A laser-assisted grinding method and apparatus

Abstract

The application provides a laser-assisted grinding method and device, mainly comprising a hollow grinding head, an Er:yag laser, a cooling pipeline, a hollow gear shaft, a hollow cup motor, a sealing ring, a chuck, a water inlet sleeve and a shell, the hollow grinding head is connected with the water inlet sleeve through the chuck, the water inlet sleeve is connected on the hollow gear shaft, and the Er:yag laser is installed on the upper end of the hollow gear shaft. The device realizes the combined machining of laser and grinding, first, the laser quickly ablates the difficult-to-grind bone tissue at the bottom of the grinding head, then the grinding head removes the high-precision and high-efficiency heat damage layer left by the laser ablation, and the residual bone chips in the grinding are flushed out from the bottom by the cooling liquid, so that the spherical grinding head can obtain effective cooling when grinding a deep hole. Therefore, the purpose of smaller trauma and higher efficiency of bone tissue removal in minimally invasive surgery is achieved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a laser-assisted grinding method and apparatus. Background Technology

[0002] Grinding, as a traditional precision machining method, has been increasingly used in orthopedic surgery in recent years. For example, in cervical decompression surgery, surgeons often use micro-spherical diamond grinding heads to remove bone tissue at high speed. Compared to milling and drilling, this machining method is more precise, causes less trauma to soft tissue, and better avoids accidental mechanical damage (such as overcutting), making it popular among surgeons. However, grinding efficiency is low, the linear velocity at the bottom of the grinding head is too low, making it difficult to remove the bottom material, and generating excessive grinding heat, which can cause thermal necrosis of surrounding nerve tissue. These are key problems that urgently need to be solved in bone grinding technology. The patent "Laser Orthopedic Drilling Device" with publication number CN 111053611B uses an adjustable optical fiber numerical aperture NA and the angle of the corresponding output laser band. With the assistance of a CCD positioning camera, the drilling device can penetrate deep into the bone tissue and focus the laser onto the bone tissue at the drilling site. However, this technology still suffers from the problems of low efficiency and long processing time when using laser to ablate bone tissue over a large area, and the presence of a difficult-to-remove layer of laser thermal damage to the bone tissue.

[0003] To overcome the shortcomings of existing bone grinding technologies, such as thermal damage to bone tissue during the grinding process, patent CN107184245 B, entitled "A Bone Grinding Device," describes a low-temperature saline spray generation device with controllable gas-liquid ratio by mixing high-pressure gas with low-temperature saline. In this device, the nozzle is attached to a high-speed spindle, with its left end attached to the outer surface of the spindle drive motor housing and its right end close to the spherical grinding head. The saline is then carried into the bone grinding area by the grinding tangential force. However, this grinding device uses external spray cooling, which makes it difficult for the spray to penetrate deep into the grinding area, thus failing to achieve a good cooling effect. Summary of the Invention

[0004] To overcome the shortcomings of existing bone grinding techniques for deep hole grinding, such as excessively low grinding head speed at the bottom and excessive pressure and heat generated by the bottom contact with bone tissue, this invention provides a laser-assisted grinding method and apparatus. This laser-assisted grinding device utilizes laser radiation absorbed by water, converting it into heat energy that causes localized heat concentration at the irradiation point. This instantly raises the water temperature to its boiling point, resulting in a micro-explosion. This induces enormous mechanical force on the bone tissue surface, rapidly ablating localized bone tissue that is difficult to grind away at the bottom of the grinding head. The subsequent grinding head can then remove the thermally damaged tissue left by the laser ablation. Simultaneously, internal cooling ensures efficient cooling of the grinding head during deep hole grinding. The combination of grinding and laser technology results in higher surgical efficiency and less surgical trauma.

[0005] The present invention achieves the above-mentioned technical objectives by employing the following technical means.

