An ultrafast laser scanning system suitable for ophthalmic surgery

Abstract

The application belongs to the technical field of laser control, and discloses an ultrafast laser scanning system suitable for ophthalmic surgery, which comprises a laser source, an optical path adjusting structure and an eyeball fixing structure, and the optical path adjusting structure comprises a scanner; the scanner comprises first to fourth optical wedge prisms arranged in sequence along a common axis, the direction of the common axis is the same as the direction of the central axis of incident light of the scanner, the first optical wedge prism and the second optical wedge prism are used for adjusting a scanning diameter, and the third optical wedge prism and the fourth optical wedge prism are used for adjusting a scanning track pattern; the two groups of optical wedge prisms are combined, and each optical wedge prism is adjusted, so that laser scanning can be quickly performed, the diameter of the scanning track and the scanning pattern can be flexibly adjusted, and the safety of the surgery is improved.

Description

Technical Field

[0001] This invention belongs to the field of laser control technology, and more specifically, relates to an ultrafast laser scanning system suitable for ophthalmic surgery. Background Technology

[0002] With advancements in laser medical technology, femtosecond laser-assisted ophthalmic surgeries, such as cataract surgery, are increasingly being chosen by patients due to their safety and precision. Compared to traditional phacoemulsification, femtosecond laser-assisted ophthalmic surgeries offer superior treatment outcomes. Clinical studies have shown that the incisions in femtosecond laser-assisted ophthalmic surgeries are highly repeatable and predictable, independent of the surgeon's skill level, and exhibit greater surgical stability.

[0003] Taking femtosecond cataract surgery as an example, this procedure requires sequential lens nucleus splitting, capsular resection, and corneal lateral incision. The ablation requirements differ at each stage. For instance, the diameter of the ablation area for lens nucleus splitting is typically 4.0mm–6.0mm, while the diameter for corneal lateral incision is generally 12mm. Currently, most scanning devices on the market are galvanometers, such as the Chinese patent CN 102573717B related to Alcon's ophthalmic equipment. This patent allows for a series of operations, including lens nucleus splitting, capsular resection, and corneal lateral incision, by controlling the galvanometer. However, the galvanometer scanning speed is relatively slow, resulting in a longer laser ablation time. Generally, the greater the degree of lens fragmentation, the more favorable it is for the surgery. However, the greater the degree of lens fragmentation, the more complex the required ablation trajectory, the longer the procedure takes, and the higher the risk of negative pressure detachment from the eyeball.

[0004] Dual-beam wedge prism rotational scanning offers relatively fast scanning speeds. For example, Chinese patent CN 117331214 A proposes a dual-beam wedge prism rotational scanning scheme that allows for rapid scanning by rotating the prisms. Furthermore, adjusting the rotational speed ratio of the two wedge prisms can yield petal-shaped scanning trajectories with varying densities. However, this scheme cannot flexibly adjust the diameter of the petal-shaped scanning trajectory. The scanning diameter depends on the wedge angle of the wedge prism used. Once the wedge prism is selected, the diameter of the scanning trajectory is determined. For instance, to accommodate lens nucleus splitting, a wedge prism with a scanning trajectory diameter of 5.0 mm might be chosen, but this would not meet the 12 mm diameter requirement for corneal lateral incision.

[0005] Therefore, how to flexibly adjust the scanning diameter and increase the laser scanning speed to quickly complete the entire laser cutting process is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides an ultrafast laser scanning system suitable for ophthalmic surgery. Its purpose is to flexibly adjust the scanning diameter and increase the laser scanning speed to quickly complete the entire laser ablation process, thereby reducing surgical risks.

[0007] To achieve the above objectives, the present invention provides an ultrafast laser scanning system suitable for ophthalmic surgery. The ultrafast laser scanning system includes a laser source, an optical path adjustment structure, and an eye fixation structure. The laser source emits a laser beam, and the eye fixation structure fixes the patient's eyeball. After being adjusted by the optical path adjustment structure, the laser performs laser scanning at a designated location on the patient's eyeball to achieve ablation. The optical path adjustment structure includes a scanner.

