Blood pressure monitoring method and blood pressure monitoring device based on SMF-FMF sensing structure

Abstract

The invention provides a blood pressure monitoring method based on an SMF-FMF sensing structure and a sensing device. The blood pressure monitoring method based on the SMF-FMF sensing structure comprises the steps that a high-order mode is excited in the SMF-FMF sensing structure through an incoherent optical time domain reflectometer under multiple different specified blood pressure values; detecting the SMF-FMF sensing structure through an incoherent optical time domain reflectometer to obtain a back Rayleigh scattering intensity curve; demodulating each back Rayleigh scattering intensity curve to obtain a final jump intensity value of each back Rayleigh scattering intensity curve, and establishing a corresponding relationship between the specified blood pressure value and the final jump intensity value; the SMF-FMF sensing structure is arranged at a blood pressure to-be-measured position, a back Rayleigh scattering intensity curve detected by the incoherent optical time domain reflectometer at the blood pressure to-be-measured position is calculated to obtain an actual jump intensity value of the blood pressure to-be-measured position, and an actual blood pressure value of the blood pressure to-be-measured position is calculated according to the actual jump intensity value and the corresponding relation. The technical effect of improving blood pressure monitoring convenience can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber sensing and medical technology, and in particular to a blood pressure monitoring method and a blood pressure monitoring device based on a SMF-FMF sensing structure. Background Art

[0002] Heart and blood diseases are increasingly threatening human health, among which high blood pressure is particularly common. Blood pressure reflects the degree of cardiovascular health and is a reliable indicator of the human cardiovascular system. Due to the unhealthy diet and lack of exercise of many people, and due to the aging of society, high blood pressure has become a major threat to the health of the elderly, and the problem of high blood pressure has become very common among the population. Problems such as increased labor costs, increased medical expenses, and shortage of medical personnel have gradually surfaced. Therefore, smart blood pressure monitoring is very important in daily life.

[0003] Commercial sphygmomanometers usually use inflatable cuff technology, and its basic principle is mainly the oscillometric method. The discomfort and inconvenience it brings to people during the measurement process are its main problems. Therefore, in order to make blood pressure monitoring more comfortable, convenient and accurate, high-quality blood pressure monitoring solutions are urgently needed. With the development of optical fiber technology, optical fiber sensors are gradually applied to the field of smart healthcare. For example, sensors based on fiber Bragg gratings achieve blood pressure monitoring by detecting the spectral fluctuations of fiber Bragg gratings, but they have the disadvantages of high cost and complex demodulation methods. In addition, there is also a blood pressure monitoring technology based on plastic optical fiber optical fiber sensors, which have low cost and simple demodulation, but have the disadvantage of low sensitivity.

[0004] That is, how to provide a blood pressure monitoring method and a sensing device based on the SMF-FMF sensing structure to achieve the technical effect of reducing costs while maintaining high sensitivity is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0005] In view of the above-mentioned problems, the present invention aims to provide a blood pressure monitoring method and a sensing device based on a SMF-FMF sensing structure, so as to solve at least one of the above-mentioned technical problems.

[0006] In order to at least solve the above technical problems, in a first aspect, the present invention provides a blood pressure monitoring method based on a SMF-FMF sensing structure, the method comprising:

[0007] Incoherent optical time-domain reflectometry was used to excite high-order modes in the SMF-FMF sensing structure at multiple different specified blood pressure values;

[0008] Detecting the high-order modes transmitted in the SMF-FMF sensing structure by the incoherent optical time domain reflectometer to obtain a backscattering Rayleigh intensity curve corresponding to each of the specified blood pressure values;

[0009] Demodulating each of the Rayleigh backscattering intensity curves to obtain a final transition intensity value of each of the Rayleigh backscattering intensity curves, and establishing a corresponding relationship between the designated blood pressure value and the final transition intensity value;

[0010] The SMF-FMF sensing structure is placed at a location where the blood pressure is to be measured, and the back Rayleigh scattering intensity curve detected by the incoherent optical time domain reflectometer at the location where the blood pressure is to be measured is calculated to obtain an actual transition intensity value at the location where the blood pressure is to be measured, and the actual blood pressure value at the location where the blood pressure is to be measured is calculated based on the actual transition intensity value and the corresponding relationship.

[0011] Preferably, the SMF-FMF sensing structure is an optical fiber sensing structure formed by eccentrically fusing a section of SMF and a section of FMF, the SMF is a single-mode optical fiber, and the FMF is a few-mode optical fiber.

[0012] Preferably, the method of exciting a high-order mode in a SMF-FMF sensing structure using an incoherent optical time domain reflectometer at a plurality of different specified blood pressure values ​​comprises:

[0013] A plurality of different designated blood pressure values ​​are set, and for each designated blood pressure value, an incoherent optical time domain reflectometer is used to inject a laser signal into an end of the SMF away from the FMF to excite a high-order mode in the FMF.

