Cylindrical homogenizing laser fiber

Abstract

The application discloses a columnar uniform light laser optical fiber, and the optical fiber is sequentially provided with a fiber core, a cladding layer and a sleeve layer from inside to outside, the fiber core is sleeved in the cladding layer, the sleeve layer is coated on the outer surface of the optical fiber, and N scattering monomers or N scattering birefringent points are sequentially arranged along the length direction of the fiber core at the end of the fiber core according to the design requirements of the columnar light emitting length. The scattering body particles are filled in each scattering monomer or the birefringent points are continuously written and arranged to form a scattering continuum, the cladding layer of the sleeved fiber core is butted against the scattering continuum, so that the laser treatment optical fiber realizes lateral columnar uniform light transmission in the length direction within a target set distance range. The laser optical fiber can be used for the treatment of spinal nerve injury, including intervertebral disc herniation, spinal stenosis, spondylolisthesis or traumatic fracture of each segment of cervical vertebra, thoracic vertebra, lumbar vertebra and sacral vertebra.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, and in particular relates to a cylindrical uniform light laser optical fiber for treating spinal nerve injuries. Background Art

[0002] Spinal cord injury (SCI) is caused by various injury factors that damage the spinal cord structure and function, resulting in functional disorders (motor, sensory, reflex, etc.) below the injury level, and is characterized by a high disability rate and poor prognosis.

[0003] Spinal nerve injury can be caused by a variety of factors, including degenerative conditions such as cervical and thoracic spinal stenosis and lumbar disc herniation. Traumatic injury can also occur, most commonly from high-energy impact injuries such as falls from heights and car accidents. Furthermore, spinal deformities, spinal infections, and spinal tumors can all potentially cause spinal nerve injury to varying degrees.

[0004] The therapeutic effect of spinal nerve injury depends on the type and severity of the injury itself. According to the pathology after spinal nerve injury, it can be divided into primary spinal nerve injury and secondary spinal nerve injury. Primary injury is directly caused by a variety of diseases such as vertebral fracture displacement, spinal canal stenosis and intervertebral disc herniation. Primary injury triggers a series of downstream cellular reactions (microcirculation disorders, inflammatory infiltration, nerve cell apoptosis, etc.), which leads to secondary spinal cord injury. Secondary spinal nerve injury refers to various adverse events that occur over time after the primary injury. From early bleeding, edema, and acute inflammatory response to mid-term microcirculation disorders, calcium ion influx, free radical formation, and even late secondary ischemia and hypoxia, nerve demyelination, and glial scar formation, they may occur alone or simultaneously. Therefore, the development of a therapeutic optical fiber that can cover different patients, different types of diseases, different inflammations or pathological changes has broader market value.

[0005] Surgery remains the primary treatment for spinal nerve injuries. Trauma and degeneration are the two main causes of surgery, with cervical spondylosis, lumbar disc herniation, and compression fractures accounting for a relatively high proportion of these procedures. While surgical techniques have advanced significantly over the past four decades, existing treatment options for central nervous system injuries remain largely based on past experience, surgically removing compressive factors such as fractures and spinal stenosis. Recovery from spinal nerve damage relies primarily on medication, acupuncture, physical therapy, and massage, with unsatisfactory results. Medical professionals have also experimented with various reparative treatments, including hormone shock, anti-inflammatory medications, nerve nutrition, neural cell transplantation, and tissue engineering material implantation. However, no reliable and effective treatment currently achieves complete functional recovery in patients with spinal nerve injuries. This is one of the reasons for the increasing conflict between doctors and patients regarding these conditions. Both medical professionals and patients are eager for a rehabilitation method that directly targets the damaged spinal cord and effectively accelerates and improves its recovery. Therefore, repair of central nervous system injuries remains a major challenge in rehabilitation medicine.

[0006] Low-level lasers, due to their non-invasive nature, have been adopted by researchers in clinical research due to their diverse photochemical, biostimulatory, and thermotherapeutic effects, including anti-inflammatory, analgesic, and injury-repair promotion. For example, transcutaneous and intravascular irradiation techniques, still in the research phase, have both revealed technical risks in clinical studies. Transcutaneous irradiation can hinder light from reaching the surface of the spinal cord, affecting spinal cord tissue absorption and limiting its bioregulatory effects. Intravascular irradiation, on the other hand, can increase the risk of postoperative and hematogenous infections due to the placement of irradiation components within blood vessels.

[0007] Most organs and tissues in the human body are cell-stacked, and the loss or apoptosis of a small number of cells has no effect on the function of the organ or tissue. However, the spinal cord and other nerves are cell-connected tissues. The loss and apoptosis of a single nerve cell can cause the interruption of upstream and downstream electrical signal transmission, resulting in serious functional impairment and changes. As an important carrier of life information transmission, each cell of the spinal nerve has the same repair needs for light. The repair and improvement of a single cell is crucial to the overall repair of spinal nerve connections. Therefore, higher clinical requirements are placed on the uniformity and reliability of laser irradiation. In addition, in different cases, the length of the injured segment of the spinal nerve varies. The shorter ones generally only involve one vertebral segment, and the longer ones may involve 4 or more vertebral lengths. For damaged areas of different lengths, higher requirements are also placed on the uniformity of the optical fiber.

