SYSTEMS FOR SHORT PULSE LASER EYE SURGERY

Abstract

A system for short pulse laser eye surgery and a short pulse laser system, in which a beam guidance device passes through a corresponding articulated arm, and through an applicator head and a microscope head of the system, which is movable in a three-dimensional volume both independently of one another as well as connected to each other. The system also includes, an easy-to-use patient interface with a one-piece contact element, a computer program product for methods of the incision guidance and sequentially operating referencing methods with patient interfaces containing markings.

Claims

1.-72. (canceled)

73. A system for short pulse laser eye surgery, comprising a short pulse laser system including a short pulse laser source, a beam guidance device and an applicator head for directing a short pulse laser radiation from the short pulse laser source to the eye to be operated on; a surgical microscope having a microscope head; and a control unit adapted to control the system for the short pulse laser eye surgery; a housing enclosing at least the short pulse laser source, and supporting a first and a second articulated arm arranged at the housing or at an extension of the housing; wherein the microscope head is operably coupled to the first articulated arm and the applicator head is operably coupled to the second articulated arm; further comprising an interface between the applicator head and the microscope head, by which the applicator head and the microscope head are releasably connectable both mechanically and optically; wherein the beam guidance device passes through the second articulated arm; and wherein the applicator head and the microscope head are movable in a three-dimensional volume independently from each other as well as connected to each other via the interface.

74. The system for short pulse laser eye surgery according to claim 73, further comprising an optical coherence tomography (OCT) module containing an OCT light source, an interferometer and a detector.

75. The system for short pulse laser eye surgery according to claim 74, wherein the system is adapted to selectively couple radiation emitted from the OCT-light source into the microscope head or into the applicator head.

76. The system for short pulse laser eye surgery according to claim 74, further comprising a ring mirror that merges the short pulse laser radiation and the radiation emitted from the OCT light source.

77. The system for short pulse laser eye surgery according to claim 73, wherein the first articulated arm and the second articulated arm each have at least three joints.

78. The system for short pulse laser eye surgery according to claim 73, wherein the control unit comprises coding for automatic tracking of the position of the short pulse laser radiation in dependence on the position of the second articulated arm.

79. The system for short pulse laser eye surgery according to claim 73, wherein the second articulated arm further comprises at least one device for a weight compensation independent from the first articulated arm.

80. The system for the short pulse laser eye surgery according to claim 73, wherein the system includes a parking position, a transport position or both the parking position and the transport position for the second articulated arm with the applicator head at the housing and, further wherein the parking position, the transport position or both the parking position and the transport position are coordinated with the geometry of the second articulated ann, the applicator head or both the geometry of the second articulated arm and of the applicator head.

81. The system for short pulse laser eye surgery according to claim 73, further comprising a mechanism switched by an operator or an automatically switched mechanism that releases or connects the interface between the applicator head and the microscope head.

82. The system for short pulse laser eye surgery according to claim 73, further comprising adjustable elements at least one of the first articulated arm, at the second articulated arm, at the applicator head or at the microscope head, which enable a movement of at least one of the microscope head or of the applicator head, the movement being controlled by the control unit.

83. The system for a short pulse laser eye surgery according to claim 73, wherein the beam guidance device comprises a photonic crystal fiber with a hollow core.

84. The system for a short pulse laser eye surgery according to claim 73, wherein the short pulse laser source comprises a femtosecond (fs) laser source.

Description

[0126] The present invention shall now be explained by means of exemplary embodiments. It shows:

[0127] FIG. 1: a first system for short pulse laser eye surgery;

[0128] FIG. 2: a second system for short pulse laser eye surgery;

[0129] FIG. 3: the positions when connecting the applicator head and microscope head in plan view;

[0130] FIG. 4: the transport position of the articulated arm with applicator head in plan view;

[0131] FIG. 5: a device for an independent weight compensation of an articulated arm;

[0132] FIG. 6: a method for positioning an applicator head and a microscope head in a system for short pulse laser eye surgery;

[0133] FIG. 7: a short pulse laser system for eye surgery (beam generation and optical system);

[0134] FIG. 8: a structure for the merging of short pulse laser radiation from the short pulse laser source and OCT radiation from the OCT light source;

[0135] FIGS. 9a and 9b: the control of a short pulse laser system for eye surgery by means of signals from a confocal detector and an OCT module;

[0136] FIG. 10: the movement of the focus of the short pulse laser radiation with a laterally scanning objective of a short pulse laser system;

[0137] FIG. 11a: the incision layers in the tissue of an eye with a small field of the x/y-incision area projection;

[0138] FIG. 11b: a process for the focus shift of short pulse laser radiation in a short pulse laser system for eye surgery;

[0139] FIG. 12a: the incision layers in the tissue of an eye with a larger field of the x/y-incision area of the projection;

[0140] FIG. 12b: an alternative method for the focus shift of the short pulse laser radiation in a short pulse laser system for eye surgery;

[0141] FIGS. 13a and 13b: the focus guidance of the focus of a short pulse laser radiation or the incision guidance by means of a short pulse laser radiation in the lens tissue of an eye;

[0142] FIGS. 14a and 14b: the focus guidance of the focus of a short pulse laser radiation with an eye lens tilted with regard to the optical axis of the short pulse laser;

[0143] FIG. 15: the focus guidance of the focus of a short pulse laser radiation with an eye lens slightly tilted with regard to the optical axis of the short pulse laser;

[0144] FIG. 16: an x/y-projection of the focal points of a short pulse laser radiation in a first incision guidance of a short pulse laser system for performing the capsulotomy;

[0145] FIG. 17a: an x/y-projection of the focal points of a short pulse laser radiation in a second incision guidance of a short pulse laser system for performing the capsulotomy;

[0146] FIG. 17b: an x/y-projection of the focal points of a short pulse laser radiation in a third incision guidance of a short pulse laser system for performing the capsulotomy;

[0147] FIG. 17c: an x/y-projection of the focal points of a short pulse laser radiation in a fourth incision guidance of a short pulse laser system for performing the capsulotomy;

[0148] FIG. 18: a patient interface at a short pulse laser system for eye surgery;

[0149] FIG. 19a: a first structure for referencing laser incisions with a patient interface at a short pulse laser system;

[0150] FIG. 19b: a second structure for referencing laser incisions with a patient interface at a short pulse laser system;

[0151] FIG. 20: a method for referencing the incision guidance in a short pulse laser system for eye surgery;

[0152] FIG. 21a: a third structure for referencing laser incisions with a patient interface at a short pulse laser system;

[0153] FIG. 21b: a fourth structure for referencing laser incisions with a patient interface at a short pulse laser system;

[0154] FIG. 21b: a fifth structure for referencing laser incisions with a patient interface at a short pulse laser system;

[0155] FIG. 22: a method for referencing the orientation of an intraocular lens when inserting into an eye.

[0156] In the following examples of a system for short pulse laser eye surgery, femtosecond lasers or fs lasers are used as short pulse lasers for a short pulse laser system and for the corresponding methods, which are the most commonly used short pulse lasers in the field of eye surgery by means of lasers—and therefore also the best understood. Nonetheless, all systems and methods described herein can also be implemented with other short pulse lasers. Fs lasers are thus, unless no explicit reference is made to the pulse length as a differentiating characteristic, synonymous with short pulse lasers.

[0157] OCT, optical coherence tomography, is also referred to in the following. OCT is thereby, unless explicitly not differentiated regarding the different variants a synonym for all methods that measure distances in the eye using the by the optical short coherence or can detect images from the eye or its components, such as time domain optical coherence tomography (TD-OCT), spectrometer-based frequency domain OCT (FD-OCT) or wavelength sweeping-based swept source OCT (SS-OCT).

System Design of the Entire System and Workflow

[0158] In order to improve the integration of the different components with respect to an optimized workflow and an optimized work environment for the operator, thus preferably a physician, especially an eye surgeon, a structure of a first and a second system for short pulse laser eye surgery 100 is disclosed in FIG. 1 and in FIG. 2, which contains an fs laser system as a short pulse laser system 200 with a short pulse laser source 210, here thus an fs laser source, a beam guidance means 230 and an applicator head 220 for directing the fs laser radiation to the eye 900 to be operated on.

[0159] The structure of the first and the second system for the short pulse laser eye surgery 100 further comprises a surgical microscope 300 with a surgical microscope head 320. The entire surgical microscope and the optical system determining its function is thereby arranged in the microscope head 320.

[0160] The first system for short pulse laser eye surgery 100 of FIG. 1 further comprises the OCT module 400, which contains an OCT light source 405, an interferometer and a detector. The second system of FIG. 2 can also contain such an OCT module in principle. For the cooperation of the system components shown in FIG. 1 and FIG. 2, the presence of an OCT module is however not mandatory.

[0161] The first and the second system for short pulse laser eye surgery of FIG. 1 and of FIG. 2 will be controlled by a common control device, that is, a control unit 500, which is either arranged centrally here or is distributed in several sub-units over the system. For this, communication paths between the control unit and individual components of the system or also between sub-units of the control unit can be used.

[0162] The systems for short pulse laser eye surgery 100 of FIGS. 1 and 2 further contain a housing 110, which may also be referred to as a console. This housing 110 encloses the fs laser source 210 and the control device as the central control unit 500, in the case of the first system of FIG. 1, the housing 110 also encloses the OCT module 400.

[0163] The microscope head 320 is attached to a first articulated arm 120 and the applicator head 220 is attached to a second, separate articulated arm 130, through which the light of the fs laser source 210 is supplied to the applicator head 220. For this, a beam guidance means 230 passes through the second articulated arm 130. The first articulated arm 120 and the second articulated arm 130 are mounted on the housing 110 or on an extension of the housing 110.

[0164] An interface 150 is provided at or in the vicinity of the applicator head 220 and of the microscope head 320, through which the applicator head 220 and the microscope head 320 can be connected with each other mechanically and optically.

[0165] For releasing or merging the microscope head and the applicator head 220 with the help of the interface 150 is provided a mechanism to be switched by the physician or an automatically switched mechanism.

[0166] The second articulated arm 130 contains the same degrees of freedom as the first articulated arm 120, which simultaneously forms the tripod of surgical microscope 300. The necessary degrees of freedom are generated by a corresponding number, arrangement and design of the joints 140 of the articulated arms 120 and 130, through which the applicator head 220 and the microscope head 320 are movable in a three-dimensional volume both independently of one another as well as connected to each other. In the case of the first system for short pulse laser eye surgery 100 of FIG. 1, this is achieved by means of three joints 140 with a ball joint function.

[0167] In the second system for short pulse laser eye surgery 100 of FIG. 2, equivalent degrees of freedom as the three joints 140 with ball joint function through three joints for rotation about the vertical axes 140-O1, 140-O2, 140-O5 and 140-L1, 140-L2, 140-L5 and a parallel carrying arm 145, which represents an articulated member of the first or of the second articulated arm 120, 130 with horizontal rotary 140-O3, 140-O4 and 140-L3, 140-L4 for up and down movement, thus a tilting movement.

[0168] The first articulated arm 120 with the microscope head 320 additionally has a horizontal tilt axis for the inclination of the microscope head 140-O6. This can also be realized through the applicator head 220 for the coupling +/−90°, in that this is suspended rotatably on the horizontal axis 140-L6 of the last joint member is suspended. In the coupling position 0°, the surgical microscope head 320 can only be coupled in a vertical position. This is represented in FIG. 3, which shows the positions when connecting the applicator head 220 and microscope head 320.

[0169] The thick arrow thereby shows the direction of view of the physician into the oculars of the surgical microscope head 320.