[0014] Preferably, demodulating each of the Rayleigh backscattering intensity curves to obtain a final transition intensity value of each of the Rayleigh backscattering intensity curves comprises:

[0015] A window corresponding to a preset pulse width is set as a master window, and a signal curve segment is slidably intercepted in each of the collected back Rayleigh scattering intensity curves according to the master window; the preset pulse width is the pulse width of a single pulse emitted by the incoherent optical time domain reflectometer;

[0016] Performing transition intensity demodulation on the signal curve segment to obtain an intermediate transition intensity value corresponding to the signal curve segment; one of the Rayleigh backscattering intensity curves has a plurality of intermediate transition intensity values;

[0017] The maximum value of the plurality of intermediate transition intensity values ​​corresponding to each of the Rayleigh backscattering intensity curves is obtained to obtain a final transition intensity value of each of the Rayleigh backscattering intensity curves.

[0018] Preferably, the performing transition intensity demodulation on the signal curve segment to obtain an intermediate transition intensity value corresponding to the signal curve segment includes:

[0019] Establishing a first child window with the starting end of the mother window as the center;

[0020] The average intensity in the first sub-window is calculated according to a first calculation formula, and the calculated average intensity in the first sub-window is used as the starting intensity of the mother window; the first calculation formula is:

[0021] I 1 (t 0 )=mean(I(t 0 -τ / 2-τ 1 / 2,t 0 +τ / 2+τ 1 / 2));

[0022] Establishing a second sub-window with the terminal of the mother window as the center, wherein the width of the second sub-window is 5% of the width of the mother window;

[0023] The average intensity in the second sub-window calculated according to the second calculation formula is used as the cutoff intensity of the main window; the second calculation formula is:

[0024] I 2 (t 0 )=mean(I(t 0 +τ / 2-τ 1 / 2,t 0 +τ / 2+τ 1 / 2))

[0025] The differential intensity between the cut-off intensity and the starting intensity is calculated according to a differential calculation formula, wherein the differential intensity is an intermediate transition intensity value corresponding to the signal curve segment, and the differential calculation formula is:

[0026] ΔI(t 0 )=I 2 (t 0 )-I 1 (t 0 )

[0027] The width of the first sub-window and the second sub-window are the same; both are 5% of the width of the mother window; 0 is the center position of the mother window, I 1 (t 0 ) is t 0 The initial intensity at I 2 (t 0 ) is t 0 The cutoff intensity of the pair, τ is the width of the mother window, τ 1 is the width of the first sub-window or the second sub-window, ΔI(t 0 ) is the final obtained t 0 The intermediate transition intensity value at , mean is the mean function.

[0028] Preferably, the width of the first sub-window and the second sub-window are both 5% of the width of the mother window.

[0029] Preferably, the establishing of the corresponding relationship between the designated blood pressure value and the final transition intensity value comprises:

[0030] A plurality of the designated blood pressure values ​​and the final transition intensity value corresponding to each of the designated blood pressure values ​​are fitted to obtain a fitting curve between the blood pressure value and the transition intensity value, wherein the fitting curve is the corresponding relationship.

[0031] Preferably, placing the SMF-FMF sensing structure at a location where blood pressure is to be measured comprises:

[0032] The SMF-FMF sensing structure is packaged and then embedded in a wearable textile, and the subject wears the wearable textile to place the SMF-FMF sensing structure at the location where the blood pressure of the subject is to be measured.

[0033] In a second aspect, the present invention further provides a blood pressure monitoring device based on a SMF-FMF sensing structure, the sensing device comprising:

[0034] Incoherent optical time domain reflectometer, packaged SMF-FMF sensor structure and data processor,

[0035] The pulse transmitting end of the incoherent optical time domain reflectometer is connected to the SMF-FMF sensing structure, and the data processor is connected to the data output interface of the incoherent optical time domain reflectometer;

[0036] The incoherent optical time domain reflectometer is used to excite high-order modes in the SMF-FMF sensing structure; and detect the high-order modes transmitted in the SMF-FMF sensing structure to obtain the corresponding backscattering Rayleigh intensity curve;

[0037] The SMF-FMF sensing structure is used to excite high-order modes under the pulse action of the incoherent optical time domain reflectometer;

[0038] The data processor is used to establish a corresponding relationship between the blood pressure value and the transition intensity value, and demodulate the back Rayleigh scattering intensity curve to obtain the final transition intensity value of the back Rayleigh scattering intensity curve, and calculate the actual blood pressure value corresponding to the final transition intensity value at the blood pressure test point according to the corresponding relationship.

