Novel two-photon printing optical fiber miniature spiral pulse sensing probe

Abstract

The invention discloses a novel two-photon printing optical fiber miniature spiral pulse sensing probe, and belongs to the field of patch type pulse sensing. The novel two-photon printing optical fiber miniature spiral pulse sensing probe comprises an optical fiber, an L-shaped resin structure and a spiral resin structure which are connected in sequence, the lower end of the spiral resin structure is connected with a reflective resin bottom plate structure, and a rectangular resin structure is arranged on the outer side of the spiral resin structure; the L-shaped resin structure, the spiral resin structure and the reflective resin bottom plate structure can be surrounded at the same time; a PDMS film is arranged at the bottom of the probe, and one side of the optical fiber is connected with an optical fiber adapter; pulse signals and the like of different positions of a user are monitored in real time through micro-displacement of the spiral structure, and the advantages of small size, high sensitivity and the like are achieved.

Description

Technical Field

[0001] The invention belongs to the field of patch-type pulse sensing, and in particular relates to a novel dual-photon printing optical fiber micro-spiral pulse sensing probe. Background Art

[0002] With the rapid development of medical devices and wearable devices, pulse detection technology has made significant progress, especially in non-contact and real-time monitoring. At present, pulse detection technology is mainly divided into two categories: contact and non-contact:

[0003] Contact pulse detection technology is the most popular pulse monitoring technology at present, mainly relying on the following methods: 1) Photoplethysmography (PPG): The light emitted by the LED light source penetrates the skin, and the light is absorbed by the blood. The blood flow is detected by the change in the intensity of the light reflection, and then the pulse is calculated. PPG technology is often used in wearable devices such as smart bracelets and watches. 2) Electronic blood pressure monitor: The blood vessels are compressed by inflating the cuff, and then the air pressure is gradually released, and the pulse is calculated by monitoring the change in pressure. This technology is highly accurate, but usually requires certain equipment and time. 3) Electrocardiogram (ECG): The electrical activity of the heart is detected through electrode patches or wearable devices, and the pulse and heart rate are indirectly calculated. It can provide more detailed heart health information and is often used in medical equipment.

[0004] Non-contact pulse detection technology is usually used in non-invasive monitoring or high-demand scenarios:

[0005] 1) Radar sensor: Use millimeter wave radar or microwave radar to monitor small changes in human body movement, such as chest rise and fall caused by heartbeat. This technology is developing rapidly, especially in sleep monitoring and health monitoring equipment.

[0006] 2) Video PPG: It uses a regular camera to capture subtle changes in skin color to calculate pulse, which is suitable for long-distance monitoring. This technology is still in the development stage and is greatly affected by environmental factors such as light and movement.

[0007] Pulse monitoring is extremely necessary and is a very important basic physiological parameter of the human body. The pulse reflects the basic functions of the cardiovascular system and is a key part of health monitoring. Regular pulse monitoring can: detect heart abnormalities early: such as arrhythmia, bradycardia or tachycardia, which can help prevent more serious heart problems. Track health trends: By monitoring pulse changes over a long period of time, users can obtain information on their own health trends, such as changes in physical condition, exercise effects, etc. Emergency response: Real-time pulse monitoring, especially for patients with heart disease, can respond early in an emergency and reduce health risks.

[0008] However, traditional pulse monitoring has some disadvantages, such as limitations: traditional pulse detection is achieved through patch-type cardiac electrodes or fingertip probes, which are too large and can generally only detect pulses in specific parts of the body, and cannot detect pulse information in any part of the body. Detecting pulse information at multiple points in the body has important medical and health management value, and can provide more comprehensive and in-depth physiological data than single-point pulse monitoring. Monitoring multiple points of pulse information at the same time has important value and application scenarios. Therefore, there is an urgent need for a micron-level micro pulse probe that is resistant to electromagnetic interference. Summary of the invention

[0009] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a novel two-photon printing optical fiber micro-spiral pulse sensor probe to solve the problems in the prior art.

