Apparatus for cutting human or animal tissue comprising an optical coupler

Abstract

This invention relates to an instrument for cutting human or animal tissue, including an optical coupler. The cutting instrument includes - a femtosecond laser (1), - a shaping system (2) located downstream of the femtosecond laser (1) for forming a phase-modulated laser beam, - an optical scanner (4) located downstream of the shaping system (2), - an optical focusing system (5) located downstream of the optical scanner (4), and - a control unit (6) for controlling the shaping system (2), the optical scanner (4), and the optical focusing system (5). The instrument is characterized in that it further includes an optical coupler (3) between the femtosecond laser (1) and the shaping system (2), the optical coupler (3) including a photonic crystal fiber for filtering the phase-modulated laser beam (21) from the shaping system (2).

Description

[0001] This application is a divisional application of Chinese patent application No. 201980009833.5, with an international filing date of January 25, 2019, entitled "An instrument for cutting human or animal tissue including an optical coupler". Technical Field

[0002] This invention relates to the technical field of treating eye diseases using femtosecond lasers, and more specifically, to the technical field of ophthalmic surgery, particularly the application of cutting the cornea or lens.

[0003] This invention relates to a device for cutting human or animal tissue (e.g., cornea or lens) using a femtosecond laser.

[0004] A femtosecond laser is a light source that can emit laser beams in the form of ultrashort pulses, with a duration between 1 femtosecond and 100 picoseconds, preferably between 1 and 1000 femtoseconds, especially on the order of 100 femtoseconds. Background Technology

[0005] It has been proposed to use femtosecond lasers to perform eye surgeries, such as cutting the cornea or lens.

[0006] Document FR 3049847 describes an instrument for cutting human or animal tissue (e.g., cornea or lens). The instrument includes: - A femtosecond laser, which produces a laser beam. - A shaping system, located in the path of the laser beam, for modulating the phase of the wavefront of the laser beam according to a modulation command to obtain a phase-modulated laser beam, the modulation command being calculated such that the energy of the laser beam is distributed to at least two impact points forming a pattern on a focal plane corresponding to the cutting plane. - An optical scanner, positioned downstream of the shaping system, moves the pattern to multiple locations on the cutting plane along the direction of movement. - Optical components, including mirrors and lenses between the shaping system and the optical scanner, for transmitting a modulated laser beam to the scanner. - An optical focusing system that focuses the laser beam onto the cutting plane.

[0007] Using a shaping system can reduce the time required to cut biological tissue by generating multiple impact points simultaneously.

[0008] Furthermore, using a shaping system, essentially equal impact points can be obtained (the shape, position, and diameter of each point are dynamically controlled by a phase mask calculated and displayed on the shaping system).

[0009] Therefore, the bubbles generated at the impact point and the bubbles from the torn and cut biological tissue are approximately the same size.

[0010] This improves the quality of results obtained using a uniform cutting plane, in which residual tissue bridges (between adjacent impact points) have substantially the same size. This uniformity in the size of the tissue bridges allows clinicians to perform anatomy of acceptable quality regarding the importance of the surface condition quality of the cut tissue (e.g., the cornea).

[0011] However, to facilitate anatomical procedures by clinicians, it is best to minimize the size of residual tissue bridges between adjacent impact points.

[0012] Since the size of tissue bridges depends on the uniformity of different impact points, the purpose of this invention is to propose a technical solution that can improve the uniformity of energy distribution among different impact points generated simultaneously by the shaping system.

[0013] Another object of the present invention is to provide a technical solution that improves the instrument described in document FR 3 049 847 to reduce the size of residual tissue bridges between adjacent impact points.