[0008] The scanner includes: first to fourth optical wedge prisms arranged sequentially along a common axis, the direction of which is the same as the direction of the incident light central axis of the scanner; the first and second optical wedge prisms are used to adjust the diameter of the scanning trajectory, the diameter of which is the diameter of the smallest circle covering the scanning trajectory; and the third and fourth optical wedge prisms are used to adjust the pattern shape of the scanning trajectory.

[0009] Preferably, the optical path adjustment structure further includes a beam expander Z-focusing device and a focusing objective lens, wherein the beam expander Z-focusing device is used to adjust the focusing distance of the laser in the Z direction; and the focusing objective lens is used to converge the light to the patient's eyeball.

[0010] The laser emitted by the laser source is first focused by the beam expander Z-focuser to adjust the focusing distance, then the scanner adjusts the scanning trajectory, and the focusing objective focuses the light onto the patient's eyeball for laser ablation.

[0011] Preferably, the beam expander Z-focusing device comprises:

[0012] The first concave lens is used to diverge the parallel laser emitted from the laser source;

[0013] The second convex lens is used to converge the diverging light rays emitted from the first concave lens.

[0014] Preferably, the optical path adjustment structure further includes:

[0015] The first beam splitter is used to reflect the outgoing light from the scanner to the focusing objective lens and transmit imaging light, the imaging light including anterior segment imaging light and intraoperative observation visible light;

[0016] The second beam splitter is used to reflect the imaging light of the anterior segment of the eye and transmit the visible light for intraoperative observation.

[0017] The ultrafast laser scanning system also includes:

[0018] An anterior segment imaging module is used to receive the anterior segment imaging light to achieve anterior segment imaging of the patient;

[0019] The intraoperative imaging module is used to receive the intraoperative visible light to observe the scanning trajectory.

[0020] Preferably, the optical path adjustment structure further includes a controller, which controls the scanner to sequentially enter the nucleus splitting mode, the capsule circumcision mode, and the corneal lateral incision mode.

[0021] When entering the nucleus splitting mode, first adjust and fix the included angle of the first and second optical wedge prisms according to the diameter of the scanning trajectory required for nucleus splitting, then control the first to fourth optical wedge prisms to rotate in the same direction along the common axis and the first to third optical wedge prisms to rotate at the same speed. Adjust the speed of the third and fourth optical wedge prisms according to the pattern shape of the scanning trajectory required for nucleus splitting to achieve nucleus splitting.

[0022] When entering the capsule circumcision mode, first adjust the angle between the third and fourth optical wedge prisms to 0° and fix the angle; adjust the angle between the first and second optical wedge prisms according to the diameter of the scanning trajectory required for capsule circumcision and fix the angle; then control the first to fourth optical wedge prisms to rotate in the same direction and at the same speed along the common axis to achieve capsule circumcision.

[0023] When entering the corneal lateral incision mode, first adjust the angle between the first and second optical wedge prisms according to the diameter of the scanning trajectory required for corneal lateral incision and fix the angle, keep the angle between the third and fourth optical wedge prisms at 0°, and then control the first to fourth optical wedge prisms to rotate in the same direction and at the same speed along the common axis to achieve corneal lateral incision.

[0024] Preferably, in the split nucleus mode, the diameter of the scanning trajectory required for split nucleus is in the range of 4.0 mm to 6.0 mm.

[0025] Preferably, in the split nucleus mode, the rotational speed ratio of the third optical wedge prism and the fourth optical wedge prism is in the range of 3 to 6.

[0026] Preferably, in the capsule circumcision mode, the diameter of the scanning trajectory required for capsule circumcision is 4.0 mm to 6.0 mm.

[0027] Preferably, in the corneal lateral incision mode, the diameter of the scanning trajectory required for corneal lateral incision is 11.0 mm to 13.0 mm.

[0028] Preferably, in the corneal lateral incision mode, the corneal lateral incision only makes two incisions, the centers of the two incisions are located on the same diameter of the scanning trajectory, one incision is 1.0 mm long and the other incision is 2.0 mm long.

[0029] Preferably, the initial included angle of each optical wedge prism in the scanner is 0°. When adjusting the included angle of the first optical wedge prism and the second optical wedge prism according to the diameter of the required scanning trajectory in each mode, the first optical wedge prism is rotated forward by half the included angle relative to the initial position, and the second optical wedge prism is rotated backward by half the included angle relative to the initial position.