[0010] The purpose of the present invention can be achieved through the following technical solutions:

[0011] A novel two-photon printed optical fiber micro-spiral pulse sensor probe comprises an optical fiber, an L-shaped resin structure and a spiral resin structure which are connected in sequence, wherein the lower end of the spiral resin structure is connected to a reflective resin bottom plate structure, a rectangular resin structure is arranged on the outer side of the spiral resin structure, and can surround the L-shaped resin structure, the spiral resin structure and the reflective resin bottom plate structure at the same time; a PDMS film is arranged at the bottom of the probe, and a fiber optic adapter is connected to one side of the optical fiber.

[0012] Furthermore, light enters from the fiber core, passes through the L-shaped resin structure and is transmitted to the end of the L-shaped resin structure to form the first reflection; then it is transmitted through the spiral resin structure to reach the reflective resin bottom plate structure to form the second reflection; the length of the spiral resin structure will move back and forth with the pulse vibration, thereby affecting the optical path difference and ultimately causing the light intensity to change. The pulse can be detected by detecting the change in light intensity with a photoelectric detector.

[0013] Furthermore, the core of the optical fiber coincides with the center of the starting end of the L-shaped resin structure.

[0014] Furthermore, the optical fiber is a single-mode optical fiber, and the outer diameter of the optical fiber cladding is not less than 50 microns; the thickness of the L-shaped resin structure is not less than 20 microns; the length of the spiral resin structure does not exceed 50 microns; the thickness of the rectangular resin structure is greater than 10 microns; and the thickness of the PDMS film is not greater than 200 microns.

[0015] Furthermore, the gap spacing between the spiral resin structure and the rectangular resin structure is 30 microns, and the gap between the reflective resin bottom plate structure and the rectangular resin structure is not less than 5 microns.

[0016] Furthermore, the optical fiber adapter is a standard optical fiber adapter; its interface types include LC, ST, SC, FC, and MPO interfaces.

[0017] Furthermore, the L-shaped resin structure, the spiral resin structure, and the reflective resin bottom plate structure are all formed at the end of the optical fiber by 3D printing.

[0018] Furthermore, a rectangular protective cover is printed on the outer side of the probe.

[0019] The above-mentioned novel two-photon printed optical fiber micro-spiral pulse sensor probe is applied in pulse monitoring.

[0020] A pulse monitor comprises the novel two-photon printed optical fiber micro-spiral pulse sensor probe.

[0021] Beneficial effects of the present invention:

[0022] 1. The present invention proposes a novel two-photon printed micro-spiral optical fiber pulse sensor probe, which prints a micro-L-shaped micro-nano structure, a spiral structure and a reflective end plate structure on the end face of the optical fiber. It uses the micro-displacement of the spiral structure to monitor the pulse signals of the user at different positions in real time, and has the advantages of small size and high sensitivity.

[0023] 2. The present invention protects the sensor unit from being damaged by printing a rectangular protective cover on the periphery of the optical fiber.

[0024] 3. The present invention arranges a layer of PDMS (polydimethylsiloxane) film at the bottom of the optical fiber. The Young's modulus of PDMS is small, which can improve the sensitivity of detecting tiny pulse vibrations. In addition, it can also enhance the connection strength between the resin structure and the optical fiber, and improve firmness and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a schematic diagram of the overall structure of the pulse sensor probe of the present invention;

[0027] Figure 2 It is a schematic diagram of micro-displacement change of the pulse sensor probe of the present invention;

[0028] Figure 3 is a schematic diagram of the operating framework of the pulse sensor probe of the present invention;

[0029] Figure 4It is a pulse waveform diagram collected by the pulse sensor probe of the present invention.

[0030] In the figure: 1-optical fiber, 11-fiber core, 2-L-shaped resin structure, 3-spiral resin structure, 4-reflective resin bottom plate structure, 5-rectangular resin structure, 6-PDMS film, 7-optical fiber adapter. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] like Figure 1 As shown, a novel two-photon printed optical fiber micro-spiral pulse sensor probe comprises an optical fiber 1, an L-shaped resin structure 2, a spiral resin structure 3, a reflective resin bottom plate structure 4, a rectangular resin structure 5, a PDMS film 6 and an optical fiber adapter 7;