[0014] Another object of the present invention is to improve the safety of the instrument described in document FR 3 049 847 by integrating a safety element therein, which can interrupt the transmission of the laser beam to the tissue to be treated in the event of a deviation of the laser beam (e.g., in the event of an impact to the instrument). Summary of the Invention

[0015] Therefore, the present invention provides an instrument for cutting human or animal tissues, such as the cornea or lens, the instrument comprising: - A femtosecond laser, which emits an initial laser beam in the form of pulses. - A shaping system, such as a spatial light modulator (SLM), located downstream of a femtosecond laser, converts an initial laser beam into a phase-modulated laser beam. This shaping system is capable of modulating the phase of the wavefront of the initial laser beam according to a modulation command calculated to distribute the energy of the laser beam to at least two impact points that form a pattern in the focal plane. - An optical scanner, located downstream of the shaping system, moves the pattern along a predefined path on the focal plane. - An optical focusing system, located downstream of the optical scanner, moves the focal plane of the modulated laser beam within the desired cutting plane of the tissue. - Control unit, which operates the shaping system, optical scanner, and optical focusing system. The instrument is characterized in that it further includes an optical coupler between the femtosecond laser and the shaping system, the optical coupler comprising a photonic crystal fiber for filtering the laser beam from the femtosecond laser.

[0016] In the context of this invention, "impact point" refers to a region of a laser beam on its focal plane, wherein the intensity of the laser beam is sufficient to generate bubbles in tissue.

[0017] In the context of this invention, "adjacent impact points" refers to two impact points that are arranged facing each other and are not separated by another impact point. "Proximity impact points" refers to two points that are the closest to each other in a set of adjacent points.

[0018] In the context of this invention, "pattern" refers to multiple laser impact points simultaneously generated on the focal plane of a shaped (i.e., phase-modulated) laser beam to distribute its energy to several different spots on the focal plane corresponding to the cutting plane of the device.

[0019] Therefore, this invention enables the modification of the intensity distribution of a laser beam on the cutting plane according to a selected profile, thereby improving cutting quality or speed. This modification of the intensity distribution is achieved by modulating the phase of the laser beam.

[0020] Optical phase modulation is performed using a phase mask. After modulation, the energy of the incident laser beam is preserved, and beam shaping is achieved by acting on its wavefront. The phase of an electromagnetic wave represents the instantaneous state of its amplitude. This phase depends on time and space. In the case of spatial shaping of a laser beam, only the spatial variation of the phase is considered.

[0021] A wavefront is defined as a surface of points of light beam with equal phase (i.e., a surface composed of points whose propagation time from the source emitting the light beam is equal). Therefore, modifications to the spatial phase of a light beam include modifications to its wavefront.

[0022] This technology allows for faster and more efficient cutting surgery because it utilizes multiple laser spots, each cutting according to a controlled contour.

[0023] Positioning an optical coupler comprising a photonic crystal fiber between the femtosecond laser and the shaping system (rather than between the shaping system and the optical scanner) can eliminate any interference in laser beam shaping performed by the shaping system. In fact, introducing an optical coupler comprising a photonic crystal fiber between the shaping system and the optical scanner would cause filtering of the modulated laser beam (from the shaping system), which would degrade its shaping and reduce its power.

[0024] The following are preferred, but not limiting, aspects of the cutting instrument: - The optical fiber may be a hollow-core photonic crystal fiber, the optical fiber comprising a hollow core and at least one cladding surrounding the hollow core; - Optical couplers may also include: • One aspect includes a first connection unit for connecting the optical coupler to the shaping system, and On the other hand, it includes a second connection unit for connecting the optical coupler to the optical scanner. - Each connection unit can be hermetically mounted at the corresponding end of the photonic crystal fiber; - Each connection unit may include: • Outer shell • A transmission channel, contained within the housing, that allows the laser beam to pass through the housing. • A window that is transparent to laser radiation at one end of the transmission channel, and the window is designed to face the femtosecond laser or shaping system; - The instrument may further include at least one vacuum pump, and each connection unit includes at least one connection terminal facing an external opening of the housing and intended to be connected to the vacuum pump; - The control unit may include means for manipulating the activation of a vacuum pump to draw gas contained in the hollow core of a photonic crystal fiber. Attached Figure Description

