disposed on the surface of the first flexible film 12 or the second flexible film 13, such that the newly added base film 11 and the first flexible film 12 or the second flexible film 13 are added. A new barrier is formed between them, and a new compartment accommodates the remaining fiber portion of the fiber 14 therein. Similarly, a second flexible film 13 or the first flexible film 12 may be additionally disposed on the new base film 11, such that the newly added second flexible film 13 or the first flexible film 12 is A new spacer layer is formed between the above-mentioned newly added base film 11, and the remaining fiber portion of the optical fiber 14 can be further disposed therein, and so on.

As shown in FIG. 4 , in the top view of the second embodiment of the present invention, the optical fiber sensing device 10 further includes a third flexible film disposed on the first flexible film 12 and the first flexible film. 12 collectively defines a third compartment, the optical fiber 14 further includes a third fiber portion 14c, and the third fiber portion 14c is disposed in the third layer in the first direction. In the present embodiment, the first optical fiber portion 14a, the second optical fiber portion 14b, and the third optical fiber portion 14c do not overlap each other or are staggered in the projection direction. The light decay signal generated when the fiber is deformed can be used to reflect one of the parameters, such as breathing, heartbeat, sleep, temperature, and humidity. Alternatively, two or more parameters can be reflected with different fiber portions of a single fiber. For example, the first fiber portion 14a in the first compartment 19a is used to reflect breathing, heartbeat, and sleep, while the third fiber portion 14c in the third compartment is used to reflect temperature and humidity. Alternatively, different compartments may be utilized to reflect different parameters; for example, the first compartment 19a reflects sleep, the second compartment 19b reflects breathing; or the first compartment 19a reflects breathing, heartbeat, sleep, second compartment The layer 19b reflects the temperature and the like. In this way, the application combination of the above-mentioned optical fiber sensing device 10 is made richer and more widely used.

As shown in FIG. 1, the working principle of the present embodiment is that when the optical fiber sensing device 10 is applied to a mattress, a pillow, a clothes, an insole, a seat cushion, a sofa, a carpet, a floor, or the like, the physiological activity of the human body or the animal, for example, The breathing and the heartbeat, etc., cause the first fiber portion 14a and the first flexible film 12 to simultaneously slide or vibrate and be deformed by force, thereby increasing the amount of change in the light decay signal. Different force levels, even with only a slight vibration, can clearly distinguish different physiological activity patterns due to the large difference in the amount of change in the light decay signal, and have a high resolution. In practical application, the change amount of the light decay signal is first input into the light processing circuit, and then the change amount of the light decay signal is converted into a charge signal calculation unit, and finally the charge signal calculation unit is input to the processor, and is obtained by the processor calculation. The physiological activity signal of the human body.

As shown in FIG. 1 and FIG. 3, the optical fiber sensing device 10 uses at least one base film 11 to partition the space between the first flexible film 12 and the second flexible film 13 into at least two compartments in the up and down direction. That is, the first barrier layer 19a and the second barrier layer 19b. At least one fiber portion is disposed in each of the partitions, and each of the fiber portions is disposed in a sturdy manner, and the appearance is formed by connecting a plurality of S-shaped wires in series. As a result, the portions of the fibers in each of the spacers are uniformly and densely distributed in the lateral direction and the longitudinal direction on the first flexible film 12 and the second flexible film 13, and a uniformly dense fiber sensing region 90 is formed. Moreover, the portions of the fibers between the upper and lower adjacent barrier layers are staggered in the projection direction and do not overlap, and the fiber sensing regions 90 formed on each of the barrier layers are staggered in the projection direction. In this way, even if the local fiber portion is defective and the local induction dead zone is caused, the sensing can be supplemented by the fiber sensing region 90 of the different interlayer. In addition, when the same pressure acts on different sensing points or faces in the same fiber sensing region 90, the optical fiber has a high density and a uniform force, and the optical fading of the optical fiber is uniform, and the light fading value is relatively uniform, so that the optical fiber sensing device 10 can be improved. Sensitivity and uniformity of the overall sensitivity of the fiber optic sensing device 10. In addition, the optical fiber sensing device 10 is also characterized by being thin, compact, and resistant to electromagnetic interference.