[0008] Existing therapeutic optical fibers typically consist of two main components: a high-refractive-index core and a low-refractive-index, optically scattering cladding. Dispersants are evenly incorporated into the optically scattering cladding to disrupt the reflective interface between the core and cladding. When incident light encounters these dispersants at the reflective interface, it is transmitted through the fiber core. However, conventional technologies have various drawbacks. For example, weak laser light tends to be focused into a small area, resulting in significant light transmission losses, weak and uneven light intensity throughout the fiber, and the inability to reliably and stably control the light intensity. Furthermore, uniform light output along the lateral direction of a specific length (treatment area) of the laser fiber cannot be ensured. Therefore, there is a need to develop a weak laser uniforming fiber whose treatment area can accommodate the needs of different patients, different types of spinal nerve injuries, and different inflammatory and pathological conditions. While maintaining variable laser power output, it also ensures uniform light output along the entire target length, with adaptively adjustable light intensity.

[0009] To address the aforementioned technical issues, there are two main methods for homogenizing and shaping the existing optical fiber mode field to achieve beam homogenization in optical fiber structures: 1) directly homogenizing the energy distribution of the fundamental mode Gaussian beam, transferring part of the energy at the center of the beam to the edge of the beam to obtain a fundamental mode output with a flat energy distribution, ultimately achieving the purpose of homogenizing the beam energy; and 2) increasing the proportion of high-order modes in the output laser to enhance the energy at the edge of the fundamental mode, ultimately achieving multimode output and thus achieving a uniform energy distribution of the output light spot.

[0010] However, the above-mentioned existing fiber homogenization methods are all used to achieve uniform energy distribution of the output light spot at the fiber end face, and cannot effectively ensure that the fiber is uniformly illuminated within a specific target length range, especially along the side of the central axis to form a "columnar" stable and uniform light emission, thereby meeting the needs of spinal nerve injury treatment. Summary of the Invention

[0011] In response to the shortcomings and technical problems of the existing technology, the present invention aims to provide a cylindrical homogenized laser fiber. This fiber, while maintaining a long emitting distance, has a wide transmission spectrum, low light transmission loss, and the ability to achieve a specific target length range, with uniform and efficient transmission along all four sides of the fiber's axis.

[0012] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0013] A columnar uniform light laser optical fiber, the optical fiber consists of a core, a cladding and a jacket from the inside to the outside, the core is sleeved in the cladding, and the outer surface of the optical fiber is covered with a jacket. At the end of the core, according to the design requirements of the columnar light emitting length, N sections of scattering monomers or N scattering inflection points are arranged in sequence along the length direction of the core. A scattering continuum is formed by filling scatterer particles in each scattering monomer or continuously writing and arranging inflection points. The cladding sleeved on the core is docked with the scattering continuum, thereby realizing lateral columnar uniform light transmission of the laser treatment optical fiber along the length direction within the target set distance range.

[0014] Furthermore, one of the optical fiber structures of the present invention is a scattering monomer-filled structure. If scattering particles are filled in each scattering monomer, different numbers of scattering particles should be evenly filled in the scattering monomer matrix according to the distance between the longitudinal boundary of each scattering monomer and the end of the fiber core, thereby forming a discontinuous and irregular scattering particle filling distribution in the scattering continuum. A sheath is coated on the outer surface of the optical fiber, so that the laser treatment optical fiber can realize concentrated lateral columnar uniform light transmission within the target set distance range along the length direction.

[0015] Furthermore, another optical fiber structure of the present invention, namely the scattering inflection point structure, if the inflection points are arranged continuously, the inflection points should be non-uniformly and continuously written in the scattering continuum through the femtosecond laser system according to the distance of each inflection point from the end of the fiber core, so that the laser treatment optical fiber can realize concentrated lateral columnar uniform light transmission within the target set distance range along the length direction.

[0016] Furthermore, the overall structure of the optical fiber of the present invention can also be provided with a total reflection cylindrical mirror at the end of the scattering continuum, and the cladding of the sleeved fiber core is docked with the scattering continuum to form an optical fiber together with the total reflection cylindrical mirror, and the outer surface of the optical fiber is covered with a sleeve layer.

[0017] A coating layer is also coated on the outside of the scattering continuum, and the refractive index of the coating layer is required to be lower than the refractive index of the scattering monomer matrix.

[0018] One type of scattering monomer-filled optical fiber has a relative refractive index difference between the fiber core and the scattering monomer matrix of less than or equal to 0.15, and the reflectivity of light at the interface between the fiber core and the scattering monomer is less than 5%; the relative refractive index difference between the scattering monomer matrix and the scattering particles is 0.1-0.5; and the refractive index of the coating layer is lower than the refractive index of the scattering monomer matrix.

