Medical laser for microsurgery

Abstract

Embodiments of the present disclosure disclose a medical laser suitable for microsurgery. A specific embodiment of the medical laser comprises a mirror, a gain crystal, a prism group, a Q switch and an output coupling mirror. The mirror is located at the starting point of the outgoing laser, and the gain crystal is arranged behind the mirror. The outgoing laser enters the prism group comprising a first prism, a second prism and a translation assembly from the gain crystal. The first prism is installed on the translation assembly and has a triangular prism structure. The second prism has a quadrangular prism structure. The largest side of the first prism is parallel to the largest side of the second prism. The translation assembly is configured to drive the first prism to translate along a direction perpendicular to the direction of the laser beam propagating between the first prism and the second prism. The Q switch and the output coupling mirror are arranged in sequence behind the prism group. By changing the resonant cavity length through the double prisms and the translation assembly, the pulse width is adjusted in a wide range. Thus, the embodiment improves the efficiency of clinical surgery.

Description

Technical Field

[0001] Embodiments of this disclosure relate to the field of medical laser equipment technology, and more specifically to medical lasers suitable for microsurgery. Background Technology

[0002] With the development of minimally invasive microsurgical techniques, higher demands have been placed on the tissue adaptability of medical lasers. Different lesion depths in different patients and individual differences necessitate medical lasers outputting pulse energies with varying pulse widths to achieve the desired fit. Currently, commonly used pulse-width-adjustable medical lasers achieve this by inserting a multi-pass cavity (MPC) into the resonant cavity and adjusting the waveplate angle to change the laser polarization state within the cavity. This allows the resonant cavity to switch between short and long cavities, and the pulse width to switch between short and long pulses.

[0003] However, commonly used multi-cavity medical lasers often present the following technical problems in practical applications: Because a single multi-cavity medical laser cannot achieve a wide range of adjustable output pulse widths, it is difficult to adapt to the differentiated treatment needs of different lesions. Even lasers capable of wide-range pulse width adjustment are bulky and difficult to use in microsurgical scenarios. When dealing with different patients, it is necessary to disassemble and replace the laser with the appropriate pulse type, increasing the workflow and operational difficulty for medical staff, leading to decreased surgical efficiency, increased risk of operational errors, and frequent equipment changes can also cause optical path calibration deviations, affecting the stability of laser output.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background of the present disclosure concept, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The summary portion of this disclosure is intended to provide a brief overview of the concepts, which will be described in detail in the detailed description portion. This summary portion is not intended to identify key or essential features of the claimed technical solutions, nor is it intended to limit the scope of the claimed technical solutions.

[0006] Some embodiments of this disclosure provide medical lasers suitable for microsurgery to address one or more of the technical problems mentioned in the background section above.

[0007] Some embodiments of this disclosure provide a medical laser suitable for microsurgery. The medical laser for microsurgery includes a mirror, a gain crystal, a prism assembly, a Q-switch, and an output coupling mirror. The mirror is located at the starting point of the emitted laser beam, and the gain crystal is positioned behind the mirror in the path of the emitted laser beam. The emitted laser beam, after passing through the gain crystal, enters the prism assembly. The prism assembly includes a first prism, a second prism, and a translation component. The first prism is a triangular prism with an isosceles right-angled triangle base and is mounted on the translation component. The second prism is a quadrangular prism with an isosceles trapezoidal base. The side surface with the largest area on the first prism is parallel to the side surface with the largest area on the second prism. The translation component is configured to drive the first prism to translate, and the translation direction of the translation component is perpendicular to the direction of the laser beam propagating between the first and second prisms. The Q-switch and the output coupling mirror are sequentially positioned behind the prism assembly along the path of the emitted laser beam.

[0008] Optionally, the translation component is provided with a moving stop, and the moving distance value of each moving stop is an even multiple of a preset reference value, wherein the preset reference value is the distance between the gain crystal and the laser beam passing through the center of the second prism, and the preset reference value is an even multiple of the moving distance value; the width of the second prism is less than twice the preset reference value, and the width of the first prism is greater than twice the preset reference value.

[0009] Optionally, the above-mentioned translation component can be driven by at least one of two methods: manual drive and electric drive.

[0010] Optionally, the Q switch is at least one of an acousto-optic Q switch and an electro-optic Q switch; when the Q switch is an electro-optic Q switch, a quarter-wave plate and a polarizer are sequentially provided in front of the Q switch along the optical path of the emitted laser.

[0011] Optionally, the incident surface of the polarizer forms a preset angle with the propagation direction of the emitted laser.

[0012] Optionally, the crystal type of the above-mentioned gain crystal is at least one of neodymium-doped yttrium aluminum garnet crystal, neodymium-doped yttrium vanadate crystal, ytterbium-doped yttrium aluminum garnet crystal, and erbium-ytterbium co-doped phosphate glass.

[0013] Optionally, the first prism and the second prism are made of at least one of quartz glass, K9 glass, pure yttrium aluminum garnet crystal, and sapphire.

[0014] Optionally, the aforementioned medical laser further includes a controller and a pulse width detection photodetector; the pulse width detection photodetector is fixedly mounted in the laser output optical path section between the Q switch and the output coupling mirror; the detection end face of the pulse width detection photodetector is positioned facing the laser output optical path; the signal output terminal of the pulse width detection photodetector is electrically connected to the input terminal of the controller; the signal output terminal of the controller is electrically connected to the input terminal of the translation component; the translation component is configured to perform the following steps: acquiring the pulse width amplitude information of the output laser through the photodetector; obtaining the actual pulse width deviation value based on the pulse width amplitude information and a preset reference pulse width amplitude value; in response to the actual pulse width deviation value being greater than a critical error threshold, determining an adjustment offset vector based on the actual pulse width deviation value; and controlling the first prism to move according to the adjustment direction and distance corresponding to the adjustment offset vector.