[0025] Other features and advantages of the invention will become apparent from the following illustrative, rather than limiting, description with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of the components including a cutting instrument according to the present invention; Figure 2 This shows the intensity distribution of the laser beam on its focal plane; Figure 3 Show Figure 1 An example of an optical coupler for a cutting instrument is shown; Figure 4 The movement path of the cutting pattern is shown; Figure 5 The cutting plane shows the volume of the tissue to be destroyed; Figure 6 A treatment instrument including a hinged arm is shown. Detailed Implementation

[0026] This invention relates to an instrument for cutting human or animal tissue using a femtosecond laser. In the following description, the invention will be described by way of example for cutting the cornea of ​​a human or animal eye.

[0027] 1. Cutting instruments refer to Figure 1 The diagram illustrates one embodiment of a cutting instrument according to the present invention. This cutting instrument can be positioned upstream of the target 7 to be treated. The target 7 is, for example, human or animal tissue to be cut, such as the cornea or lens.

[0028] Cutting instruments include: - Femtosecond laser 1, - Shaping system 2, which is located downstream of femtosecond laser 1, - Optical coupler 3, which is located between femtosecond laser 1 and shaping system 2. - Optical scanner 4, which is downstream of shaping system 2, - Optical focusing system 5, which is downstream of optical scanner 4. - Control unit 6, which can operate femtosecond laser 1, shaping system 2, optical scanner 4 and optical focusing system 5.

[0029] The femtosecond laser 1 is capable of emitting an initial laser beam in the form of pulses. For example, laser 1 emits light with a wavelength of 1030 nanometers in the form of 400 femtosecond pulses. The power of laser 1 is between 2W and 20W, preferably on the order of 8W, and the frequency is between 100kHz and 500kHz.

[0030] Optical coupler 3 can transmit the laser beam 11 from femtosecond laser 1 to shaping system 2.

[0031] Shaping system 2 extends along the path of the initial laser beam 11 from femtosecond laser 1. Shaping system 2 can convert the initial laser beam 11 into a modulated laser beam 21. More specifically, shaping system 2 can modulate the phase of laser beam 11 to distribute the energy of the laser beam to multiple impact points in its focal plane, which define pattern 8.

[0032] The optical scanner 4 can orient the modulated laser beam 21 to move the pattern 8 along a user-defined motion path in the focal plane 71.

[0033] The optical focusing system 5 can move the focal plane 71 (corresponding to the cutting plane) of the deflected laser beam 41 from the optical scanner 4.

[0034] therefore: - Optical coupler 3 enables the laser beam 11 to propagate between the femtosecond laser and the shaping system 2. - The shaping system 2 can simultaneously generate multiple impact points 81 that define pattern 8. - The optical scanner 4 can move the pattern 8 within the focal plane 71, and - The optical focusing system 5 can move the focal plane 71 in depth to create a cut in a continuous plane with a defined volume.

[0035] The various components that make up the cutting instrument will now be described in more detail with reference to the accompanying drawings.

[0036] 2. Components of the cutting instrument 2.1. Plastic Surgery System The spatial shaping system 2 can change the wavefront of the initial laser beam 11 to obtain impact points 8 that are separated from each other in the focal plane 71.

[0037] More specifically, the shaping system 2 can modulate the phase of the initial laser beam 11 from the femtosecond laser 1 to form intensity peaks in the focal plane 71, each intensity peak generating a corresponding impact point on the focal plane corresponding to the cutting plane. According to the illustrated embodiment, the shaping system 2 is a liquid crystal spatial light modulator, abbreviated as SLM.

[0038] SLM can modulate the final energy distribution of a laser beam, particularly in the focal plane 71 corresponding to the cutting plane of tissue 7. More specifically, SLM is adapted to modify the spatial distribution of the wavefront of the primary laser beam 11 from femtosecond laser 1 to distribute the energy of the laser beam to different focused spots in the focal plane 71.

