Femtosecond laser operation system based on wavefront modulation

Abstract

The invention discloses a femtosecond laser surgery system based on wavefront modulation, a laser device of the femtosecond laser surgery system emits double-pulse laser, and the first pulse laser is low in energy and is used for exciting glow / fluorescence signals in a turbid crystalline lens; the excitation light signal penetrates through the turbid medium and is imaged on the wavefront measurer through the focusing lens; the excitation signal light wave front carries turbid medium scattering information on a light propagation path. The wavefront measurer carries out conjugate processing on captured wavefront information and loads the information to the wavefront modulator, wavefront pre-modulation is carried out on a second strong pulse laser, and scattering of light in a turbid medium is compensated. The second cutting intense pulse laser is focused in the turbid medium in a high-quality mode, and effective focusing is achieved.

Description

Technical Field

[0001] The present invention relates to the field of femtosecond laser systems, and particularly to a femtosecond laser surgery system based on wavefront modulation. Background Art

[0002] Femtosecond laser has become an important method for cataract treatment due to its precision and minimally invasive advantages. However, the strong light scattering characteristics of the cataract lens severely restrict the efficient development of laser surgery. As the cataract grade increases, the light scattering increases, resulting in a decrease in the quality of the focused spot. To achieve effective cutting, the laser pulse energy needs to be increased. Compared with femtosecond laser corneal ablation, the pulse energy for cataract lens ablation needs to be increased by 50 - 70 times, up to 10 - 15 uJ. Higher laser energy will cause more thermal damage. Therefore, how to improve the penetration of the laser in the cataract lens and reduce light scattering has become a key issue. Summary of the Invention

[0003] The present invention provides a femtosecond laser surgery system based on wavefront modulation, which can effectively adjust the laser wavefront, focus the laser with high quality in the turbid medium, reduce laser scattering, and improve the utilization rate of laser cutting energy.

[0004] A femtosecond laser surgery system based on wavefront modulation includes a laser, a wavefront modulation unit, a scanner, a beam splitter, and a lens;

[0005] Among them, the laser is used to emit double-pulse laser. The wavefront modulation unit includes a wavefront modulator and a wavefront measurer. The first pulse laser sequentially passes through the wavefront modulator, the scanner, the beam splitter, and the focusing lens and is focused on the eye tissue to excite fluorescence. The wavefront measurer is used to obtain the scattered wavefront information of the fluorescence and send it to the wavefront modulator. The second laser pulse is shaped by the wavefront modulator and focused inside the eye tissue.

[0006] Preferably, it further includes a beam expander and collimator, and the beam expander and collimator are used to expand and collimate the femtosecond laser.

[0007] Preferably, the scanner is used for three-dimensional scanning ablation of femtosecond laser.

[0008] Preferably, it further includes an anterior segment imaging system, and the anterior segment imaging system obtains image information through the beam splitter and measures the three-dimensional spatial positions of the cornea, aqueous humor, and lens.

[0009] Preferably, it further includes an intraoperative imaging system, and the intraoperative imaging system obtains image information through the beam splitter to observe the cutting trajectory of the femtosecond laser during the surgery.

[0010] Preferably, the first laser pulse and the second laser pulse are a detection pulse and a cutting pulse respectively, and the pulse laser energy of the detection pulse is lower than that of the cutting pulse.

[0011] Preferably, the wavefront measurer is used to measure the heat dissipation wavefront information of the glow excited by the detection pulse focused on the eye tissue, perform conjugate processing, and load it onto the wavefront modulator, and the wavefront modulator modulates the cutting pulse.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The laser of the present invention emits double-pulse laser. The energy of the first pulse laser is low and is used to excite the glow / fluorescence signal (excitation light signal) in the turbid crystal lens. The excitation light signal penetrates the turbid medium and is imaged on the wavefront measurer through the focusing lens. The wavefront of the excitation signal carries the scattering information of the turbid medium on the light propagation path; the wavefront measurer conjugates the captured wavefront information and loads it onto the wavefront modulator to pre-modulate the wavefront of the second strong pulse laser and compensate for the scattering of light in the turbid medium. The second cutting strong pulse laser is focused on the turbid medium with high quality, achieving effective focusing. Description of the Drawings

[0013] Figure 1 It is a schematic diagram of a femtosecond laser surgery system;

[0014] Figure 2 It is a working flow chart of the detection pulse;

[0015] Figure 3 It is a working flow chart of the wavefront modulation unit;

[0016] Figure 4 It is a working flow chart of the cutting pulse;

[0017] Figure 5 It is the detection wavefront phase surface carrying scattering information;

[0018] Figure 6 It is the wavefront phase surface conjugated and fed back to the wavefront modulator;

[0019] Figure 7 It is a comparison schematic diagram of the spot quality generated after correction by the wavefront modulation unit and the spot quality without correction.

