LASER ABLATING DEVICE AND METHODS FOR OPERATING AND MANUFACTURING SUCH A DEVICE

Abstract

A laser ablating device for cutting human or animal natural or artificial hard tissue includes: a cutting laser source adapted to provide a pulsed cutting laser beam lasing at a wavelength suitable for ablating the hard tissue; an imaging laser source adapted to provide an imaging laser beam covering a broadband spectral region; and a beam mixing structure and a movable scanner mirror positioned after the beam mixing structure. The beam mixing structure is adapted to redirect the cutting laser beam of the cutting laser source and/or the imaging laser beam of the imaging laser source such that an optical axis of the cutting laser beam is parallel to an optical axis of the imaging laser beam. The scanner mirror is arranged to direct the imaging laser beam and the cutting laser beam when having parallel optical axes.

Claims

58. A laser ablating device for cutting human or animal natural or artificial hard tissue, comprising: a cutting laser source adapted to provide a pulsed cutting laser beam lasing at a wavelength suitable for ablating the hard tissue; an imaging laser source adapted to provide an imaging laser beam covering a broadband spectral region; a beam mixing structure; and a movable scanner mirror positioned after the beam mixing structure, wherein the beam mixing structure is adapted to redirect the cutting laser beam of the cutting laser source and/or the imaging laser beam of the imaging laser source such that an optical axis of the cutting laser beam is parallel to an optical axis of the imaging laser beam, and the scanner mirror is arranged to direct the imaging laser beam and the cutting laser beam when having parallel optical axes.

59. The laser ablating device of claim 58, further comprising a controlling unit being arranged and configured to evaluate a reflection of the imaging laser beam between two subsequent cutting laser pulses of the cutting laser beam, wherein the controlling unit preferably is arranged and configured to evaluate the reflection of the imaging laser beam immediately before and immediately after each cutting laser pulse of the cutting laser beam.

60. The laser ablating device of claim 59, wherein the controlling unit is arranged and configured to control the cutting laser beam according to information derived from the evaluated reflection of the imaging laser beam.

61. The laser ablating device of claim 60, wherein controlling the cutting laser beam comprises changing the power of a next cutting laser beam pulse, the repetition rate of the cutting laser beam pulses of the cutting laser beam, and/or a shape of a next cutting laser beam pulse.

62. The laser ablating device of claim 60, wherein the information derived from the evaluated reflection of the imaging laser beam comprises a transversal cross section of a cut in the hard tissue and/or an indication of a distance to tissue neighboring the hard tissue.

63. The laser ablating device of claim 59, wherein the controlling unit is arranged and configured to evaluate a reflection of the imaging laser beam in real-time.

64. The laser ablating device of claim 58, wherein the imaging laser source is comprised by an OCT system.

65. The laser ablating device of claim 58, wherein a temporal pulse width of the cutting laser beam is in a range of about 1 nanosecond to about 1 millisecond or in a range of about 1 microsecond to about 900 microseconds or in a range of about 200 microseconds to about 500 microseconds, and/or a pause between two subsequent cutting laser beam pulses is in a range of about 1 millisecond to about 200 millisecond or in a range of about 10 milliseconds to about 100 milliseconds.

66. The laser ablating device of claim 58, comprising a temperature sensor arranged to sense a temperature of a surface of the hard tissue after being hit by a cutting beam laser pulse generated by the cutting laser source, wherein the temperature sensor preferably comprises a remote infrared sensor.

67. The laser ablating device of claim 58, further comprising an aiming laser source adapted to provide a visible aiming laser beam for indicating a target location where the cutting laser beam is intended to impact the hard tissue, wherein the beam mixing structure is adapted to redirect the aiming laser beam of the aiming laser source such that an optical axis of the aiming laser beam is parallel to the optical axis of the imaging laser beam and to the optical axis of the cutting laser beam, and the scanner mirror is arranged to direct the aiming laser beam, the imaging laser beam and the cutting laser beam when having parallel optical axes.

68. The laser ablating device of claim 58, wherein the beam mixing structure comprises an optomechanical structure, and/or the scanner mirror is adapted to focus the cutting laser beam and the imaging laser beam.

69. The laser ablating device of claim 58, wherein the imaging laser beam is wavelength scanable and/or a fixed broadband wavelength emission.

70. A method of operating a laser ablating device, comprising: a cutting laser source of the laser ablating device providing a pulsed cutting laser beam preferably lasing at a wavelength suitable for ablating a human or animal natural or artificial hard tissue; an imaging laser source of the laser ablating device providing an imaging laser beam covering a broadband spectral region; a beam mixing structure of the laser ablating device redirecting the cutting laser beam of the cutting laser source and/or the imaging laser beam of the imaging laser source such that an optical axis of the cutting laser beam is parallel to an optical axis of the imaging laser beam; and a movable scanner mirror of the laser ablating device positioned after the beam mixing structure of the laser ablating device directing the imaging laser beam and the cutting laser beam having parallel optical axes.