[0039] Phase modulation of the wavefront can be viewed as a two-dimensional interference phenomenon. Each portion of the initial laser beam 11 from laser source 1 is delayed or advanced relative to the initial wavefront, such that each of these portions is redirected to produce constructive interference at N different points on the focal plane of the lens. Energy redistribution to multiple impact points 81 occurs only in a single plane (i.e., focal plane 71), rather than along the propagation path of the modulated laser beam. Therefore, because this phenomenon, which can be approximated as constructive interference (occurring only in one plane, rather than throughout the propagation as in the case where the initial laser beam splits into multiple secondary laser beams), observations of the modulated laser beam before or after the focal plane cannot identify the energy redistribution to multiple different impact points 81.

[0040] To better understand the wavefront phase modulation phenomenon Figure 2 The diagram schematically illustrates the intensity distributions 72a-72e obtained for three different optical component examples. Figure 2As shown, the initial laser beam 11 emitted by laser source 1 produces a Gaussian-shaped intensity peak 72a at the impact point 73a in the focal plane 71. Inserting a beam splitter 9 between laser source 1 and focal plane 71 results in the generation of multiple secondary laser beams 91, each producing corresponding impact points 73b and 73c on its focal plane 71. Finally, inserting an SLM 2 between laser source 1 and focal plane 71 modulates the phase of the wavefront of the initial laser beam 11 from laser source 1, the SLM 2 being programmed using a phase mask that forms modulation instructions. The wavefront-phase-modulated laser beam 21 can result in the generation of several intensity peaks 73d and 73e, spatially separated on focal plane 71, each peak 72d and 72e corresponding to the respective impact points 73d and 73e for cutting. This wavefront phase modulation technique allows for the simultaneous generation of multiple bubbles in the target tissue without multiplying the initial laser beam 11 generated by the femtosecond laser 1.

[0041] A liquid crystal lamp (SLM) is a device composed of liquid crystal layers with controlled orientation that can dynamically shape the wavefront, thereby shaping the phase of a laser beam. The liquid crystal layers in an SLM are organized into a grid (or array) of pixels. The optical thickness of each pixel is electrically controlled by the orientation of the liquid crystal molecules belonging to the surface corresponding to that pixel. SLM utilizes the anisotropy of liquid crystals, meaning that the modification of the liquid crystal's refractive index is based on its spatial orientation. This orientation can be achieved using an electric field. Therefore, modifying the refractive index of the liquid crystal alters the wavefront of the laser beam.

[0042] In a known manner, an SLM implements a phase mask, which determines how to modify the phase of the beam to obtain a given amplitude distribution in its focal plane 71. The phase mask is a two-dimensional image, with each point associated with a corresponding pixel of the SLM. By converting the value associated with each point of the mask into a control value, the phase mask can control the refractive index of each liquid crystal in the SLM; the value associated with each point is represented by a grayscale level between 0 and 255 (thus from black to white), and the control value is represented by a phase between 0 and 2π. Therefore, the phase mask is a modulation instruction displayed on the SLM to induce a non-uniform spatial phase shift in the laser beam illuminating the SLM during reflection. Of course, those skilled in the art will understand that the grayscale range can vary depending on the SLM model used. For example, in some cases, the grayscale range can be between 0 and 220. The calculation of the phase mask generally employs an iterative algorithm based on Fourier transform, or various optimization algorithms, such as genetic algorithms or simulated annealing algorithms. The SLM can employ different phase masks depending on the number and location of the desired impact points on the focal plane of the laser beam. In all cases, those skilled in the art know how to calculate the value at each point of the phase mask in order to distribute the energy of the laser beam to different focused spots on the focal plane.

[0043] Therefore, SLM enables the energy of a Gaussian laser beam that generates a single impact point to be distributed by phase modulation using a phase mask, so that a single laser beam shaped by phase modulation (a single beam upstream and downstream of the SLM) can simultaneously generate several impact points on its focal plane.