It should be noted that the minimum bending radius of the conventional fiber is 5 mm. Therefore, the minimum diameter of the first fiber portion 14a and the second fiber portion 14b of the fiber sensing device 10 provided in this embodiment is at least 10 mm.

As shown in FIGS. 1 and 3, the first fiber portion 14a has a plurality of first bending segments 141 and a plurality of first straight segments 142, each of the first bending segments 141 having an arc of 180°. It is advantageous to keep the first straight sections 142 connected to the two ends of the first bending section 141 parallel to each other, which is advantageous for regularly, uniformly and densely distributing the optical fiber lines on the flexible film.

As shown in FIGS. 3 and 4, in the first optical fiber portion 14a, the radii of curvature of the first bent sections 141 at both ends of the same first straight line section 142 are different from each other. In addition, the radius of curvature of the second bending section 143 at the two ends of the same second straight section 144 may also be different from each other, and the radius of curvature of the second bending section 145 at the two ends of the same third straight section 146 is also Can be different from each other. In order to make all the fiber portions in the projection direction do not overlap or stagger, the radius of curvature of the bending portions adjacent to each other in the different directions of the different fiber portions in the different layers is as shown in FIG. The direction gradually increases or decreases, so that the fiber line of the fiber sensing device 10 is more regular and dense, and the fiber sensing area 90 can more sensitively sense the pressure, thereby more sensitively and accurately capturing the change of the light decay signal, so that The optical fiber sensing device 10 has uniform sensitivity, relatively uniform light attenuation values, high sensitivity, adjustable, and high resolution.

As shown in Figures 3 and 5, a third embodiment of the present invention is disclosed in which the radius of curvature of the bent sections of the optical fiber portion of the same compartment is equal. For example, all of the first bending sections 141 of the first fiber portion 14a have equal radii of curvature. The radius of curvature of the bent sections of all the optical fibers is regularly changed, which facilitates regular, uniform, and dense distribution of the optical fiber lines, so that the optical fiber sensing device 10 has uniform sensitivity, relatively uniform light attenuation values, high sensitivity, and adjustable High resolution.

As shown in Figures 3 and 6, a fourth embodiment of the present invention is disclosed. In this embodiment, the straight sections of the same fiber portion of the same compartment are not of equal length. For example, each of the first straight sections 142 of the first fiber portion 14a is not of equal length.

As shown in Figs. 3 and 7, a fifth embodiment of the present invention is disclosed, which is an optimization of the fourth embodiment. In this embodiment, the radius of curvature of the bent section of the same fiber portion of the same spacer gradually increases or decreases in the first direction. For example, the plurality of first bending sections 141 of the first fiber portion 14a in Fig. 7 are gradually decreased or incremented along the first direction. In this way, the adjacent two fiber portions compensate each other for the blank area. Such a line layout can more fully utilize the space, so that the fiber line is more densely distributed, so that the sensitivity of the fiber sensing device 10 is uniform and the light attenuation value is relatively Consistent, sensitive, adjustable, and high resolution.

As shown in FIG. 3 and FIG. 8, a sixth embodiment of the present invention is disclosed. In this embodiment, the line layout patterns of all the optical fiber portions of the respective spacers are uniform, and the optical fiber portions of the adjacent two spacer layers are bent. The folded sections are staggered by the same distance in the first direction. For example, the line layout patterns of the first fiber portion 14a, the second fiber portion 14b, and the third fiber portion 14c are identical, and the first bending portion 141 of the first fiber portion 14a and the second bending portion of the second fiber portion 14b are Segments 143 are offset by the same distance in the first direction. In this embodiment, since each of the optical fiber portions has an "S" shape, the straight sections on both sides of each of the bent sections are parallel to each other, and the distance between the straight sections on both sides is not less than a minimum. The distance between the ends of the bend section. Therefore, each straight line segment has a certain interval along the first direction. The bent sections of the upper and lower adjacent layers of the optical fiber are staggered by the same distance in the first direction, so that the straight sections on both sides of the upper bending section just fall on the straight sections of the lower side of the lower bending section. In the interval, the sensing blind zone caused by the excessive interval is avoided, so that the fiber sensing device of the embodiment has uniform sensitivity, relatively uniform light attenuation value, high sensitivity, adjustable, and high resolution.