[0170] The surgical microscope head 320 thus has its own tilt axis 140-O6, which can be operated manually. In the coupling position +/−90°, this tilt angle can be balanced by an additional rotational axis 140-L6 in the applicator head 220. This is not possible in the coupling position 0°. Furthermore, it must be excluded implicitly that the operator, thus usually the physician, manually adjusts the tilt axis 140-O6 of the microscope head 320 after the coupling to the applicator head 220. The joints of the second articulated arm 130 could be deformed thereby, leading to deviations of the optical axis of the second articulated arm 130, in particular of the beam guidance means 230 contained therein, and thus to deviations of the position of the focus of the femtosecond laser radiation in the eye 900. This problem is solved by a motorization of the tilt axis 140-O6 of the microscope head 320. The operation is similar to the manual operation with a rotary knob laterally of the microscope head suspension. Before coupling, thus connecting the microscope head 320 and the applicator head 220 via the interface 150, it can be checked by the software whether the microscope head 320 is vertical. The operator receives a request to correct when there are deviations, or the microscope head 320 is automatically brought into a vertical position. During the laser treatment of the eye 900 of the patient an actuation of the tilt axis 140-O6 can be prevented by the software.

[0171] The lengths of the joint members of the second articulated arm 130 of FIG. 2 are designed so that the entire working range of the surgical microscope head 320 can be used in a semicircle of 180° in front of the device, thus in front of the system for short pulse laser eye surgery 100. By means of the lengths of the joint members result areas to the right and to the left of the device 100, which cannot be reached in the coupled state, thus, when the microscope head 320 and the applicator head 220 are connected. However, this is compensated in that the stored second articulated arm 130, on which the applicator head 220 is arranged, can be bent to the right or to the left as required. For this, the applicator head 220 is taken by hand from a parking tray on the parking arm 190, pivoted to the other side and stored again. The electrical locking of the parking tray is released with a switch on the applicator head 220 for this. In addition, two gripping knobs 142 are provided to avoid a dead-center position, at which the second articulated arm 130 can be guided through a dead-center position, in which its joint members are stretched in a plane. The gripping knobs 142 are preferably arranged at a joint member between the penultimate and the last joint 140 or between the penultimate and the last joint 140 with a respectively vertical rotation axis. In order to move the articulated arm 130 out of the dead-center position again, an operator grasps both gripping knobs 142 and swivels the articulated arm 130 in again thereby. The gripping knobs 142 can be coated in a sterile manner, with a corresponding coating being changed after each surgery, so that, also during the course of a surgery, the second articulated arm 130 can be grasped at the gripping knobs 142 after a surgery step if necessary without compromising the sterility.

[0172] The joint 140-L3 of the second articulated arm 130 on which the applicator head 220 is arranged lies higher in order to enable the passing of objects, e.g. through the surgery assistance under the second articulated arm 130. The height of the arrangement of the joint 140-L3 is selected so that the minimum squeeze distances to the first articulated arm 120, on which the surgical microscope head 320 is arranged, are complied with. For rotation angles above 180°, there is a risk of a collision of the two articulated arms 120, 130. In order to exclude this, the rotation angle of the E-Box, as the joint 140-O1 of the first articulated arm 120 is restricted to +/−95° by a stop in the axis of the joint 140-O1. Despite this restriction, this is sufficient to achieve an extended, three-dimensional volume in front of the device 100 and consequently to place a patient roughly on a couch in front of the device 100 and to complete everything else by the movement of the articulated arms 120, 13. In this manner, one can operate with different position possibilities of patient and special preferences of the physician regarding the arrangement of the patient and the system for short pulse laser eye surgery 100 can also be considered.

[0173] The applicator head 220 is located between the patient and microscope head 320 and has to be designed in a very compact manner for this reason. The necessary actuators for displacing the focus of the femtosecond laser radiation in the z-direction, i.e., along the optical axis, in the eye 900 are very space-consuming and their accommodation in the applicator head 220 is therefore not sensible. These actuators are therefore arranged in the console, thus the housing 110, in front of the second articulated arm 130 carrying the applicator head 220. In order transmit the wandering focus generated there into the eye 900, relay objectives are necessary in each joint member of the second articulated arm 130. These objectives are afocal. A wandering focus results in each relay depending on the focal position. The numerical aperture must be as low as possible in order to avoid optical breakthroughs and thus power losses in the second articulated arm 130 or in the beam guidance means 230 passing through the second articulated arm 130. This requires long relay systems. The joint member lengths of the individual joint members of the second articulated arm 130 are adapted to the lengths of the relay systems.

[0174] High demands are made of the accuracy of the optical transmission of the laser beam from the optical system in the housing 110 into the applicator head 220, particularly in connection with the movement possibilities of the second articulated arm 130. During the adjustment, one must pay particular attention that the mechanical rotation axis and the axis of the laser beam do not deviate both in the angle and in the location. Each deviation leads to wobbling of the laser focus in the eye 900 during a movement of the second articulated arm 900. In addition, elastic deformations due to the heavy weight of the second articulated arm 130 and the applicator head 220 arranged thereon are to be expected, which are highly dependent on the position of the second articulated arm 130. Therefore, the adjustment of the second articulated arm 130 is only possible in one position. In any other position deviations are to be expected. These are balanced by an automatic beam tracking, which measures the deviations and readjusts the position of the laser beam. This correction takes place within certain limits, which are given by the geometry of and the adjusting ranges of the actuators. The free diameter of the optical system is dimensioned so that, during utilization of the adjusting range, no vignetting of the laser beam results. The necessary stiffness of the bearings and the parts of the second articulated arm 130 results from the possible adjustment range of the automatic beam tracking. Elastic deformations shall not exceed the possibilities of the beam tracking. The stiffness of the joint member between the joints 140-L1 and 140-L2 of the second articulated arm 130, which is strained the most, is achieved by a strong ribbing, a box-shaped design and additional steel plates on both sides of the joint member. Highly stiff slewing rings are used for the bearing, which are biased without play axially with two needle bearings and radially with one needle bearing. Alternatively, angular contact ball bearings are possible in the O-constellation with a large distance of the ball runway.

[0175] The second articulated arm 130 offers possibilities for passing electrical cables through, the OCT optical fiber 410 and the vacuum hoses for the suction of a patient interface 600 to the eye 900 of the patient as well as for the suction of the patient interface to the applicator head 220. At the junction of the joints 140-L2/140-L3 and 140-L4/L5-140 all cables are guided outside joints 140, in order to avoid too much strain of the cables against torsion. At the joint 140-L1, the cables are guided concentric to the optical system through the joint 140.

[0176] Depending on the embodiment variant a shelf 190 for the applicator head 220 is marked on the housing 110 or a storage structure 190 matched to the geometry of the applicator head 220 is mounted.

[0177] For the transport, that is for example for driving the device 100 by means of a transport device 180 fixed under the device 180 through doors, the second articulated arm 130 and the applicator head 220 may not project laterally beyond the housing 110. This is achieved in that the applicator head 220, stored and locked in a parking tray, which is located on a parking arm 190, is pivoted into a position above the housing 110 and laterally backwards to the column of the surgical microscope 300, see FIG. 4. For this, the parking arm 190 also has to be pivoted about approximately 60°.

[0178] In order to bring the applicator head 220 into a resting or parking position, whose requirements differ from those of a transport position in that the projection of the second articulated arm 130 and the applicator head 220 over the housing 110 is less critical, the applicator head 220 is simply pivoted to the side and placed on the articulated arm. The locking of the transportation and parking position takes place for example with force-fitting detents.

[0179] The parking position preferably corresponds to a coupling position for connecting the microscope head 320 and the applicator head 220. However, it shall definitely enable a placement of a patient interface 600 on the applicator head 220. For this purpose, it is fully accessible from both sides. This is achieved by arranging a parking tray for storage and locking of the last joint member of the second articulated arm 130 in front of the applicator head 220.

[0180] The parking tray is rotatably mounted about +/−90° on a parking arm 190. The parking arm 190 is again rotatably mounted about 70° about the main axis 140-L1 of the second articulated arm 130. The parking tray is provided with detent positions for the parking position and the transport position. It contains an electromechanical locking mechanism for the articulated arm 130 of the applicator head 220, a force sensor and an inductive sensor for detecting the presence of the applicator head 220 or the last joint member in front of the applicator head 220 in the parking tray. The parking arm 190 and the parking tray are dimensioned so that the applicator head 220 overhangs in front of the device 100, is freely accessible from below for attaching the patient interface 600, and preferably at the same time the possibility exists to couple the microscope head 320 from both sides without hindrance. The length of the second articulated arm 130 at which the applicator head 220 is arranged, is dimensioned so that a coupled microscope head 320 also with an assistant microscope head cannot collide with the second articulated arm 130 and at the same time the minimum squeeze distances are observed.

[0181] In another embodiment variant, handles 143 with optionally sterile, exchangeable coatings are attached to the microscope head 20 for positioning the microscope head 320. By the positioning of the microscope head 320 the applicator head 220 is finally also positioned in the coupled state of both. The handles can be executed as switches for releasing electromagnetic brakes of the first articulated arm 120 on which the microscope head is disposed 320, be or as pure mechanical levers with friction brakes.

[0182] In a further embodiment variant, elements adjustable via the control device 500 as e.g. motors are provided on the first and/or the second articulated arm 120, 130 or on the applicator head 200 or on the microscope head, which enable a movement of the microscope head 320 and/or the applicator head 220 controlled by the control device 500.

[0183] Spring elements are advantageously provided on one or both articulated arms 120, 130, which are coordinated so that the respective associated applicator head 220 or the microscope head 320 stays within a predetermined spatial area around the housing 110 and the surgical field without external forces.

[0184] The applicator head 220 weighs about 5 kg and cannot be carried by the surgical microscope 300 or the microscope head 320. The spring balancing of the first articulated arm 120, on which the microscope head 320 is arranged, is already used to capacity up to 1 kg with insight, oculars and possibly monitors. The second articulated arm 130, on which the applicator head 220 is arranged, thus contains a device for an independent weight balancing, as shown in FIG. 5.

[0185] The weight balancing for all masses to be balanced thereby takes place with respect to the joint 140-L3 (140-A in FIG. 5). The part of the second articulated arm 130 between the joints 140-L3 and 140-L4 (140-B in FIG. 5) is executed as a parallel support arm 145. The parallel support arm 145 consists mainly of four joints 140-A, 140-B, 140-C, 140-D and four joint members: the first rotary head 141-1, the second rotary head 141-2, the spring arm 145-1 and the stay 145-2. The weight balancing is realized by a compression spring 147 in the lower arm 145-1. The compression spring 147 pulls on a toothed belt 148, which is deflected into the stay 145-2 over two toothed belt wheels 149-1 and 149-2. There, the toothed belt 148 is suspended on a fastening 146-2. The compression spring 147 produces a moment about the joint 140-A, which is opposed by the moment generated by the weight G about point A and compensates this. The lever arm of the compensation moment is generated by the vertical spacing of the toothed belt 148 to the joint 140-A. This lever arm depends on the angular position of the spring arm 145-1. The spring constant of the compression spring 147 is dimensioned so that the position-dependent change of both moments is compensated. This ensures that in the weight compensation in the entire pivoting range lies within a predetermined tolerance range. The balanced weight force G is independent of the pivot position of the articulated arm 130 for the applicator head 220. Although the distance of the center of gravity changes to the pivot point 140-A by the pivoting of the applicator head 220, but this has no influence on the weight compensation. The moment changing thereby is supported by the stay 145-2, which is suspended in the pivot points 140-C and 140-D.

[0186] In an embodiment variant, is a video recording unit and an illumination unit are provided. These can alternatively be coupled into beam path to the or from the eye 900 via the applicator head 220 or the microscope head 320. In a specific embodiment, the second articulated arm 130, on which the applicator head.