[0019] Another type of scattering inflection point structure optical fiber has a core refractive index of 1.41, an inflection point refractive index of 1.43±1%, an inflection point diameter of 50μm±5μm, an fs laser power of 50-100μJ, and an fs laser repetition rate of 10-100KHz.

[0020] In the scattering monomer-filled structure of the present invention, the length of the columnar light emission is determined according to the application scenario. The length of the scattering monomer is divided by the number of scattering monomers N to obtain the length of the scattering monomer. The unit length of the scattering monomer determines the peak-to-valley fluctuation of the lateral luminous intensity of the columnar light-emitting area. Based on the distance x from the longitudinal boundary of each scattering monomer to the end of the fiber core, different numbers of scatterer particles are uniformly filled in the scattering monomer substrate. The number of scatterer particles filled with different numbers y is filled and arranged according to a certain distribution pattern. The diameter of the scatterer particles is between one and eight times the wavelength of the incident light.

[0021] Furthermore, the core of the cylindrical homogenized laser optical fiber of the present invention is low-hydroxyl pure quartz glass, the cladding is fluorine-containing acrylic resin, and the jacket is epoxy resin and / or silica gel.

[0022] Furthermore, in one of the scattering inflection point structures of the present invention, the inflection points are non-uniformly and continuously written in the scattering continuum by a femtosecond laser system, and the distribution change pattern of the inflection points is:

[0023] in Indicates the serial number of the inflection point; z indicates the distance from the corresponding inflection point to the starting inflection point 0, unit: mm; where: A=0.83265±0.08307, B=1.30798±0.00894, C=-0.01167±0.0002; the maximum value of w is a positive integer in the interval [38, 49].

[0024] The columnar uniform light laser fiber of the present invention does not emit light from the laser light source to the end of the fiber core, and the optical power density of the columnar uniform light generated between the end of the fiber core and the tail of the scattering continuum is 20mW / cm 2 -730mW / cm 2 The uniformity of the light power density distribution of the columnar uniform light is 9%-15%.

[0025] The cylindrical homogenized laser fiber of the present invention can be used to treat spinal nerve injuries and is suitable for treating intervertebral disc herniation, spinal stenosis, spondylolisthesis or traumatic fractures in various segments of the cervical, thoracic, lumbar and sacral vertebrae.

[0026] Compared with the prior art, the present invention has the following technical advantages:

[0027] 1. The cylindrical uniform light laser fiber of the present invention realizes uniform light emission in all directions along the axis of the luminous treatment area, thus laying a solid foundation for meeting the individualized treatment and rehabilitation needs of patients with different disease severity.

[0028] 2、The columnar uniform light laser optical fiber of the application can adjust the uniform light power density according to the clinical disease treatment target requirement and the treatment target area size, and ensure the uniform light emission stability and reliability, and is more suitable for the treatment and repair of deep spinal nerve tissue damage.

[0029] 3、The columnar uniform light laser optical fiber of the application realizes the adjustment of the refractive index distribution of the optical fiber scattering continuum to control the rate and efficiency of weak laser lateral scattering leakage, so as to meet the clinical requirements for the treatment and repair of spinal nerve tissue damage in a specific target area. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1a It is a schematic diagram of the whole structure (scattering monomer filling type) of the optical fiber of the application.

[0031] Figure 1b It is a schematic diagram of another whole structure (scattering birefringence point type) of the optical fiber of the application.

[0032] Figure 2a It is a schematic diagram of the local amplification of the whole structure (scattering monomer filling type) of the optical fiber of the application.

[0033] Figure 2b It is a schematic diagram of the local amplification of the whole structure (scattering birefringence point type) of the optical fiber of the application.

[0034] Figure 3a It is a schematic diagram of the local amplification of another structure (scattering monomer filling type) of the optical fiber of the application.

[0035] Figure 3b It is a schematic diagram of the local amplification of another structure (scattering birefringence point type) of the optical fiber of the application.

[0036] Figure 4a It is a schematic diagram of the effect verification test of the optical fiber (scattering monomer filling type) of the application.

[0037] Figure 4b It is a schematic diagram of the effect verification test of the optical fiber (scattering birefringence point type) of the application.

[0038] Figure 5a It is a schematic diagram of the light tracing effect of the optical fiber (scattering monomer filling type) of the application.

[0039] Figure 5b It is a schematic diagram of the light tracing effect of the optical fiber (scattering birefringence point type) of the application.

[0040] Figure 6a1 It is a light intensity distribution diagram of the fiber core end of the optical fiber (scattering monomer filling type) of the application. Figure 6a2 It is a light intensity distribution diagram of the scattering continuum end of the optical fiber (scattering monomer filling type) of the application. Figure 6b1This is the light intensity distribution diagram of the optical fiber (scattering inflection point type) core end of the present invention; Figure 6b2 Light intensity distribution diagram at the end of the scattering continuum of the optical fiber (scattering inflection point type) of the present invention.