[0015] Some embodiments of this disclosure provide a medical laser suitable for microsurgery that can improve clinical surgical efficiency. Specifically, the reason for the low efficiency of most clinical surgeries is that current multi-cavity medical lasers cannot achieve a wide range of adjustable output pulse widths, making it difficult to adapt to the differentiated treatment needs of different lesion tissues. Even if there are lasers that can achieve a wide range of adjustable pulse widths, they are too bulky to be used in microsurgery. When dealing with different patients, it is necessary to disassemble and replace the laser with a suitable pulse model, increasing the workflow and operational difficulty for medical workers. Based on this, some embodiments of this disclosure provide a medical laser suitable for microsurgery. The medical laser suitable for microsurgery includes: a reflector, a gain crystal, a prism group, a Q-switch, and an output coupling mirror. The reflector is located at the starting point of the emitted laser, and the gain crystal is located behind the reflector in the path of the emitted laser. The emitted laser, after passing through the gain crystal, enters the prism group. The prism group includes a first prism, a second prism, and a translation component. The first prism is an isosceles right triangle with a base. The laser beam has a triangular prism structure, with the first prism mounted on the translation assembly. The second prism is a quadrangular prism with an isosceles trapezoidal base. The side surface with the largest area on the first prism is parallel to the side surface with the largest area on the second prism. The translation assembly is configured to drive the first prism to translate, and the translation direction of the translation assembly is perpendicular to the direction of the laser beam propagating between the first and second prisms. The Q-switch and the output coupling mirror are sequentially arranged behind the prism assembly along the optical path of the output laser. By changing the resonant cavity length using a dual-prism combination with the translation assembly, a wide range of adjustable pulse widths can be achieved while ensuring minimal changes in laser volume, significantly increasing the treatment scenarios that a single device can cover. This improves clinical surgical efficiency. Attached Figure Description

[0016] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and elements are not necessarily drawn to scale.

[0017] Figure 1 This is a schematic diagram of the structure of a medical laser suitable for microsurgery according to some embodiments of this disclosure; Figure 2 This is a top view of a medical laser suitable for microsurgery, according to some embodiments of this disclosure. Detailed Implementation

[0018] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0019] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other.

[0020] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are used only to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0021] It should be noted that the terms "a" and "a plurality of" used in this disclosure are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0022] The names of messages or information exchanged between multiple devices in the embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

[0023] This disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the structure of a medical laser suitable for microsurgery, according to some embodiments of this disclosure. Figure 1 It includes a reflector 1, a gain crystal 2, a first prism 3, a translation component 4, a second prism 5, a polarizer 6, a quarter-wave plate 7, a Q switch 8, and an output coupling mirror 9.

[0025] Figure 2 This is a top view of a medical laser suitable for microsurgery, according to some embodiments of this disclosure. Figure 2 It includes a reflector 1, a gain crystal 2, a first prism 3, a translation component 4, a second prism 5, a polarizer 6, a quarter-wave plate 7, a Q switch 8, and an output coupling mirror 9.

[0026] It needs to be explained that, Figure 1 and Figure 2 The lines running through the various components shown represent the laser propagation path inside the laser and do not represent the specific hardware structure.

[0027] In some embodiments, the medical laser suitable for microsurgery described above may include a reflector 1, a gain crystal 2, a prism assembly, a Q-switch 8, and an output coupling mirror 9. The reflector 1 may be located at the starting point of the emitted laser. The reflector 1 may be a planar total reflection mirror, with its surface coated with a high-reflectivity film corresponding to the wavelength of the oscillating laser, used to perform total internal reflection of the oscillating laser within the resonant cavity, providing feedback for laser oscillation. The gain crystal 2 may be located behind the reflector 1 in the emitted laser's optical path. The gain crystal 2 may be a solid-state laser gain medium, used to provide gain for laser oscillation under the excitation of an external pump source, achieving population inversion and generating stimulated emission. The emitted laser passing through the gain crystal 2 can enter the prism assembly. The prism assembly can be used to change the total optical path length of the resonant cavity, thereby adjusting the pulse width of the output laser from the medical laser. The prism assembly may include a first prism 3, a second prism 5, and a translation component 4. The first prism 3 can be a triangular prism structure with an isosceles right-angled triangle as its base, and it can be mounted on the translation component 4. The sides corresponding to the two right-angled sides of the first prism 3 can be total reflection surfaces, used to perform total reflection of the incident laser beam and change its propagation direction. The second prism 5 can be a quadrangular prism structure with an isosceles trapezoidal base. The sides corresponding to the two legs of the second prism 5 can be total reflection surfaces, and the sides corresponding to the upper and lower bases can be light-transmitting surfaces, used in conjunction with the first prism 3 to complete multiple folding and transmission of the laser beam. The side with the largest area on the first prism 3 and the side with the largest area on the second prism 5 can be arranged parallel to each other. This arrangement allows the laser beam to achieve folding and transmission between the first prism 3 and the second prism 5, maintaining a stable propagation direction of the laser beam during the translation of the first prism 3. The aforementioned translation component 4 can be configured to drive the first prism 3 to translate, and the translation direction of the translation component 4 can be perpendicular to the direction of the laser beam propagating between the first prism 3 and the second prism 5. The translation component 4 can drive the first prism 3 to translate, thereby changing the number of times the laser beam refracts between the first prism 3 and the second prism 5, changing the total optical path length of the resonant cavity, and thus adjusting the pulse width of the output laser from the medical laser. The translation component 4 can be a device for driving the first prism 3 to translate, such as an electric displacement stage, without specific limitations. The Q switch 8 and the output coupling mirror 9 can be sequentially arranged behind the prism group along the optical path of the output laser. The Q switch 8 can be an optical component for compressing the laser pulse width to generate nanosecond-level high peak power pulsed laser, such as an electro-optic Q switch, without specific limitations.The aforementioned output coupling mirror 9 can be a cavity mirror that partially reflects and partially transmits light. It can be used to transmit the pulsed laser that meets the requirements inside the resonant cavity to the outside of the cavity, while reflecting part of the laser back into the resonant cavity to maintain the continuous oscillation of the laser.

