Method and system for laser ablation of biological hard tissue based on hollow optical fiber water diversion flow

Abstract

The invention discloses a method and system for laser ablation of biological hard tissue based on hollow optical fiber water diversion flow. The system mainly comprises a water supply system, an air supply system, a laser transmission system, an optical fiber fixing system and a waste liquid recovery system. According to the invention, a mode of introducing water flow from the center of the hollow fiber and the outer wall of the hollow fiber is adopted, and the structure reflects laser into the hollow fiber through the reflector for coupling and then acts on biological hard tissues. Water transmitted by the water supply system flows to a laser ablation area along the outer wall of the optical fiber through the water cavity, meanwhile, the air supply system introduces gas with certain pressure through the center of the hollow optical fiber to reduce the thickness of a water layer in a laser acting area on the surface of bone tissue, laser absorption of the water layer is reduced, and high ablation efficiency is guaranteed. According to the invention, high ablation efficiency and high cooling efficiency can be simultaneously realized in laser ablation of biological hard tissues.

Description

Technical Field

[0001] The present invention relates to the field of biological hard tissue laser ablation technology. The specific method is to use water cooling to assist ablation, use a series of reflective lenses to couple the laser into a hollow optical fiber, and at the same time, introduce gas into the center of the hollow optical fiber to thin and homogenize the water layer in the ablation area, thereby reducing the absorption of Er:YAG laser by water. The above method forms a laser ablation biological hard tissue system with high efficiency ablation and low thermal damage. Background Art

[0002] Traditional dental surgery and bone and hard tissue treatment methods have great limitations, are very traumatic, take a long time to recover and are prone to postoperative complications. Surgery for bone lesions in complex areas is difficult and risky. People are in urgent need of more efficient and safer treatment methods. Lasers have the characteristics of high energy, high directionality, and high monochromaticity, and can accurately focus on specific tissue areas to achieve precise ablation.

[0003] In the early stage, laser ablation of teeth and bone hard tissues caused great thermal damage because the laser wavelength was not suitable for biological hard tissues. The use of Er:YAG laser and Er,Cr:YSGG laser can reduce thermal damage, but the thermal damage caused in clinical applications is still unacceptable. Studies have found that water assistance can effectively reduce thermal damage, making the temperature of unablated tissue lower than 47°C, avoiding irreversible damage to nerves, blood vessels and cells. However, Er:YAG laser, Er,Cr:YSGG laser and other lasers have high absorption rates for water and poor penetration in water. In addition, water absorbs laser evaporation and takes away part of the energy, resulting in low laser energy utilization and insufficient ablation depth.

[0004] Therefore, in view of the above-mentioned problems, a method and system for laser ablation of biological hard tissues is developed, which can effectively reduce thermal damage and ensure high-efficiency ablation. Summary of the invention

[0005] This patent proposes a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow. The characteristic is that it combines water-assisted cooling technology, gas-assisted technology and laser ablation technology. The present invention adopts the method of hollow optical fiber center ventilation optical fiber outer wall water flow. This structure reflects the laser into the hollow optical fiber through a reflector for coupling, and acts on the biological hard tissue after being transmitted by the optical fiber. The water supply system transmits water through the water cavity along the outer wall of the optical fiber to the surface of the biological tissue. At the same time, the gas supply system passes a certain pressure gas through the center of the hollow optical fiber to reduce the thickness of the water layer in the laser action area on the surface of the biological hard tissue, thereby reducing the absorption of the laser by the water layer and ensuring high ablation efficiency. The present invention can achieve efficient cooling of biological hard tissue by the water layer under high ablation efficiency.

[0006] In order to achieve the above effects, this patent adopts the following technical methods:

[0007] A method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow comprises a laser transmission system, a water supply system, an air supply system, an optical fiber fixing system and a waste liquid recovery system.

[0008] The laser transmission system includes a laser, a focusing lens, a reflector, a hollow optical fiber, and an optical coupling system in sequence; the laser is an Er:YAG laser generator with a power density of 2940nm wavelength. By utilizing the high absorption rate of Er:YAG laser to water, a higher ablation efficiency for biological hard tissue can be obtained; the focusing lens is used to focus the parallel laser beam generated by the laser onto the reflector; the reflector couples the laser into a fixed optical fiber, the hollow optical fiber transmits the laser by precise coupling through the central through hole of the optical fiber, and the optical coupling system is a single focusing lens or a coupling lens group composed of a concave lens and a focusing lens to diverge and converge the laser, thereby achieving the effect of precise laser transmission.

[0009] The water supply system includes a water tank, a flow sensor, a flow regulating valve, a filter device, and a medical pump. The medical pump is used as the core of the liquid supply system. Water is sucked out of the water tank, and pure water is obtained through the filter device. The water flow is adjusted by the flow regulating valve.

[0010] The air supply system includes an air compressor, a pressure regulating valve, and an air pressure sensor. The pressure regulating valve is adjusted according to the parameters provided by the air pressure sensor to control the air compressor to supply air to the air cavity of the optical fiber fixing device.

[0011] The waste liquid recovery system includes a water suction pump, a filter device, and a water tank. The waste water purified by the filter device is recovered to the water tank through the water suction pump for easy treatment.