[0187] In a special embodiment variant, the second articulated arm 130, on which the applicator head 220, is complemented by a photonic crystal fiber with a hollow core as beam guidance means 230. The fs-laser radiation is guided in the fiber within the hollow core and by means of periodic photonic structures analogous to a Bragg mirror. In this way—similar to the free radiation—only a small pulse propagation takes place due to dispersion. Compared to a guidance through the second articulated arm 130 by means of a mirror system, the photonic crystal fiber has the advantage that it ensures a much more flexible laser beam guidance and reduces the complexity of the optical design. In this embodiment variant, the second articulated arm 130 to which the applicator head 220 is mounted, serves in principle only for the mechanical holding of the applicator head 220, thus no longer influences the beam guidance through its structure itself.

[0188] The structure of a system for short pulse laser eye surgery 100 described herein supports method for the positioning of the applicator head and of the microscope head on the patient's eye illustrated below and with reference to FIG. 6, which contains the steps of:

(a) If the applicator head 220 and the microscope head 320 are separated, they are merged by the operator, for example, the physician. For this purpose, the operator sets the microscope head 320 on the applicator head 220 at the interface 150, and actuates a lock; or a mechanism automatically leads to a lock when reaching the desired connection.
(b) The operator guides and positions the microscope head 320 over the eye 900 to be operated on. Thus, the applicator head 220 is also positioned over the eye 900.
(c) The operator looks through the ocular of the microscope head 320 and lowers the microscope head 320 and thus the applicator head 220 as far, possibly with a further lateral alignment of the microscope head 320 on the eye 900, until the applicator head 220 is in a predefined position above the eye is 900 or a patient interface 600) mounted releasably on the applicator head, which contains a contact element 610 is in contact with the eye 900.
(d) The operator carries out the processing of an eye tissue 910, thus of the lens and/or the capsular bag and/or the cornea by means of fs laser.
(e) The operator lifts the microscope head 320 and thus also the applicator head 220.
(f) The operator brings the applicator head 220 into the parking position, hereby places the applicator head 320 on the shelf or the storage structure 190 at the housing 110 in one embodiment variant.
(g) The operator releases the microscope head 320 from the applicator head 220 by the locking mechanism or the release occurs automatically when the correct positioning of the applicator head 220 the storage structure 190 is reached. As a result, the separation of the microscope head 320 from the applicator head 220 takes place.
(h) The operator positions the microscope head above the eye 900 of the patient.
(i) The operator carries out the further incisions of the phacoemulsification and/or of the suction of the liquefied lens and the insertion of intraocular lens.
(j) The operator positions the microscope head 320 in a parking position away from the surgical field. In one embodiment variant, the operator sets the microscope head on the applicator head, which is located on storage structure 190 on the device 100 and locks the locking mechanism or the locking mechanism is locked automatically when reaching the connection.

[0189] In an embodiment variant of the method, the control device 500 calculates control commands for adjustable elements at the articulated arms 120, 130 and 220 or the applicator head and/or the microscope head 320 with the aid of obtained OCT images and/or video images, so that in particular, the steps (c) and/or (e), possibly all further steps, with the exception of step (i), are controlled automatically by the control unit 500.

[0190] In a further embodiment variant of the method, once the microscope head 320 is locked with the applicator head 220, e.g. via a sensor, the device state is changed by the control unit 500. The fs laser can e.g. be switched on automatically and an illumination above the surgical microscope 300 can be switched off. Accordingly, in the unlocked, that is, the separated state of the microscope head 320 and the applicator head 220, the fs laser can be switched off and an illumination above the surgical microscope 300 can be switched on.

[0191] Structurally, the housing 110, in particular the housing interior, is preferably designed so that the components of the short pulse laser system 200 which are enclosed by the housing, thus the short pulse laser source 210 (here an fs-laser source) and optical components as part of the beam guidance means, can be displaced in the mounted state as a whole and on a container laterally over the column 310 of the surgical microscope 300. The column 310 thereby represents as an extension of the housing 110 a support structure for the first articulated arm 120, at which the microscope head 320 is arranged. The components of short pulse laser system 200 enclosed by the housing 110 are thus placed onto the footplate of the surgical microscope 300 in the mounted state and are fastened at four locations. In the second system for the short pulse laser eye surgery of FIG. 2, this takes place as close as possible to the wheels, which are fastened below the footplate as a transport device 180, as a rigid fastening with about 6 mm distance above the footplate.

[0192] To guarantee the stability of the optical adjustment of the components of the short pulse laser system 200 in the housing 110 and in the second search articulated arm 130, different arrangements are necessary. Elastic deformation of the supporting parts of the housing 110 by position changes of the first and/or second articulated arm 120, 130 must not affect the state of adjustment of the optical system between the fs laser source 210 and the entrance into the second articulated arm 130, on which the applicator head 220 arranged. These elastic deformations are not negligible especially when it is considered that the first articulated arm 120 with the microscope head 320 and the second link arm 130 with the applicator head 220, including the device for an independent weight balance in the form of a parallel support arm 145 and their structures respectively have a weight in the magnitude of 50 kg. During pivoting, center of gravity displacements result, which can lead to deformations in the range of several tenths of a millimeter. Elastic deformations of the second articulated arm 130, on which the applicator head 220 is arranged, or its joint members, are balanced by their own beam stabilization. Deformations of the optical system of the short pulse laser system 200 in the housing 110, thus before entering the second articulated arm, however cannot be balanced. The accuracy requirements of the console optical system, thus the optical system that is arranged in the housing 110 behind the short pulse laser source 210 and in front of the second articulated arm 130, however, are in the micrometer range and cannot be met without special constructive measures.

[0193] To comply with the requirements, the entire optical system of the short pulse laser system 200 located in the housing 110 prior to the entry of the second articulated arm in the beam path of the short pulse laser radiation including the output of the fs laser source 210 is arranged on an optical system bench on an optical bench or bolted thereto. The optical system bench itself is secured with three points on or at the housing 110. All deformations of the fastening surface of the housing thus have no influence on the state of adjustment of the parts on the optical system bench, but on the position of the optical system bench to enter the second articulated 130.

[0194] Changes of this position can be balanced by a beam stabilization with a system for stabilizing a beam passageway 280. A first active mirror of such a system for stabilizing a beam passageway 280 is located indirectly in the optical system bench. Another active mirror is located in the second articulated arm 130. Both form a beam walk. A laser diode 281 in the applicator head 220 emits a laser beam over all mirrors of the second articulated arm 130 including the mirror of the system for stabilizing a beam passageway 280 to two quadrant receivers 282 in the housing 110, which are fixed to the optical system bench. Deviations by deformations when moving the second articulated arm, or through movement of the optical system bench are recognized here and can be balanced by means of counter controls by means of the active mirrors. The optical system of such a system for stabilizing a beam passageway 280 is shown in FIG. 7.

[0195] As already described, the components of the short pulse laser system 200, which are enclosed by the housing, are preferably fastened at four points as near as possible to the wheels 180 mounted to the footplate. The second articulated arm 130 as well as the electronics or the control unit 500 is also suspended indirectly therefrom. Alternating forces by pivoting the first articulated arm 120, on which the microscope head 320 is arranged or of the second articulated arm 130 on which the applicator head 220 is arranged, are transferred directly to the wheels 180 and the floor. The device 100 may not drive during a laser treatment. Changes in the force relations at the wheels 180 due to unevenness of the floor have a direct effect on the state of adjustment of the laser optical system. In the stationary operation, this influence will be balanced once before each surgery. The console is bolted at four points with the footplate of the surgical microscope 300. Two of the four points at which the components of the short pulse laser system 200 are bolted with the footplate can be adjusted in their height. Thereby, over determinancies arising from the fastening at four points can be balanced. Stresses due to expected unevennesses between the components of the short pulse laser system 200 mounted usually in and on a container and of the footplate of the surgical microscope 300 are avoided in that a distance of about 6 mm is produced between a bottom plate of the container and the footplate of the surgical microscope 300.

[0196] The container preferably consists essentially of base and cover plate, which are riveted with vertical walls to form a box. In comparison to a frame, in a compact size, transverse stresses can more easily be absorbed thereby. The container is firmly embedded in the housing 110: Components fastened on the container have therefore also a fixed relationship with the housing 110.

[0197] A cover plate separates the optical part above from electronic components and cables below. It is partially executed as a sandwich in order to guide the cables in intermediate spaces to the electronic components. The optical system bench with the output of the fs laser source 210 and the second articulated arm 130 is bolted to the cover plate. The plate-shaped construction of the container ensures sufficient stability for the optical system bench, but not for the second articulated arm 130, on which the applicator head 220 is arranged. In order to remain within the possibilities of the beam stabilization, the second articulated arm 130 fixed in a very stable manner. This is achieved by four rigid pillars directly under the screw points of the second articulated arm 130, which guide support forces directly into the base plate. The pillars will be charged only under pressure and can be realized by bending the walls twice, which usually consist of a metal sheet, can be realized. Buckling is prevented by skillful position of the bending edges.

[0198] The back of the container form parallel vertical walls, which both contribute to the stiffening of the container and serve for the accommodation of electronic components. The electronic components are vertical and parallel next to each other and can be pulled backwards out to the rear from the device 100 for servicing. A space for the cabling is reserved between the back wall of the device 100 and the electronic components.

[0199] The vertical arrangement results in a natural chimney effect for warm air, which can be used for the aeration. Therefore, openings are mounted in the vicinity of the electronic components, so that warm air from fans can be drawn pulled through the electronic components, and can be pushed out to the back. Thereby, a region of the room close to the surgery is largely spared by air movements that raise dust or can dry out the region near the surgery. The use of radial fans, that can be used to save space, is advantageous. A closed sheet metal plate is arranged above the fans, which separates the electronic components from the upper part of the device interior, in which components of the short-pulse laser system 200 are housed. The components of the short pulse laser system 200 are thereby largely shielded from the heat developing in the lower part.

System Structure of the Short Pulse Laser System: Beam Generating and Optical System

[0200] In order to enable a time-optimized processing of the cornea in terms of access incisions and/or relaxation incisions, or incisions for processing the lens or a capsulotomy with an fs laser, the FIG. 3 shows an fs laser system 200 for eye surgery, especially for cataract surgery, which contains an fs laser light source 210. The light pulses of the pulsed laser radiation generated herein are guided into the eye 900 via a lens varying the divergence or a lens system 211 varying the divergence and further focus-adjusting optical elements 212, with which a controlled z-displacement of the focus of the pulsed laser radiation can be achieved, an x/y-mirror scanner 240 comprising an x-mirror scanner and a y-mirror scanners, or alternatively via gimbal-mounted mirror scanner or again alternatively via an x-mirror scanner with a downstream element for rotation about the optical axis, further a second articulated arm 130 contained over a mirror, an objective lens 225 movable in x/y direction and a patient interface 600 containing a contact element and are focused in the eye 900.

[0201] Due to the lens varying the divergence or by the lens system 211 varying the divergence, which is changed along the optical axis—which corresponds to the z-axis—via an adjusting mechanism controlled by the control unit 500 in the position (its lenses to each other and to the optical axis), the divergence of the pulsed laser radiation and via other upper fixed optical elements such as a relay optical system 213, and/or movable focusing elements 212, the focusing position of the pulsed laser radiation is changed along the optical axis, that is in z-direction, in the eye 900.

[0202] By the x/y-movable lens 225, the lateral focusing position of the pulsed laser radiation is vertically set to the optical axis of the device, that is, in the x- and y-direction. Given the position of the x/y-mirror scanner 240, the femtosecond laser pulses are focused on a spot with a width of about 5 μm within which focuses the region of the eye 900 defined by the movement region of the movable objective 225.

[0203] During the scanning using the x/y-mirror scanner 240 and with an objective 225 remaining in a fixed position, the focal position of femtosecond laser pulses is displaced within the eye 900 within the image field of view of the objective 225.

[0204] With a simultaneous scanning by means of the x/y mirror scanner 240 and method of the movable objective 225, a superimposition movement results.

