3D direct two-photon laser printing miniature optical fiber pulse sensing probe

Abstract

The invention belongs to the technical field of sensing probe equipment, and particularly relates to a 3D direct two-photon laser printing miniature optical fiber pulse sensing probe which comprises an optical fiber, an L-shaped resin structure, a rectangular resin structure, a PDMS film and an optical fiber adapter. The optical fiber adapter is connected to the left end face of the optical fiber, the right end face of the optical fiber is connected with an L-shaped resin structure and a rectangular resin structure, the connecting points of the L-shaped resin structure and the end face of the optical fiber are located above an optical fiber core, and the rectangular resin structure completely wraps the end face of the optical fiber and completely wraps the L-shaped resin structure. The PDMS film is connected with the rectangular resin structure and is connected with the optical fiber.

Description

Technical Field

[0001] The invention belongs to the technical field of sensor probe equipment, and in particular relates to a 3D direct two-photon laser printed micro-optical fiber pulse sensor probe. Background Art

[0002] Traditional pulse detection (i.e., pulse diagnosis in traditional Chinese medicine) involves the doctor palpating the patient's artery with his fingers and judging the health status based on the frequency, strength, rhythm, etc. of the pulse. This method has some disadvantages, including: strong subjectivity: the judgment of the pulse depends on the doctor's experience and lacks objective data support. Poor real-time performance: traditional pulse diagnosis cannot provide continuous, accurate real-time data. Low repeatability: different doctors may have different judgments on the pulse of the same patient, and the consistency of the diagnosis results is not high. Although experienced doctors can provide valuable diagnoses in some cases, this method lacks accuracy and standardization, so it is gradually replaced or supplemented in modern medicine. Modern pulse detection technology has made significant progress in technical means and applications, including: Photoplethysmography (PPG): This is the most common pulse detection method currently, based on light sources and photodetectors, and measures pulse by detecting changes in light absorption caused by blood flow. PPG is widely used in smart watches, fitness devices, and medical monitoring devices. Ultrasonic technology: Ultrasonic waves measure pulses by detecting the movement of arterial walls and are often used in high-precision medical equipment. Pressure sensor: Pulse data is obtained by detecting the expansion and contraction of arterial blood vessels through physical pressure sensors. This method is generally used in clinical environments.

[0003] However, the current pulse monitoring technology has some disadvantages, including being too large and limited monitoring locations. There is an urgent need for a micron-level miniature pulse probe that is resistant to electromagnetic interference and can be used to detect the pulse in various parts of the body. Summary of the invention

[0004] In view of the deficiencies of the prior art, the object of the present invention is to provide a 3D direct two-photon laser printed micro-fiber pulse sensor probe.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A 3D direct two-photon laser printed micro-fiber pulse sensor probe comprises: an optical fiber, an L-shaped resin structure, a rectangular resin structure, a PDMS film, and an optical fiber adapter; the optical fiber adapter is connected to the left end face of the optical fiber, the right end face of the optical fiber is connected to the L-shaped resin structure and the rectangular resin structure, the connection points of the L-shaped resin structure and the optical fiber end face are both located above the optical fiber core, the rectangular resin structure completely wraps the optical fiber end face and completely wraps the L-shaped resin structure, and the PDMS film is connected to the rectangular resin structure and to the optical fiber.

[0007] Furthermore, the optical fiber is a G.652.D single-mode optical fiber, and the optical fiber includes a cladding and a core. The outer diameter of the cladding is 125 microns, and the diameter of the core is 8 microns.

[0008] Furthermore, the optical fiber adapter is a standard optical fiber adapter including LC, ST, SC, FC, and MPO interfaces.

[0009] Furthermore, the PDMS film is a flexible material with a thickness of 100 microns.

[0010] Furthermore, the thickness of the L-shaped resin structure is 20 microns, and the center position of the starting end of the L-shaped resin structure is set at 24 microns away from the center of the optical fiber core.

[0011] Furthermore, the thickness of the rectangular resin structure is 50 micrometers, and the gap spacing between the L-shaped resin structure and the rectangular resin structure is 30 micrometers.

[0012] A method for monitoring pulse based on 3D direct two-photon laser printing of a micro-optical fiber pulse sensor probe, the method comprising:

[0013] S1. Set the change of pulse intensity over time as p(t). As the pulse changes, the PDMS film at the bottom of the monitoring probe will have a small mutation, causing the L-shaped resin structure to rotate at an angle of α(p(t)). According to the trigonometric formula, the change of the cavity length is vertical.