[0041] Figure 7a This is the lateral light intensity distribution diagram of the scattering continuum of the optical fiber (scattering monomer filled type) of the present invention; Figure 7b This is the lateral light intensity distribution diagram of the scattering continuum of the optical fiber (scattering inflection point type) of the present invention.

[0042] Figure 8a This is a diagram showing the lateral luminous intensity distribution at different positions of the scattering continuum of the optical fiber (scattering monomer filled) of the present invention.

[0043] Figure 8b This is a diagram showing the lateral luminous intensity distribution at different positions of the scattering continuum of the optical fiber (scattering inflection point type) of the present invention.

[0044] Figure 9a The figure shows the relationship between the position of the scattering monomers and the number of scattering particles filled in the optical fiber (scattering monomer filled type) of the present invention, as well as the lateral light intensity distribution diagram at different positions of the corresponding scattering continuum.

[0045] Figure 9b This is a diagram showing the lateral luminous intensity distribution corresponding to the position distribution of the inflection point of the optical fiber (scattering inflection point type) of the present invention.

[0046] Figure 10 This is the luminous intensity distribution diagram of traditional diffuse optical fiber.

[0047] Figure 11 This is the lateral light intensity distribution diagram of traditional diffuse optical fiber. DETAILED DESCRIPTION

[0048] The specific content and mechanism of the present invention are further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that structures with equivalent transformations based on the same technical concept of the present invention all fall within the scope of protection claimed by the present invention.

[0049] See also Figure 1a 、 Figure 1b Schematic diagram of two columnar uniform light laser fiber structures based on the same technical concept of the present invention. One structure is simply referred to as a scattering monomer filling structure. Figure 1a Another structure is referred to as the scattering inflection point structure, such as Figure 1b .

[0050] See also Figure 1a 、 Figure 2aThe present invention's columnar homogenized laser fiber comprises, from the inside out, a core 1, a cladding 2, and a jacket 5. The core 1 is sheathed within the cladding 2. At the end of the core 1, N scattering monomers 3 or N scattering inflection points 9 are sequentially arranged along the length of the core, depending on the design requirements for the columnar light emission length. A scattering continuum 4 is formed by filling each scattering monomer 3 with scatterer particles 7 or by continuously inscribing and arranging the inflection points 9. The cladding 2 sheathed within the core 1 is butted against the scattering continuum 4, thereby achieving concentrated lateral columnar homogenization along the length of the laser treatment fiber within a target set distance.

[0051] One of the optical fiber structures of the present invention is a scattering monomer-filled structure. If scattering particles 7 are filled in each scattering monomer 3, different numbers of scattering particles 7 are uniformly filled in the base material of the scattering monomer 3 according to the difference in the distance between the longitudinal boundary of each scattering monomer 3 and the end of the fiber core 1, thereby forming a discontinuous and irregular scattering particle filling distribution in the scattering continuum 4.

[0052] See also Figure 3a A total reflection cylindrical mirror can also be provided at the end of the scattering continuum 4. The cladding 2 of the sleeved fiber core 1 is docked with the scattering continuum 4, and together with the total reflection cylindrical mirror 8, an optical fiber is drawn through a rod-tube drawing furnace. The outer surface of the optical fiber is coated with a jacket 5, so that the laser treatment optical fiber can realize lateral columnar uniform light transmission within the target set distance range along the length direction.

[0053] Specifically, the fiber core 1 of the present invention is made of low-hydroxy pure quartz glass, the cladding 2 is made of fluorine-containing acrylic resin, and the jacket 5 is made of epoxy resin and / or silica gel to ensure its flexibility and biocompatibility. The fiber core 1 is made of low-hydroxy pure quartz glass with a refractive index of 1.4532.

[0054] Based on the specific requirements of the application, a side-emitting region is provided at the end of the fiber core to achieve uniform and efficient lateral leakage of light energy within a fixed length. The scattering monomer at the end of the fiber core contains an optically transparent continuous phase and a dispersed phase with a different refractive index from the continuous phase. The continuous phase is used for axial transmission of light, while the dispersed phase is used to scatter light and emit it laterally.

[0055] The length of the columnar light is determined by the application scenario. Dividing the columnar light length by the number of scattering monomers N gives the unit length of the scattering monomers. The length of the scattering monomers determines the peak-to-valley fluctuations in the lateral light intensity of the columnar light-emitting area. Within the same columnar light-emitting length, a larger number of scattering monomers N results in a smaller unit length, making it easier to achieve smaller peak-to-valley fluctuations in light intensity.

[0056] The scattering continuum 4 is also coated with a coating layer 6. To maintain stable light transmission within the scatterer and reduce interference from the external environment, the refractive index of the coating layer 6 must be lower than that of the scattering continuum phase (the matrix of the scattering monomers 3). Possible materials include PDMS and acrylic resins.