[0044] In addition to reducing corneal cutting time, phase modulation techniques for laser beams can achieve other improvements, such as better post-cut surface quality or reduced endothelial mortality. For example, different impact points of the pattern can be regularly spaced in two dimensions of the laser beam's focal plane to form a grid of laser spots.

[0045] Therefore, the shaping system 2 can perform surgical incisions quickly and efficiently. The SLM can dynamically shape the wavefront of the laser beam because it is digitally parameterized. This modulation allows the laser beam to be shaped in a dynamic and reconfigurable manner.

[0046] SLMs can be configured to shape the wavefront of a laser beam in any other way. For example, each impact point can have any geometry other than a circle (e.g., ellipse, etc.). Depending on the application under consideration, this can have certain advantages, such as improved cutting speed and / or quality.

[0047] 2.2. Optical Coupler The optical coupler 3 enables the transmission of the laser beam 11 between the femtosecond laser 1 and the shaping system 2.

[0048] refer to Figure 3 The optical coupler 3 advantageously includes an optical fiber 31. This allows the optical coupler 3 to function as an "optical fuse." In fact, if the direction of the laser beam 11 (i.e., its aiming point) suddenly changes (e.g., in the event of an impact to the cutting equipment), then the laser beam 11 will no longer penetrate the optical fiber, thus limiting the risk of errors when treating the patient. This would be impossible for optical components including mirrors and lenses used to transmit the laser beam from the femtosecond laser.

[0049] Advantageously, fiber 31 can be a photonic crystal fiber. A photonic crystal fiber, or "PCF," is a waveguide formed by a periodic network of inclusions in two dimensions, which extend the entire length of the fiber. The transmission of laser beams through such fibers is based on the properties of photonic crystals. Due to the structure of photonic crystals, these fibers ensure the confinement of electromagnetic waves within the fiber core. These photonic crystal fibers offer a variety of possibilities for guidance by adjusting their optical geometry parameters, such as the diameter of the inclusions, the distribution of the inclusions, the periodicity (the spacing between two inclusions), the number of layers, and the refractive index of the material used.

[0050] Preferably, the optical fiber 31 is an air-core photonic crystal fiber. An air-core photonic crystal fiber is an optical fiber that guides light substantially within a hollow region (the core of the optical fiber) such that only a small portion of the optical power propagates in the solid optical fiber material (usually silica). According to the standard physical mechanism for guiding light into an optical fiber, this is impossible: generally, the refractive index of the core should be higher than that of the surrounding cladding material, and at least in the optical region, a glass refractive index lower than that of air or vacuum cannot be obtained. However, a different guiding mechanism can be used based on the photonic bandgap, just as in a photonic crystal fiber. Such an optical fiber is also called a photonic bandgap fiber. The demand for air-core photonic crystal fibers is mainly due to the primary guiding in the hollow region minimizing the nonlinear effects of the laser beam 11 and allowing a high damage threshold.

[0051] For example, the document FR 3 006 774 describes a waveguide in the form of an air-core photonic crystal fiber that includes a cladding and a central hollow portion without capillaries. The air-core photonic crystal fiber can be used to filter the laser beam 11 from the femtosecond laser 1 so that the shaping system 2 can shape it. More specifically, using the air-core photonic crystal fiber can limit the divergence (i.e., the expanding profile) of the laser beam 11 by improving its directivity (making the laser beam 11 cleaner by restricting the expansion of its profile). In fact, the air-core photonic crystal fiber can limit light more effectively than a conventional solid-core optical fiber. The air-core photonic crystal fiber includes: - an air core 311, - an inner cladding 312, which is based on silica and surrounds the air core, and the refractive index n1 of the inner cladding < nc, where nc is the effective refractive index of the air core, - an outer cladding 313, which surrounds the inner cladding 312.