[0039] Preferably, the incoherent optical time domain reflectometer comprises:

[0040] A broadband laser source, a semiconductor optical amplifier, an erbium-doped fiber amplifier, a photodetector and a circulator, wherein the output end of the broadband laser source is connected to the input end of the semiconductor optical amplifier, the input end of the semiconductor optical amplifier is connected to the input end of the erbium-doped fiber amplifier, the output end of the erbium-doped fiber amplifier is connected to the first port of the circulator, the second port of the circulator is connected to the SMF-FMF sensing structure, and the third port of the circulator is connected to the photodetector;

[0041] Among them, the wide-spectrum laser source is used to output continuous signal light; the semiconductor optical amplifier is used to receive the continuous signal light and modulate the continuous signal light to form a pulse signal light; the erbium-doped fiber amplifier is used to amplify the power of the received pulse signal light; the photodetector is used to convert the optical signal of the back-Rayleigh scattered light returned by the SMF-FMF sensing structure under test into an electrical signal; and the circulator is used to guide the optical path direction of the detection light and the back-Rayleigh scattered light.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention provides a blood pressure monitoring method based on an SMF-FMF sensing structure. First, a high-order mode is excited in the SMF-FMF sensing structure by using an incoherent optical time domain reflectometer at multiple different specified blood pressure values. The high-order mode excited in the SMF-FMF sensing structure is sensitive to disturbances, and the vibration deformation caused by the pulse wave of the blood pressure change is reflected in the deformation of the sensing structure attached to the surface of the human arterial skin. Then, the high-order mode transmitted in the SMF-FMF sensing structure is detected by the incoherent optical time domain reflectometer to obtain the backscattered Rayleigh light corresponding to each specified blood pressure value. Intensity curve; demodulate each back Rayleigh scattering intensity curve to obtain the final transition intensity value of each back Rayleigh scattering intensity curve, thereby calculating the transition intensity under different perturbations, and establishing a corresponding relationship between the specified blood pressure value and the final transition intensity value based on the calculation result, and finally placing the SMF-FMF sensing structure at the blood pressure to be measured, and calculating the back Rayleigh scattering intensity curve detected by the incoherent optical time domain reflectometer at the blood pressure to be measured to obtain the actual transition intensity value at the blood pressure to be measured, and substituting the actual transition intensity value into the corresponding relationship to obtain the actual blood pressure value at the blood pressure to be measured, so as to realize human blood pressure monitoring. The method provided by the embodiment of the present invention effectively solves the defects of the traditional fiber grating sensor-based demodulation being complex and costly, and can achieve high sensitivity response and high-precision measurement characteristics of blood pressure comparable to traditional fiber grating sensors, greatly broadening the application capability of the distributed sensing technology of incoherent optical time domain reflection technology, and achieving the technical effect of reducing costs while maintaining high sensitivity.

[0044] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A flow chart of a blood pressure monitoring device based on a SMF-FMF sensing structure provided by an embodiment of the present invention;

[0047] Figure 2 A schematic diagram of the structure of a blood pressure monitoring device based on an SMF-FMF sensing structure provided by an embodiment of the present invention;

[0048] Figure 3 A schematic diagram of the structure of an incoherent optical time domain reflectometer in a blood pressure monitoring device provided by an embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of the structure of a data processor in a blood pressure monitoring device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention; the "and / or" keyword involved in this implementation represents both and, or. In other words, A and / or B mentioned in the embodiments of this specification represent both A and B, and A or B, and describe the three states of A and B. For example, A and / or B means: only A is included but not B; only B is included but not A; A and B are included.

[0051] Meanwhile, in the embodiments of this specification, when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a central component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time.

[0052] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0053] Before introducing the specific embodiments of the present application, it is necessary to supplement the following:

[0054] Since the existing blood pressure monitors mainly use inflatable cuff technology, the main problem is the discomfort and inconvenience caused during measurement. The fiber-optic sensors that have solved this problem are mainly fiber Bragg grating sensors, which have the problems of complex demodulation and high cost. In addition, although the blood pressure monitor based on plastic optical fiber solves the problems of cost and complex demodulation, the measurement sensitivity is low, and new blood pressure monitoring technology is still in urgent need of development.

[0055] In the past, incoherent optical time-domain reflectometry was mainly used to locate breakpoints and fault points on the optical fiber path. Since it directly realizes sensing through intensity changes, it has the characteristics of simple structure and simple demodulation, and has great potential in medical applications. Since the high-order modes excited in few-mode optical fibers are more sensitive to disturbances, the Rayleigh scattering intensity in incoherent optical time-domain reflectometry is more sensitive to external disturbances. Therefore, applying the SMF-FMF sensing structure to incoherent optical time-domain reflectometry, supplemented by an improved and optimized intensity demodulation algorithm, can not only retain the advantages of simple system structure and demodulation algorithm, but also achieve high-sensitivity detection of blood pressure, and is expected to become a new generation of blood pressure monitoring technology.