[0057] The relative refractive index difference between the fiber core 1 and the matrix of the scattering monomers 3 is kept as close as possible, preferably as small as possible. This is primarily to minimize reflections at the fiber interface. A larger refractive index difference results in higher reflectivity, which can cause light energy to be reflected back into the fiber and even back into the laser source. The relative refractive index difference between the fiber core 1 and the matrix of the scattering monomers 3 is ≤0.15, and the reflectivity of light at the interface between the core 1 and the scattering monomers 3 is less than 5%. The relative refractive index difference between the matrix of the scattering monomers 3 and the scattering particles 7 is between 0.1-0.5.

[0058] See also Figure 4a 、 Figure 9a , according to the distance x (unit: mm) from the longitudinal boundary of each scattering monomer 3 to the end of the fiber core 1, different numbers of scattering particles 7 are uniformly filled in the base material of the scattering monomer 3; the basis for filling different numbers y (unit: pieces) of scattering particles 7 is:

[0059]

[0060] Among them: A=24674.42±5527.51, B=2781.64±848.73, C=-343.78±164.75, D=13.02±10.21, E=-0.013±0.179.

[0061] The present invention combines the scattering principle and sets the diameter of the scatterer particles 7 to be between one and eight times the wavelength of the incident light. To obtain the best scattering effect, the scatterer size is preferably one wavelength.

[0062] See also Figure 1b 、 Figure 2b , which is another structural scattering inflection point structure with the same technical concept of the present invention. If the inflection points 9 are arranged continuously, the inflection points 9 should be written non-uniformly and continuously in the scattering continuum 4 through the femtosecond laser system according to the distance of each inflection point 9 from the end of the fiber core, so that the laser treatment optical fiber can realize lateral columnar uniform light transmission in the target set distance range along the length direction.

[0063] See also Figure 3b The end of the scattering continuum 4 is also provided with a total reflection cylindrical mirror 8, and the cladding 2 of the sleeved fiber core 1 is connected to the scattering continuum 4, together with the total reflection cylindrical mirror 8 to form an optical fiber, and the outer surface of the optical fiber is covered with a jacket 5. Figure 2bThe refractive index of the fiber core 1 is 1.41, the refractive index of the inflection point 9 is 1.43±1%, the inflection point diameter is 50μm±5μm, the fs laser power of the femtosecond laser system is: 50-100μJ, and the fs laser repetition rate is: 10-100KHz.

[0064] See also Figure 9b , the distribution change rule of inflection point 9 is:

[0065] in Indicates the serial number of the inflection point; z indicates the distance from the corresponding inflection point to the starting inflection point 0, unit: mm; where: A=0.83265±0.08307, B=1.30798±0.00894, C=-0.01167±0.0002; the maximum value of w is a positive integer in the interval [38, 49].

[0066] See also Figure 4a 、 Figures 4b to 8a 、 Figure 8b Two optical fiber structures based on the same concept of the present invention were tested for their uniform light effects. The optical fiber structure of the present invention achieves zero light emission from the laser source to the end of the fiber core 1, effectively reducing transmission energy loss. It also rapidly and stably achieves the required therapeutic light intensity in the target area of ​​luminous therapy, and continuously and evenly emits light along the entire axis, forming a "columnar" light body.

[0067] In comparison, under the same conditions, see Figure 10-11 The luminous intensity effect diagram of traditional diffuse optical fiber. Traditional diffuse optical fiber needs to go through a certain distance of optical fiber transmission from the starting end of the light emission to achieve the required therapeutic light intensity. Moreover, as the optical fiber is extended, the light intensity gradually decays, and the optical fiber transmission efficiency decreases, making it impossible to achieve uniform light intensity output and unable to accurately cover the target treatment area.

[0068] Example: The cylindrical light-homogenizing laser fiber of the present invention is specifically applied in clinical spinal nerve injury treatment and repair applications. First, the length of the columnar light "light column" should be set and selected based on the location of the spinal nerve injury. Second, the light irradiation energy parameters should be set based on the clinical treatment needs. Third, the cylindrical light-homogenizing laser fiber is implanted in the surgically exposed spinal cord of the spinal nerve injury patient.

[0069] The functional test of two equivalent columnar uniform light laser fibers of the present invention was carried out. The fiber did not emit light in the circumferential direction from the laser light source to the end of the fiber core 1, and the optical power density of the columnar uniform light generated between the end of the fiber core and the tail of the scattering continuum was 20 mW / cm 2 -730mW / cm 2The spot rate density distribution uniformity of the columnar uniform light can reach 9%-15%, which fully meets the industry standard requirements of medical laser fiber.

[0070] The columnar light-homogenizing laser optical fiber of the present invention can be used for treating spinal nerve injuries.