[0028] Optionally, the translation component 4 may be provided with movement stops. These movement stops can be multiple preset sets of fixed locking structures, each set corresponding to a fixed translation position, providing a positional reference for the movement of the translation component 4. The movement distance at each movement stop can be an even multiple of a preset reference value. This movement distance can be the displacement value generated after the translation component 4 drives the first prism 3 to complete the position switching. (Refer to...) Figure 1 and Figure 2 By limiting the translation distance of the first prism 3 each time, each displacement adjustment of the translation component 4 can be made so that it does not affect the optical path of the laser beam when entering and exiting the prism group, allowing the laser beam to pass through the central axis of the second prism 5 and the gain crystal 2. The preset reference value can be the distance between the gain crystal 2 and the laser beam passing through the center of the second prism 5. The laser beam passing through the center of the second prism 5 can be the reference optical path. The preset reference value can be the vertical distance between the reference optical path and the optical path where the gain crystal 2 is located, providing a basic reference for setting the position of the translation component 4. The preset reference value can be an even multiple of the movement distance value. The width of the second prism 5 can be less than twice the preset reference value, so that the laser beam can be successfully reflected from the first prism 3 out of the prism group. The width of the second prism 5 can be the side length of the second prism 5 along the translation direction of the translation component 4. If the width of the second prism 5 is greater than or equal to twice the preset reference value, it will block the light path of the laser beam exiting the prism group. The width of the first prism 3 can be greater than twice the preset reference value. The width of the first prism 3 can be the side length of the first prism 3 along the translation direction of the translation component 4. The width of the first prism 3 can cover the width range of the second prism 5 so that the laser beam can be reflected from the first prism 3 out of the prism group. For example, let the preset reference value be D, the moving distance be d, the width of the first prism 3 be W1, and the width of the second prism 5 be W2. Then D = 2nd (n ≥ 1, "n" represents a positive integer greater than or equal to 1, which has no actual physical meaning here), and we can deduce 2n = D / d, combined with Figure 2It can be seen that 2n can be used to refer to the total number of parallel beams (including incident and outgoing beams) between the first prism 3 and the second prism 5. The relationship between the width of the first prism 3 and the width of the second prism 5 and the preset reference value can be expressed as W2 < 2D = 4nd < W1. When the total number of parallel beams between the first prism 3 and the second prism 5 is greater than or equal to 4 (i.e., 2n ≥ 4, n ≥ 2), W2 can be greater than 4·(n-1)d. As an example, if D = 36mm, the distance between the first prism 3 and the second prism 5 is 100mm, and the total number of parallel beams 2n = 8, then the moving distance value d can be determined to be 4.5mm. At this time, the width W2 of the second prism 5 needs to satisfy 4·(n-1)d < W2 < 4nd, that is, 54mm < W2 < 72mm, for example, W2 can be 63mm. The width W1 of the second prism 5 mentioned above needs to satisfy W1 > 4nd, that is, W1 > 72mm, for example, W1 can be 80mm. According to the above settings, the laser will travel back and forth 8 times inside the above prism group, the cavity length of the resonant cavity will increase, thereby enabling the output of long pulse laser.

[0029] Optionally, the driving method of the translation component 4 can be at least one of manual driving and electric driving. The manual driving method can adopt a graduated micrometer head driving structure, which facilitates the user to manually adjust the translation position of the first prism 3. The electric driving method can adopt an electric displacement stage driving structure, which can control the translation position of the first prism 3 through electrical signals to achieve automatic adjustment.

[0030] Optionally, the Q-switch 8 described above can be at least one of an acousto-optic Q-switch and an electro-optic Q-switch. An acousto-optic Q-switch can change the loss within the resonant cavity through the acousto-optic effect to achieve laser Q-switching; it has a relatively simple structure and high operational stability. An electro-optic Q-switch can change the polarization state within the resonant cavity through the electro-optic effect to achieve laser Q-switching; it has a faster switching speed, narrower output pulse width, and higher peak power. When the Q-switch 8 described above is an electro-optic Q-switch, reference can be made to... Figure 1 Along the optical path of the emitted laser, a quarter-wave plate 7 and a polarizer 6 can be sequentially arranged in front of the Q-switch 8. The polarizer 6 can be used to filter the polarization state of the oscillating laser in the resonant cavity, outputting linearly polarized light with a fixed polarization direction. The quarter-wave plate 7 can be used to convert the linearly polarized light into circularly polarized light, working in conjunction with the electro-optic Q-switch to complete the loss adjustment in the resonant cavity and realize the Q-switching function.