[0052] Advantageously, the hollow region 311 of the air-core photonic crystal fiber can be placed under vacuum to limit the propagation loss of the laser beam 11 from the femtosecond laser 1. As a variant, a gas can be injected into the hollow region to utilize the high light intensity in the optical fiber, for example, for high harmonic generation of the laser beam 11 from the femtosecond laser 1. For this purpose, the optical coupler 3 includes a first connection unit 32 and a second connection unit 33, which are sealed and installed at each end of the air-core photonic crystal fiber.

[0053] Each connection unit 32, 33 includes: [[ID=1�]] - housings 321, 331, - transmission channels 322, 332 contained within the housings 321, 331, and the transmission channels 322, 332 allow the laser beam 11 to pass through the housings 321, 331, - A window 323, 333 at one end of the transmission channels 322, 332 that is transparent to laser radiation serves as the entrance (or exit) for the laser beam 11. - A connector (not shown) at the other end of the transmission channel, which is sealed to one end of the optical fiber 31. - Connection terminals 324, 334, which face the external openings of housings 321, 331 and are intended to be connected to vacuum pump P.

[0054] Enabling the vacuum pump P allows the hollow core 311 of the optical fiber 31 to be placed under vacuum by evacuating the connection units 32, 33 located at both ends of the optical fiber 31. Evacuating at each end of the optical fiber 31 makes it easier to place the hollow core of the optical fiber 31 under vacuum along its entire length.

[0055] 2.3. Optical Scanner The optical scanner 4 can deflect the phase-modulated laser beam 21 to move the pattern 8 to multiple positions 43a–43c in the focal plane 71 corresponding to the cutting plane.

[0056] Optical scanner 4 includes: - An inlet aperture, which is connected to the optical coupler 3 to receive the phase-modulated laser beam 21 from the shaping unit 2. - One (or more) optical mirrors that pivot about at least two axes to deflect the phase-modulated laser beam 21, and - An exit aperture that sends the deflected, modulated laser beam 41 toward the optical focusing system 5.

[0057] The optical scanner 4 used is, for example, the IntelliScan III scanning head from SCANLAB AG. The diameter of the inlet and outlet holes of this optical scanner 4 is approximately 10 mm to 20 mm, and the scanning speed that can be achieved is approximately 1 m / s to 10 m / s, depending on the focal length of the optical elements used.

[0058] The reflector is connected to one (or more) motors so that it can pivot. The motors used to pivot the reflector are advantageously operated by a control unit 6, which will be described in more detail below.

[0059] The control unit 6 is programmed to manipulate the optical scanner 4 to move the pattern 8 along a movement path 42 included in the focal plane 71. In some embodiments, the movement path 42 includes multiple cut intervals 42a–42c. The movement path 42 may advantageously have a slot or spiral shape, etc.

[0060] The scanning of the beam is crucial to the resulting cut. In fact, the scanning speed and scanning spacing are parameters that affect the cut quality.

[0061] When using multi-point shaping 81, the use of an optical coupler including a hollow bulk crystal type fiber 31 (instead of an optical assembly consisting of mirrors to guide the laser beam 11) can improve the uniformity of energy distribution among multiple points in critical conditions where the impact points are very close (the center distance between two shaping points is less than the diameter of the point).

[0062] In one embodiment, the cutting instrument further includes a Dove prism. The Dove prism is advantageously positioned between the optical coupler 3 and the optical scanner 4. The Dove prism allows for rotation of the pattern 8, which may be useful in certain applications, or for limiting the size of the starting region of each cutting interval 42a–42c.

[0063] Advantageously, the control unit 6 is programmable to activate the femtosecond laser 1 when the scanning speed of the optical scanner 4 exceeds a threshold. This allows the emission of the laser beam 11 to be synchronized with the scanning of the optical scanner 4. More specifically, the control unit 6 activates the femtosecond laser 1 when the pivoting speed of the mirror of the optical scanner 4 is constant. This enables improved cutting quality by achieving a uniform surface treatment of the cutting plane.

[0064] 2.4. Optical Focusing System The optical focusing system 5 enables the focal plane 71 of the modulated and deflected laser beam 41 to be moved within the cutting plane of the tissue 7 as desired by the user.