In addition, stacking the straight sections on both sides of the upper bending section in the interval of the straight sections on both sides of the lower bending section facilitates reducing the thickness of the fiber sensing device in the vertical direction, and tending to Thin.

As shown in Figs. 9 and 10, a seventh embodiment of the present invention is disclosed. The first fiber portion 14a includes a plurality of first bending segments 141 and a plurality of first straight segments 142. The two ends of each of the first bending segments 141 are respectively connected to the first straight segment 142, and each of the first straight segments 142 is Extending in a second direction that is substantially perpendicular to the first direction. The second fiber portion 14b includes a plurality of second bending sections 143 and a plurality of second straight sections 144, and two ends of each of the second bending sections 143 are respectively connected to the second straight section 144, and each of the second straight sections The 144 series extends along the first direction. That is, the second straight line segment 144 of the first fiber portion 14a is perpendicular to the second straight line segment 144 of the second fiber portion 14b in the projection direction. As a result, the stacking of the upper and lower layers of the optical fiber lines in the vertical direction will form a grid shape, thereby forming a grid-shaped fiber sensing region 90.

As shown in Figs. 3 and 11, an eighth embodiment of the present invention is disclosed. In this embodiment, a specific embodiment for detecting temperature and humidity is newly added to the optical fiber sensing device 10. For example, the temperature sensitive unit 81 and the humidity sensitive unit 82 may be disposed in the first compartment 19a, when the temperature sensitive unit 81 is Expanded by heat, or when the humidity sensitive unit 81 expands due to moisture absorption, the temperature sensitive unit 81 and the humidity sensitive unit 82 squeeze the first optical fiber portion 14a due to expansion, causing the first optical fiber portion 14a to be locally deformed, so that the first optical fiber The light decay value of portion 14a changes. The fiber optic sensing device 10 of the present embodiment can be applied to the detection of urine temperature and humidity.

As shown in FIG. 12, a functional block diagram of a ninth embodiment of the present invention is disclosed. The present embodiment provides a monitoring system 300 using the optical fiber sensing device 10, which includes a light source 301 in addition to the optical fiber sensing device 10. The light detecting element 302 and the processing circuit 303. Light source 301 is coupled to the entrance end of fiber 14 of fiber optic sensing device 10 for generating light in the fiber. The light detecting element 302 is connected to the exit end of the optical fiber 14 for detecting the light decay value of the light propagating in the optical fiber 14 to generate a light decay signal. The processing circuit 303 is coupled to the photodetecting element 302 for generating a physiological activity parameter for reacting the physiological activity of the human body based on the light decay signal. The human physiological activity parameter may further be transmitted to the terminal device 400 by means of a signal transmission means such as a USB, a wired network or a wireless network. The terminal device 400 can be a user's computer or a mobile smart device. For example, if the physiological activity parameters of the human body are transmitted to the smart phone of the user, the user can monitor the physiological activity parameters at any time; if the physiological physiological activity parameters are transmitted to the computer, the management system on the computer can be used. The physiological activity parameters of a large number of users are processed and monitored in batches.

Although the technical content of the present invention has been disclosed in the above embodiments, it is not intended to limit the present creation, and any person who is familiar with the art should make some changes and refinements without departing from the spirit of the creation, and should cover the scope of the creation. Therefore, the scope of protection of this creation is subject to the definition of the scope of the patent application.

10‧‧‧Fiber sensing device
11‧‧‧Base film
111‧‧‧ first surface
112‧‧‧ second surface
12‧‧‧First flexible film
13‧‧‧Second flexible film
14‧‧‧Fiber
14a‧‧‧First fiber section
141‧‧‧First bend section
142‧‧‧First straight section
14b‧‧‧second fiber section
143‧‧‧Second bending section
144‧‧‧Second straight section
14c‧‧‧ third fiber section
145‧‧‧ Third bending section
146‧‧‧ third straight section
19a‧‧‧ first compartment
19b‧‧‧Second compartment
300‧‧‧Monitoring system
301‧‧‧Light source
302‧‧‧Light detection components
303‧‧‧Processing Circuit
400‧‧‧ Terminal devices
81‧‧‧Temperature sensitive unit
82‧‧‧ Humidity sensitive unit
90‧‧‧Fiber sensing area