[0033] The core 11 of the optical fiber 1, the L-shaped resin structure 2 and the spiral resin structure 3 are connected in sequence, the lower end of the spiral resin structure 3 is connected to the reflective resin bottom plate structure 4, the rectangular resin structure 5 surrounds the L-shaped resin structure 2, the spiral resin structure 3 and the reflective resin bottom plate structure 4, the PDMS film 6 is arranged at the bottom of the probe, and the optical fiber adapter 7 is connected to the optical fiber 1;

[0034] Light enters from the fiber core 11, is transmitted to the end of the L-shaped resin structure through the L-shaped resin structure to form the first reflection, and is further transmitted through the spiral resin structure to reach the reflective resin bottom plate structure 4 to form the second reflection. The length of the spiral resin structure will move back and forth with the pulse vibration, thereby affecting the optical path difference and ultimately causing the light intensity to change. The pulse can be detected by detecting the change in light intensity through a photoelectric detector.

[0035] In this embodiment, the optical fiber 1 is a G.652.D single-mode optical fiber with a length of 1 m, a cladding outer diameter of the optical fiber 1 of 125 microns, and a core 11 diameter of 8 microns; in other embodiments, the cladding outer diameter of the optical fiber 1 may be no less than 50 microns; the optical fiber 1 may also be other types of single-mode optical fibers;

[0036] In this embodiment, the center position of the starting end of the L-shaped resin structure 2 coincides with the center of the fiber core 11; and the thickness of the L-shaped resin structure 2 is 50 microns; in other embodiments, the thickness of the L-shaped resin structure 2 is not less than 20 microns.

[0037] In this embodiment, the length of the spiral resin structure 3 is 45 micrometers. In other embodiments, the length of the spiral resin structure 3 does not exceed 50 micrometers.

[0038] In this embodiment, the gap between the spiral resin structure 3 and the rectangular resin structure 5 is 30 micrometers, and the reflective resin bottom plate structure 4 and the rectangular resin structure 5 are not integrated, and there is a gap of not less than 5 micrometers.

[0039] In this embodiment, the thickness of the rectangular resin structure 5 is 60 micrometers; in other embodiments, the thickness of the rectangular resin structure 5 is greater than 10 micrometers.

[0040] In this embodiment, the thickness of the PDMS film 6 is 100 micrometers; in other embodiments, the thickness of the PDMS is not greater than 200 micrometers.

[0041] In this embodiment, the optical fiber adapter 7 is a standard optical fiber adapter with an LC interface; in other embodiments, it can also be an ST, SC, FC, or MPO interface.

[0042] In addition, in this embodiment, the L-shaped resin structure 2, the spiral resin structure 3, and the reflective resin bottom plate structure 4 are all formed by 3D printing, and a rectangular protective cover is printed on the outside of the probe to protect the sensor unit from being damaged.

[0043] When the probe is placed at a pulse detection point on the human body during use, the micro-vibration will first cause the PDMS film 6 to undergo micro-deformation, which in turn causes the spiral resin structure 3 inside the probe to undergo periodic micro-displacement vibrations, further causing changes in the length of the optical path interference cavity. Therefore, the interference phase difference will have an additional slight change. When detecting the light intensity, the motion period of the micro-displacement can be detected, and ultimately the pulse information can be obtained.

[0044] Specifically, if Figure 2 As shown in FIG. 1 , when the intensity change of the pulse over time is set as p(t), as the pulse moves, the PDMS film 6 at the bottom of the monitoring probe has a small mutation, resulting in the expansion and contraction of the spiral resin structure 3 by a length of L(p(t). Assume that L2 is the cavity length corresponding to the strongest pulse (i.e., the length of the spiral resin structure 3), and L1 is the original cavity length. At this time, the change in the interference optical path difference Δφ can be expressed as:

[0045]

[0046] Where n is the refractive index of air, which can be approximately considered to be 1; λ is the wavelength of the incident light in a vacuum;

[0047] When light enters the optical fiber, a beam of light is reflected at the resin-air interface. A As the light propagates, the second beam of light I is reflected at the air-resin interface.B , the two beams of light are coupled and interfere in the core 11 of the optical fiber 1, which can be expressed as:

[0048]

[0049] Where π is due to the half-wave loss at the air-resin interface, φ is based on the optical path difference of the cavity length and is related to the pulse motion, and I O It is the light intensity detected by the photodetector.