[0030] In summary, compared with the prior art, the technical solutions conceived in this invention have the following main advantages:

[0031] The ultrafast laser scanning system for ophthalmic surgery proposed in this invention employs two sets of optical wedge prisms in the scanner. The first and second optical wedge prisms form the first set, while the third and fourth optical wedge prisms form the second set. The diameter of the scanning trajectory can be adjusted by regulating the first and second optical wedge prisms, and the pattern shape of the scanning trajectory can be adjusted by regulating the third and fourth optical wedge prisms. By combining the two sets of optical wedge prisms and adjusting the rotation and relative position of each optical wedge prism, laser scanning can be performed quickly, and the diameter and scanning pattern of the scanning trajectory can be flexibly adjusted, thus improving the safety of the surgery.

[0032] Furthermore, a controller is also involved, which can specifically control the scanner. By adjusting the angle between the first and second optical wedge prisms, the scanning diameter can be flexibly adjusted. By adjusting the rotational speed ratio of the third and fourth optical wedge prisms, the scanning trajectory pattern can be flexibly adjusted. Based on the controller's control scheme, laser operations in nucleus splitting mode, capsular circumcision mode, and corneal lateral keratotomy mode can be completed continuously without changing the optical wedge prisms midway, thus improving the safety of the surgery. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an ultrafast laser scanning system suitable for ophthalmic surgery according to one embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the optical path when the included angle between the first optical wedge prism and the second optical wedge prism is 0 in one embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the optical path when the included angle between the first optical wedge prism and the second optical wedge prism is 180° in one embodiment of the present invention.

[0036] Figure 4 This is the 3-ring split nucleus trajectory formed when the rotational speed ratio of the third and fourth optical wedge prisms in one embodiment of the present invention is 4.

[0037] Figure 5This is the 5-ring split nucleus trajectory formed when the rotational speed ratio of the third and fourth optical wedge prisms in one embodiment of the present invention is 6;

[0038] Figure 6 This is a schematic diagram of the trajectory of a circumferential incision of the capsule in one embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the corneal lateral incision trajectory in one embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of a beam expander Z-focusing device for controlling the collimation output of the beam in one embodiment of the present invention;

[0041] Figure 9 This is a schematic diagram of the structure of a beam expander Z-focusing device for controlling beam divergence output in one embodiment of the present invention;

[0042] Figure 10 This is a detailed structural diagram of an ultrafast laser scanning system according to an embodiment of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0044] like Figure 1 The diagram shows a schematic of an ultrafast laser scanning system suitable for ophthalmic surgery according to an embodiment of the present invention. The ultrafast laser scanning system generally includes a laser source, an optical path adjustment structure, and an eye fixation structure. The laser source emits a laser beam, the eye fixation structure is used to fix the patient's eyeball, and the laser beam, after being adjusted by the optical path adjustment structure, performs laser scanning at a designated position on the patient's eyeball to achieve laser ablation. The optical path adjustment structure includes a scanner.

[0045] Specifically, the scanner includes a first optical wedge prism 31, a second optical wedge prism 32, a third optical wedge prism 33 and a fourth optical wedge prism 34 arranged sequentially along a common axis, with the direction of the common axis being the same as the direction of the incident light central axis of the scanner.

[0046] In this invention, two sets of optical wedge prisms are provided. The first set of optical wedge prisms, 31 and 32, are mainly used to control the scanning diameter. The third set of optical wedge prisms, 33 and 34, are mainly used to control the pattern of the scanning trajectory. By combining the two sets of optical wedge prisms and adjusting the rotation of each optical wedge prism, laser scanning can be performed quickly, and the diameter of the scanning trajectory and the scanning pattern can be flexibly adjusted.

[0047] Furthermore, it also includes a controller for controlling the scanner to sequentially enter the nucleus splitting mode, the capsule circumcision mode, and the corneal lateral incision mode.

[0048] At the initial moment, the initial included angle of each optical wedge prism can be set to 0°.