[0006] A laser-assisted grinding device includes a hollow grinding head 1, an Er:Yag laser 10, a cooling pipe 6, a sealing ring 8, a hollow cup motor 13, and a housing 14. The hollow grinding head 1 has a through hole at its center, a hollow gear shaft 16 has a through hole at its center, and a lens 17 is embedded at its lower end for sealing and focusing. A water inlet sleeve 8 has a U-shaped groove. The hollow grinding head 1 is connected to a clamp 3 and a water inlet sleeve 8 via a chuck 2. The water inlet sleeve 8 is connected to the hollow gear shaft 16 via a bayonet. The hollow gear shaft 16 is connected to a gear shaft 15 via a gear connection. The gear shaft 15 is connected to the main shaft of the hollow cup motor 13 via a coupling 12. The hollow cup motor 13 is powered by an external power supply. The water inlet sleeve 8 and the hollow gear shaft 1... 6 is mounted on the housing via bearings. The housing 14 and the sealing ring form a sealed coupling cavity at the connection between the water inlet sleeve 8 and the hollow gear shaft 16. The coupling cavity needs to be connected to a cooling pipe 6. The Er:Yag laser 10 is mounted on the upper end of the hollow gear shaft 16. The coolant needs to enter the coupling cavity from the cooling pipe 6 and spray out from the bottom of the through hole of the hollow grinding head 1 through the "U" groove of the water inlet sleeve 8 to increase the ablation efficiency of the laser. The Er:Yag laser 10 needs to pass through the through hole of the hollow gear shaft 16 and the hollow grinding head 1 shaft and ablate the bone tissue at the bottom of the grinding head. The hollow grinding head 1 removes the residual thermal damage layer after laser ablation with high precision and efficiency. The residual bone fragments are flushed out from the bottom by the coolant, ensuring that the spherical grinding head can obtain effective cooling when grinding deep holes.

[0007] Furthermore, a pressure gauge and a flow meter are also installed along the path of the coolant pipe 6 where the coolant is introduced.

[0008] Furthermore, the outer casing 14 is provided with locking pins 5, which are used to lock the main shaft where the water inlet sleeve 6 is located, and to replace the hollow grinding head 1.

[0009] Furthermore, the device adopts a handheld design, making grinding more convenient and applicable to more grinding scenarios.

[0010] A laser-assisted grinding method, characterized by: using the laser-assisted grinding apparatus described in claim 1, comprising the following steps, wherein the steps are performed sequentially.

[0011] Step 1: Laser focusing; Place the hollow grinding head 1 into the sleeve and position it to be processed using the laser spot;

[0012] Step 2: Start processing; Use water-induced Er:Yag laser 10 to remove the bone tissue at the bottom of the hollow grinding head 1. The grinding head is fed downwards synchronously to remove the heat damage layer remaining from the laser and the surrounding bone tissue. Coolant is sprayed out from the bottom of the grinding head to cool the bone chips while flushing them out at the depth of grinding.

[0013] Step 3: Processing complete; when bone tissue removal is about to be completed, gradually reduce the power of Er:Yag laser 10, and continue to feed the hollow grinding head 1 downwards. After removing the residual thermal damage layer from the laser, stop the laser, grinding head, and coolant in sequence, and then pull the grinding head out of the sleeve.

[0014] In the first step, the Er:Yag laser 10 passes through the axis of the hollow grinding head 1, and the laser spot can assist in grinding positioning, making grinding more accurate and positioning more convenient.

[0015] In the second step, the water-induced Er:Yag laser 10 can generate shock waves through the cavitation effect, which accelerates the rate of laser removal of bone tissue.

[0016] In the second step, the thickness of the coolant layer between the laser processing head and the bone tissue in the laser processing area should be around 0.4 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] ① Eliminating pressure at the bottom of the grinding head. Due to the excessively low grinding linear speed at the bottom of ordinary spherical diamond grinding heads, it is difficult to remove bone tissue. This device combines laser and grinding, designing a water-induced laser bone ablation-assisted bone grinding device. It uses laser to directly ablate bone tissue in the area at the bottom of the grinding head, thus solving the problem of high pressure at the bottom of the grinding head caused by excessively low grinding speed.