[0014] Trigonometric formula: L2=L1+H*tana(p(t))

[0015] L2 is the cavity length after rotation of angle α, L1 is the original cavity length, and H is the spacing of the L-shaped resin structure offset from the optical fiber core;

[0016] S2, calculate the change of interference optical path difference Δφ;

[0017]

[0018] n is the refractive index of air, which is approximately 1, and λ is the wavelength of the incident light in a vacuum;

[0019] S3. When light enters the optical fiber, a beam of light I is reflected at the optical fiber-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 fiber core, and the calculation formula is:

[0020] 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; when φ changes slightly by Δφ, I O The light intensity will also change accordingly.

[0021] The nouns, conjunctions or adjectives involved in the above technical solution are explained as follows:

[0022] Fixed connection: refers to a connection in which parts or components are fixed without any relative movement. It is divided into detachable connection and non-detachable connection.

[0023] (1) Removable connection: The parts are fixed together by screws, splines, wedge pins, etc. This connection method can be disassembled for maintenance without damaging the parts. However, the specifications of the connectors used must be correct (such as the length of the bolts, keys, and wedge pins) and they must be properly tightened.

[0024] (2) Non-detachable connection: mainly refers to welding, riveting and tenoning. Since forging, sawing or oxygen cutting are required for disassembly during maintenance or replacement, spare parts generally cannot be reused. At the same time, attention should be paid to process quality, technical inspection and remedial measures (such as calibration, polishing, etc.) during connection.

[0025] Beneficial effects of the present invention: The present invention uses the high resolution of two-photon 3D printing to print a complex L-shaped micro-nano structure on the end face of the optical fiber, and prints a rectangular protective cover on the periphery of the optical fiber to protect the sensing unit from being damaged. In addition, a layer of PDMS (polydimethylsiloxane) film is set at the bottom of the optical fiber, so that the sensor probe can monitor the pulse information of different positions of the user in real time, and has the advantages of small size, high sensitivity, high precision, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] Figure 1 This patent is a 3D direct two-photon laser printed micro-fiber pulse sensor probe;

[0028] Figure 2 This is a schematic diagram of the micro-displacement change of a 3D direct two-photon laser printed micro-fiber pulse sensor probe of this patent;

[0029] Figure 3 This is a schematic diagram of the overall system device of a 3D direct two-photon laser printed micro-fiber pulse sensor probe of this patent.

[0030] Figure 4 This is a wrist pulse signal diagram measured using this patent. 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] A 3D direct two-photon laser printed micro-fiber pulse sensor probe comprises: an optical fiber, an L-shaped resin structure, a rectangular resin structure, a PDMS film, and an optical fiber adapter; the optical fiber adapter is connected to the left end face of the optical fiber, the right end face of the optical fiber is connected to the L-shaped resin structure and the rectangular resin structure, the connection points of the L-shaped resin structure and the optical fiber end face are both located above the optical fiber core, the rectangular resin structure completely wraps the optical fiber end face and the L-shaped resin structure to protect the internal L-shaped resin structure from being damaged; the PDMS film is connected to the rectangular resin structure and to the optical fiber to enhance firmness.

[0033] As a preferred solution of the present invention, the optical fiber is a G.652.D single-mode optical fiber, and the optical fiber includes a cladding and a core. The outer diameter of the cladding is 125 microns, and the diameter of the core is 8 microns.

[0034] As a preferred solution of the present invention, the optical fiber adapter is a standard optical fiber adapter including LC, ST, SC, FC, and MPO interfaces.

[0035] As a preferred solution of the present invention, the PDMS film is a flexible material with a thickness of 100 microns.

[0036] As a preferred solution of the present invention, the thickness of the L-shaped resin structure is 20 microns, and the center position of the starting end of the L-shaped resin structure is set at 24 microns away from the center of the optical fiber core.

[0037] As a preferred solution of the present invention, the thickness of the rectangular resin structure is 50 microns, and the gap spacing between the L-shaped resin structure and the rectangular resin structure is 30 microns.

[0038] The human body's pulse movement will produce weak vibrations locally as the heart contracts. When the monitoring probe is placed at a pulse detection point on the human body, the micro-vibration will first cause the PDMS film to undergo micro-deformation, which in turn causes the L-shaped resin structure inside the monitoring probe to undergo periodic micro-displacement. The micro-displacement of the L-shaped resin structure will further cause changes in the optical path interference cavity length (such as Figure 2 ), therefore, the interference phase difference will add a small change. When detecting the light intensity, the movement cycle of the micro-displacement can be detected, and finally the pulse information can be obtained.