[0020] Description of the Reference Numerals:

[0021] 1 - Laser, 2 - Beam expander collimator, 3 - Scanner, 4 - Beam splitter, 5 - Focusing lens, 6 - Anterior segment imaging system, 7 - Intraoperative imaging system, 8 - Wavefront modulator, 9 - Wavefront measurer. Detailed Embodiments

[0022] The following combines the drawings to describe in detail a specific embodiment of the present invention, but it should be understood that the protection scope of the present invention is not limited by the specific embodiment.

[0023] As Figures 1 to 7As shown in the figure, a femtosecond laser surgery system based on wavefront modulation provided by an embodiment of the present invention includes a laser 1, a beam expander collimator 2, a scanner 3, a beam splitter 4, a focusing lens 5, a wavefront modulation unit, an anterior segment imaging system 6, and an intraoperative imaging system 7;

[0024] Among them, the laser 1 outputs femtosecond double-pulse laser. The first laser pulse is a detection pulse, and the second laser pulse is a cutting pulse;

[0025] The beam expander collimator 2 expands and collimates the femtosecond laser;

[0026] The scanner 3 is used for three-dimensional scanning cutting of the femtosecond laser;

[0027] The beam splitter 4 is used to separate the processing light, the detection light, and the imaging light;

[0028] The focusing lens 5 is used to focus the laser beam;

[0029] The anterior segment imaging system 6 is used to measure the three-dimensional spatial positions of the cornea, the aqueous humor, and the lens, and guide the laser cutting path planning;

[0030] The intraoperative imaging system 7 is used to observe the cutting trajectory of the femtosecond laser during the operation;

[0031] The wavefront modulation unit includes a wavefront measurer 9 and a wavefront modulator 8. The wavefront measurer 9 is used to measure the optical wavefront carrying the medium scattering information and feed it back to the wavefront modulator 8; the wavefront modulator 8 is used to modulate the laser wavefront and pre-shape the laser wavefront;

[0032] As Figure 2 shown in the figure, the weak-energy detection pulse is focused on the eye tissue to excite fluorescence. At this time, the wavefront modulator 8 adds an empty phase surface and does not modulate the wavefront of the detection pulse;

[0033] As Figures 3 - 6 shown in the figure, the scattered wavefront information (scattering information) of the fluorescence excited by the detection pulse focused on the eye tissue is collected by the wavefront measurer 9 (as Figure 5 shown in the figure, the detection wavefront phase surface carrying the tissue scattering information), and the conjugate term of the heat dissipation wavefront information is fed back to the wavefront modulator 8 (as Figure 6 shown in the figure, the wavefront phase surface conjugated and fed back to the wavefront modulator 8), modulating the high-energy processing pulse. The modulated high-energy processing pulse (cutting pulse) can be well focused in the eye tissue;

[0034] As Figure 7 shown in the figure, through actual tests, the spot quality of the laser corrected by the wavefront modulation unit of this embodiment focused in the scattering medium is better than that of the uncorrected spot.

[0035] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit and basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0036] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A femtosecond laser surgery system based on wavefront modulation, characterized in that: It includes a laser, a wavefront modulation unit, a scanner, a beam splitter and a lens; Among them, the laser is used to emit double-pulse laser, and the wavefront modulation unit includes a wavefront modulator and a wavefront meter. The first pulse laser passes through the wavefront modulator, scanner, beam splitter, and focusing lens in sequence to focus on the eye tissue and stimulate the glow. The wavefront meter is used to obtain the scattered wavefront information of the glow and send it to the wavefront modulator. The second laser pulse is shaped by the wavefront modulator and focused in the eye tissue.

2. The femtosecond laser surgery system based on wavefront modulation according to claim 1, characterized in that: The invention also comprises a beam expansion collimator, which is used for expanding and collimating the femtosecond laser.

3. The femtosecond laser surgery system based on wavefront modulation according to claim 1, characterized in that: The scanner is used for three-dimensional scanning and cutting of femtosecond laser.

4. The femtosecond laser surgery system based on wavefront modulation according to claim 1, characterized in that: The anterior segment imaging system is also included, which obtains image information through a beam splitter and measures the three-dimensional spatial positions of the cornea, aqueous humor and lens.

5. The femtosecond laser surgery system based on wavefront modulation according to claim 1, characterized in that: It also includes an intraoperative imaging system, which obtains image information through a beam splitter to observe the cutting trajectory of the femtosecond laser during surgery.

6. The femtosecond laser surgery system based on wavefront modulation according to claim 1, characterized in that: The first laser pulse and the second laser pulse are respectively a detection pulse and a cutting pulse, and the pulse laser energy of the detection pulse is lower than the pulse laser energy of the cutting pulse.

7. The femtosecond laser surgery system based on wavefront modulation as claimed in claim 6, characterized in that: The wavefront measuring device is used to measure the heat dissipation wavefront information of the glow excited by the detection pulse focusing on the eye tissue, and perform conjugate processing, and load it into the wavefront modulator, and the wavefront modulator modulates the cutting pulse.

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