[0031] Optionally, such as Figure 1 and Figure 2As shown, the incident surface of the polarizer 6 and the propagation direction of the emitted laser can form a preset angle. The preset angle can be the Brewster angle, which allows the laser with the corresponding polarization direction to pass through the polarizer 6 without reflection loss, while filtering out lasers with other polarization directions, reducing transmission loss in the resonant cavity and improving polarization efficiency.

[0032] Optionally, the gain crystal 2 can be at least one of neodymium-doped yttrium aluminum garnet (Nd:YAG), neodymium-doped yttrium vanadate (Nd:YAV), ytterbium-doped yttrium aluminum garnet (YAV), and erbium-ytterbium co-doped phosphate glass. Nd:YAV crystals have high thermal conductivity and mechanical strength, making them suitable for high-power continuous or pulsed laser output applications. Nd:YAV crystals have a high stimulated emission cross-section and high pump absorption efficiency, making them suitable for miniaturized laser structures. Ytterbium-doped yttrium aluminum garnet crystals have a wide pump absorption band and high optical conversion efficiency, with low thermal load. The erbium-ytterbium co-doped phosphate glass can output lasers in wavelengths safe for the human eye, making it suitable for microsurgical treatments close to sensitive human tissues.

[0033] Optionally, the first prism 3 and the second prism 5 can be made of at least one of quartz glass, K9 glass, pure yttrium aluminum garnet crystal, and sapphire. Quartz glass has an extremely low coefficient of thermal expansion, maintaining high optical surface stability during temperature changes. K9 glass has excellent optical uniformity and low processing cost, making it suitable for mass production. Pure yttrium aluminum garnet crystal and sapphire have high thermal conductivity and laser damage threshold, making them suitable for high peak power pulsed laser transmission applications.

[0034] Optionally, the aforementioned medical laser may further include a controller and a pulse width detection photodetector. The controller may be a device used to control and coordinate the operation of various components of the medical laser, such as an embedded microcontroller unit (MCU), digital signal processor (DSP), field-programmable gate array (FPGA), or ARM processor. The pulse width detection photodetector may be a photodetector used to detect the output laser pulse width information, capable of acquiring the pulse signal of the output laser and obtaining the laser pulse width information. The pulse width detection photodetector may be fixedly mounted in the laser output optical path section between the Q switch 8 and the output coupling mirror 9. This mounting position allows the pulse width detection photodetector to acquire the pulsed laser signal after Q-switching by the Q switch 8, ensuring a high degree of consistency between the acquired pulse width information and the final output laser pulse width information. The detection end face of the pulse width detection photodetector may be positioned facing the laser output optical path to enable the photodetector to acquire the output laser pulse signal. The signal output terminal of the pulse width detection photodetector may be electrically connected to the input terminal of the controller. The signal output terminal of the controller may be electrically connected to the input terminal of the translation component 4. The aforementioned electrical connection allows the pulse width signal acquired by the pulse width detection photodetector to be transmitted to the controller, providing data for the displacement adjustment of the translation component 4. The aforementioned medical laser can be configured to perform the following steps: The first step is to acquire the pulse width amplitude information of the output laser using a photodetector. This pulse width amplitude information refers to the pulse width value characterizing the output laser. In practice, the medical laser described above can continuously acquire the pulsed laser output pulses using the photodetector at a preset sampling frequency to obtain the pulse width amplitude information. The preset sampling frequency can be once every 10 μs, and is not specifically limited here.

[0035] The second step involves obtaining the actual pulse width deviation value based on the pulse width amplitude information and the preset reference pulse width amplitude value. The preset reference pulse width amplitude value can refer to the target pulse width value pre-stored by the user. The actual pulse width deviation value can be the difference between the pulse width value actually acquired by the photodetector and the preset reference pulse width amplitude value. In practice, the medical laser can obtain the actual pulse width deviation value by subtracting the preset reference pulse width amplitude value from the pulse width amplitude information. For example, assuming the preset reference pulse width amplitude value is 20 ns and the actually acquired pulse width amplitude value is 21.2 ns, the actual pulse width deviation value is -1.2 ns.

[0036] The third step involves determining an adjustment offset vector based on the actual pulse width deviation value, in response to the actual pulse width deviation value exceeding the critical error threshold. The critical error threshold can be a user-stored maximum value representing the allowable fluctuation range of the output laser pulse width. For example, it could be 0.3 ns, without specific limitation. The actual pulse width deviation value exceeding the critical error threshold indicates that the absolute value of the actual pulse width deviation value is greater than the critical error threshold. The adjustment offset vector can be a set of parameters used to control the translational movement of the first prism, including the adjustment direction and adjustment distance of the first prism. In practice, the medical laser can compare the actual pulse width deviation value with a preset deviation-offset vector mapping table to determine the adjustment offset vector. This preset deviation-offset vector mapping table can be a table recording the mapping relationship between the actual pulse width deviation value and the adjustment offset vector. For example, when the actual pulse width deviation value is -1.2 ns, the corresponding adjustment offset vector can be -9.6 mm. Here, "-9.6 mm" represents a 9.6 mm negative translation of the first prism. It should be noted that the sign of the translation direction of the first prism can be preset by the user and is not specifically limited here.

[0037] The fourth step involves controlling the first prism to move according to the adjustment direction and distance corresponding to the adjustment offset vector. In practice, the aforementioned medical laser can output a corresponding driving voltage signal to the translation component according to the generated adjustment offset vector, controlling the translation component to move the first prism according to the adjustment direction and distance corresponding to the adjustment offset vector. The mapping relationship between the adjustment offset vector and the driving voltage signal can be pre-stored by the user within the aforementioned medical laser.