[0012] A method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow, comprising the following steps:

[0013] 1. Start the water supply system. The water supply system obtains the required water inlet flow and generates a stable water flow by adjusting the flow control valve. After being transmitted through the pipeline, it enters the water cavity and reaches the area to be ablated along the outer wall of the hollow optical fiber.

[0014] 2. Start the waste liquid recovery system to absorb, filter and discharge the accumulated water and residue in the ablation area in real time.

[0015] 3. Start the air supply system, which transmits compressed air to the air cavity and acts on the ablation area through the central hole of the hollow optical fiber, reducing the concentration and stagnation time of water in the ablation area and reducing the absorption of water on the Er:YAG laser. It can also blow away the remaining residues of ablation in time, reduce thermal accumulation damage and clean the ablation area.

[0016] 4. Start the laser to emit laser; transmit the laser beam to the reflector through the focusing lens, and the reflector couples the laser light into the central hole of the hollow optical fiber through the concave and convex lens group, and the end of the hollow optical fiber is close to the ablation area; while the laser ablates the biological hard tissue, water rushes to the ablation area in time for timely and effective cooling, and at the same time, compressed air acts on the ablation surface through the inner hole of the optical fiber, which thins and homogenizes the water layer, and can blow away the ablation residue, thereby improving the ablation efficiency and cleaning the ablation surface.

[0017] 5. After ablation is completed, turn off the laser first, then turn off the gas supply system, and finally turn off the water outlet in the water supply system. After ensuring that there is no excess water in the ablation area, turn off the water absorption device to ensure the cleanliness of the ablation area.

[0018] The present invention has the following beneficial effects:

[0019] 1. The present invention provides a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow. The optical fiber fixing device is detachable, which is convenient for replacing the optical fiber. In addition, the processability is good, which is conducive to mass production and replacement of some parts.

[0020] 2. The present invention provides a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow, characterized in that the laser is an Er:YAG laser, which can generate 2940nm wavelength infrared light that is well absorbed by water. The wavelength coincides with the main peak of water absorption, and its water absorption coefficient is 10 times that of carbon dioxide laser. It has a good ablation effect on biological hard tissue and a low degree of retained heat damage.

[0021] 3. The present invention provides a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow. The method of ventilation from the central hole of the hollow optical fiber can better reduce the thickness of the water layer in the laser action area on the surface of the biological hard tissue. Since water has a large absorption of Er:YAG laser, this method can effectively reduce the thickness of the water layer on the ablation surface and can make the water layer in the ablation area uniform, thereby reducing the absorption and interference of water on the Er:YAG laser and improving the ablation efficiency.

[0022] 4. The present invention provides a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow. The method of ventilation from the central through hole of the hollow optical fiber can timely clean the ablation residues in the ablation area and help clean the ablation surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the overall structure of a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow in Example 1 of the present invention

[0024] Figure 2A partial diagram of a hollow-core optical fiber fixing method and system for laser ablation of biological hard tissue based on hollow-core optical fiber water flow

[0025] Figure 3 A method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow and ablation area diagram

[0026] Description of Reference Numerals 1.1—Laser, 1.2—Focusing lens, 1.3—Reflector, 1.4—Concave lens, 1.5—Convex lens, 2.1—Air pressure sensor, 2.2—Pressure regulating valve, 2.3—Air compressor, 3.1—Flow sensor, 3.2—Flow regulating valve, 3.3—Medical pump, 3.4—Filter, 3.5—Water tank, 4.1—Air cavity, 4.2—Middle nozzle, 4.3—Water cavity, 4.4—Lower nozzle, 5—Hollow optical fiber, 6—Hard biological tissue, 7—Workbench, 8.1—Filter, 8.2—Suction pump, 8.3—Waste water tank. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] Example 1

[0029] The present invention discloses a method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow, which comprises a laser transmission system, a water supply system, an air supply system, an optical fiber fixing system and a waste liquid recovery system.

[0030] The laser transmission system includes a laser 1.1, a focusing lens 1.2, a reflector 1.3, a concave lens 1.4, a convex lens 1.5, and a hollow optical fiber 5. Figure 1 As shown, the laser beam emitted by the laser 1.1 is transmitted to the reflector 1.3 through the focusing lens 1.2. The reflector 1.3 reflects the laser light to the concave lens 1.4 through a specific reflection angle for divergence, and then is focused by the convex lens 1.5. After the transmission process, the laser light is coupled into the inner hole of the hollow optical fiber 5. The laser energy is radiated to the surface to be ablated through the hollow optical fiber 5.

[0031] The water supply system includes a flow sensor 3.1, a flow regulating valve 3.2, a medical pump 3.3, a filter device 3.4, and a water tank 3.5. The medical pump 3.3 draws pure water from the water tank 3.5, passes through the filter device 3.4, and enters the water cavity for operation. At the same time, the flow regulating valve 3.2 can be adjusted according to the real-time data reflected by the flow sensor 3.1 to obtain the required flow rate.