[0019] ② Rapid and precise positioning of the grinding area. First, the laser spot accurately locates the diseased bone tissue to be removed. Then, the grinding head precisely grinds and removes the diseased bone tissue from the designated area. Therefore, this device helps to quickly determine and lock the target location during surgery, reducing surgical time, improving surgical accuracy, and enhancing the safety and effectiveness of the procedure.

[0020] ③ Significantly enhances cooling effect. In this device, coolant is sprayed from the bottom of the hollow grinding head to the deep grinding area, and residual bone chips are flushed out from the bottom by the coolant. This internal cooling method ensures that the spherical grinding head can be effectively cooled when grinding deep holes, reducing the temperature of the grinding area and effectively reducing surgical thermal damage.

[0021] ④ Significantly improves bone tissue removal efficiency. A combined laser and grinding processing method is employed. First, the laser rapidly ablates the difficult-to-grind bone tissue at the bottom of the grinding head. Then, the grinding head quickly and precisely removes the surrounding diseased bone tissue and the residual thermal damage layer from the laser ablation. Therefore, bone tissue processing efficiency is higher and damage is less. Attached Figure Description

[0022] Figure 1 This is an isometric view of the present invention.

[0023] Figure 2This is the front view of the present invention.

[0024] Figure 3 This is a schematic diagram of the grinding principle of the present invention.

[0025] Figure 4 This is a schematic diagram of the grinding process of the present invention.

[0026] Figure 5 for Figure 2 A magnified view of a portion of the image.

[0027] Figure 6 This is a flowchart illustrating the use of this invention.

[0028] Explanation of reference numerals in the attached drawings: 1-Hollow grinding head, 2-Chuck, 3-Clamping sleeve, 4-Bearing 1, 5-Locking pin, 6-Cooling pipe, 7-Pipe sealing ring, 8-Water inlet sleeve, 9-Shaft sealing ring, 10-Er:Yag laser, 11-Bearing 2, 12-Coupling, 13-Hollow cup motor, 14-Housing shell, 15-Gear shaft, 16-Hollow gear shaft, 17-Lens Detailed Implementation

[0029] The present invention will now be further described with reference to the accompanying drawings.

[0030] Reference Figures 1-6 A laser-assisted grinding device includes a hollow grinding head 1, an Er:Yag laser 10, a cooling pipe 6, a sealing ring 8, a hollow cup motor 13, and a housing 14. The hollow grinding head 1 has a through hole at its center, and a hollow gear shaft 16 has a through hole at its center, with a lens 17 embedded at its lower end for sealing and focusing. A water inlet sleeve 8 has a U-shaped groove. The hollow grinding head 1 is connected to a clamp 3 and a water inlet sleeve 8 via a chuck 2. The water inlet sleeve 8 is connected to the hollow gear shaft 16 via a bayonet. The hollow gear shaft 16 is connected to a gear shaft 15 via a gear connection. The gear shaft 15 is connected to the main shaft of the hollow cup motor 13 via a coupling 12. The hollow cup motor 13 is powered by an external power supply. The water inlet sleeve 8 and the hollow gear shaft 1... 6 is mounted on the housing via bearings. The housing 14 and the sealing ring form a sealed coupling cavity at the connection between the water inlet sleeve 8 and the hollow gear shaft 16. The coupling cavity needs to be connected to a cooling pipe 6. The Er:Yag laser 10 is mounted on the upper end of the hollow gear shaft 16. The coolant needs to enter the coupling cavity from the cooling pipe 6 and spray out from the bottom of the through hole of the hollow grinding head 1 through the "U" groove of the water inlet sleeve 8 to increase the ablation efficiency of the laser. The Er:Yag laser 10 needs to pass through the through hole of the hollow gear shaft 16 and the hollow grinding head 1 shaft and ablate the bone tissue at the bottom of the grinding head. The hollow grinding head 1 removes the residual thermal damage layer after laser ablation with high precision and efficiency. The residual bone fragments are flushed out from the bottom by the coolant, ensuring that the spherical grinding head can obtain effective cooling when grinding deep holes.