[0065] The optical focusing system 5 includes: - An inlet aperture that receives a phase-modulated and deflected laser beam from the optical scanner 4. - One (or more) electrically powered lenses that translate along the optical path of a phase-modulated and deflected laser beam, and - The exit port sends a focused laser beam to the tissue to be treated.

[0066] The lens used with the optical focusing system 5 can be a plan lens. A plan lens can obtain a focal plane across the entire XY field, unlike a standard lens which is concave. This ensures a constant focused beam size across the entire field.

[0067] The control unit 6 is programmed to manipulate the movement of the lens of the optical focusing system 5 along the optical path of the laser beam to move the focal plane 71 to at least three corresponding cutting planes 72a–72e, forming a stack of cutting planes for the tissue 7. This allows cutting to be performed in volume 74, for example, in refractive surgery.

[0068] The control unit 6 is capable of manipulating the movement of the optical focusing system 5 to sequentially move the focal plane 71 between a first extreme position 72a and a second extreme position 72e. Advantageously, the second extreme position 72e is closer to the femtosecond laser 1 than the first extreme position 72a.

[0069] Therefore, starting from the deepest cutting plane 72a in the tissue, successive cutting planes are stacked until the outermost cutting plane 72e in the tissue 7, thus forming cutting planes 72a-72e. This avoids problems associated with laser beam penetration into the tissue 7. In effect, the bubbles form an opaque bubble layer (called OBL), preventing energy from the laser beam from propagating beneath the bubbles. Therefore, it is preferable to generate the deepest bubbles first to improve the efficiency of the cutting instrument.

[0070] Advantageously, the use of an optical coupler comprising a hollow-core photonic crystal type fiber 31 (instead of an optical assembly consisting of mirrors to guide the laser beam 11) allows the laser signal 11 from the femtosecond laser to be filtered by removing its possible aberrations. Therefore, the distance between two consecutive cutting planes (smaller than the diameter of the impact point) can be reduced to achieve high-precision cutting within volume 74.

[0071] 2.5. Control Unit As described above, the control unit 6 can control the various components that make up the cutting instrument, namely the femtosecond laser 1, the shaping system 2, the optical scanner 4, and the optical focusing system 5.

[0072] Control unit 6 is connected to these various components via one (or more) communication buses, thereby allowing: - Transmit control signals, for example: • Transmit the phase mask to the shaping system. • Transmit the enable signal and power setting value to the femtosecond laser. • Transmit scanning speed to the optical scanner, • Transmit the position of the optical scanner along the moving path. • Transmit the cutting depth to the optical focusing system.

[0073] - Receive measurement data from various components of the system, such as: • The scanning speed achieved by the optical scanner, or • The location of the optical focusing system, etc.

[0074] The control unit 6 may include one or more workstations and / or one or more computers, or may be any other type known to those skilled in the art. The control unit 6 may include, for example, a mobile phone, an electronic tablet computer (e.g., iPad®), a personal digital assistant (or “PDA”), etc. In all cases, the control unit 6 includes a processor programmed to manipulate the femtosecond laser 1, the shaping system 2, the optical scanner 4, and the optical focusing system 5, etc.

[0075] 2.6. Articulated Arm Because of the use of an optical coupler (3) including a photonic crystal fiber (31), the cutting instrument described above can be installed in a treatment instrument including a hinged arm 200, such as... Figure 6 As shown.

[0076] Arm 200 includes multiple arm sections 201-204, which are connected by electrically operated hinges 205-207 (pivot or ball joint connectors) to allow the different sections 201-204 to automatically rotate and move relative to each other. Specifically, the arm is hinged so that the free end of the arm can move along three orthogonal axes X, Y, and Z: • The X-axis defines the vertical direction in the horizontal direction. • The Y-axis defines the horizontal direction, and together with the X-axis, defines the horizontal plane XY. • The Z-axis defines the vertical direction, which is perpendicular to the horizontal plane XY.