[0038] In addressing the aforementioned technical challenges in employing technical solutions, the intended application scenario—macular retinal microscopic photocoagulation repair surgery—often presents the following technical issues: increased risk of thermal damage to retinal cells during eye surgery. The macular retina has an extremely low tolerance threshold for thermal damage; a heat-affected zone exceeding 2μm can cause permanent necrosis of photoreceptor cells and complete loss of central vision. Considering the following requirements for this application scenario: pulse width adaptation to varying macular hole thicknesses, photocoagulation to minimize thermal damage to retinal tissue, and photocoagulation localization of micron-sized lesions in the macular region, we have decided to adopt the following solution: Optionally, the aforementioned translation component 4 can employ a stacked piezoelectric ceramic drive mechanism. This stacked piezoelectric ceramic drive mechanism can generate nanometer-level linear displacement through the inverse piezoelectric effect, exhibiting high displacement resolution and fast response speed, and can be used to drive the first prism 3 to achieve high-precision translation adjustment. Both the first prism 3 and the second prism 5 can be fixed using a low-stress optical positioning base. The low-stress optical positioning base can be a device that provides a mounting and positioning reference for the first prism 3 and the second prism 5 while generating low compressive stress on the prisms; for example, it can be a metal bracket covered with a soft rubber material. The low-stress optical positioning base can reduce stress deformation on the optical surfaces of the prisms during clamping, maintaining the optical surface accuracy of the prisms. The aforementioned stacked piezoelectric ceramic drive mechanism can incorporate an absolute grating ruler feedback component. This absolute grating ruler feedback component can be used to acquire the absolute displacement information of the first prism 3 in real time. The scale grating of the absolute grating ruler feedback component can be coaxially mounted with the low-stress optical positioning base of the first prism 3, and the reading head can be fixed to the base plate of the medical laser resonant cavity. This mounting method allows the scale grating to move synchronously with the first prism 3, and the reading head can read the displacement change data of the first prism 3 in real time, ensuring, to a certain extent, that the displacement detection data remains consistent with the actual position of the first prism 3. The signal output terminal of the absolute grating ruler feedback component can be electrically connected to the control input terminal of the stacked piezoelectric ceramic drive mechanism. This electrical connection can form a displacement closed-loop control circuit, allowing the stacked piezoelectric ceramic drive mechanism to correct displacement deviations and improve the translational positioning accuracy of the first prism 3 based on the real-time displacement data collected by the absolute grating ruler feedback component. The mover end of the stacked piezoelectric ceramic drive mechanism can be rigidly connected to the low-stress optical positioning base of the first prism 3. The aforementioned rigid connection allows the displacement generated by the stacked piezoelectric ceramic drive mechanism to be transmitted to the first prism 3 without loss, reducing backlash and hysteresis during transmission and improving the response speed and accuracy of displacement control. The output optical path of the medical laser can also be equipped with a microscopic aiming and focusing assembly coaxially coupled to an ophthalmic surgical microscope. This assembly can consist of a collimating lens, a coaxial beam splitter, a focusing lens group, and a standard microscopic docking bayonet. The coaxial beam splitter is fixed at 45° to the laser output optical path, the collimating lens is located at the laser incident end, and the focusing lens group is located at the laser emitting end. The entire assembly is coaxially assembled with the ophthalmic surgical microscope via the microscopic docking bayonet. This assembly can be used to focus the output laser onto the microsurgical treatment target, while simultaneously achieving coaxial alignment of the laser focused spot with the field of view of the ophthalmic surgical microscope, facilitating real-time observation of the laser's position during surgery. The light-transmitting surfaces of the first prism 3 and the second prism 5 can be coated with an anti-reflection medium film for oscillating laser light.The aforementioned antireflection dielectric film can reduce the reflection loss of laser light on the light-transmitting surface of the prism, improve the transmission efficiency of laser light within the prism assembly, and reduce useless losses in the resonant cavity. The aforementioned translation component 4 may also be equipped with a repeating locking component. The repeating locking component may include an electromagnetic locking plate, an elastic pin, and a locking base; the locking base can be fixed to the fixed end of the translation component 4, the electromagnetic locking plate can be fixed to the moving end of the translation component 4, and the elastic pin can be mounted on the locking base, with its pressing end correspondingly engaging with the electromagnetic locking plate. The repeating locking component can be used to lock and fix the position of the first prism 3 after it has moved to the target position, reducing positional drift of the first prism 3 during operation.

[0039] The above-described optional embodiments, as an inventive point of this disclosure, solve the technical problem of "medical lasers easily causing thermal damage to retinal cells during eye surgery." The specific factors leading to thermal damage to retinal cells by medical lasers during eye surgery are as follows: insufficient laser displacement adjustment precision and lack of closed-loop feedback control, easily resulting in pulse width and energy runaway; prism clamping stress and temperature deformation easily causing optical path deviation and spot diffusion, leading to an expansion of the heat-affected zone after laser energy dispersion. Solving these factors can reduce the likelihood of thermal damage to retinal cells by medical lasers during eye surgery. To achieve this effect, this disclosure also provides a laser control structure. On one hand, a nanoscale displacement closed loop is formed by combining a stacked piezoelectric ceramic driving mechanism with an absolute grating ruler, precisely adjusting the resonant cavity length to match the appropriate pulse width for different macular hole thicknesses, thus stabilizing laser output energy from the source. On the other hand, by using a low-stress optical positioning base to reduce prism deformation and a repeating locking component to fix the prism position, combined with a coaxially coupled microscopic aiming and focusing component, precise targeting and focusing of the laser spot are achieved, reducing the heat-affected zone of the laser. This effectively reduces the risk of thermal damage to retinal cells caused by medical lasers during eye surgery.