[0031] Furthermore, a pressure gauge and a flow meter are also installed along the path of the cooling pipe 6 where the coolant is introduced.

[0032] Furthermore, the outer casing 14 is provided with locking pins 5, which are used to lock the main shaft where the water inlet sleeve 6 is located, and to replace the hollow grinding head 1.

[0033] Furthermore, the device adopts a handheld design, making grinding more convenient and applicable to more grinding scenarios.

[0034] A laser-assisted grinding method, characterized by: using the laser-assisted grinding apparatus described in claim 1, comprising the following steps, wherein the steps are performed sequentially.

[0035] Step 1: Laser focusing; Place the hollow grinding head 1 into the sleeve and position it to be processed using the laser spot;

[0036] Step 2: Start processing; Use water-induced Er:Yag laser 10 to remove the bone tissue at the bottom of the hollow grinding head 1. The grinding head is fed downwards synchronously to remove the thermal damage layer remaining from the laser and the surrounding bone tissue. Coolant is sprayed out from the bottom of the grinding head to cool the bone chips while flushing them out in the deep grinding process.

[0037] Step 3: Processing complete; when bone tissue removal is about to be completed, gradually reduce the power of Er:Yag laser 10, and continue to feed the hollow grinding head 1 downwards. After removing the residual thermal damage layer from the laser, stop the laser, grinding head, and coolant in sequence, and then pull the grinding head out of the sleeve.

[0038] In the first step, the Er:Yag laser 10 passes through the axis of the hollow grinding head 1, and the laser spot can assist in grinding positioning, making grinding more accurate and positioning more convenient.

[0039] In the second step, the water-induced Er:Yag laser 10 can generate shock waves through the cavitation effect, which accelerates the rate of laser removal of bone tissue.

[0040] In step three, the thickness of the coolant layer between the laser processing head and the bone tissue in the laser processing area should be approximately 0.4 mm.

[0041] In this embodiment, the device adopts a handheld design, with the outer shell 14 as the main body. The hollow grinding head 1 is connected to the water inlet sleeve 8 via the chuck 2 and the clamp 3. The water inlet sleeve 8 is connected to the hollow gear shaft 16 via a bayonet. The hollow gear shaft 16 and the gear shaft 15 are connected by gears. The gear shaft 15 is connected to the main shaft of the hollow cup motor 13 via the coupling 12. Bearings are installed at the shoulders of the water inlet sleeve 8, the hollow gear shaft 16, and the gear shaft 15, and the bearings are embedded in the slots of the outer shell 14 to achieve a fixed effect. The hollow cup motor 13... A specific slot is inserted to provide power to the device; the cooling pipe 8 is connected to the coupling cavity of the outer shell 14 to introduce the cryogenic coolant into the coupling cavity; the water inlet sleeve 8 is provided with a "U" shaped groove to allow the cryogenic coolant to flow in and finally spray out from the bottom of the hollow grinding head 1; the Er:Yag laser 10 is connected above the hollow spindle 16 to facilitate the rapid ablation of bone tissue at the bottom of the grinding head through the hollow through hole of the grinding head, and the grinding head quickly grinds away the surrounding bone tissue and the thermal damage layer remaining by the laser. Combining the characteristics of laser and grinding, the surgical efficiency is greatly improved.