[0071] Clinical studies have found that uniformity of laser irradiation is crucial for the overall repair of spinal nerve connections. Through detailed studies of the causes and mechanisms of different spinal nerve injuries, it has been found that the present invention's cylindrical uniform light laser fiber has significantly improved the clinical therapeutic effects of treating and repairing intervertebral disc herniation, spinal stenosis, spondylolisthesis, and traumatic fractures in various segments of the cervical, thoracic, lumbar, and sacral spine. Specific manifestations are as follows:

[0072] 1) The present invention's cylindrical homogenized laser fiber can treat mild lumbar disc herniation (clinically manifested as pain and numbness without muscle weakness). The selected irradiation treatment parameters are: 808nm wavelength, 300mW power, and 0.5-1 hour of continuous daily irradiation for 7-10 days after surgery. Therapeutic mechanism: Homogenized illumination reduces the abnormal upregulation of various pain-related sodium ion channels on the membranes of spinal neurons and dorsal root ganglion cells after nerve injury. These sodium ion channels are voltage-gated transmembrane proteins. Homogenized illumination reduces the entry of sodium ions into the cells, thereby inhibiting the generation and progression of neuralgia.

[0073] 2) The present invention's cylindrical homogenized laser fiber is used to treat severe lumbar disc herniation (clinically manifested by pain, numbness, and muscle weakness). The selected irradiation treatment parameters are: 808nm wavelength, 500mW power, and 0.5-1 hour of continuous daily irradiation for 7-10 days after surgery. Therapeutic mechanism: Homogenized illumination modulates macrophage polarization, inhibiting astrocyte activation and secretion. This shifts macrophage activation toward the M2 rather than M1 state, suppressing the expression of the astrocyte marker glial fibrillary acidic protein (GFAP) and the secretion of chondroitin sulfate proteoglycans (CSPGs), thereby reducing the number of M1 macrophages in the body. During photobiomodulation therapy, homogenized illumination is more conducive to regulating the interaction between macrophages and astrocytes after spinal nerve injury, thereby inhibiting glial scar formation and promoting neural tissue self-repair.

[0074] 3) The present invention's cylindrical homogenized laser fiber is used to treat mild lumbar spinal stenosis (clinically manifested by pain and numbness alone, without muscle weakness). The selected irradiation treatment parameters are: 808nm wavelength, 400mW power, and 0.5-1 hour of continuous daily irradiation for 7-10 days after surgery. Therapeutic mechanism: Homogenized illumination can reduce the accumulation of inflammatory cells at the injury site, alleviate autoinflammatory damage, and promote nerve regeneration. Photobiomodulation therapy can promote motor function recovery, inhibit the activation of neurotoxic microglia and astrocytes, reduce neuroinflammation and tissue apoptosis, and increase the number of neurons preserved after SCI. Photobiomodulation therapy can inhibit the upregulation of lipocalin 2 (Lcn2) and the activation of the Janus kinase 2-signal transducer and activator of transcription 3 (JAK2-STAT3) pathway after SCI.

[0075] 4) The cylindrical homogenized laser fiber of this invention is used to treat severe cervical spinal stenosis (clinically manifested by upper limb pain and numbness, as well as decreased upper and lower limb muscle strength, increased muscle tone, and brisk tendon reflexes). The irradiation treatment parameters are: 808nm wavelength, 500mW power, and 0.5-1 hour of continuous daily irradiation for 7-10 days after surgery. Therapeutic mechanism: Homogenized illumination can increase interleukin-10 (IL-10) levels in the injured nerve area. IL-10 can inhibit overexpression of autoimmune inflammatory responses, thereby alleviating nerve damage, promoting nerve regeneration, and facilitating motor function recovery in the later stages of injury. Although IL-10 expression begins early in SCI, its expression is low and slow, reaching its peak only 5 days after injury. Low-level laser irradiation significantly increases both the expression rate and level of IL-10. It can be considered that the increase in IL-1O expression in damaged tissue after weak laser irradiation can not only antagonize the secondary inflammatory response caused by proinflammatory factors and improve the injured microenvironment, but also play a direct neuroprotective role through the upregulation of IL-1O expression, thereby increasing the number of surviving nerve cells and facilitating the recovery of motor function in the later stages of spinal nerve injury. This is the molecular mechanism by which weak laser uniform illumination promotes the repair of spinal nerve injury.

[0076] 5) The cylindrical homogenized laser fiber of this invention is used to treat mild cervical spondylolisthesis (clinically manifested by neck pain only, mild pain and numbness in both upper limbs, and no muscle weakness). The irradiation treatment parameters are: an 808nm wavelength, 300mW irradiation power, and 1-2 hours of daily pulsed irradiation for 7-14 days after surgery. The treatment mechanism: Homogenized illumination promotes the growth of new nerve fibers, reduces scar formation after nerve injury, and ultimately reduces the formation of syrinxes after spinal nerve injury. Photobiomodulation therapy reduces the extent of spinal cord cavities, glial scarring within the injury area, and decreased expression of chondroitin sulfate proteoglycans (CSPGs), thereby alleviating secondary injury and promoting axonal regeneration and functional recovery.