[0040] In addressing the technical challenge of thermal damage to retinal cells caused by medical lasers during ophthalmic surgery, the following technical issues arise in the intended application scenario: single-device retinal microcoagulation repair surgery in the macular region, such as in primary ophthalmic operating rooms. These issues are often accompanied by prism thermal stress deformation caused by thermal expansion and localized heating of the surgical lamp, leading to misalignment of the resonant cavity optical path. Considering the following requirements for this application scenario—namely, the need for low thermal stress under thermal expansion conditions, the need to withstand localized heating caused by prolonged localized irradiation by the surgical lamp, and the need to maintain clamping accuracy in scenarios requiring frequent sterilization of medical equipment—we have decided to adopt the following solution: Optionally, the absolute difference in the coefficient of thermal expansion between the material of the aforementioned low-stress optical positioning base and the corresponding prism can be less than a preset standard value. The preset standard value can be 1.0 × 10⁻⁶.-6 / K, without specific limitations. By setting the coefficient of thermal expansion, the thermal expansion deformation of the aforementioned low-stress optical positioning base and the corresponding prism can maintain a high degree of consistency when the ambient temperature changes, reducing thermal stress caused by differences in thermal expansion and lowering the probability of deformation of the prism's optical surface. The non-light-transmitting contact surface of the aforementioned low-stress optical positioning base and the corresponding prism can also be provided with symmetrically distributed beryllium copper elastic pressure plates. These beryllium copper elastic pressure plates have stable elastic deformation capabilities, which can be used to press and fix the prism, and at the same time, they can release the thermal deformation stress generated by the prism when the temperature changes through their own elastic deformation. An optical buffer pad can be embedded at the contact end between the aforementioned beryllium copper elastic pressure plate and the corresponding prism, and the optical buffer pad and the corresponding prism can be made of the same material. The optical buffer pad can isolate the aforementioned beryllium copper elastic pressure plate from direct contact with the prism, reducing scratches on the prism surface caused by the pressure plate. At the same time, the same material ensures that the thermal expansion at the contact points is consistent, reducing local stress at the contact point. A composite thermal isolation component can be provided between the aforementioned low-stress optical positioning base and the resonant cavity base plate of the aforementioned medical laser. This composite thermal isolation component can block heat conduction from the resonant cavity base plate to the low-stress optical positioning base, reducing temperature fluctuations between the low-stress optical positioning base and the corresponding prism. The composite thermal isolation component may include a polyimide thermal insulation pad and an annular air gap thermal insulation groove. The polyimide thermal insulation pad may have low thermal conductivity and can be used to isolate heat conducted through solid-to-solid contact. The polyimide thermal insulation pad may be a polyimide pad with thermal insulation function. The annular air gap thermal insulation groove may be a closed annular hollow gap formed around the bottom of the low-stress optical positioning base, leaving a static air layer between the low-stress optical positioning base and the resonant cavity base plate. The annular air gap thermal insulation groove can further reduce heat conduction efficiency and improve thermal isolation effect through the air medium. The interior of the low-stress optical positioning base may also be processed with a connected thermal homogenization groove to homogenize the overall temperature field of the low-stress optical positioning base. The aforementioned interconnected thermal homogenization tank allows the temperature of all parts of the low-stress optical positioning base to quickly become uniform, reducing uneven thermal deformation caused by local temperature differences. This interconnected thermal homogenization tank can be an open channel, interconnected within the low-stress optical positioning base. Through natural air convection within the tank, it quickly disperses localized heat generated by the surgical lamp's localized irradiation, resulting in a more uniform overall temperature for the base and reducing uneven thermal deformation caused by localized temperature differences. The surface of the low-stress optical positioning base can be coated with an inert passivation film, and before coating, all contact surfaces between the low-stress optical positioning base and the prism can be optically polished. Optical polishing reduces surface roughness and minimizes localized stress concentration points. The inert passivation film enhances the corrosion resistance of the low-stress optical positioning base, making it resistant to corrosive media during medical sterilization processes.The aforementioned inert passivation film can be a chemically inert, dense protective film layer that meets the requirements for medical biocompatibility and is deposited on the surface of the aforementioned low-stress optical positioning base.

[0041] The above-described optional embodiments, as an inventive point of this disclosure, solve the technical problem of "the prism thermal stress deformation caused by thermal expansion of the medical laser and local heating of the surgical lamp, resulting in misalignment of the resonant cavity optical path." The specific factors causing the prism thermal stress deformation and resonant cavity optical path misalignment due to thermal expansion of the medical laser and local heating of the surgical lamp are as follows: an excessively large difference in the coefficient of thermal expansion between the prism and the fixing device, easily generating thermal stress that compresses the prism and causes deformation during temperature changes; prolonged local irradiation by the surgical lamp causes uneven local heating of the base, leading to irregular thermal deformation; lack of heat insulation and heat homogenization structures, resulting in rapid heat conduction and accumulation that exacerbates prism deformation; and rough base contact surfaces creating stress concentration points. Solving these factors can reduce the thermal stress deformation of the prism caused by thermal expansion. To achieve this effect, this disclosure also provides a prism zero-stress clamping and control structure that is low in thermal stress, resistant to local heating, and resistant to sterilization. On the one hand, by controlling the difference in thermal expansion coefficients between the base and the prism within a preset standard value, and using a beryllium copper elastic pressure plate and an optical buffer pad of the same material, thermal expansion stress is released, reducing the probability of prism deformation. On the other hand, by using a composite thermal isolation component to block heat conduction, a connected thermal homogenization groove to homogenize local temperature, combined with optical polishing to reduce stress concentration, and an inert passivation film to resist disinfection corrosion, the prism's clamping accuracy and morphological stability are maintained over the long term. Thus, the effect of reducing prism thermal stress deformation caused by thermal expansion is achieved.