[0205] In a preferred embodiment variant, a system for stabilizing a radiation passage 280 through the second articulated arm 130 is integrated into the short-pulse laser system 200 for eye surgery. As FIG. 7 shows, it comprises a light source 281 at one end of the second articulated arm 130, which couples its light in the second articulated arm with the help of the mirrors, which also guide and transfer the pulsed laser radiation as beam guidance means, and a position-sensitive 282 at the other end the second articulated arm. The light coupling takes place at an angle to the optical axis of the second articulated arm 130, that is, that e.g. the light source 281 is not arranged on the optical axis or, e.g. the light source 281 is arranged on the optical axis, but does not radiate symmetrically in the direction of the optical axis.

[0206] This beam stabilization allows, in spite of different positions of the second articulated arm, the deflection of the focus of short-pulse laser radiation by the x/y mirror scanner 240 of the x/y-positioning of the movable objective lens 225 in each direction x and/or y to accurately position and balance mechanical tolerances of the second articulated arm 130 and the mirror orientations.

[0207] For this, the steps of the following method are applied: [0208] 1. Determining the deposit position of the light beam of the light source 281 of a system for stabilizing a beam passage 280 on the sensor 282 with spatial resolution in front of a reference position or a reference angular position of the joint members of the second articulated arm 130. The deposit position depends on the rotation of the elements, that is, the joint members of the second articulated arm 130 to each other. [0209] 2. Calculation of the control magnitude to adjust the x/y-mirror scanner 240 for the focus positioning of the short-pulse laser radiation using the information for the deposit position or deposit positions of various positions of the second articulated arm 130. Essentially, the phase position of the swinging mirrors of the x/y-mirror scanner or the x/y swinging directions of a gimbal mirror are set. In an embodiment variant, if the deposit positions exceed a predetermined value, the laser beam guidance on the eye 900 is interrupted or cancelled.

[0210] In addition, the arrangement already described above those of the optical system of the short pulse laser system 200, which is located in front of the second articulated arm 130 on an optical system bench is a measure to avoid the influences of mechanical deformation on the adjustment of the laser optical system.

[0211] In an embodiment variant of the short pulse laser system 200 for eye surgery, the field of view of the objective 225 which is covered by the x/y mirror scanner 240, is larger than 1 mm in cross-section but smaller than 6 mm. In a preferred variant, it is larger than 1.5 mm but smaller than 3 mm.

[0212] A field of view which is too small causes that e.g. with lateral smaller incisions in the eye 900, the fast movement of the x/y scanner 240 alone is not sufficient, to carry out a complete incision. This has the consequence that the generation of the complete incision lasts considerably longer through the movement of the objective 225 through the then necessary slow method. The field magnitude of the objective 225 should therefore be chosen that that for example access incisions in the cornea 910 of an eye 900 with a length of about 1.5 mm in the x direction and during the incision into the depth of the corneal tissue 910, a projected y width of 2 mm do not need a movement of the objective 225, but only scanning with the scanning mirrors of the x/y-mirror scanner 240. However, the field of view should also not be too large, as otherwise the objective 225 becomes too heavy and thus will become too sluggish and slow for large-scale movements as e.g. during capsulotomy.

[0213] When coupling the microscope head 320 and the applicator head 220 via an interface 150, the beam path for the light to be received through the microscope head 320 passes through the applicator head 220. There are alternative solutions to ensure this:

[0214] In a first solution, a laser optics in the applicator head 220 may be designed so that the mirror 224, whose role it is to deflect laser radiation coming from the fs laser source 210 to the objective 225 in the applicator head 220, has a partial transparency—particularly in the region of visible light, which is needed for the observation of the eye 900 with the microscope head 320, while the short pulse laser beam is reflected virtually completely. A further lens 335 for the adaptation of the radiation coming from the laser can thereby be arranged movably in front of the objective 330 of the microscope head 320 in the beam path of the surgical microscope 300.

[0215] In an alternative solution, the laser optical system, which then contains a fully reflecting mirror 224, can be extended into the applicator head 220 by means of a slide. In order to utilize the microscope head 320 for observing the eye 900, the laser optical system is removed from the beam path of the surgical microscope 300, which passes through the applicator head 220. During the use of the short pulse laser radiation, the surgical microscope 300 cannot be used for observing the eye 900. To still create a possibility a possibility for the observation, the eye is 900 observed with light by a camera, preferably an infrared camera 300 via a beam divider prism 350, for which the camera is sensitive, thus IR light here.

Optical Coherence Tomography and Navigation

[0216] To define the processing pattern in the eye 900, the structures of the eye 900, in particular the structures of the anterior chamber of the eye 900 are measured by means of the optical coherence tomography (OCT). In the OCT imaging, the light of a short-coherence light source is scanned laterally over the eye 900, i.e. vertical to the optical axis of the eye 900. Light reflected or scattered from the eye 900 is brought to interference with the light of a reference beam path. The interference signal measured by a detector is analyzed. From this, the axial distances of structures in the eye 900 can then be reconstructed. In conjunction with the lateral scanning, structures in the eye 900 can then be captured in a three-dimensional manner.

[0217] In order to determine an incision pattern in the eye 900 to be generated with the focus of a short pulse laser radiation, FIG. 7 shows the (optical) integration of an OCT module 400 in the configuration of a short pulse laser system for eye surgery 200 and, consequently also in a system for short pulse laser eye surgery 100.

[0218] In a variant of the structure, the same OCT-light source 405 is optionally coupled into the surgical microscope head 320 and into the applicator head 220. Accordingly, the light reflected back reflected light of the OCT-light source 405 through the same interferometer with the superimposed reference light and detected by the same detector. This is illustrated in FIG. 7:

[0219] In order to improve the integration of the various components in an optimized workflow for the physician and to improve an optimized work environment, a structure is disclosed in FIG. 7, in which an fs laser source 210, an applicator head 220, a beam guidance means 230 (in FIG. 7 components of the beam guide means 230 are referred to only in an exemplary manner) for guiding the fs laser radiation into the applicator head 220 and from there to the eye to be operated 900 on, a microscope head 320, a movable second articulated arm 130 containing mirrors and an OCT module 400 containing a light source 405, a reference beam path, an interferometer, a detector and one or more switching points 420, controlled by a control device 500—not shown in FIG. 7—are controlled. The switching points 420 guide the light emitted from the OCT light source 405 and the light of the OCT-light source 405 returning from the eye 900 in a first state only via the applicator head 220 and in a second state only via the microscope head 320. This permits for example, the use of the OCT module together with the microscope head 320 for the surgery part of inserting the intraocular lens (IOL), in which the applicator head is not used and remains in a parking position decoupled from the microscope head 320 ensures on the other hand that the illumination and detection beam path of the OCT module 400 for setting the incisions by means of the focus of the fs laser radiation corresponds to the beam path of the fs-laser radiation, whereby alignment errors can be avoided. This is possible by the switching point or switching points 420, without having to integrate a further OCT module.

[0220] In order to improve the integration of the OCT module 400, FIG. 7 shows a short pulse laser system 200 for eye surgery containing an fs laser source 210 and an OCT module 400 containing a short coherence light source 405 and an interferometer, wherein the fs laser radiation and the radiation of the OCT short coherence light source 405 are fed to the applicator head 220 via the same second articulated arm 130 via the same articulated arm 130 containing mirrors and via this to the eye 900. After the merging of the radiation of both light sources, both are thereby laterally deflected via the same x/y mirror scanner 240. In this case, interferometer associated with the OCT module is arranged with a beam splitter and two mirrors in the beam path directly in front of the exit location on the objective 225 is arranged (not shown in FIG. 7).

[0221] This solution has the advantage that only a single beam guide means 230, here in the form of a guidance optical system formed with the aid of mirrors is necessary for the fs laser radiation and the radiation of the OCT light source 405 to the applicator head 130. Alternatively to the second articulated arm 130 containing mirrors, a photonic crystal fiber may be used as beam guidance means 230 for feeding the fs laser radiation and the radiation of the OCT short coherence source 405. In this case, the joint members of the second articulated arm 130 can be designed without mirrors.

[0222] In order to further improve the integration of the OCT module 400 and to offer alternatives, a further solution is also sketched in FIG. 7: The short pulse laser system 200 shown here also shows an fs laser source 210 and an OCT module 400 which contains a short coherence light source 405 and an interferometer, wherein the fs laser radiation is guided to an applicator head 220 via an x/y mirror scanner 240 for the lateral deflection and then via a second articulated arm 130 containing mirrors, the radiation of the OCT short coherence light source however is guided to the applicator head 220 via a light guide fiber 410 without being guided over the x/y mirror scanner 240. The beam path of the fs laser and of the radiation from the OCT light source is thereby merged in the applicator head 220 and guided into the eye via a laterally movable objective 225.

[0223] This solution has the advantage that none of the many optical elements of the second articulated arm 130 containing the mirror are arranged in the optical beam path OCT and thus their annoying reflections in the OCT detection signal no longer occur.

[0224] For an integration of the OCT module 400 with an OCT short coherence light source 405 and an interferometer, FIG. 8 shows a further detail, which enables to merge the radiation from a fs laser source 210 and from an OCT short coherence light source 405 of an OCT module 400 in a short pulse laser system on a common optical axis 215 and to follow a common optical beam path 250 to and from the eye 900. For this, the fs laser radiation coming from a fs laser source 210 on to a ring mirror 430 after a fs laser beam formation optical system 211 and is reflected on this in the direction of the eye 900 The radiation of the OCT short coherence light source 405 of the OCT module 400 however passes through a hole arranged centrally in the ring mirror 430 in the direction of the eye and thus on the same path as the fs laser radiation. Further, an OCT detector arranged in the OCT module 400 is detecting light coming from the eye via the hole in the ring mirror 430.

[0225] This has the advantage that mainly the high aperture regions are used for the forming of the fs laser radiation through the fs laser beam forming optical element 211. The focusing is improved thereby on the one hand. On the other hand, when focusing the fs laser radiation into the lens of an eye 900 during the further passage through the eye 900 in the region of the retina, only the peripheral regions are illuminated, whereby the risk for the patient sinks to be damaged by the radiation in the central macula region. The ring aperture division further has the advantage that the radiation of the OCT short coherence light source 405, thus the OCT measuring and detection beam, is guided onto the optical axis 215 of the short pulse laser system 200 without an optically interfering surface by means of its reflexes. This is not the case with a coupling by means of dichromatic filters or with virtually the same wavelength of the radiation of the OCT short coherence light source 405 and the fs laser radiation when coupling by means of a color-neutral divider. The color-neutral division would also lead to additional intensity losses for the radiation of the OCT short coherence light source 404 and for the fs laser radiation.

[0226] In a further embodiment not shown here, the axis of the radiation of the OCT short coherence light source 405 is not identical to the optical axis 215 of the short pulse laser system 200, but has a small angle therewith. This has the advantage that further optical elements necessary for the bean formation of the f laser radiation to the eye 900 do not throw back OCT illumination light into the OCT detection beam path and thus affect the OCT signal.

[0227] In order to improve the accuracy of the calibration of the OCT imaging for positioning the focus of the pulsed laser radiation, FIG. 7 shows a confocal detector 260, whose focal aperture is located conjugated to the focal position of the fs laser radiation.

[0228] This confocal detector 260 permits to also measure structures of the eye when scanning the focus of the fs laser radiation in all spatial directions.