[0056] Embodiment 1

[0057] See also Figure 1-3 Specifically, in the implementation of the blood pressure monitoring method based on the SMF-FMF sensing structure, the method includes the following steps S110 to S140:

[0058] Step S110, using incoherent optical time domain reflectometry to excite high-order modes in the SMF-FMF sensing structure at a plurality of different specified blood pressure values;

[0059] Among them, the SMF-FMF sensing structure of the present application is a fiber optic sensing structure formed by eccentrically fusing a section of SMF and a section of FMF, SMF is a single-mode fiber, and FMF is a few-mode fiber.

[0060] The sensing medium used in traditional fiber optic sensing systems is mostly single-mode optical fiber. Therefore, in order to utilize high-order transmission modes, it is necessary to introduce appropriate few-mode optical fiber structures to stimulate high-order transmission modes. Here, single-mode optical fiber and few-mode optical fiber are eccentrically fused to form an SMF-FMF sensing structure.

[0061] Furthermore, the above step S110 involves exciting a high-order mode in the SMF-FMF sensing structure using an incoherent optical time domain reflectometer at a plurality of different specified blood pressure values, specifically including the following contents:

[0062] A plurality of different designated blood pressure values ​​are set. For each designated blood pressure value, an incoherent optical time domain reflectometer is used to inject a laser signal into the end of the SMF (single-mode fiber) away from the FMF (few-mode fiber) to excite a high-order mode in the FMF (few-mode fiber).

[0063] The incoherent optical time domain reflectometer uses an incoherent light source. The pulsed detection light generated by the incoherent light source is injected from the single-mode end of the sensing structure, which can excite high-order modes at the off-core fusion point and then form high-order transmission modes in the few-mode optical fiber part.

[0064] Among them, the specific number of multiple different designated blood pressure values ​​set is not limited and can be selected according to actual conditions.

[0065] In this embodiment, the SMF-FMF sensing structure that can excite high-order transmission modes is used for sensing measurement, so as to utilize the high-order mode transition intensity of the SMF-FMF sensing structure to monitor blood pressure. The high-order modes transmitted in such optical fibers can produce a large change in Rayleigh scattering light intensity when perturbed, and reflect a large intensity step change on the incoherent back-Rayleigh scattering intensity curve, so the method provided in this embodiment can be used to achieve blood pressure monitoring.

[0066] Step S120, detecting the high-order modes transmitted in the SMF-FMF sensing structure by an incoherent optical time domain reflectometer to obtain a backscattered Rayleigh scattering intensity curve corresponding to each specified blood pressure value;

[0067] It can be understood that a specified blood pressure value corresponds to a Rayleigh backscattering intensity curve, and a Rayleigh backscattering intensity curve can be demodulated and calculated to obtain a corresponding transition intensity value.

[0068] Step S130, demodulating each backscattering Rayleigh intensity curve to obtain a final transition intensity value of each backscattering Rayleigh intensity curve, and establishing a corresponding relationship between the specified blood pressure value and the final transition intensity value;

[0069] In a possible implementation manner, the demodulation of each backscattering Rayleigh intensity curve involved in the above step S130 to obtain the final transition intensity value of each backscattering Rayleigh intensity curve specifically includes the following sub-steps:

[0070] (1) setting a window corresponding to a preset pulse width as a master window, and slidingly intercepting a signal curve segment in each collected backscattering intensity curve according to the master window; the preset pulse width is the pulse width of a single pulse detection light emitted by an incoherent optical time domain reflectometer;

[0071] Among them, a pulse detection light of one cycle emitted by the incoherent optical time domain reflectometer can detect a back Rayleigh scattering intensity curve, and a pulse detection light of one cycle has a corresponding pulse width, and the preset pulse width in the present application is the same as the pulse width of the pulse detection light of one cycle. The time axis of the back Rayleigh scattering intensity curve has a corresponding relationship with the position of the optical fiber path. The point where the intensity on the back Rayleigh scattering intensity curve suddenly changes, that is, the point where the jump intensity is the maximum, corresponds to the FMF intensity change at the blood pressure test position. Therefore, the maximum value of the jump intensity on the optical fiber path corresponds to the blood pressure change at the blood pressure test position on the optical fiber path.

[0072] (2) performing transition intensity demodulation on the signal curve segment to obtain an intermediate transition intensity value corresponding to the signal curve segment; a Rayleigh backscattering intensity curve has multiple intermediate transition intensity values;

[0073] (3) Obtaining the maximum value of a plurality of intermediate transition intensity values ​​corresponding to each backscattering Rayleigh intensity curve, and obtaining the final transition intensity value of each backscattering Rayleigh intensity curve.