[0049] When entering the nucleus splitting mode, first adjust and fix the included angle of the first optical wedge prism 31 and the second optical wedge prism 32 according to the diameter of the nucleus splitting scanning trajectory. Then control the first optical wedge prism 31, the second optical wedge prism 32, the third optical wedge prism 33 and the fourth optical wedge prism 34 to rotate in the same direction along the common axis, and the rotation speed of the first optical wedge prism 31, the second optical wedge prism 32 and the third optical wedge prism 33 is the same. Adjust the rotation speed of the third optical wedge prism 33 and the fourth optical wedge prism 34 according to the pattern of the nucleus splitting scanning trajectory to achieve nucleus splitting.

[0050] Specifically, the included angles of the first optical wedge prism 31 and the second optical wedge prism 32 are different, resulting in different diameters of the scanning trajectory. Therefore, after determining the diameter of the scanning trajectory, the included angles of the first optical wedge prism 31 and the second optical wedge prism 32 can be directly calculated based on the optical path. Generally, in the nucleus splitting mode, the diameter of the nucleus splitting scanning trajectory ranges from 4.0 mm to 6.0 mm. The diameter of the nucleus splitting scanning trajectory is the diameter of the smallest circle covering the nucleus splitting scanning trajectory.

[0051] like Figure 2 The diagram shown illustrates the optical path when the angle between the first and second optical wedge prisms in one embodiment of the present invention is 0°, with an optical path deflection of θ2 and a scanning distance of r2. Figure 3 The diagram shows the optical path when the angle between the first optical wedge prism and the second optical wedge prism in one embodiment of the present invention is 180°, with the optical path deflection being θ1 and the scanning distance being r1.

[0052] Specifically, after determining the diameter of the scanning trajectory, the included angle between the first optical wedge prism 31 and the second optical wedge prism 32 can be directly calculated based on the optical path. The relationship between the included angle and the diameter is given below:

[0053] D=2·L·tan(-kγ 2 )

[0054] Where D is the scanning diameter; L is the distance between the four-light wedge prism and the imaging surface; γ is the wedge angle; and k is the scaling factor, which is obtained through experimental calibration after the scanning system is fixed.

[0055] Specifically, different rotational speeds of the third optical wedge prism 33 and the fourth optical wedge prism 34 result in different patterns for the nucleus splitting scanning trajectory. The nucleus splitting mode is used to split the lens nucleus. The higher the degree of lens fragmentation, the more complex the required cutting trajectory and the longer the time required. Therefore, the pattern of the nucleus splitting scanning trajectory can be preset according to the needs in the early stages, and then the rotational speed ratio of the third optical wedge prism 33 and the fourth optical wedge prism 34 can be determined based on the preset pattern. Specifically, a rotational speed ratio in the range of 3 to 6 is sufficient to meet the nucleus splitting requirements. The larger the rotational speed ratio, the more petals the scanning pattern has and the more complex the trajectory. Figure 4 The image shows a three-ring split nucleus trajectory formed when the rotational speed ratio of the third and fourth optical wedge prisms in one embodiment of the present invention is 4. This forms a three-ring split nucleus trajectory 39 on the lens 35, as shown below. Figure 5 The image shows a 5-ring split nucleus trajectory formed when the rotational speed ratio of the third and fourth optical wedge prisms in one embodiment of the present invention is 6, which forms a 5-ring split nucleus trajectory 40 on the lens 35.

[0056] After determining the angle between the first and second optical wedge prisms and the rotational speed ratio between the third and fourth optical wedge prisms, the optical wedge prisms are rotated according to the determined parameters. In the nucleus splitting mode, the first optical wedge prism 31, the second optical wedge prism 32, the third optical wedge prism 33, and the fourth optical wedge prism 34 rotate in the same direction along a common axis, and the rotational speeds of the first optical wedge prism 31, the second optical wedge prism 32, and the third optical wedge prism 33 are the same. The third optical wedge prism 33 and the fourth optical wedge prism 34 rotate according to the calculated rotational speed ratio, thereby achieving the cutting of the preset pattern within the preset area. The femtosecond laser performs complex trajectory cutting in the turbid lens, splitting the lens and completing the lens nucleus splitting operation.

[0057] After completing the lens nucleus splitting procedure, the capsule circumferential resection mode is entered.