[0229] Thus, in a short pulse laser system, which contains a confocal detector 260 and an OCT detector in an OCT module, the following method of controlling the short pulse laser system for eye surgery can advantageously be carried out, also see FIGS. 9a and 9b. [0230] a) Recording a B scan or an A scan 450 by means of an OCT module, which shows at least two structures 455-a and 456-a of the eye 900, e.g. of the cornea anterior and the cornea posterior. [0231] b) Recording an intensity profile 460 of the signal of the confocal detector when passing through the z-focal position through the same two structures 455-b and 456-b of the eye 900, when illuminating the eye 900 through the fs laser radiation. [0232] c) Calculating an offset and a scaling factor from the z-positions of the signals of the corresponding two structures obtained from the B or A scan and in the intensity profile [0233] d) Recording OCT images for setting the desired incision positions, setting the desired incision positions (by means of these OCT images) [0234] e) Calculating and controlling the focus of the fs laser radiation using the OCT images and the desired incision positions and the offsets and the scaling factor

[0235] By means of this method of controlling the short pulse laser system 200 it is ensured that the differences between the focal positions of the structures determined with the confocal detector 260, illuminated by the fs laser radiation or the same structures determined with the OCT module, e.g. by different wavelengths or different apertures, have no or only a slight effects on the control of the fs laser incisions and thus on the success of the surgery.

[0236] In order to improve the integration of the different components in a workflow optimized for an physician and an optimized work environment, a structure is further disclosed in FIG. 7, where a fs laser source 210, a beam guidance means 230 for guiding the fs laser radiation above the applicator head 220 on the eye 900 to be operated on and a swept source OCT module 400 containing an OCT light source 405 and an interferometer, will be controlled by a control device 500, which is not shown in FIG. 7. The applicator head 220 thereby contains a laterally scanning, movable objective 225. In one embodiment variant, the coherence length of the OCT light source 405 in air is thereby larger than 45 mm, particularly preferred larger than 60 mm.

[0237] By means of the large coherence length of the OCT light source 405 it is possible that the entire anterior chamber section within an A scan given by the tuning of the swept source is detected, even when the optical path to the eye 900) extends or changes by the lateral objective movement, without the optical path length of the reference beam path has to be adapted e.g. by displacing a reference mirror.

[0238] Such a change of the optical path length due to the objective movement is shown in FIG. 10. Between the objective positions 225-1 and 225-2 of the objective 225, the focus between positions 465-1 and 465-2 is displaced correspondingly, which coincides with a change of the optical path length of the OCT illumination beam path.

[0239] In order to balance the influence of the movement of the objective 225 on the OCT signal, the path length differences—typically up to 6 mm with different objective positions—are considered when calculating the A scan from the OCT signals. For this, when obtaining the A scans from the measured OCT signals, in a structure according to FIG. 7, the following steps are carried out in addition to other steps: [0240] (1) Detection of the first OCT signals during the tuning of the OCT light source 405 at the objective position 225-1 [0241] (2) Detection of the second OCT signals during the tuning of the OCT light source 405 at the objective position 225-2 [0242] (3) Fourier transformation of the first OCT signals for obtaining the A scan; Fourier transformation of the second OCT signals multiplied with a phase factor depending on the relative position of the object position 225-2 to the objective position 225-1.

[0243] In order to balance the influence of the movement of the objective 225 on the OCT signal, in an alternative solution, the A scans obtained from the OCT signals are corrected by a position-dependent objective displacement along the measuring axis. For this, the following steps are carried out: [0244] (1) Detection of the first OCT signals during the tuning of the OCT light source 405 at the objective position 225-1 [0245] (2) Detection of the second OCT signals during the tuning of the OCT light source 405 at the objective position 225-2 [0246] (3) Fourier transformation of the first OCT signals for obtaining a first A scan [0247] (4) Fourier transformation of the second OCT signals for obtaining a second A scan [0248] (5) Displacing the second A scan along the measuring axis by an amount depending on the relative position of the objective position 225-2 with respect to the objective position 225-1

Incision Guidance

[0249] The above-described construction of the system for short pulse laser eye surgery 100 and of the short pulse laser system 200 supports the following method for the laser incision guidance in a special way, which is shown in FIGS. 11a and 11b:

[0250] If the incisions 920-1 to be executed in the tissue 910 of an eye 900 are in their focal positions 921-1, which are respectively projected on the x/y plane section, thus the incision 920-1, which is projected in an x/y plane is smaller than the field of view 226 of the objective 225, e.g. for small and steep access incisions, as shown in FIG. 11a, the following steps are selected for the method of the laser incision guidance, see also FIG. 11b:

(1) x/y-positioning of the objective 225, so that the x/y-focal positions to be projected, that is, the positions of the respective focus of fs laser radiation in x and y, are within the field of view 226.
(2) Projecting the focal positions of the incision pattern through the objective 225 fixed in its x/y-position using the x/y-scanning system, here thus the x/y-mirror scanner 240 optionally after each deflection of the focal position taking place after each x/y scan or parallel to the x/y scan by means of the lens changing the divergence or the lens system 211 varying the divergence along the optical axis 215. This is a preferred solution e.g. for small and steep access incisions.

[0251] If there is the necessity due to application reasons to implement larger incisions 920-2 or flatter incisions 920-2 perform with larger projected x and/or y extension than detectable simultaneously from the field of view 226 of the objective 225, see FIG. 12a, then the objective 225 can respectively be displaced so that the new field of views and the field of view 226 of the original objective position cover the entire incision area 920-2. For the respective new field of view, the still missing incision parts, can possibly be made up for by means of the x/y-scanning system, in this case 240, here thus the x/y-mirror scanner 240, possibly by changing the z-position of the focal position of the fs-laser radiation, be rescheduled. That is, one works with successively other lateral positions of the objective 225, until the entire incision 920-2 through the various sub-scanning has taken place. The x/y-mirror scanner 240 for the partial fields allow thereby to cover larger fields systematically and accurately in partial fields in a simple manner, particularly preferred square partial fields, by an incremental objective movement.

[0252] In the event that the incisions 920-2 lie very flat in the tissue 910, e.g. the cornea, i.e. the projected y-extension of the focal positions 921-2 of the incisions 920-2 projected in an x/y plane cannot be achieved completely with a y-scanner with a fixed objective 225 because the field of view 226 of the objective 225 is too small, while the incision length along the x axis lies within the field of view 226, then, alternatively to the above partial field scan, the following method can be chosen, see also FIG. 12b:

(1) simultaneous movement of the objective in the y-direction and movement of the lens or lens system for adjusting the z-focal position 211 and
(2) superposition of the fast x-mirror scanner movement.

[0253] If the incisions 920-2 are rather long and steep, thus have a large extension along the x-axis to a small extent in the y-direction, then it is accordingly advantageous to implement these incisions through simultaneous movement of the objective 225 along the x-axis and movement of the lens for the adjustment of the z-focal position 211 by superimposing the fast y-scanner movement.

[0254] Generalized to an incision 920-2, whose projected extension of the x and y extension which is, in focal positions 921-2 projected in an x/y plane larger in both x- and y-direction than the field of view 226 of the objective 225, this method can of course be applied in both directions.

[0255] While in the above description the z positioning means takes place by a lens varying the divergence or a lens system 211 varying the divergence, the above description of the incision applies generally for any type of z-focus adjustment, for example, even if the position of the z-focus takes place by positioning or movement of the lens 225 in the applicator head 220 along the optical axis 215.

[0256] In order to set as few fs processing pulses as possible fir the disintegration of the lens 910 and thereby to still ensure that in the subsequent phacocmulsification no or only little ultrasonic energy has to be applied, a method and an incision pattern is shown is in FIGS. 13a and 13b, which weakens the lens 910 of an eye 900 in its structure. The method of the incision thereby comprises the following steps:

(S0) Positioning the focal point SP of a short pulse laser radiation, in the example of an fs laser radiation, in the lens 910 of an eye 900 to be processed. In one embodiment variant, the focal point SP in the lens 910 is positioned with a safety distance to the posterior and anterior capsular bag of the eye 900.
(S1) Feeding the objective 225 in the radial direction in a meridian plane 940-1 of the lens 910 for a length L with superposition of an oscillating focus displacement 935 along the optical axis 215, 950 of both the fs laser system as well as of the eye with an amplitude A, wherein, in a first variant, only with the posterior to the anterior focus movement laser pulses are passed into the eye 900, and, in a second variant, laser pulses of the fs-laser radiation over the entire cycle. The meridian plane 940 of the lens 910 is thereby given by a plane passing through the center of the lens 910 in the vicinity of the optical axis 950 of the lens 910 or the optical axis 215 of the fs laser system 200 and proceeds approximately parallel to the optical axis 215, 950. Thus, an incision surface 925-1 is created. In a third variant, based on variant one, the anterior to posterior focus movement is performed faster, i.e. under a lower feed distance, thus less lateral movement than the feed distance at posterior to anterior focus movement. This results, with a constant laser pulse frequency, in that the laser pulses between two upward movements are laterally closer together and that incision surface 925-1 results.
(S2) Feeding of the focal point of the feed fs laser radiation along the optical axis 215, 950 by a height HR, wherein HR is selected so that the foci of the laser pulses set in the next step do not overlap with those foci of the laser pulses set in the previous step. In a variant, a distance D of 10-50 μm is kept between the laser foci of the two incision surfaces 925-1, 925-2. On the one hand, this positive distance ensures that unnecessary incisions are not set in resulting cavitation bubble of the posterior section 925-1. On the other hand, no incisions are necessary distance region, because the bubble formation leads to a sufficiently large weakening in the tissue 910 and the two incision surfaces 925-1 and 925-2 possibly even merge together.
(S3) Repeating step S1 by reversing the feed direction in the radial direction and if necessary, step S2 (which is not necessary in FIG. 13b due to the size relations in this example). In one embodiment variant, these steps S1 and S2 are repeated until a safety distance to the posterior capsular bag is reached. In one variant, further supplementary steps are undertaken for the complete weakening of the lens, for example by simultaneous superimposed shifting of the laser focus deposit by means of a fast lateral scanner during the implementation of the steps S1 and S2.
(S4) Feeding of the focal point radially in the meridian plane 940 by a length of the VR and along the optical axis 215, 950 about the length HR, so that the incisions 925-x resulting in the following steps do not radially overlap with the preceding incisions 925-1, 925-2, etc. or have in one embodiment variant a radial distance D, with D preferably between 10-50 μm. In FIG. 13b possible lengths VR and HR are given in an exemplary manner, but other lengths can also be selected as long as the incisions 925-x yet to be generated do not overlap preceding sections 925-1, 925-2, etc. Repeating steps S1-S4 (see S1′, S2′, S3′) until the lens 910 is interspersed across the median plane 940 with incisions 925-1, 925-2, . . . 925-x, in an embodiment variant, except for a minimum distance from the capsular bag and to the iris.
(S5) Positioning the focal point to the edge of another meridian plane 940-2. In a preferred embodiment variant, the change of meridian planes 940-1, 940-2, . . . takes place in the region of the incision line of the meridian planes 940-1, 940-2, . . .
(S6) Repeating steps S1-S6 until the entire lens 910 is interspersed with incisions 925-1, 925-2, . . . 925-x.

[0257] In addition to this incision pattern along the median planes 940-1, 940-2, . . . different overall incision patterns can be realized by the positioning of the basic-incision pattern of step (S1)-(S3). In this manner, lattice planes can also be realized, which are interspersed with incision surfaces. In all three-dimensional patterns at incision surfaces 925-1, 925-2, . . . 925-x, the degree of weakening of the lens cohesion can be adjusted via the distance of the incision surfaces 925-1, 925-2, . . . 925-x in connection with the bubble formation. Also, the distance of the incision 925-2 described in step S2 to the other comparable sections 925-1, 925-2, . . . 925-x according to step S2 in step in all can be adapted in all three spatial directions to the desired degree of weakening.