[0074] In a possible implementation manner, the step of performing transition intensity demodulation on the signal curve segment in the above sub-step (2) to obtain an intermediate transition intensity value corresponding to the signal curve segment specifically includes the following contents:

[0075] Establishing the first child window with the starting end of the parent window as the center;

[0076] The average intensity in the first sub-window is calculated according to the first calculation formula, and the calculated average intensity in the first sub-window is used as the starting intensity of the main window; the first calculation formula is:

[0077] I 1 (t 0 )=mean(I(t 0 -τ / 2-τ 1 / 2,t 0 +τ / 2+τ 1 / 2));

[0078] A second child window is established with the terminal of the parent window as the center, and the width of the second child window is 5% of the width of the parent window;

[0079] The average intensity in the second sub-window calculated according to the second calculation formula is used as the cutoff intensity of the main window; the second calculation formula is:

[0080] I 2 (t 0 )=mean(I(t 0 +τ / 2-τ 1 / 2,t 0 +τ / 2+τ 1 / 2));

[0081] The differential intensity between the cut-off intensity and the starting intensity is calculated according to the differential calculation formula. The differential intensity is the intermediate transition intensity value corresponding to the signal curve segment. The differential calculation formula is:

[0082] ΔI(t 0 )=I 2 (t 0 )-I 1 (t 0 );

[0083] The width of the first sub-window is the same as that of the second sub-window; 0 is the horizontal axis center position of the mother window, I 1 (t 0 ) is the parent window t 0 The initial intensity at I 2 (t 0 ) is the parent window t 0 The cutoff intensity at τ is the width of the mother window, τ 1 is the width of the first sub-window or the second sub-window, ΔI(t 0 ) is the final obtained t 0 The intermediate transition intensity value at the position, mean is the mean function, I(t 0 -τ / 2-τ 1 / 2,t 0 -τ / 2+τ 1 / 2) represents the first sub-window enveloping the horizontal coordinate {t 0 -τ / 2-τ 1 / 2} to the horizontal axis {t 0 -τ / 2+τ 1 / 2}; mean(I(t 0 -τ / 2-τ 1 / 2,t 0 -τ / 2+τ 1 / 2)) indicates that the first sub-window envelops the horizontal coordinate {t 0-τ / 2-τ 1 / 2} to the horizontal axis {t 0 -τ / 2+τ 1 / 2} between the average of all the jump intensity values ​​of the signal curve segment; I(t 0 +τ / 2-τ 1 / 2,t 0 +τ / 2+τ 1 / 2) represents the second sub-window enveloping the horizontal coordinate {t 0 +τ / 2-τ 1 / 2} to the horizontal axis {t 0 +τ / 2+τ 1 / 2}; mean(I(t 0 +τ / 2-τ 1 / 2,t 0 +τ / 2+τ 1 / 2)) indicates that the second sub-window envelops the horizontal coordinate {t 0 -τ / 2-τ 1 / 2} to the horizontal axis {t 0 -τ / 2+τ 1 / 2} is the average value of all transition intensity values ​​of the signal curve segment between

[0084] In a possible implementation, the width of the first sub-window and the second sub-window are both 5% of the width of the mother window. There is no specific range requirement for the height of the mother window, the first sub-window and the second sub-window, as long as the selected signal curve segment of corresponding width is enclosed.

[0085] Specifically, a backscattered Rayleigh scattering intensity curve can be slidably intercepted to obtain multiple signal curve segments, and a corresponding intermediate transition intensity value can be calculated for each signal curve segment. Based on the multiple intermediate transition intensity values, an intermediate transition intensity series of the backscattered Rayleigh scattering intensity curve can be formed according to the sliding generation order, and the maximum transition intensity value in each intermediate transition intensity series is obtained. The interface obtains the final transition intensity value of each of the backscattered Rayleigh scattering intensity curves.

[0086] In a possible implementation manner, the establishment of a corresponding relationship between a specified blood pressure value and a final transition intensity value involved in the above step S130 specifically includes the following sub-steps:

[0087] A plurality of designated blood pressure values ​​and a final transition intensity value corresponding to each designated blood pressure value are fitted to obtain a fitting curve between the blood pressure value and the transition intensity value. The fitting curve is the corresponding relationship between the blood pressure value and the transition intensity value.

[0088] At present, there are many fitting methods for fitting multiple points in the prior art, such as least squares method, polynomial fitting, function fitting, etc. In this application, each pair of specified blood pressure value and jump intensity value can be regarded as a point, and then multiple points can be fitted. The curve fitting involved can be implemented by the existing fitting method, and the specific fitting method will not be described in detail here.

[0089] Step S140, place the SMF-FMF sensing structure at the blood pressure to be measured, calculate the back Rayleigh scattering intensity curve detected by the incoherent optical time domain reflectometer at the blood pressure to be measured to obtain the actual transition intensity value of the blood pressure to be measured, and calculate the actual blood pressure value of the blood pressure to be measured based on the actual transition intensity value and the corresponding relationship.

[0090] In a possible implementation manner, placing the SMF-FMF sensing structure at the location where the blood pressure is to be measured in the above step S140 specifically includes the following:

[0091] The SMF-FMF sensing structure is packaged and embedded in a wearable textile, and the subject wears the wearable textile to place the SMF-FMF sensing structure at the location where the blood pressure of the subject is to be measured.