[0032] The air supply system includes an air pressure sensor 2.1, a pressure regulating valve 2.2, and an air compressor 2.3. Pure compressed air is introduced from the air compressor 2.3 into the air cavity through the air pipe, and the required air pressure can be obtained by the pressure regulating valve 2.2 according to the parameters reflected by the air pressure sensor 2.1.

[0033] The optical fiber fixing system includes an air cavity 4.1, a middle nozzle 4.2, a water cavity 4.3, and a lower nozzle 4.4. The optical fiber fixing system of the method and system for laser ablation of biological hard tissue based on hollow optical fiber water flow of the present invention is characterized by being multi-section and detachable, which is convenient for component replacement and also convenient for installation and replacement of the hollow optical fiber 5.

[0034] The waste liquid recovery system includes a filter device 8.1, a water suction pump 8.2, and a waste water tank 8.3. The waste water obtained after ablation is filtered by the water suction pump 8.2 through the filter device 8.1 to filter the waste residue and then suck the purified waste water into the waste water tank 8.3, which is convenient for waste water classification treatment and recycling.

[0035] In the actual processing process, the steps are as follows: (1) Start the water supply system first, adjust the flow rate to the set parameters, and allow the outer wall of the hollow fiber 5 to obtain a stable water flow; (2) The waste liquid recovery system is turned on to collect the accumulated water and residues in the workbench 7 in real time; (3) Start the air supply system, transmit compressed air through the inner hole of the hollow fiber to the surface of the biological hard tissue to thin and homogenize the water layer. (4) Start the laser 1.1, and the laser is coupled with the hollow fiber after being transmitted through the focusing lens 1.2, the reflector 1.3, the concave lens 1.4, and the convex lens 1.5. The laser energy acts on the surface of the biological hard tissue at the end of the hollow fiber 5 to ablate; (4) When the ablation is completed, first turn off the laser 1.1, then turn off the air supply system, then turn off the water supply system, and finally turn off the waste liquid recovery system.

[0036] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. Any known variations such as various changes, modifications, substitutions and variations of these embodiments without departing from the principle and spirit of the present invention still fall within the technical scope to be protected by the present invention.

Claims

1. The present invention discloses a method and system for laser ablation of biological hard tissue based on hollow optical fiber water diversion flow. The present invention discloses a method and system for laser ablation of biological hard tissue based on hollow optical fiber water diversion flow, which mainly includes a water supply system, an air supply system, a laser transmission system, an optical fiber fixing system, and a waste liquid recovery system. The present invention adopts a method of diverting water flow through the outer wall of the hollow optical fiber through the ventilation center of the hollow optical fiber. The structure reflects the laser into the hollow optical fiber through a reflector for coupling, and acts on the biological hard tissue after being transmitted through the optical fiber. The water supply system transmits water through the water cavity along the outer wall of the optical fiber to the surface of the biological hard tissue. At the same time, the air supply system introduces a certain pressure gas through the center of the hollow optical fiber to reduce and even the thickness of the water layer in the laser action area on the surface of the biological tissue. Finally, the waste liquid generated by ablation is recovered and processed by the waste liquid recovery system.

2. A method and system for laser ablation of biological hard tissue based on hollow fiber water flow according to claim 1, characterized in that The laser is an Er:YAG laser, which can produce 2940nm wavelength infrared light that is well absorbed by water. This wavelength coincides with the main peak of water absorption. Its water absorption coefficient is 10 times that of carbon dioxide laser. It has a good ablation effect on biological hard tissues and a low degree of retained heat damage.

3. A method and system for laser ablation of biological hard tissue based on hollow fiber water flow according to claim 1, characterized in that The optical fiber fixing device in this patent is detachable, which is convenient for replacing the optical fiber. In addition, it has good processability, which is conducive to mass production.

4. A method and system for laser ablation of biological hard tissue based on hollow fiber drainage according to claim 1, characterized in that The method of ventilating from the center of the hollow optical fiber can better thin and homogenize the water layer in the ablation area on the surface of biological hard tissue. Since water has a strong absorption of Er:YAG laser, this method can effectively reduce the absorption of Er:YAG laser by water and improve the ablation efficiency.

5. A method and system for laser ablation of biological hard tissue based on hollow fiber drainage according to claim 1, characterized in that By ventilating from the center of the hollow optical fiber, the ablation residues in the ablation area can be blown away in time, which helps to clean the ablation surface.

6. A method and system for laser ablation of biological hard tissue based on hollow fiber drainage according to claim 1, characterized in that The steps to use are as follows: S1 turns on the water supply system, which obtains the required water inlet flow by adjusting the flow regulating valve and generates a stable water flow into the water cavity, flowing along the outer wall of the optical fiber to the tissue action area. S2 starts the waste liquid recovery system to absorb, filter and discharge the accumulated water and residue in the ablation area in real time; S3 starts the gas supply system, which transmits compressed air to the ablation area. S4 starts and controls the laser generating device, and the laser emits laser light; the laser beam is transformed into a large angle through a focusing lens and then coupled into a hollow optical fiber, and acts on the ablation area through optical fiber reflection transmission. After S5 ablation is completed, turn off the laser first and then the water outlet in the hydraulic system to ensure the cleanliness of the ablation area.

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