[0258] In order to permit an efficient cutting of the capsular bag 910-2 in capsulotomy for a fast z-scanning system, a method for the focus guidance with an inclined eye lens 910-1 in relation to the optical axis 215 of the laser system is shown in side view SA in FIG. 14a and in a plan view from above in FIG. 14b AO: [0259] (1) Bringing the capsular bag 910-2 to be cut in an x/y/z-focal position SP, which gives a start position, behind the most posterior point 913 of the region of the capsular bag 910-2, which needs to be cut for the capsulotomy with the laser. [0260] (2) Feeding the focal point or focus of the fs laser radiation along the z-axis 215 anterior by the distance H, while simultaneous feeding the focal point of the fs laser radiation in an x/y plane 922 along the edge of the capsulotomy 926 projected on the x/y plane 922 in direction D1, whereby the focal point, after passing through the distance H, lies anterior of the capsular bag 910-2. [0261] (3) Feeding the focal point along the z-axis 215 posterior by altogether the distance H1 with simultaneous feeding the focal point in the x/y plane 922 along the path projected on the x/y plane 922 path in the direction D1, wherein H1 is less than H, and the focus lies posterior of the capsular bag 910-2 after passing through the distance H1. [0262] (4) Repeating steps (2) and (3) until the most anterior point 914 of the region of the capsular bag 910-2, which is to be cut for the capsulotomy 926 with the pulsed fs laser radiation, has been reached. [0263] (5) For the completion of the capsulotomy 926 the above steps are repeated while feeding the focal point of the fs laser radiation in the x/y plane 922 along the path projected in the x/y plane 922 in the opposite direction D2 (see FIG. 14b).

[0264] For slightly inclined lenses 910-1 and the choice of a larger feeding in the x/y plane 922, the influence of the bubble formation of previous laser pulses on the pulse to be set can be neglected. Then the following sequence of steps is advantageous, see FIG. 15 as a top view of AO:

(1) Bringing the capsular bag 910-2 to be cut in an x/y/z-focal position SP posterior to the location of the region 926 of the capsular bag, which needs to be cut for the capsulotomy with the laser.
(2) Feeding the focal point of the fs laser radiation along the z-axis anterior by altogether the distance H with simultaneous feeding the focal point in the x/y plane 922 along the edge of the capsulotomy 926 projected on the x/y plane 922 in direction D1, whereby the focal point, after passing through the distance H, lies anterior of the capsular bag 910-2.
(3) Feeding the focal point along the z-axis 215 posterior by altogether the distance H1 with simultaneous feeding the focal point in the x/y plane 922 along the path of the capsulotomy 926 projected on the x/y plane 922 path in the direction D1, wherein H1 is less than H in a first embodiment variant, and the focal point lies posterior of the capsular bag 910-2 after passing through the distance H1.
(4) Repeating steps (2) and (3) until the most anterior point 914 of the region 926 of the capsular bag 910-2, which is to be cut for the capsulotomy 926 with the laser, has been reached.
(5) Repeating steps (2) and (3) while maintaining the feeding in the x/y plane 922 in direction D1, wherein, in the first embodiment variant H1 is however larger than H, and until the most posterior point 913 of the region 926 of the capsular bag 910-2 is reached, which is to be cut with the laser.
(6) Repeating steps (2) and (3) while maintaining the feeding in the x/y plane 922 in direction D1, wherein, in the first embodiment variant H1 is however now smaller than H, and until the capsulotomy 926 is closed in point SP.

[0265] In a second embodiment variant, with slightly inclined lenses 910-1 and the choice of a larger feeding in the x/y plane 922, the incision path of the capsulotomy 926 can be passed through in the opposite direction D2. Also see FIG. 15: [0266] (1) Bringing the capsular bag 910-2 to be cut in an x/y/z-focal position SP posterior to the location of the region 926 of the capsular bag, which needs to be cut for the capsulotomy with the laser. [0267] (2) Feeding the focus of the fs laser radiation or another short pulse laser radiation along the z-axis 215 anterior by altogether the distance H with simultaneous feeding the focal point in the x/y plane 922 along the edge of the capsulotomy 926 projected on the x/y plane 922 in direction D2, whereby the focal point, after passing through the distance H, lies anterior of the capsular bag 910-2. [0268] (3) Feeding the focal point along the z-axis 215 posterior by altogether the distance H1 with simultaneous feeding the focal point in the x/y plane 922 along the path of the capsulotomy 926 projected on the x/y plane 922 path in the direction D2, wherein H is larger than H, and the focal point lies posterior of the capsular bag 910-2 after passing through the distance H1. [0269] (4) Repeating steps (2) and (3) until the most posterior location 913 of the region 926 of the capsular bag, which is to be cut for the capsulotomy 926 with the laser, has been reached. [0270] (5) Repeating steps (2) and (3) while maintaining the feeding in the x/y plane 922 in direction D2, wherein, in the second embodiment variant H1 is however smaller than H, and until the most anterior location 914 of the region 926 of the capsular bag 910-2 is reached, which is to be cut with the laser. [0271] (6) Repeating steps (2) and (3) while maintaining the feeding in the x/y plane 922 in direction D2, wherein H1 is again however now larger than H, and until the capsulotomy 926 is closed in point SP.

[0272] With inclined lenses 910-1 and with lenses 910-1 vertical relative to the axis 215, the cutting of the capsulotomy 926 with fs laser systems 200 with a fast z-scan, i.e. a speed of the z-focus deflection larger than or comparable to the speed of the x/y focus deflection, can take some time, so that the relative movement of the eye 900 changes with respect to the optical axis 215 of the laser system. The following steps of a method for laser focus control with a capsulotomy 926, see also FIG. 16 as a view from above AO, ensure even with slight movements of the capsular bag 910-2 in the x/y plane 922, but also in the z-axis 215, that a capsular bag segment still separated completely from the rest of the capsular bag 910-2 results: [0273] (1) Positioning the focus of the femtosecond laser radiation in the x/y plane 922, and with respect to the z-position in the vicinity of the capsular bag 910-2. [0274] (2) Guiding the focal point or focal point in the x/y plane 922, along the edge of the area the capsular bag 910-2, which needs to be cut, in a first section A1 with a first radius R1. [0275] (3) Guiding the focus in the x/y plane in a second section A2 with a second radius R2. [0276] (4) Guiding the focus in the x/y plane 922 in a third section A3 with a third radius R3, wherein the first radius R1 and the third radius R3 is smaller than the second radius R2, such that the path of the focal point, which is results by the setting of individual pulses cuts through the first section A1 or the second section A2.

[0277] Thereby, in steps 2, 3 and 4, the z-position of the focus of the femtosecond laser radiation is changed in an oscillating manner with such a large oscillation amplitude, that the laser pulses set during the oscillations cut through the capsular bag 910-2 by photodisruption processes.

[0278] In steps 2, 3 and 4, simultaneously to the guidance of the focus in the x/y plane 922 also in an oscillating manner, at least once, preferably several times, particularly preferably more than five times, the z focal position is changed periodically for each of the sections A1, A2 and A3.

[0279] In systems with fast x/y scanning systems 240 for cutting the capsulotomy 926, that is, x/y scanning systems 240, whose speed of the x/y-focus deflection is larger than the speed the z-focus deflection, the problem of meeting the third section A3 of the capsulotomy incision with the first section A1 of the capsulotomy incision in the x/y plane 922 does not occur in such a measure as with fast z-scanning systems due to the high movement speed of the focus in the x/y plane 922.

[0280] The simple incision geometry or radiation geometry described up to now does particularly not ensure with slow lateral scanning movement in the x- and/or y-direction with respect to the eye movement that the capsulotomy takes p-lace in an approximately circular manner. With a significant eye movement it can now occur that the third section A3 meets the first section A1 of the capsulotomy incision immediately at the beginning thereof and thus a significant dent and thus deviation from an approximately round capsulotomy 926 results, as shown in FIG. 16. A circular capsulotomy is however advantageous for improved centering of the intraocular lens (IOL) inserted later in the capsular bag 910-2 for many IOL types.

[0281] Therefore, the incision geometries suggested in FIG. 17a to 17b are disclosed as alternatives, where, instead of a continuous incision, at least two temporally separately carried out incisions in the form of non-closed curves 927 take place, wherein each of the end regions 928-1, 928-2 of the non-closed curves is arranged within the capsulotomy 926 resulting later, thus within the circular opening.

[0282] Thus, as shown in FIGS. 17a and 17b, in a method for an incision guidance of a capsulotomy 926 by means of a short pulse laser system 200 for eye surgery, an opening can be generated in that focal points of a short pulse laser radiation by means of an x/y scanning system 240 are positioned in their x- and y-focal positions and thereby results a first non-closed curve 927-1 with a radius R in two steps and a second non-closed curve 927-2 with a radius R, and respectively with a first and a second end region 928-1, 928-2 of a respectively rectified curvature, wherein the first end portion 928-1 of the first non-closed curve 927-1 has a first end region radius R.sub.E11 and the second end region 928-2 of the first non-closed curve 927-1 a second end region radius R.sub.E12 and the first end region radius R.sub.E11 as well as the second end region radius R.sub.E12 is smaller than the radius R and the first end region 928-1 of the second non-closed curve 927-2 has a first end region radius R.sub.E22 and the second end region 928-2 of the second non-closed curve 927-1 a second end region radius R.sub.E22 and the first end region radius R.sub.E21 and the second end region radius R.sub.E22 is smaller than the radius R, all the end regions 927-1, 927-2 each have an end 929, and the first end portion 928-1 of the second non-closed curve 927-2 intersects the second end portion 928-2 of the first non-closed curve 927-1 and the second end region 928-2 of the second non-closed curve 927-2 intersect the first end region 928-1 of the first non-closed curve 927-1 in such a manner that the ends 929 of all end regions 928-1, 928-2 are arranged inside of a closed curve of the capsulotomy 926 formed by the first and the second non-closed curve 927-1, 927-2.

[0283] Also, in an advantageous manner, as shown in FIG. 17c, in a method for incision guidance of a capsulotomy using a short pulse laser system 200 for eye surgery, an opening of the capsular bag 910-2 can be generated in that the focal points of a short pulse laser radiation by means of an x/y scanning system 240 are positioned in their x- and y-focal positions, and thereby results in four steps a first, a second, a third and a fourth non-closed curve 927-1, 927-2, 927-3, 927-4 with a radius R, and each with a first and a second end 928-1, 928-2 of a respective rectified curvature, wherein the first end region 928-1 of the first non-closed curve 927-1 has a first end region radius R.sub.E11 and the second end region 928-2 of the first non-closed curve 927-1 a second end region radius R.sub.E12, the first end region 928-1 of the second non-closed curve 927-2 a first end region radius R.sub.E21 and the second end region 928-2 of the second non-closed curve 927-2 a second end region radius R.sub.E22, the first end region 928-1 of the third non-closed curve 927-3 a first end region radius R.sub.E31 and the second end region 928-2 of the third non-closed curve 927-3 a second end region radius R.sub.E32 and the first end region 928-1 of the fourth non-closed curve 927-4 a first end region radius R.sub.E41 and the second end region 928-2 of the fourth non-closed curve 927-4 a second end region radius R.sub.E42 has and all end region radii R.sub.E11, R.sub.E12, R.sub.E21, R.sub.E22, R.sub.E31, R.sub.E32, R.sub.E41 and R.sub.E42 are smaller than the radius R, wherein all end regions 928-1, 928-2 respectively have an end 929, and the first end region 928-1 of the second non-closed curve 927-2 intersects the second end region 928-2 of the first non-closed curve 927-1, the first end region 928-1 of the third non-closed curve 927-3 the second end region 928-2 of the second non-closed curve 27-2, the first end region 928-1 of the fourth non-closed curve 927-4 the second end region 928-2 of the third non-closed curve 927-3 and the second end region 928-2 of the fourth non-closed curve 927-4 the first end region 928-1 of the first non-closed curve 927-1 in such a manner that the ends of all the end regions 928-1, 928-2 are arranged in the inside of a closed curve of the capsulotomy 926 formed by the first, second, third and fourth non-closed curve 927-1, 927-2, 927-3, 927-4.