[0092] That is, after obtaining the relationship between blood pressure and transition intensity, the SMF-FMF sensing structure can be encapsulated and embedded in a wearable textile, and placed at the patient's blood pressure test site for actual detection, which is generally the wrist or arm. After performing transition intensity demodulation on the incoherent Rayleigh backscattering intensity curve of the blood pressure test site, the blood pressure at the test site can be obtained through the corresponding relationship between the transition intensity and blood pressure obtained in step 130.

[0093] In summary, the embodiment of the present invention provides a blood pressure monitoring method based on an SMF-FMF sensing structure. First, the high-order modes are excited in the SMF-FMF sensing structure respectively under multiple different specified blood pressure values ​​by using an incoherent optical time domain reflectometer, so as to utilize the characteristic that the high-order modes excited in the SMF-FMF sensing structure are sensitive to disturbances, and the vibration deformation caused by the pulse wave of the blood pressure change is reflected in the deformation of the sensing structure attached to the surface of the human arterial skin; then, the high-order modes transmitted in the SMF-FMF sensing structure are detected by the incoherent optical time domain reflectometer to obtain the back-propagation corresponding to each specified blood pressure value. Rayleigh scattering intensity curve; demodulate each back Rayleigh scattering intensity curve to obtain the final transition intensity value of each back Rayleigh scattering intensity curve, thereby calculating the transition intensity under different perturbations, and establishing a corresponding relationship between the specified blood pressure value and the final transition intensity value based on the calculation result, and finally placing the SMF-FMF sensing structure at the blood pressure to be measured, and calculating the back Rayleigh scattering intensity curve detected by the incoherent optical time domain reflectometer at the blood pressure to be measured to obtain the actual transition intensity value at the blood pressure to be measured, and substituting the actual transition intensity value into the corresponding relationship to obtain the actual blood pressure value at the blood pressure to be measured, so as to realize human blood pressure monitoring. The method provided by the embodiment of the present invention effectively solves the defects of the traditional fiber grating sensor-based demodulation being complex and costly, and can achieve high sensitivity response and high-precision measurement characteristics of blood pressure comparable to traditional fiber grating sensors, greatly broadening the application capability of the distributed sensing technology of incoherent optical time domain reflection technology, and achieving the technical effect of reducing costs while maintaining high sensitivity.

[0094] Embodiment 2

[0095] On the basis of the blood pressure monitoring method based on the SMF-FMF sensing structure provided in the first embodiment above, the present invention further provides a blood pressure monitoring device based on the SMF-FMF sensing structure that can be used to implement the above method.

[0096] See also Figure 2 , Figure 2Schematic diagram of the device architecture of an embodiment of the present invention. Specifically, the blood pressure monitoring device based on the SMF-FMF sensing structure is used to implement the blood pressure monitoring method based on the SMF-FMF sensing structure as described in any one of the embodiments of the first embodiment, and specifically includes: an incoherent optical time domain reflectometer, a packaged SMF-FMF sensing structure and a data processor, wherein the pulse transmitting end of the incoherent optical time domain reflectometer is connected to the SMF-FMF sensing structure, and the data processor is connected to the data output interface of the incoherent optical time domain reflectometer; wherein the incoherent optical time domain reflectometer is used to transmit the pulse of the SMF-FMF sensing structure to the SMF-FMF sensing structure; The high-order modes are excited in the F-FMF sensing structure; and the high-order modes transmitted in the SMF-FMF sensing structure are detected to obtain the corresponding back-Rayleigh scattering intensity curve; the SMF-FMF sensing structure is used to excite the high-order modes under the pulse action of the incoherent optical time domain reflectometer; the data processor is used to establish a corresponding relationship between the blood pressure value and the transition intensity value, and demodulate the back-Rayleigh scattering intensity curve to obtain the final transition intensity value of the back-Rayleigh scattering intensity curve, and calculate the actual blood pressure value corresponding to the final transition intensity value at the blood pressure test point according to the corresponding relationship.

[0097] The SMF-FMF sensing structure excites the high-order mode according to step 110 in the first embodiment.

[0098] like Figure 3 As shown, in a possible implementation manner, the incoherent optical time domain reflectometer used in the device includes: a broadband laser source (LD), a semiconductor optical amplifier (SOA), an erbium-doped fiber amplifier (EDFA), a photodetector (PD) and a circulator, the output end of the broadband laser source is connected to the input end of the semiconductor optical amplifier, the input end of the semiconductor optical amplifier is connected to the input end of the erbium-doped fiber amplifier, the output end of the erbium-doped fiber amplifier is connected to the first port of the circulator, the second port of the circulator is connected to the SMF-FMF sensing structure, and the third port of the circulator is connected to the photodetector;

[0099] Among them, the wide-spectrum laser source is used to output continuous signal light; the semiconductor optical amplifier is used to receive the continuous signal light and modulate the continuous signal light to form a pulse signal light; the erbium-doped fiber amplifier is used to amplify the power of the received pulse signal light; the photodetector is used to convert the optical signal of the back-Rayleigh scattered light returned by the SMF-FMF sensing structure under test into an electrical signal; and the circulator is used to guide the optical path direction of the detection light and the back-Rayleigh scattered light.