[0077] The free end of arm 2 may include a fixation member equipped with a suction ring capable of aspirating the eye tissue to be treated and holding it firmly in place.

[0078] For example, arm 2 is the TX260L sold by STAUBLI. Advantageously, the shaping system 2, optical scanner 4, and optical focusing system 5 can be mounted in the end section 204 of arm 200, while the femtosecond laser 1 can be integrated into the movable housing 210 of the treatment instrument, and the optical coupler 3 extends between housing 210 and end section 204 to propagate the laser beam 11 from femtosecond laser 1 to the shaping system 2.

[0079] 3. Conclusion Therefore, the present invention can configure an efficient and precise cutting tool. The reconfigurable modulation of the laser beam wavefront allows for the simultaneous generation of multiple impact points 81, each with a size and controlled position within the focal plane 71. These different impact points 81 form a pattern 8 within the focal plane 71 of the modulated laser beam.

[0080] Using an optical coupler 3 comprising a hollow-core photonic crystal fiber 31 can reduce the distance between different impact points forming a pattern. In fact, by limiting spectral spread, an optical coupler comprising a hollow-core photonic crystal fiber can make the phase-modulated laser beam cleaner.

[0081] The reader will understand that many modifications can be made to the above invention without fundamentally departing from the new teachings and advantages described herein. Therefore, all modifications of this type are intended to be incorporated within the scope of the appended claims.

Claims

1. A cutting instrument for human or animal tissue, said human or animal tissue being, for example, a cornea or lens, said instrument comprising: - A femtosecond laser (1) that emits an initial laser beam in the form of pulses. - A shaping system (2), such as a spatial light modulator (SLM), located downstream of a femtosecond laser (1), to convert an initial laser beam into a phase-modulated laser beam, the shaping system being able to modulate the phase of the wavefront of the initial laser beam according to a modulation instruction calculated to distribute the energy of the laser beam to at least two impact points (81) forming a pattern (8) in the focal plane (71). - An optical scanner (4), located downstream of the shaping system (2), moves the pattern (8) along a predefined movement path in the focal plane (71). - An optical focusing system (5), located downstream of the optical scanner (4), moves the focal plane (71) of the modulated laser beam in the desired cutting plane of the tissue (7). - Control unit (6), which is capable of operating the shaping system (2), the optical scanner (4) and the optical focusing system (5). The instrument is characterized in that it further includes at least one vacuum pump and an optical coupler (3) between the femtosecond laser (1) and the shaping system (2), the optical coupler (3) comprising: - Hollow-core photonic crystal fiber (31) for filtering laser beam (11) from femtosecond laser (1); the hollow-core photonic crystal fiber (31) includes a hollow core (311) placed in a vacuum and at least one cladding (312, 313) surrounding the hollow core (311). - A first connection unit for connecting an optical coupler to a femtosecond laser, the first connection unit having an external opening facing the housing and at least one connection terminal connected to a vacuum pump; and - A second connection unit for connecting an optical coupler to a shaping system, the second connection unit having an external opening facing the housing and at least one connection terminal connected to a vacuum pump.

2. The cutting instrument according to claim 1, wherein, Each connection unit (32, 33) is hermetically mounted at the corresponding end of the photonic crystal fiber (31).

3. The cutting instrument according to claim 1, wherein, Each connection unit (32, 33) includes: - Casing (321, 331). - A transmission channel (322, 332), contained within a housing (321, 331), wherein the transmission channel (322, 332) allows the laser beam (11) to pass through within the housing (321, 331). - A window (323, 333) that is transparent to laser radiation at one end of the transmission channel (322, 332), the window being intended to face the femtosecond laser (1) or the shaping system (2).

4. The cutting instrument according to claim 1, wherein, The control unit includes a device capable of manipulating the activation of a vacuum pump to draw gas contained in the hollow core of the photonic crystal fiber (31).

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