[0042] In addressing the aforementioned technical issues in the process of adopting technical solutions, the following technical problems often arise in the intended application scenario: a dental root canal micro-laser debridement treatment center. These problems are often accompanied by the following issues: the corrosive aerosols used in dental clinics and the double sterilization process can easily cause equipment corrosion and seal failure, resulting in a shorter equipment lifespan. Considering the following requirements for this application scenario: adaptability to corrosive dental clinical sterilization aerosols, adaptability to rapid intraoperative replacement, and adaptability to synergistic sterilization using low-temperature plasma and hydrogen peroxide fumigation, we have decided to adopt the following solution: Optionally, both the inner and outer surfaces of the output coupling mirror 9 can be coated with an antireflective dielectric film using ion sputtering. Ion sputtering can produce a high-density film layer with strong adhesion to the substrate and a high laser damage threshold, reducing laser reflection loss on the surface of the output coupling mirror 9 and improving laser output efficiency. The film layer on the outer surface of the output coupling mirror 9 can undergo densification and passivation treatment. This densification and passivation treatment further improves the density of the film layer, reduces its porosity, enhances its corrosion resistance and abrasion resistance, and extends the service life of the output coupling mirror 9. The housing of the medical laser can be formed from an austenitic stainless steel substrate, and a sterilization-resistant inert passivation film can be deposited on the entire outer surface of the housing. The austenitic stainless steel substrate is adaptable to the corrosion of the oral environment and frequent disinfection substances, exhibiting excellent corrosion resistance and biocompatibility. The sterilization-resistant inert passivation film enhances the housing's ability to withstand repeated medical sterilization cycles and reduces corrosion from disinfection media. The aforementioned inert passivation film can be a diamond-like carbon (DLC) hard passivation film prepared using physical vapor deposition (PVD). This DLC hard passivation film possesses high hardness and wear resistance, a low surface friction coefficient, and can withstand the erosion of medical disinfection media, maintaining the performance stability of the aforementioned shell surface. The DLC hard passivation film prepared by PVD can withstand dental standard low-temperature plasma and hydrogen peroxide fumigation disinfection cycles. All seams on the aforementioned shell can be sealed with fluororubber. Fluororubber has excellent corrosion resistance and high / low temperature resistance, and can be used to fill the seams of the aforementioned shell, preventing external moisture and corrosive aerosols from entering the interior of the medical laser, protecting the internal optical and electrical components. A detachable optical isolation window can be provided at the laser output port of the aforementioned medical laser. This detachable optical isolation window can include an optically transparent window, a screw-on latch, and a silicone rubber sealing ring. The aforementioned optical window can be fixed at the center of the aforementioned screw-on latch, and the aforementioned silicone rubber sealing ring can be fitted onto the connecting end face of the aforementioned screw-on latch. The aforementioned detachable optical isolation window can be used to prevent external contaminants such as saliva, blood, and tissue debris from entering the output optical path of the aforementioned medical laser, protecting the internal optical components. The aforementioned detachable optical isolation window can be detachably connected to the laser output port of the aforementioned medical laser via a screw-on latch structure, and a silicone rubber sealing ring can be provided at the connecting surface for end face sealing. The aforementioned screw-on latch structure allows for quick installation and removal of the aforementioned optical isolation window, facilitating replacement, cleaning, and disinfection of the aforementioned optical isolation window during surgery. The aforementioned silicone rubber sealing ring can seal the connecting surface, reducing the entry of external moisture and contaminants into the laser output port through the connection gaps. Both the front and rear light-transmitting surfaces of the aforementioned optical isolation window can be coated with a hydrophobic, anti-fouling, and anti-reflective film.The aforementioned hydrophobic, antifouling, and antireflective film can reduce the reflection loss of laser light on the surface of the optical isolation window, while also reducing the adhesion of liquids and contaminants to the film surface, thus maintaining the stable light transmission performance of the optical isolation window. This hydrophobic, antifouling, and antireflective film can be a composite nanofilm. This composite nanofilm can achieve both antireflective and hydrophobic / antifouling effects through a multi-layered film structure, meeting the needs of medical and clinical applications.

[0043] The above-mentioned optional embodiments, as an inventive point of this disclosure, solve the technical problem that "medical lasers are prone to corrosion and sealing failure due to dental corrosive aerosols and double disinfection, resulting in a short service life." The specific factors leading to a short service life are as follows: the output coupling mirror film layer has low density and lacks densification and passivation treatment, making it easily corroded and damaged by dental corrosive aerosols and disinfection media; the laser shell lacks a disinfection-resistant protective film layer, making it unable to withstand low-temperature plasma and hydrogen peroxide fumigation double disinfection, and prone to corrosion and aging; the shell splicing gaps have poor sealing performance, allowing corrosive aerosols and moisture to easily penetrate and damage optical and electrical components, causing equipment corrosion, sealing failure, and a significantly shortened service life. Solving these factors can extend the service life of the equipment. To achieve this effect, this disclosure also provides a corrosion-resistant sealing and quick-change window protection structure for dental microscopic lasers. On one hand, by densifying and passivating the output coupling mirror film layer, using a diamond-like carbon disinfection-resistant passivation film on the shell, and sealing the gaps with fluororubber, the overall resistance of the machine to corrosive aerosols and double disinfection is improved, preventing external corrosive media from penetrating the equipment. On the other hand, a screw-on snap-on detachable optical isolation window, coated with a hydrophobic and anti-fouling composite nano-coating, allows for rapid intraoperative replacement, reducing contaminant adhesion and protecting internal optical components from contamination and damage. This extends the equipment's lifespan.