[0100] like Figure 4 As shown, the data processor includes one or more processors and a memory. Figure 4 A processor is taken as an example.

[0101] The processor and the memory may be connected via a bus or other means. Figure 4The example of connecting through bus is taken in the following.

[0102] As a non-volatile computer-readable storage medium, the memory can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as the processing contents involved in the blood pressure monitoring method based on the SMF-FMF sensor structure in Example 1, such as "establishing a corresponding relationship between the blood pressure value and the transition intensity value, demodulating the back Rayleigh scattering intensity curve, obtaining the final transition intensity value of the back Rayleigh scattering intensity curve, and calculating the actual blood pressure value corresponding to the final transition intensity value at the blood pressure to be measured according to the corresponding relationship". The processor executes various functional applications and data processing of the blood pressure monitoring device based on the SMF-FMF sensor structure by running the non-volatile software programs, instructions and modules stored in the memory.

[0103] The memory may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0104] The program instructions / modules are stored in the memory, and when executed by one or more processors, the relevant contents of the blood pressure monitoring method based on the SMF-FMF sensing structure in the above-mentioned embodiment 1 are executed, for example, the above-described Figure 1 The corresponding steps are shown.

[0105] An embodiment of the present invention further provides a non-volatile computer storage medium, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions are executed by one or more processors, such as Figure 4 A processor in can enable the one or more processors to execute the blood pressure monitoring method based on the SMF-FMF sensing structure in Example 1, for example, to execute the above-described Figure 1 The corresponding steps are shown.

[0106] It is worth noting that the information interaction, execution process, etc. between the modules and units within the above-mentioned devices and systems are based on the same concept as the processing method embodiment of the present invention. The specific contents can be found in the description of the method embodiment of the present invention and will not be repeated here.

[0107] A person skilled in the art may understand that all or part of the steps in the various methods of the embodiments may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, and the storage medium may include: a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A blood pressure monitoring method based on SMF-FMF sensing structure, characterized in that: The method comprises: Incoherent optical time-domain reflectometry was used to excite high-order modes in the SMF-FMF sensing structure at multiple different specified blood pressure values; Detecting the high-order modes transmitted in the SMF-FMF sensing structure by the incoherent optical time domain reflectometer to obtain a backscattering Rayleigh intensity curve corresponding to each of the specified blood pressure values; Demodulating each of the Rayleigh backscattering intensity curves to obtain a final transition intensity value of each of the Rayleigh backscattering intensity curves, and establishing a corresponding relationship between the designated blood pressure value and the final transition intensity value; The SMF-FMF sensing structure is placed at a location where the blood pressure is to be measured, and the back Rayleigh scattering intensity curve detected by the incoherent optical time domain reflectometer at the location where the blood pressure is to be measured is calculated to obtain an actual transition intensity value at the location where the blood pressure is to be measured, and the actual blood pressure value at the location where the blood pressure is to be measured is calculated based on the actual transition intensity value and the corresponding relationship.

2. The blood pressure monitoring method based on the SMF-FMF sensing structure according to claim 1, characterized in that: The SMF-FMF sensing structure is an optical fiber sensing structure formed by eccentrically fusing a section of SMF and a section of FMF, wherein the SMF is a single-mode optical fiber and the FMF is a few-mode optical fiber.

3. The blood pressure monitoring method based on the SMF-FMF sensing structure according to claim 2, characterized in that: The method of using incoherent optical time domain reflectometry to excite high-order modes in the SMF-FMF sensing structure at multiple different specified blood pressure values ​​includes: A plurality of different designated blood pressure values ​​are set, and for each designated blood pressure value, an incoherent optical time domain reflectometer is used to inject a laser signal into an end of the SMF away from the FMF to excite a high-order mode in the FMF.

4. The blood pressure monitoring method based on the SMF-FMF sensing structure according to claim 1, characterized in that: Demodulating each of the backscattered Rayleigh scattering intensity curves to obtain a final transition intensity value of each of the backscattered Rayleigh scattering intensity curves includes: A window corresponding to a preset pulse width is set as a master window, and a signal curve segment is slidably intercepted in each of the collected back Rayleigh scattering intensity curves according to the master window; the preset pulse width is the pulse width of a single pulse emitted by the incoherent optical time domain reflectometer; Performing transition intensity demodulation on the signal curve segment to obtain an intermediate transition intensity value corresponding to the signal curve segment; one of the Rayleigh backscattering intensity curves has a plurality of intermediate transition intensity values; The maximum value of the plurality of intermediate transition intensity values ​​corresponding to each of the Rayleigh backscattering intensity curves is obtained to obtain a final transition intensity value of each of the Rayleigh backscattering intensity curves.