[0042] The working process of this invention is as follows: Coolant is introduced at the beginning, and Er:Yag laser 10 is turned on. The laser shines directly above the hollow gear shaft 16, passes through the hollow gear shaft 16, the water inlet sleeve 8 and the axial hole of the hollow grinding head 1, and finally irradiates the bone tissue at the bottom of the grinding head, ablating the bone tissue at the bottom to eliminate grinding pressure and reduce grinding heat; low temperature coolant is transmitted to the sealed coupling cavity of the outer shell 14 through the coolant pipe 6, and then enters the axial hole of the hollow grinding head 1 through the water inlet sleeve 8 from the coupling cavity, and finally sprays out from the bottom of the grinding head. Then, the main shaft of the hollow cup motor 13 drives the gear shaft 15 to rotate at high speed, the gear shaft 15 drives the hollow gear shaft 16 to rotate, and the hollow gear shaft 16 drives the hollow grinding head 1 to rotate, thereby grinding the bone tissue and achieving good cooling and bone tissue removal effects.

[0043] The embodiments described above merely illustrate preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that any modifications and improvements made by those skilled in the art without departing from the concept of the present invention are within the scope of protection of the present invention.

Claims

1. A laser-assisted grinding method, characterized in that, The processing using a laser-assisted grinding device includes the following steps in sequence: Step 1: Laser focusing; Place the hollow grinding head (1) into the sleeve and position it to be processed by the laser spot; Step 2: Start processing; Er:Yag laser (10) enters from above the hollow gear shaft (16), passes through the hollow gear shaft (16), the water inlet sleeve (8) and the central hole of the hollow grinding head (1), and irradiates the bone tissue at the bottom of the hollow grinding head (1). The water-induced Er:Yag laser (10) removes the bone tissue at the bottom of the hollow grinding head (1) first. The hollow grinding head (1) feeds downwards synchronously to remove the thermal damage layer and surrounding bone tissue left by the laser ablation. Coolant enters the sealed coupling cavity from the cooling pipe (6), and is sprayed from the bottom of the through hole of the hollow grinding head (1) to the deep grinding area through the "U" groove of the water inlet sleeve (8), increasing the ablation efficiency of the laser and flushing out the residual bone chips while cooling in the deep grinding area. The hollow grinding head (1) is effectively cooled when grinding deep holes by internal cooling. In the second step, the thickness of the coolant layer between the hollow grinding head (1) and the bone tissue in the laser processing area should be 0.4 mm. Step 3: Processing completed; When the bone tissue removal is about to be completed, gradually reduce the power of the Er:Yag laser (10), and the hollow grinding head (1) continues to feed downward. After the residual heat damage layer of the laser is removed, stop the laser, grinding head and coolant in sequence, and pull the hollow grinding head (1) out of the sleeve. The laser-assisted grinding method is implemented using a laser-assisted grinding device, which includes a hollow grinding head (1), an Er:Yag laser (10), a cooling pipe (6), a sealing ring (9), a hollow cup motor (13), and a housing (14). The hollow grinding head (1) has a through hole at the center of the shaft, and the hollow gear shaft (16) has a through hole at the center, and a lens (17) for sealing and focusing is inlaid at the lower end; the water inlet sleeve (8) has a "U" shaped groove, the hollow grinding head (1) is connected to the clamp (3) and the water inlet sleeve (8) through the chuck (2), the water inlet sleeve (8) is connected to the hollow gear shaft (16) through the bayonet, the hollow gear shaft (16) is connected to the gear shaft (15) through the gear connection, the gear shaft (15) is connected to the main shaft of the hollow cup motor (13) through the coupling (12), and the hollow cup motor (13) is powered by an external power supply line; The water inlet sleeve (8) and the hollow gear shaft (16) are mounted on the housing (14) by bearings. The housing (14) and the sealing ring (9) form a sealed coupling cavity at the connection between the water inlet sleeve (8) and the hollow gear shaft (16). The sealed coupling cavity is connected to a cooling pipe (6). A pressure gauge and a flow meter are provided on the path of the cooling pipe (6) leading to the coolant. The Er:Yag laser (10) is mounted on the upper end of the hollow gear shaft (16).

2. The laser-assisted grinding method as described in claim 1, characterized in that: In the second step, the water-induced Er:Yag laser (10) generates shock waves through the cavitation effect to accelerate the rate of laser removal of bone tissue.

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