[0077] 6) The cylindrical homogenized laser fiber of this invention is used to treat severe lumbar spondylolisthesis (clinically manifested by pain and numbness, as well as muscle weakness and intermittent claudication). The irradiation treatment parameters are: an 808nm wavelength, 500mW power, and 7-14 days of post-operative irradiation, with daily pulsed irradiation for 1-2 hours at a 30Hz pulse rate. The therapeutic mechanism: By extending the homogenized irradiation time, it maintains the stability of the blood-spinal cord barrier, repairs damaged blood-spinal cord barriers, and reduces local inflammatory cell infiltration and damage caused by blood-spinal cord barrier damage. Once damage occurs, the blood-spinal cord barrier is disrupted, neurons undergo oxidative stress and necroptosis, and a large number of inflammatory cells accumulate, causing further damage. Macrophages are the primary inflammatory cells involved in this process. Photobiomodulation therapy can promote the survival and axon regeneration of dorsal root ganglia under SCI oxidative stress, increase the CCL2 secretion level of dorsal root ganglia, and this change can reduce the polarization of macrophages to M1, further indicating that photobiomodulation therapy can promote the repair of spinal nerve injury.

[0078] 7) The present invention's cylindrical homogenized laser fiber is used to treat mild thoracic spinal stenosis (clinical manifestations: mild pain and numbness in both lower limbs). The irradiation treatment parameters are: 808nm wavelength, 400mW power, 7-14 days of post-operative irradiation, 1-2 hours of pulsed irradiation daily, and a 20Hz pulse schedule. Therapeutic mechanism: Uniformed light irradiation promotes the differentiation of neural stem cells and other stem cells with directed differentiation functions into neurons, replenishing damaged or apoptotic nerve cells. Photobiomodulation therapy can increase the permeability of nerve cell membranes, thereby changing the Ca 2+ The permeability of Ca 2+ It can affect the growth of neurites and the migration of growth cones, enhance the nerve growth factor's effect on promoting nerve regeneration, and thus promote nerve regeneration and repair.

[0079] 8) The cylindrical homogenized laser fiber of this invention is used to treat severe thoracic spinal stenosis (clinical manifestations include decreased sensation and numbness in the trunk and lower extremities, significantly increased muscle tone in the lower extremities, hyperreflexia, and positive pathological signs). The irradiation treatment parameters are: 808nm wavelength, 400mW irradiation power, 7-14 days post-operatively, daily pulsed irradiation for 1-2 hours, and a 10Hz pulse schedule. Therapeutic mechanism: Uniform illumination improves microcirculation around the spinal nerves, increases blood flow in microvessels, and reduces local peroxide and oxidative stress damage.

[0080] 9) The cylindrical homogenized laser fiber of this invention is used to treat cervical vertebral fracture-dislocation (clinical manifestations: significant loss of sensation and strength in the trunk and limbs, with positive pathological signs). Irradiation treatment parameters: 808nm wavelength, 500mW power, 1 hour daily for 7-14 days after surgery. Therapeutic mechanism: Homogenized illumination stimulates autophagy in neuronal mitochondria, rapidly clearing damaged tissue and enhancing neuronal resistance to hypoxia and free radical damage.

[0081] Studies have shown that the optical fiber of the present invention was placed above the spinal cord and irradiated continuously with appropriate treatment parameters over a treatment cycle. The safety of cylindrical homogenized fiber photobiomodulation was evaluated using vital signs (temperature, blood pressure, respiratory rate, heart rate, and blood oxygen saturation), infection markers (white blood cell counts, neutrophils, high-sensitivity C-reactive protein, and procalcitonin), photosensitivity markers (eosinophils and basophils), coagulation markers (prothrombin time, activated partial thromboplastin time, and thrombin time), and the American Spinal Injury Association (ASIA) sensory and motor scores. Patients were followed up three months after surgery. In our study, direct photobiomodulation at the site of spinal nerve injury did not cause clinical changes in patients' vital signs. Three days after irradiation, white blood cell counts, neutrophils, and high-sensitivity C-reactive protein were not significantly different from those in the control group. Changes in eosinophils and basophils, which are closely associated with allergic reactions, remained within normal ranges throughout the irradiation process. The coagulation function (prothrombin time, activated partial thromboplastin time, and thrombin time) of the patients were all within the normal range. After irradiation, the ASIA sensory and motor scores of all patients improved.

[0082] The optical fiber of this invention, placed above the surgically exposed spinal cord in patients with spinal nerve injury, overcomes the limitations of previous percutaneous or intravascular irradiation treatments, which prevented direct application of light to deeper SCI sites. Within appropriate irradiation parameters, direct photobiomodulation therapy at the site of spinal nerve injury produces no adverse reactions. This method is safe, feasible, and does not cause additional trauma to the patient.