5. The blood pressure monitoring method based on the SMF-FMF sensing structure as claimed in claim 4, characterized in that: The step of performing transition intensity demodulation on the signal curve segment to obtain an intermediate transition intensity value corresponding to the signal curve segment includes: Establishing a first child window with the starting end of the mother window as the center; The average intensity in the first sub-window is calculated according to a first calculation formula, and the calculated average intensity in the first sub-window is used as the starting intensity of the mother window; the first calculation formula is: I1(t0)=mean(I(t0-τ / 2-τ1 / 2,t0+τ / 2+τ1 / 2)); Establishing a second sub-window with the terminal of the mother window as the center, wherein the width of the second sub-window is 5% of the width of the mother window; The average intensity in the second sub-window calculated according to the second calculation formula is used as the cutoff intensity of the parent window; the second calculation formula is: I2(t0)=mean(I(t0+τ / 2-τ1 / 2,t0+τ / 2+τ1 / 2)) The differential intensity between the cut-off intensity and the starting intensity is calculated according to a differential calculation formula, wherein the differential intensity is an intermediate transition intensity value corresponding to the signal curve segment, and the differential calculation formula is: ΔI(t0)=I2(t0)-I1(t0) Among them, the width of the first sub-window is the same as that of the second sub-window; both are 5% of the width of the mother window; t0 is the center position of the mother window, I1(t0) is the starting intensity at t0; I2(t0) is the cutoff intensity at t0, τ is the width of the mother window, τ1 is the width of the first sub-window or the second sub-window, ΔI(t0) is the intermediate transition intensity value at t0 finally obtained, and mean is the averaging function.

6. The blood pressure monitoring method based on the SMF-FMF sensing structure according to claim 5, characterized in that: The width of the first sub-window and the second sub-window are both 5% of the width of the mother window.

7. The blood pressure monitoring method based on the SMF-FMF sensing structure according to claim 1, characterized in that: The establishing of the corresponding relationship between the designated blood pressure value and the final transition intensity value comprises: A plurality of the designated blood pressure values ​​and the final transition intensity value corresponding to each of the designated blood pressure values ​​are fitted to obtain a fitting curve between the blood pressure value and the transition intensity value, wherein the fitting curve is the corresponding relationship.

8. The blood pressure monitoring method based on the SMF-FMF sensing structure according to claim 1, characterized in that: Placing the SMF-FMF sensing structure at a location where blood pressure is to be measured comprises: The SMF-FMF sensing structure is packaged and then embedded in a wearable textile, and the subject wears the wearable textile to place the SMF-FMF sensing structure at the location where the blood pressure of the subject is to be measured.

9. A blood pressure monitoring device based on a SMF-FMF sensing structure, characterized in that: The sensing device comprises: Incoherent optical time domain reflectometer, packaged SMF-FMF sensor structure and data processor, The pulse transmitting end of the incoherent optical time domain reflectometer is connected to the SMF-FMF sensing structure, and the data processor is connected to the data output interface of the incoherent optical time domain reflectometer; The incoherent optical time domain reflectometer is used to excite high-order modes in the SMF-FMF sensing structure; and detect the high-order modes transmitted in the SMF-FMF sensing structure to obtain the corresponding backscattering Rayleigh intensity curve; The SMF-FMF sensing structure is used to excite high-order modes under the pulse action of the incoherent optical time domain reflectometer; The data processor is used to establish a corresponding relationship between the blood pressure value and the transition intensity value, and demodulate the back Rayleigh scattering intensity curve to obtain the final transition intensity value of the back Rayleigh scattering intensity curve, and calculate the actual blood pressure value corresponding to the final transition intensity value at the blood pressure test point according to the corresponding relationship.

10. The blood pressure monitoring device based on the SMF-FMF sensing structure according to claim 9, characterized in that: The incoherent optical time domain reflectometer comprises: A broadband laser source, a semiconductor optical amplifier, an erbium-doped fiber amplifier, a photodetector and a circulator, wherein the output end of the broadband laser source is connected to the input end of the semiconductor optical amplifier, the input end of the semiconductor optical amplifier is connected to the input end of the erbium-doped fiber amplifier, the output end of the erbium-doped fiber amplifier is connected to the first port of the circulator, the second port of the circulator is connected to the SMF-FMF sensing structure, and the third port of the circulator is connected to the photodetector; Among them, the wide-spectrum laser source is used to output continuous signal light; the semiconductor optical amplifier is used to receive the continuous signal light and modulate the continuous signal light to form a pulse signal light; the erbium-doped fiber amplifier is used to amplify the power of the received pulse signal light; the photodetector is used to convert the optical signal of the back-Rayleigh scattered light returned by the SMF-FMF sensing structure under test into an electrical signal; and the circulator is used to guide the optical path direction of the detection light and the back-Rayleigh scattered light.

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