[0039] The specific derivation is as follows: when the pulse intensity change over time is set to p(t), as the pulse moves, the PDMS film at the bottom of the monitoring probe will have a small mutation, causing the L-shaped resin structure to rotate at an angle of α(p(t)). According to the trigonometric formula, the change in cavity length can be obtained as:

[0040] L2=L1+H*tanα(p(t))

[0041] L2 is the cavity length after rotation of angle α, L1 is the original cavity length, and H is the distance between the L-shaped resin structure and the optical fiber core. At this time, the change in the interference optical path difference Δφ can be expressed as:

[0042]

[0043] 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. When light enters the optical fiber, a beam of light I is reflected at the optical fiber-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 fiber core, which can be expressed as

[0044]

[0045] π is due to the half-wave loss at the air-resin interface, and φ is based on the optical path difference of the cavity length, which is related to the pulse motion. When φ changes by a small amount, Δφ, I O The light intensity will also change accordingly. Therefore, by detecting the interference light intensity in real time through the photoelectric detector, the pulse can be monitored.

[0046] The experimental test process is as follows:

[0047] The pulse sensor probe in this embodiment is experimentally tested, and the test process is as follows:

[0048] 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.

[0049] 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 15 complete cardiac cycles. This shows that the monitoring probe can effectively collect wrist pulse.

[0050] One of the technical solutions adopted by this patent is to provide a 3D direct two-photon laser printed micro-fiber pulse sensor probe. By utilizing the high resolution of two-photon 3D printing, a complex L-shaped micro-nano structure is printed on the end face of the optical fiber, and a rectangular protective cover is printed on the periphery of the optical fiber to protect the sensor unit from being damaged. In addition, a layer of PDMS (polydimethylsiloxane) film is set at the bottom of the optical fiber, so that the sensor probe can monitor the pulse information of the user at different positions in real time, with the advantages of small size, high sensitivity and high precision.

[0051] 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.

[0052] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by 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 3D direct two-photon laser printed micro-fiber pulse sensor probe, characterized in that: include: An optical fiber, an L-shaped resin structure, a rectangular resin structure, a PDMS film, and an optical fiber adapter; the optical fiber adapter is connected to the left end face of the optical fiber, the right end face of the optical fiber is connected to the L-shaped resin structure and the rectangular resin structure, the connection point between the L-shaped resin structure and the optical fiber end face is located above the optical fiber core, the rectangular resin structure completely wraps the optical fiber end face and completely wraps the L-shaped resin structure, and the PDMS film is connected to the rectangular resin structure and to the optical fiber.

2. A 3D direct two-photon laser printed micro-fiber pulse sensor probe according to claim 1, characterized in that: The optical fiber is a G.652.D single-mode optical fiber, and comprises a cladding and a core. The outer diameter of the cladding is 125 microns, and the diameter of the core is 8 microns.

3. A 3D direct two-photon laser printed micro-fiber pulse sensor probe according to claim 1, characterized in that: The fiber optic adapter is a standard fiber optic adapter, including LC, ST, SC, FC, and MPO interfaces.

4. A 3D direct two-photon laser printed micro-fiber pulse sensor probe according to claim 1, characterized in that: The PDMS film is a flexible material with a thickness of 100 microns.

5. A 3D direct two-photon laser printed micro-fiber pulse sensor probe according to claim 1, characterized in that: The thickness of the L-shaped resin structure is 20 microns, and the center position of the starting end of the L-shaped resin structure is set at 24 microns away from the center of the optical fiber core.

6. A 3D direct two-photon laser printed micro-fiber pulse sensor probe according to claim 1, characterized in that: The thickness of the rectangular resin structure is 50 micrometers, and the gap distance between the L-shaped resin structure and the rectangular resin structure is 30 micrometers.

7. A method for monitoring pulse based on the 3D direct two-photon laser printed micro-fiber pulse sensor probe according to any one of claims 1 to 6, characterized in that: The method comprises: S1. Set the change of pulse intensity over time as p(t). As the pulse changes, the PDMS film at the bottom of the monitoring probe will have a small mutation, causing the L-shaped resin structure to rotate at an angle of α(p(t)). According to the trigonometric formula, the change of the cavity length is vertical. Trigonometric formula: L2=L1+H*tanα(p(t)) L2 is the cavity length after rotation of angle α, L1 is the original cavity length, and H is the spacing of the L-shaped resin structure offset from the optical fiber core; S2, calculate the change of interference optical path difference Δφ; n is the refractive index of air, which is approximately 1, and λ is the wavelength of the incident light in a vacuum; S3. When light enters the optical fiber, a beam of light I is reflected at the optical fiber-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 fiber core, and the calculation formula is: 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; when φ changes slightly by Δφ, I O The light intensity will also change accordingly.

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