[0058] When entering the capsule circumcision mode, first adjust the angle between the third optical wedge prism 33 and the fourth optical wedge prism 34 to 0° and fix the angle. Then adjust the angle between the first optical wedge prism 31 and the second optical wedge prism 32 according to the diameter of the capsule circumcision scanning trajectory and fix the angle. Then control the first optical wedge prism 31, the second optical wedge prism 32, the third optical wedge prism 33 and the fourth optical wedge prism 34 to rotate in the same direction and at the same speed along the common axis to achieve capsule circumcision.

[0059] Specifically, the scanning trajectory for capsule circumcision is circular. The angle between the third and fourth optical wedge prisms 33 and 34 is adjusted to 0°, and they rotate in the same direction and at the same speed to ensure a circular scanning trajectory. Furthermore, the angle between the first and second optical wedge prisms 31 and 32 is adjusted according to the diameter of the capsule circumcision scanning trajectory. If the diameter of the capsule circumcision scanning trajectory is the same as the diameter of the nucleus splitting scanning trajectory, the angle between the first and second optical wedge prisms 31 and 32 in the nucleus splitting mode can be directly maintained. After adjusting the angle, the first, second, third, and fourth optical wedge prisms 33 and 34 are controlled to rotate in the same direction and at the same speed along a common axis to achieve capsule circumcision. In a specific embodiment, the diameter of the capsule circumcision scanning trajectory is 4.0 mm to 6.0 mm, typically 5.0 mm. Figure 6 The diagram shows a circular capsule circumferential ...

[0060] After completing the capsular circumcision, the corneal lateral incision mode is entered.

[0061] When entering the corneal lateral incision mode, the angle between the first optical wedge prism 31 and the second optical wedge prism 32 is first adjusted and fixed according to the diameter of the corneal lateral incision scanning trajectory. The angle between the third optical wedge prism 33 and the fourth optical wedge prism 34 is kept at 0°. Then, the first optical wedge prism 31, the second optical wedge prism 32, the third optical wedge prism 33 and the fourth optical wedge prism 34 are controlled to rotate in the same direction and at the same speed along the common axis to achieve corneal lateral incision.

[0062] Specifically, the scanning trajectory for corneal lateral incision is circular, with a maximum diameter typically ranging from 11.0mm to 13.0mm, for example, 12mm. Therefore, it is necessary to first adjust and fix the angle between the first and second optical wedge prisms 31 and 32 according to the diameter of the corneal lateral incision scanning trajectory. Since the angle between the third and fourth optical wedge prisms 33 and 34 is 0° during capsular circumcision, it is sufficient to maintain this angle at 0° during corneal lateral incision. Then, the first, second, third, and fourth optical wedge prisms 31, 32, 33, and 34 are controlled to rotate in the same direction and at the same speed along a common axis to achieve corneal lateral incision. Corneal lateral incision only requires cutting several intermittent small incisions; therefore, during laser scanning, the areas that do not need to be cut can be blocked during light blocking, exposing the areas that need to be cut. Figure 7 The diagram shows a corneal lateral incision trajectory in one embodiment of the present invention. A corneal lateral incision scanning trajectory is formed on the cornea 38, and two incisions are actually formed. The length of one incision is 1.0 mm and the length of the other incision is 2.0 mm.

[0063] In specific operation, before scanning, each optical wedge prism is in its initial position and the initial included angle of each optical wedge prism is 0°. When entering the scanning period, in each mode, when adjusting the included angle of the first and second optical wedge prisms according to the diameter of the scanning trajectory, the first optical wedge prism is rotated forward by half the included angle relative to the initial position, and the second optical wedge prism is rotated backward by half the included angle relative to the initial position. Taking the adjustment angle of the first and second prisms as 30° as an example, the first and second prisms need to be rotated by 15° each, that is, the first prism rotates forward by 15° and the second prism rotates backward by 15°, with a relative rotation angle of 30°. After adjusting the angle, the laser is turned on and the rotation of the four optical wedge prisms is controlled. In this way, the initial position of the scanning trajectory in each mode can be accurately obtained, which is conducive to matching the laser emission timing with the scanning speed and realizing the equal-interval bursting of laser pulses.