[0044] Some embodiments of this disclosure provide a medical laser suitable for microsurgery that can improve clinical surgical efficiency. Specifically, the reason for the low efficiency of most clinical surgeries is that current multi-cavity medical lasers cannot achieve a wide range of adjustable output pulse widths, making it difficult to adapt to the differentiated treatment needs of different lesion tissues. Even if there are lasers that can achieve a wide range of adjustable pulse widths, they are too bulky to be used in microsurgery. When dealing with different patients, it is necessary to disassemble and replace the laser with a suitable pulse model, increasing the workflow and operational difficulty for medical workers. Based on this, some embodiments of this disclosure provide a medical laser suitable for microsurgery. The medical laser suitable for microsurgery includes: a reflector, a gain crystal, a prism group, a Q-switch, and an output coupling mirror. The reflector is located at the starting point of the emitted laser, and the gain crystal is located behind the reflector in the path of the emitted laser. The emitted laser, after passing through the gain crystal, enters the prism group. The prism group includes a first prism, a second prism, and a translation component. The first prism is an isosceles right triangle with a base. The laser beam has a triangular prism structure, with the first prism mounted on the translation assembly. The second prism is a quadrangular prism with an isosceles trapezoidal base. The side surface with the largest area on the first prism is parallel to the side surface with the largest area on the second prism. The translation assembly is configured to drive the first prism to translate, and the translation direction of the translation assembly is perpendicular to the direction of the laser beam propagating between the first and second prisms. The Q-switch and the output coupling mirror are sequentially arranged behind the prism assembly along the optical path of the output laser. By changing the resonant cavity length using a dual-prism combination with the translation assembly, a wide range of adjustable pulse widths can be achieved while ensuring minimal changes in laser volume, significantly increasing the treatment scenarios that a single device can cover. This improves clinical surgical efficiency.

[0045] The above description is merely a selection of preferred embodiments of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A medical laser suitable for microsurgery, characterized in that, The medical laser includes a mirror, a gain crystal, a prism assembly, a Q-switch, and an output coupling mirror, wherein... The reflector is located at the starting point of the emitted laser, and the gain crystal is located behind the reflector in the optical path of the emitted laser. The emitted laser light, after passing through the gain crystal, enters the prism assembly; The prism assembly includes a first prism, a second prism, and a translation component; The first prism is a triangular prism structure with an isosceles right triangle as its base, and the first prism is mounted on the translation component; The second prism is a quadrangular prism structure with an isosceles trapezoidal base; The side with the largest area on the first prism is parallel to the side with the largest area on the second prism. The translation component is configured to drive the first prism to translate, and the translation direction of the translation component is perpendicular to the direction of the laser beam propagating between the first prism and the second prism. The Q switch and the output coupling mirror are sequentially positioned behind the prism assembly along the optical path of the output laser.

2. The medical laser for microsurgery according to claim 1, characterized in that, The translation component is provided with a moving position, and the moving distance value of each moving position is an even multiple of a preset reference value. The preset reference value is the distance between the gain crystal and the laser beam passing through the center of the second prism, and the preset reference value is an even multiple of the moving distance value. The width of the second prism is less than twice the preset reference value, and the width of the first prism is greater than twice the preset reference value.

3. The medical laser for microsurgery according to claim 1, characterized in that, The translation component is driven by at least one of two methods: manual drive and electric drive.

4. The medical laser for microsurgery according to claim 1, characterized in that, The Q-switch is at least one of an acousto-optic Q-switch and an electro-optic Q-switch; When the Q switch is an electro-optic Q switch, a quarter-wave plate and a polarizer are sequentially arranged in front of the Q switch along the optical path of the emitted laser.

5. The medical laser for microsurgery according to claim 4, characterized in that, The incident surface of the polarizer forms a preset angle with the propagation direction of the emitted laser.

6. The medical laser for microsurgery according to claim 1, characterized in that, The gain crystal is at least one of the following: neodymium-doped yttrium aluminum garnet crystal, neodymium-doped yttrium vanadate crystal, ytterbium-doped yttrium aluminum garnet crystal, and erbium-ytterbium co-doped phosphate glass.

7. The medical laser for microsurgery according to claim 1, characterized in that, The first prism and the second prism are made of at least one of the following materials: quartz glass, K9 glass, pure yttrium aluminum garnet crystal, and sapphire.

8. The medical laser for microsurgery according to claim 1, characterized in that, The medical laser also includes a controller and a pulse width detection photodetector; The pulse width detection photodetector is fixedly mounted in the laser output optical path section between the Q switch and the output coupling mirror; The detection end face of the pulse width detection photodetector is positioned directly opposite the optical path of the laser output; The signal output terminal of the pulse width detection photodetector is electrically connected to the input terminal of the controller; The signal output terminal of the controller is electrically connected to the input terminal of the translation component; The translation component is configured to perform the following steps: The pulse width amplitude information of the output laser is obtained through the photodetector; Based on the pulse width amplitude information and the preset reference pulse width amplitude, the actual pulse width deviation value is obtained; In response to the actual pulse width deviation value being greater than the critical error threshold, an adjustment offset vector is determined based on the actual pulse width deviation value; The first prism is controlled to move according to the adjustment direction and distance corresponding to the adjustment offset vector.

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