Claims

1. A cylindrical homogenized laser optical fiber, wherein the optical fiber comprises a core (1), a cladding (2) and a jacket (5) from the inside out, the core (1) being sleeved in the cladding (2), and the outer surface of the optical fiber being covered with the jacket (5), characterized in that: At the end of the fiber core (1), according to the design requirements of the columnar light emission length, N sections of scattering monomers (3) or N scattering inflection points (9) are sequentially arranged along the length direction of the fiber core, and a scattering continuum (4) is formed by filling scattering particles (7) in each scattering monomer (3) or continuously writing and arranging the inflection points (9), and the cladding (2) of the sleeved fiber core (1) is docked with the scattering continuum (4), so that the laser treatment optical fiber can realize lateral columnar uniform light transmission in a concentrated manner within the target set distance range along the length direction; If the scattering continuum (4) is formed by filling scattering particles (7) in each scattering monomer (3), different numbers of scattering particles (7) should be quantitatively and uniformly filled in the scattering monomer (3) based on the distance between the longitudinal boundary of each scattering monomer (3) and the end of the fiber core (1). The quantitative and uniform filling of different numbers of scattering particles (7) is based on: Where: A=24674.42±5527.51, B=2781.64±848.73, C=-343.78±164.75, D=13.02±10.21, E=-0.013±0.179; x represents the distance from the longitudinal boundary of each scattering monomer (3) to the end of the fiber core (1); y represents the number of scattering particles (7) filled in each scattering monomer (3); If the scattering continuum (4) is formed by continuously writing and arranging the inflection points (9), then the inflection points (9) should be written non-uniformly and continuously by the femtosecond laser system in the scattering continuum (4) according to a specific distribution law based on the distance between each inflection point (9) and the end of the fiber core; the distribution change law of the inflection points (9) written non-uniformly and continuously by the femtosecond laser system in the scattering continuum (4) according to the specific distribution law is: in: Indicates the serial number of the inflection point; z indicates the distance from the inflection point corresponding to the serial number to the starting inflection point 0, unit: mm; where: A=0.83265±0.08307, B=1.30798±0.00894, C=-0.01167±0.0002; the maximum value of w is a positive integer in the interval [38, 49].

2. The cylindrical light-homogenizing laser fiber according to claim 1, wherein: The outer surface of the optical fiber is covered with a jacket layer (5).

3. The cylindrical light-homogenizing laser fiber according to claim 1, wherein: The end of the scattering continuum (4) is also provided with a total reflection cylindrical mirror (8), and the cladding (2) of the sleeved fiber core (1) is docked with the scattering continuum (4) to form an optical fiber together with the total reflection cylindrical mirror (8), and the outer surface of the optical fiber is coated with a sleeve layer (5).

4. The cylindrical light-homogenizing laser fiber according to claim 1, wherein: A coating layer (6) is also coated on the outside of the scattering continuum (4), and the refractive index of the coating layer (6) is required to be lower than the refractive index of the scattering monomer (3) matrix.

5. The cylindrical light-homogenizing laser fiber according to claim 2, wherein: The relative refractive index difference between the fiber core (1) and the matrix of the scattering monomer (3) is less than or equal to 0.15, and the reflectivity of light on the interface between the fiber core (1) and the scattering monomer (3) is less than 5%; The relative refractive index difference between the scattering monomer (3) matrix and the scattering particles (7) is 0.1-0.5; the refractive index of the coating layer (6) is lower than the refractive index of the scattering monomer (3) matrix.

6. The cylindrical light-homogenizing laser fiber according to claim 1, characterized in that: The fiber core (1) has a refractive index of 1.41, a refractive index of the inflection point (9) of 1.43±1%, and a diameter of 50μm±5μm.

7. The cylindrical light-homogenizing laser fiber according to claim 1 or 2, characterized in that: The columnar light luminous length is determined according to the application scenario. The columnar light luminous length is divided by the number N of scattering monomers (3) to obtain the unit length of the scattering monomers. The unit length of the scattering monomers (3) determines the peak-to-valley fluctuation of the side luminous intensity of the columnar light emitting area.

8. The cylindrical light-homogenizing laser fiber according to claim 5, characterized in that: The fiber core (1) is low-hydroxy pure quartz glass, the cladding (2) is fluorine-containing acrylic resin, and the jacket (5) is epoxy resin and / or silica gel.

9. The cylindrical light-homogenizing laser fiber according to any one of claims 2, 3, 4, 5, 6 and 8, characterized in that: The diameter of the scatterer particles (7) is between one and eight times the wavelength of the incident light.

10. The cylindrical light-homogenizing laser fiber according to any one of claims 1, 2, 3, 4, 5, 6 and 8, characterized in that: This laser fiber is used to treat spinal nerve injuries.

11. The cylindrical light-homogenizing laser fiber according to claim 10, characterized in that: The laser fiber is used to treat intervertebral disc herniation, spinal stenosis, vertebral slippage or traumatic fracture diseases in various segments of the cervical spine, thoracic spine, lumbar spine and sacral spine.

Images