[0284] If the total incision of the capsulotomy 926, as described herein, and also executable with a higher number of non-closed curves 927-1 . . . 927-n, is distributed on several separately executed incisions, this leads to a shorter incision length for each of the non-closed curves 927-1 . . . 927-n. For a given lateral scanning speed in the x and/or y-direction, this leads to a shorter incision duration for a single non-closed curve 927-1 . . . 927-n. During this shorter incision duration the eye movements lead to a lower deviation from a circular incision curve for each of the separately executed incisions of a non-closed curve 927-1 . . . 927-n. Prior to the execution of a next incision, this can be laterally realigned. Even without such a realignment, this incision geometry is particularly, but not only advantageous for such short pulse laser systems 200, whose scanning system or scanning systems moves the focus of a short pulse laser radiation for cutting the capsular bag faster along the optical axis 215 than in the lateral direction, or which a lateral partial field scanner, as mechanical tolerances of the lateral scanner or the scanner guidance of the short pulse laser system 200 can be compensated better.

[0285] For each pair of intersecting non-closed curves 927-n−1, 928-n therefore applies: The intersection is located in a second end region 928-2 of a non-closed curve 927 (n−1) and a first end portion 928-1 following an non-closed curve 927-n and the radii of curvature of the end regions R.sub.En1, R.sub.En2 are smaller than the radius R of the non-closed curves 927-n−1, 928-n, which describes the radius of curvature of the central region of a non-closed curve 927-1, . . . 928-n between the two end regions 928-1, 928-2.

[0286] The requirement that the radii of curvature of the end regions R.sub.En1, R.sub.En2 should be less than the radius R thereby also contains the case that the radii of curvature of the end portions R.sub.En1, R.sub.En2 approach the radius of curvature R from below, thus R.sub.En1, R.sub.En2.fwdarw.R. All non-closed curves 927-n−1, 928-n have the radius R in their central region. Smaller, thus insignificant differences between the radii R of two non-closed curves 927-n-1,928-n are however possible, without missing the target to generate a closed curve 926 by which the cooperation of the non-closed curves in the above described manner, which is designed approximately with a radius R, and thus fulfills the requirements for a capsulotomy incision. Further, the extension of the end regions 928-1, 928-2 between two non-closed curves 927-n−1, 928-n can also vary.

[0287] For a partial field scanner, it is thereby particularly advantageous if the number of the separate incisions, thus the number of the non-closed curves 927-1, . . . 928-n corresponds with the number of necessary partial fields corresponds for covering the total area of a capsulotomy 926.

Patient Interface/Contact Element

[0288] In order to design the workflow for the operator as simple as possible, the—for the patient interface 600 necessary for optical reasons containing a contact element 610—structure in FIG. 18 for processing the eye 900 by means of a system for short pulse laser eye surgery 100 is shown. The structure shown here contains a patient interface 600, an applicator head 220 of the system for short pulse laser eye surgery 100, wherein the patient interface 600 in FIG. 18 is fixed on the eye 900 of the patient as well as on the applicator head 220 of the system for short pulse laser eye surgery 100 and thus fixes the relative position of the eye 900 to the system for short pulse laser eye surgery 100 and, consequently, to the beam path of the short pulse laser radiation.

[0289] The patient interface 600 contains a contact element 610, which is designed as a liquid interface in this exemplary embodiment. The contact element 610 is in one piece, manufactured from a preferably uniform transparent material and contains a suction ring 612, a casing 611 and an optical element 620 at the top of the casing 611. It further comprises two openings 613, 614, to which the two leads are connected via fixing aids or permit the connection of two leads, wherein respectively one lead is or will be connected to one of the openings 613, 614.

[0290] A one-piece contact element 610, in which all the functional elements are integrated, allows a simpler handling than multi-component contact elements 610, which are only assembled on the patient's eye 900. Such multi-component contact elements 610 are described in e.g. the documents U.S. Pat. No. 7,955,324 B2, U.S. Pat. No. 8,500,723 B2, US 2013/053837 A1, WO 2012/041347 A1.

[0291] The two leads serve on the one hand for the application of a vacuum, here via the bottom opening 613, and on the other hand for feeding or removing fluid in the contact element 610, when the contact element 610 is docked to the eye 900, through the upper opening 614.

[0292] In a preferred variant, an overflow outlet 615 is further provided in the upper casing area of the contact element 610, distal to the eye 900, via which excess fluid or air can exit from the contact element 610 during filling.

[0293] Preferably, the patient interface 600 contains a mechanically releasable coupling element 651 for the mechanical fixation of the contact element 610 on the applicator head 220. Alternatively, it is possible that the patient interface 600 contains a contact element 610 with a further suction structure instead of a mechanical interface with a mechanically releasable coupling element 651, manufactured of the same material as the contact element 610. This further suction structure holds the contact element 610 on the applicator head 220 when a vacuum is applied. As this is an alternative solution, it is not shown in FIG. 18.

[0294] It is also advantageous if a surface of the optical element 620 facing away from the casing 611 and facing the applicator head 200, is arranged not vertical but inclined to the optical axis 215.

[0295] Thereby it is avoided that, during the measurement of the eye structures by means of optical coherence tomography (OCT) through the contact element 610, the reflexes of an OCT short-coherence light source on the surface of the optical element 620, are directly reflected back into the OCT detection beam path and in a critical OCT-image area, and shine over the eye structure actually to be measured and thereby falsify them. This danger exists with a vertical orientation of the surface of the optical element 620 to the optical axis 215.

[0296] The surface of the optical element 620 facing the casing 611 and thus the eye 900 is preferably convex/y curved. Thereby, an optical effect is achieved on the one hand, on the other hand, air bubbles which form travel along the curved walls upwards and to the edge or over the edge of the lens and thus outside the aperture of a short pulse laser radiation or of the OCT illumination and detection beam.

[0297] Furthermore, the surface of the optical element 620 facing the casing 611 and the eye 900 can be coated in a hydrophilic manner or be surface treated. Thereby, the wetting with water or another liquid, such as a “balanced salt solution” (BSS) and the migration of bubbles to the side is improved.

[0298] It is favorable if the surface of the optical element 620 facing the applicator head 220 is anti-reflection coated, so that the high intensity of the incident radiation short pulse laser radiation is not reflected back into the device optical system of the system for short pulse laser eye surgery 100.

[0299] A patient interface 600, which additionally contains an applicator head protector 650, which preferably has a recess in the center, is particularly advantageous for the sterility. This applicator head protector 650 can be placed and fixed over the side of the applicator head 220 facing the eye 900, as shown in FIG. 18. This applicator head protector prevents that the applicator head 220 is contaminated by e.g. fluids during surgery. The recess allows to fasten the patient interface 600 with the contact element 610 directly to the applicator head 220, so that the applicator head protector 650 does not present an obstacle in the beam path of the short pulse laser radiation between the system for short pulse laser eye surgery 100 and the optical element 620 of the contact element 610.

[0300] If the recess is thereby realized centrally in the applicator head protector 650, a spatially uniform protection of the applicator head 220 is achieved.

[0301] Preferably, the contact element 610 and the applicator head protector 650 of the patient interface 600 two separate or separable parts. An applicator head protector 650 separated from the contact element 610 has the advantage that different demands on the contact element 610, such as a high precision or geometrical and optical properties from those of the environment protection, such as a simple and cost-effective embodiment as possible can be realized separately, and thus be realized better.

[0302] Advantageously, the applicator head protector 650 is connected to the applicator head 220 by a mechanically releasable coupling element 651.

[0303] Preferably, the upper casing diameter of the contact element 610 is larger than the recess in the applicator head protector 650. Thereby, a complete protection for the applicator head surface is ensured.

[0304] In order to support the docking and in particular the lateral alignment of the application head 220, a particularly suitable illumination system for short pulse laser eye surgery is disclosed in FIG. 18: A light-guiding structure 635 is admitted into the casing 611 of the contact element 610. In the applicator head 220 of a system for short pulse laser eye surgery 100, in turn, is integrated a light source 630-1, which emits visible light and/or a light source 630-2, which emits infrared light. In particular, during the surgical procedure using a short pulse laser radiation in the eye 900 in which the short pulse laser radiation is directed into the eye 900 via optical elements of the applicator head 220 and thereby the optical path in a microscope head 320 above is blocked 320 or affected, the eye 900 can for example be illuminated with the infrared light 630-2, and the infrared light reflected from the eye 900 can be guided via beam splitter prism 350, which selectively reflects infrared light, into a camera 360, with which infrared light can be detected. However, the prism 350 does not reflect the visible light or the wavelengths which are used by the short pulse laser source 210 or by the OCT light source 405. Light of these wavelengths not reflected by the prism 350 proceed without interference through the prism 350.

[0305] This construction has the advantage that, compared to the alternative solution, the illumination by an illumination present in the surgical microscope 300, no reflexes are added by the additional optical elements of the applicator head 220 situated in the illumination beam path and affect the image.

[0306] Furthermore, it is advantageous if a force sensor 655 is integrated in the applicator head 220, which is in contact with the contact element 610 during a docking of the patient interface 600. The force sensor 655 and the visible light-emitting light source 630-1 and the infrared light-emitting light source 630-2 are advantageously connected to a control device 500, which also controls the system for short pulse laser eye surgery 100, or with an additional control unit 500′, which is in contact with the control device of the system for short pulse laser eye surgery 100 via communication paths.

[0307] The above arrangement then permits the following method of automatically switching of the illumination when docking the applicator head 220 to the eye 900: [0308] (1) Switching the light source of the visible light 630-1 on [0309] (2) Measuring the pressure and guiding the pressure signal through the force sensor 655 to the control unit 500 [0310] (3) Switching off the light source of the visible light 630-1 and switching on the light source of the infrared light 630-2 by the control device 500 as soon as the pressure signal of the force sensor 655 exceeds a predetermined value.

[0311] By this automated switching, it is prevented that the patient's eye 900 is illuminated permanently with visible light 630-1 possibly damaging the patient after the docking to the applicator head 900 by means of the patient interface 600 to the eye 900. An illumination of the patient's eye 900 then takes place with the less harmful infrared light 630-2.

Referencing and Registration

[0312] In order to be able to align transfer of preoperatively measured data e.g. the axial position of the preoperatively measured astigmatism of the eye 900 or the cornea 910 or the target position of access incisions or relaxation incisions compared to preoperatively measured astigmatism axes of the eye 90) or the cornea 910 correctly also during surgery on the eye, the preoperative data or desired target positions are fixed or referenced relative to preoperatively acquired reference marks or referenced in the state of the art. Thereby, artificially introduced markings such as dye-points or cornea incisions, but also naturally existing markings such as vascular structures in the sclera or iris structures or simply an overall image of the eye 900 with its existing structures are used as reference markings.

[0313] If a contact element 610 is used as in the laser cataract surgery, the problem results that these markings are often covered or influenced by the contact element 610, in particular by the suction ring structures 612 of the contact element 610.

[0314] To be able to also use the reference markings 640 or the referencing of the preoperative data or target positions connected with the markings with the use of a contact element 610, the following solutions are disclosed.

[0315] FIG. 19a discloses a first structure for referencing laser incisions with a patient interface 600 at a short pulse laser system 200. This structure contains a microscope head with an applicator head 320/220 or an applicator head 220, a camera 361 and a patient interface 600 with a contact element 610. The imaging beam path of the camera 361 is designed so that the field of observation detects the central part of the contact element 610, wherein the detected, free diameter d1 of the contact element 610 not covered by edges of the contact element 610 etc. is at least 14 mm.

[0316] By means of this large free diameter it is ensured that the undisturbed observation field is so great that sufficient pronounced and clearly visible markings or structures of the eye 900 are visible with the camera 361, and the referencing of the preoperative data or target positions can take place with sufficient certainty. However, for smaller eyes 900, such a contact element 610 can already too large for reliable practical application.