[0064] In one embodiment, the optical path adjustment structure further includes a beam expander Z-focuser and a focusing objective. The beam expander Z-focuser is used to adjust the focusing distance of the laser in the Z direction; the focusing objective is used to focus the light onto the patient's eyeball. The laser emitted by the laser source is first focused by the beam expander Z-focuser to adjust the focusing distance, then the scanner adjusts the scanning trajectory, and the focusing objective focuses the light onto the patient's eyeball for laser ablation.

[0065] In one embodiment, the beam expander Z-focuser includes a first concave lens and a second convex lens. The first concave lens is used to diverge the parallel laser emitted from the laser source, and the second convex lens is used to converge the diverging light emitted from the first concave lens.

[0066] like Figure 8 This is a schematic diagram of a beam expander Z-focusing device for controlling the collimated output of a beam according to an embodiment of the present invention. The focal length of the first concave lens is -f1, and the focal length of the second convex lens is f2. When the distance between the two lenses L = f2 - f1, the output beam is collimated and the laser is focused on the focal plane.

[0067] like Figure 9 This is a schematic diagram of a beam expander Z-focusing device for controlling beam divergence output according to an embodiment of the present invention. When the distance L between the two lenses is greater than f2-f1, the emitted beam diverges, and the laser is focused below the focal plane. By adjusting the value of L, the focusing position of the axial spot can be adjusted, thereby achieving axial focusing.

[0068] Specifically, the optical path adjustment structure also includes a first beam splitter and a second beam splitter: the first beam splitter is used to reflect the outgoing light from the scanner to the focusing objective lens and transmit imaging light, which includes anterior segment imaging light and intraoperative observation visible light; the second beam splitter is used to reflect the anterior segment imaging light and transmit intraoperative observation visible light; the ultrafast laser scanning system also includes an anterior segment imaging module and an intraoperative imaging module, the anterior segment imaging module is used to receive the anterior segment imaging light to achieve anterior segment imaging of the patient; the intraoperative imaging module is used to receive intraoperative observation visible light to observe the scanning trajectory.

[0069] like Figure 10 The diagram shown is a detailed structural diagram of an ultrafast laser scanning system according to an embodiment of the present invention. Laser source 1 provides the light source for laser processing. The high-power laser source can be a high-power continuous laser or a high-power ultrashort pulse laser, with laser wavelengths covering ultraviolet, visible, and infrared wavelengths. Beam expander Z-focuser 2 is used for axial scanning of the beam. Prism scanner 3 is used for XY two-dimensional scanning. Focusing objective 4 is used to converge the beam. Anterior segment imaging 5 is used for imaging the patient's anterior segment. Intraoperative imaging 6 is used for observing the scanning trajectory during surgery. Negative pressure interface 7 is used to fix the patient's eyeball. Beam splitter 9 reflects the processing light and transmits the imaging light. Beam splitter 10 reflects the anterior segment imaging light and transmits visible light for intraoperative observation.

[0070] The ultrafast laser scanning system for ophthalmic surgery proposed in this invention employs two sets of optical wedge prisms in the scanner. The first and second optical wedge prisms form the first set, and the scanning diameter can be flexibly adjusted by changing the angle between them. The third and fourth optical wedge prisms form the second set, and the scanning trajectory pattern can be flexibly adjusted by changing their rotational speed ratio. By combining the two sets of optical wedge prisms and adjusting their rotation and relative position, the system can perform laser scanning quickly and flexibly adjust the diameter and pattern of the scanning trajectory, thus improving the safety of the surgery.

[0071] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "again" are intended to illustrate the present invention and are not intended to limit the present invention.