[0050] like Figure 3 As shown in the figure, when φ changes slightly by Δφ, I O The light intensity will also change accordingly; therefore, the pulse can be monitored by detecting the interference light intensity in real time through the photoelectric detector. The light intensity detected by the photoelectric detector is further converted into a digital signal through the microprocessor through the digital-to-analog conversion peripheral, which is used for the subsequent digital signal processing and pulse signal extraction calculation.

[0051] Experimental testing;

[0052] The pulse sensor probe in this embodiment is experimentally tested, and the test process is as follows:

[0053] The monitoring probe is attached to the wrist pulse, and the photoelectric transceiver is connected to the monitoring probe through an LC / APC fiber optic adapter. The output of the photoelectric transceiver is connected to a microprocessor, which collects the pulse signal and processes it to obtain a pulse waveform.

[0054] The test results are as follows Figure 4 As shown, the horizontal axis is time and the vertical axis is voltage. It can be seen that there are 5 complete cardiac cycles. It can be seen that the monitoring probe can effectively collect wrist pulse.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0056] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A novel two-photon printed optical fiber micro-spiral pulse sensor probe, characterized in that: The probe comprises an optical fiber (1), an L-shaped resin structure (2) and a spiral resin structure (3) which are connected in sequence; the lower end of the spiral resin structure (3) is connected to a reflective resin bottom plate structure (4); a rectangular resin structure (5) is arranged outside the spiral resin structure (3) and can simultaneously surround the L-shaped resin structure (2), the spiral resin structure (3) and the reflective resin bottom plate structure (4); a PDMS film (6) is arranged at the bottom of the probe; and a fiber adapter (7) is connected to one side of the optical fiber (1).

2. A novel two-photon printing optical fiber micro-spiral pulse sensor probe according to claim 1, characterized in that: Light is injected from the fiber core (11), transmitted through the L-shaped resin structure (2) to the end of the L-shaped resin structure to form a first reflection; then it is transmitted through the spiral resin structure (3) to reach the reflective resin bottom plate structure (4) to form a second reflection; the length of the spiral resin structure (3) will move back and forth with the pulse vibration, causing the light intensity to change, and the pulse is detected by detecting the light intensity change through the photoelectric detector.

3. According to the novel two-photon printing optical fiber micro spiral pulse sensor probe described in claim 1, the core (11) of the optical fiber (1) coincides with the center of the starting end of the L-shaped resin structure (2).

4. According to the novel two-photon printing optical fiber micro spiral pulse sensor probe as described in claim 1, the optical fiber (1) is a single-mode optical fiber, and the outer diameter of the cladding of the optical fiber (1) is not less than 50 microns; the thickness of the L-shaped resin structure (2) is not less than 20 microns; the length of the spiral resin structure (3) does not exceed 50 microns; the thickness of the rectangular resin structure (5) is greater than 10 microns; the thickness of the PDMS film (6) is not greater than 200 microns.

5. According to the novel two-photon printing optical fiber micro spiral pulse sensor probe as described in claim 1, the gap spacing between the spiral resin structure (3) and the rectangular resin structure (5) is 30 microns, and the gap between the reflective resin base plate structure (4) and the rectangular resin structure (5) is not less than 5 microns.

6. According to the novel two-photon printing optical fiber micro spiral pulse sensor probe described in claim 1, the optical fiber adapter (7) is a standard optical fiber adapter; its interface types include LC, ST, SC, FC, and MPO interfaces.

7. According to the novel two-photon printing optical fiber micro spiral pulse sensor probe as described in claim 1, the L-shaped resin structure (2), the spiral resin structure (3), and the reflective resin base plate structure (4) are all formed at the end of the optical fiber (1) by 3D printing.

8. According to the novel two-photon printing optical fiber micro-spiral pulse sensor probe of claim 1, a rectangular protective cover is printed on the outer side of the probe.

9. Application of a novel two-photon printing optical fiber micro-spiral pulse sensor probe as claimed in any one of claims 1 to 8 in pulse monitoring.

10. A pulse monitor, characterized in that: A novel two-photon printing optical fiber micro-spiral pulse sensor probe comprising any one of claims 1-8.

Images