[0317] FIG. 19b thus offers a second structure for referencing laser incisions with a patient interface 600 on a short pulse laser system 200 in the undocked state. This structure contains a microscope head with an applicator head 320/220 or an applicator head 220, a camera 361 and a patient interface 600 with a contact element 610, which has at least one marking 640. The imaging beam path of the camera 361 is designed so that the observation field detects the central part of the contact element 610 and the marking 640, wherein the free visible diameter of the contact element d1 is at least 10 mm, preferably at least 11 mm, and the depth h in the image is at least at least 5 mm with a suitable magnification.

[0318] By means of the free diameter of the contact element 610 in conjunction with the depth of the image it is ensured that even in the undocked state of the patient interface 600 containing a contact element 610, the sharp field of view with a diameter d2 on the eye 900 is large enough in order to detect the preoperatively measured reference markings of the eye 900 in the field of view of the camera 361 in a sharp manner, and that the marking 640 of the contact element 610 is also visible in a sharp manner in the field of view.

[0319] With this or a similar construction, the method of the referencing for relaxation or access incisions in the cornea disclosed in the following is enabled, also see FIG. 20: [0320] (1) Recording a first image of the eye 900 under illumination in the undocked state of the patient interface 600, with a contact element 610 at the patient's eye 900, [0321] (2) Registering the position of the marking 640 of the contact element 610 relative to the reference markings of the eye 900 in the first image, [0322] (3) Recording a second image of the eye 900 in the docked state of the patient interface 600 with the contact element 610, [0323] (4) Aligning the short pulse laser incisions, preferably by a femtosecond laser radiation, by means of the discernible position of the marking 640 of the contact element 610 in the second image and the registration obtained in step (2).

[0324] If the desired incisions relative to the reference markings can be fixed or referenced in the eye 900 by means of a preoperative diagnostics, the assignment of the incisions to the reference markings can take place with the aid of the above steps, even if they are no longer visible, but are covered by the contact element 610.

[0325] In one variant of the structure, the free diameter of the contact element 610 is larger than 13 mm, and even in the docked state of the contact element 610 to the eye 900, parts of the referencing markings necessary for the referencing in the eye 900 are still visible.

[0326] If this is the case, then the above method can be further improved by supplementing steps 1-3 of the above method by the following steps: [0327] (4) Registration of the position of the marking 640 of the contact element 610 with respect to the visible reference structures of the eye 900 in the second image. [0328] (5) Aligning the short pulse laser incisions, preferably by a femtosecond laser radiation, by means of the position of the marking 640 of the contact element 610 or the visible reference markings in the second image present in the second image, provided that the registration of the position of the marking 640 compared to the visible reference markings of the eye 900 in the second image does not deviate from a predetermined amount of the registration of the position of the marking 640 with respect to the reference markings of the eye 900 in the first image.

[0329] A disadvantage of the above structure is that the optical system has to be designed elaborately on a large depth range.

[0330] FIG. 21a thus discloses a third structure for referencing laser incisions with a patient interface 600 at a short pulse laser system 200 in the undocked state. This structure contains a microscope head with an applicator head 320/220 or an applicator head 220, two cameras 361-1, 361-2 and a patient interface 600 with a contact element 610, which has at least one marking 640. The imaging beam path of the first camera 361-1 is designed so that it detects the mark 640 of the contact element 610 in a sharp manner, and the imaging beam path of the second camera 361-2 is designed so that it detects reference structures of the eye 900 in the undocked state in a sharp manner. In addition, the free visible diameter d1 of the contact element 610 is at least 10 mm, preferably at least 11 mm.

[0331] By means of the free diameter of the contact element 610 in connection with the difference in the focal position in the image, it is ensured that, even in the undocked state, the sharp image field of the second camera 361-2 with a diameter d2 on the eye 900 is large enough to recognize the preoperatively measured reference markings of the eye 900.

[0332] The following method of referencing for relaxation or access incisions is revealed with this or a similar structure:

(1) Recording a first image of the contact element 610 with its marking 640 by the first camera 361-1 and virtually simultaneous or simultaneous recording of a second image of the eye 900 with reference markings of the eye 900 by the second camera 361-2 in the undocked state of the patient interface 600, which contains the contact element 610 with its marking 640, to the patient's eye 900.
(2) Registering the position of the marking 640 of the contact element 610 in the first image relative to the reference markings of the eye 900 in the second image with a known allocation of the alignment and magnification of the image fields of camera 361-1 and 361-2, predetermined by the structure.
(3) Recording a third image of the eye 900 in the docked state of the patient interface 600 with the contact element 610 containing a marking 640 by the first camera 361-1.
(4) Aligning the short pulse laser incisions, usually the femtosecond laser incision, by means of the recognizable position of the marking 640 of the contact element 610 in the third image and the registration obtained in step (2).

[0333] In a variant of this above structure and method, the first camera 361-1 is replaced by an imaging OCT system.

[0334] Alternatively, instead of using two cameras 361-1, 361-2 in parallel, only one camera 361 with sequential focus adjustment can be used.

[0335] FIG. 21b discloses such a fourth structure for referencing laser incisions with a patient interface 600 at a short pulse laser system 200 in the undocked state. This structure contains a microscope head with an applicator head 320/220 or an applicator head 220, a camera 361, a focusing lens 362 and a patient interface 600 with a contact element 610, which has at least one marking 640. The imaging beam path of the camera 361 is designed in such a manner that, at a first position of the focusing lens 362, the marking 640 of the contact element 610 is detected in a sharp manner by the camera, and at a second position of the focusing lens 362, the reference markings of the eye 900 are detected in a sharp manner in the undocked state. The free visible diameter d1 of the contact element 610 is thereby at least 10 mm, preferably at least 11 mm.

[0336] Due to the free diameter of the contact element 610 in connection with the difference in the focal position of the image, it is ensured that even in undocked state the sharp field of view with the diameter d2 is large enough at the second position of the focusing lens 362 on the eye 900, in order to detect the reference markings of the eye 900.

[0337] The following method of referencing for relaxation or access incisions is disclosed with this or a similar structure:

(1) Recording a first image of the contact element 610 with its marking 640 with the camera 361 in a first position of the focusing lens and time-delayed, particularly preferred within seconds of recording the first image, recording a second image of the eye 900 with its reference marks by the camera 361 in a second position of the focusing lens, both in the undocked state of the contact element 610 containing the patient interface 600 to the patient's eye 900;
(2) Registering the position of the marking 640 of the contact element 610 in the first image relative to the reference markings of the eye 900 in the second image with a known allocation of the image fields of the camera 361 in the first and in the second position of the focusing lens 362 predetermined by the structure;
(3) Recording an image 3 of the eye in the docked state of the contact element 610 by the camera in or near the focal position 1;
(4) Aligning the fs incisions on the basis of the recognizable marking position of the contact element 610 in image 3 and the registering obtained in step (2).

[0338] Overall, all of the above structures and methods for referencing and registering are elaborate with regards to technical devices.

[0339] FIG. 21c thus discloses a fifth structure for referencing laser incisions with a patient interface 600 at a short pulse laser system 200 in the undocked state. This structure contains a microscope head with an applicator head 320/220 or an applicator head 220, a camera 361, a focusing lens 362 and a patient interface 600 with a contact element 610 that contains at least one marking 640. The imaging beam path of the camera 361 is designed so that the reference structures of the eye 900 are detected in a sharp manner in the undocked state, and that the free visible diameter d1 of the contact element 610 is at least 11 mm.

[0340] By means of the free diameter of the contact element 610 in connection with the focal position of the image it is ensured that, even in the undocked state with a distance h of the contact element 610 from the eye 900, the sharp field of view with a diameter d2 on the eye 900 is large enough to capture the reference markings of the eye 900.

[0341] With this or a similar structure, the following method of referencing for relaxation or access incisions is disclosed:

(1) Recording a first image of the eye 900 with reference markings by the camera 361 in the undocked state of the patient interface 600 with the contact element 610 at the patient eye 900;
(2) Docking and fixing a patient interface 600 with a contact element 610 to the eye 900 within a few seconds;
(3) Aligning the short pulse laser incisions on the basis of recognizable reference structures in the first image.

[0342] The above structures for referencing and registering also allow the orientation of intraocular lenses (IOL), after they have been inserted into the capsular bag 910-2, by means of reference markings, which are determined in a preoperative manner. Typically, this referencing of the orientation takes place at reference markings, which are recognized in preoperatively obtained images of the eye 900 or at the preoperative images themselves. If these preoperative images of the eye 900 or their reference markers are registered with images or reference markings obtained in an intraoperative manner, thus the structures respectively contained therein are associated with each other and deviations are determined, the referencing of the orientation at the preoperative images and reference markings can be transferred by means of the registration on the image obtained in an inoperative manner or its reference markings.

[0343] When docking the patient interface 600 with the contact element 610, however, the appearance of the preoperative reference markings of the eye 900 or of the eye 900) itself are often changed. Thus, e.g. deformations and bleeding occur. Therefore, the registration of images of the eye 900 obtained preoperatively is susceptible to errors regarding the images of the eye 900 obtained in an intraoperative manner during the orientation of the intraocular lens (IOL).

[0344] This error susceptibility can be avoided as described below:

[0345] By means of the previous structures and methods for referencing and registration, the preoperative image is registered to an image of the eye 900, which is used for setting the short pulse laser incisions with a docked patient interface 600 containing the contact element 610. This image of the eye 900, which is used for setting the short pulse laser incisions with a docked patient interface 600 with the contact element 610, can then be viewed as a new reference image.

[0346] Now, after the short pulse laser surgery, that is after the patient interface 600 with the contact element 610 was docked to the eye 900, an image of the eye 900 is again recorded in the undocked state of the contact element 610. This image shows all the changed structures in the eye 900. The image can be registered with the same structures to the new reference image. It is registered in the further course of the surgery, namely when inserting the intraocular lens (IOL) and its orientation in the capsular bag 910-2 with an image of the eye 900, which was recorded during the orientation of the intraocular lens (IOL). Thereby, the referencing of the desired orientation of the intraocular lens (IOL) can be transferred to the preoperative images of the eye 900 through the chain of registrations of various images in a referencing of the desired orientation of the intraocular lens (IOL) to images of the eye 900 acquired intraoperatively during the insertion of the intraocular lens (IOL).

[0347] For referencing the orientation of an intraocular lens (IOL) for a preceding short pulse laser cataract surgery, particularly femtosecond laser cataract surgery of the lens, the following method is disclosed; see FIG. 22:

(0) Generating a first image of an astigmatic eye 900 with a (usually external) diagnostics system for detecting the steep and/or flat axis and storing of the first image and axes.
(1) Generating a second image, as reference image or an image with reference markings of the eye 900, for the orientation of a treatment at a patient interface 600 with a contact element 610 docked to the eye 900, e.g. according to the method described above;
(2) Recording a third image of the eye 900 in the undocked state of the contact element 610 to the eye 900, when the patient interface 600 with the contact element 610 was undocked from the eye 900;
(3) Registering the third image with respect to the second image;
(4) Recording a fourth image of the eye 900 during the alignment of the intraocular lens (IOL) inserted into the eye 900;
(5) Registering the fourth image with respect to the third image;
(6) Aligning an orientation aid for the physician in the surgical microscope 300 for the orientation of an intraocular lens (IOL) with the aid of registering in step (3) and (5).

[0348] The characteristics mentioned above and the characteristics explained in various exemplary embodiments of the invention can thereby not only be in the exemplified combinations, but also in other combinations or alone, without leaving the scope of the present invention.

[0349] A description based on device characteristics applies with respect to these features analogously to the corresponding method, while method characteristics represent corresponding functional characteristics of the described device.