[0072] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. An ultrafast laser scanning system suitable for ophthalmic surgery, characterized in that, The device includes a laser source, an optical path adjustment structure, and an eye fixation structure. The laser source is used to emit a laser, and the eye fixation structure is used to fix the patient's eyeball. After being adjusted by the optical path adjustment structure, the laser scans at a designated position on the patient's eyeball to achieve ablation. The optical path adjustment structure includes a scanner. The scanner includes: first to fourth optical wedge prisms arranged sequentially along a common axis, the direction of which is the same as the direction of the incident light central axis of the scanner; the first and second optical wedge prisms are used to adjust the diameter of the scanning trajectory, the diameter of which is the diameter of the smallest circle covering the scanning trajectory; and the third and fourth optical wedge prisms are used to adjust the pattern shape of the scanning trajectory. The optical path adjustment structure also includes a controller, which controls the scanner to sequentially enter nucleus splitting mode, capsular circumcision mode, and corneal lateral slit mode. When entering the nucleus splitting mode, first adjust and fix the included angle of the first and second optical wedge prisms according to the diameter of the scanning trajectory required for nucleus splitting, then control the first to fourth optical wedge prisms to rotate in the same direction along the common axis and the first to third optical wedge prisms to rotate at the same speed. Adjust the speed of the third and fourth optical wedge prisms according to the pattern shape of the scanning trajectory required for nucleus splitting to achieve nucleus splitting. When entering the capsule circumcision mode, first adjust the angle between the third and fourth optical wedge prisms to 0° and fix the angle; adjust the angle between the first and second optical wedge prisms according to the diameter of the scanning trajectory required for capsule circumcision and fix the angle; then control the first to fourth optical wedge prisms to rotate in the same direction and at the same speed along the common axis to achieve capsule circumcision. When entering the corneal lateral incision mode, first adjust the angle between the first and second optical wedge prisms according to the diameter of the scanning trajectory required for corneal lateral incision and fix the angle, keep the angle between the third and fourth optical wedge prisms at 0°, and then control the first to fourth optical wedge prisms to rotate in the same direction and at the same speed along the common axis to achieve corneal lateral incision.

2. The ultrafast laser scanning system as described in claim 1, characterized in that, The optical path adjustment structure also includes a beam expander Z-focuser and a focusing objective: the beam expander Z-focuser is used to adjust the focusing distance of the laser; the focusing objective is used to converge the light to the patient's eyeball; The laser emitted by the laser source is first focused by the beam expander Z-focuser to adjust the focusing distance, then the scanner adjusts the diameter and pattern shape of the scanning trajectory, and finally the focusing objective focuses the light onto the patient's eyeball for laser ablation.

3. The ultrafast laser scanning system as described in claim 2, characterized in that, The beam expander Z-focusing device includes: The first concave lens is used to diverge the parallel laser emitted from the laser source; The second convex lens is used to converge the diverging light rays emitted from the first concave lens.

4. The ultrafast laser scanning system as described in claim 2, characterized in that, The optical path adjustment structure also includes: The first beam splitter is used to reflect the outgoing light from the scanner to the focusing objective lens and transmit imaging light, the imaging light including anterior segment imaging light and intraoperative observation visible light; The second beam splitter is used to reflect the imaging light of the anterior segment of the eye and transmit the visible light for intraoperative observation. The ultrafast laser scanning system also includes: An anterior segment imaging module is used to receive the anterior segment imaging light to achieve anterior segment imaging of the patient; The intraoperative imaging module is used to receive the intraoperative visible light to observe the scanning trajectory.

5. The ultrafast laser scanning system as described in claim 1, characterized in that, In the nucleus splitting mode, the diameter of the scan trajectory required for nucleus splitting ranges from 4.0 mm to 6.0 mm. In the capsule circumferential cutting mode, the diameter of the scan trajectory required for capsule circumferential cutting ranges from 4.0 mm to 6.0 mm.

6. The ultrafast laser scanning system as described in claim 1, characterized in that, In the split-nucleus mode, the rotational speed ratio of the third and fourth optical wedge prisms ranges from 3 to 6.

7. The ultrafast laser scanning system as described in claim 1, characterized in that, In the corneal lateral incision mode, the diameter of the scanning trajectory required for corneal lateral incision is 11.0 mm to 13.0 mm.

8. The ultrafast laser scanning system as described in claim 1, characterized in that, In the corneal lateral incision mode, only two incisions are made in the corneal lateral incision. The centers of the two incisions are located on the same diameter of the scanning trajectory. One incision is 1.0 mm long and the other is 2.0 mm long.

9. The ultrafast laser scanning system as described in claim 1, characterized in that, The initial included angle of each optical wedge prism in the scanner is 0°. When adjusting the included angle of the first optical wedge prism and the second optical wedge prism according to the diameter of the required scanning trajectory in each mode, the first optical wedge prism is rotated forward by half the included angle relative to the initial position, and the second optical wedge prism is rotated backward by half the included angle relative to the initial position.

Images