[Fig. 1] is a schematic view of a fiber optic cable according to a first embodiment of the present invention; [Fig. 2] is a plan view of a first embodiment of the creation; [Fig. 3] is a cross-sectional view of the first embodiment according to Fig. 2 [Fig. 4] is a plan view of a second embodiment of the present creation; [Fig. 5] is a plan view of a third embodiment of the creation; [Fig. 6] is a plan view of the fourth embodiment of the creation; [Fig. 7] a top view of the fifth embodiment of the present invention; [Fig. 8] is a plan view of the sixth embodiment of the present creation; [Fig. 9] is a plan view of the seventh embodiment of the creation; [Fig. 10] is according to the ninth embodiment A cross-sectional view of a seventh embodiment of the present invention; [Fig. 11] is a plan view of the eighth embodiment of the present invention; and [12] is a functional block diagram of the ninth embodiment of the present invention.

10‧‧‧Fiber sensing device

11‧‧‧Base film

14‧‧‧Fiber

14a‧‧‧First fiber section

141‧‧‧First bend section

142‧‧‧First straight section

14b‧‧‧second fiber section

143‧‧‧Second bending section

144‧‧‧Second straight section

90‧‧‧Fiber sensing area

Claims (10)

An optical fiber sensing device comprising: a base film having a first surface and a second surface; a first flexible film disposed on the first surface of the base film and defining a first surface together with the base film a second flexible film disposed on the second surface of the base film and defining a second interlayer together with the base film; and an optical fiber including a first fiber portion and a second fiber portion The first fiber portion is disposed in the first partition in a first direction, the second fiber portion is disposed in the second layer, and the second fiber portion is in the projection direction Does not overlap with the first fiber portion. The fiber-optic sensing device of claim 1, wherein the first fiber portion comprises a plurality of first bending segments and a plurality of first straight segments, and the two ends of each of the first bending segments are respectively connected to the first a straight line segment, each of the first straight line segments extending in a second direction substantially perpendicular to the first direction; the second fiber portion comprising a plurality of second bent segments and a plurality of second straight segments, each of the Two ends of the second bending section are respectively connected to the second straight section, and each of the second straight sections extends along the second direction. The optical fiber sensing device of claim 2, further comprising a third flexible film disposed on the first flexible film to define a third interlayer together with the first flexible film; the optical fiber further comprises a third optical fiber portion is disposed in the third spacer along the first direction, and the first optical fiber portion, the second optical fiber portion and the third optical fiber portion do not overlap each other in the projection direction and are not interlaced . The fiber-optic sensing device of claim 3, wherein the third fiber portion comprises a plurality of third bending segments and a plurality of third straight segments, and the two ends of each of the third bending segments are respectively connected to the first A three-linear segment, each of the third linear segments extending in a second direction that is substantially perpendicular to the first direction. The fiber sensing device of claim 4, wherein the curvatures of the first bending sections of the two ends of the same first straight section are different from each other. The fiber sensing device of claim 2, wherein the plurality of first straight line segments are spaced apart from the second direction along the first direction, and the plurality of second straight line segments are spaced apart from the second direction along the first direction . The fiber sensing device of claim 6, wherein the length of the plurality of first straight line segments is not equal, and the length of the plurality of second straight line segments is not equal. The fiber sensing device of claim 7, wherein the length of the plurality of first straight line segments decreases or increases along the first direction; the length of the plurality of second straight line segments decreases or increases along the first direction. The fiber-optic sensing device of claim 1, wherein the first fiber portion comprises a plurality of first bending segments and a plurality of first straight segments, and the two ends of each of the first bending segments are respectively connected to the first a straight line segment, each of the first straight line segments extending in a second direction substantially perpendicular to the first direction; the second fiber portion comprising a plurality of second bent segments and a plurality of second straight segments, each of the The two ends of the second bending section are respectively connected to the second straight section, and each of the second straight sections extends along the first direction. A monitoring system comprising: the optical fiber sensing device according to any one of claims 1 to 9; a light source connected to the entrance end of the optical fiber for generating a light in the optical fiber; a light detecting component, connected At the exit end of the optical fiber, for detecting the light decay value of the light propagating in the optical fiber to generate a light decay signal; and a processing circuit connected to the light detecting component, generating a physiological activity according to the light decay signal parameter.