71. The method of claim 70, comprising the scanner mirror of the laser ablating device focusing the cutting laser beam and the imaging laser beam, and/or a controlling unit of the laser ablating device evaluating a reflection of the imaging laser beam between two subsequent cutting laser pulses of the cutting laser beam.

72. The method of claim 71, wherein the controlling unit of the laser ablating device evaluates the reflection of the imaging laser beam between two subsequent cutting laser pulses of the cutting laser beam in real-time.

73. The method of claim 71, comprising the controlling unit evaluating the reflection of the imaging laser beam immediately before and immediately after each cutting laser pulse of the cutting laser beam.

74. The method of claim 71, comprising the controlling unit of the laser ablating device controlling the cutting laser beam according to information derived from the evaluated reflection of the imaging laser beam, wherein the controlling unit of the laser ablating device controlling the cutting laser beam preferably comprises changing the power of a next cutting laser beam pulse, and/or the information derived from the evaluated reflection of the imaging laser beam preferably comprises an indication of a distance to tissue neighboring the hard tissue, the cutting laser beam comprises changing the repetition rate of the cutting laser beam pulses of the cutting laser beam, and/or the cutting laser beam comprises changing a shape of a next cutting laser beam pulse.

75. The method of claim 74, wherein the information derived from the evaluated reflection of the imaging laser beam comprises a transversal cross section of a cut in the hard tissue.

76. The method of claim 70, wherein the cutting laser source of the laser ablating device provides the cutting laser beam with a temporal pulse width in range of about 1 nanosecond to about 1 millisecond or in arrange of about 1 microsecond to about 900 microseconds or in range of about 100 microseconds to about 700 microseconds, and/or a pause between two subsequent cutting laser beam pulses being a range of about 1 millisecond to about 200 millisecond or in a range of about 10 milliseconds to about 100 milliseconds.

77. The method of claim 70, further comprising a temperature sensor of the laser ablating device sensing a temperature of a surface of the hard tissue after being hit by a cutting laser beam pulse generated by the cutting laser source of the laser ablating device, and/or an aiming laser source of the laser ablating device providing a visible aiming laser beam for indicating a target location where the cutting laser beam is intended to impact the hard tissue, wherein the beam mixing structure of the laser ablating device redirects the aiming laser beam of the aiming laser source of the laser ablating device such that an optical axis of the aiming laser beam is parallel to the optical axis of the imaging laser beam and to the optical axis of the cutting laser beam, and the scanner mirror of the laser ablating device directs the aiming laser beam, the imaging laser beam and the cutting laser beam when having parallel optical axes.

78. A method of operating a laser ablating device, comprising: a cutting laser source of the laser ablating device providing a pulsed cutting laser beam preferably lasing at a wavelength suitable for ablating a human or animal natural or artificial hard tissue; an imaging laser source of the laser ablating device providing an imaging laser beam covering a broadband spectral region; a beam mixing structure of the laser ablating device redirecting the cutting laser beam of the cutting laser source and/or the imaging laser beam of the imaging laser source such that an optical axis of the cutting laser beam is parallel to an optical axis of the imaging laser beam; and a movable scanner mirror of the laser ablating device positioned after the beam mixing structure of the laser ablating device directing the imaging laser beam and the cutting laser beam having parallel optical axes.

79. The method of claim 78, further comprising a controlling unit evaluating a reflection of the imaging laser beam between two subsequent cutting laser pulses of the cutting laser beam, wherein the controlling unit preferably evaluates the reflection of the imaging laser beam between two subsequent cutting laser pulses of the cutting laser beam in real-time.

80. The method of claim 78, comprising the controlling unit evaluating the reflection of the imaging laser beam immediately before and immediately after each cutting laser pulse of the cutting laser beam, and/or controlling the cutting laser beam according to information derived from the evaluated reflection of the imaging laser beam.

81. The method of claim 80, wherein controlling the cutting laser beam comprises changing the power of a next cutting laser beam pulse, changing the repetition rate of the cutting laser beam pulses of the cutting laser beam, and/or changing a shape of a next cutting laser beam pulse.

82. The method of claim 80, wherein the information derived from the evaluated reflection of the imaging laser beam comprises a transversal cross section of a cut in the hard tissue, and/or an indication of a distance to tissue neighboring the hard tissue.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0077] The laser ablating device and methods according to the invention are described in more detail herein below by way of an exemplary embodiment and with reference to the attached drawings, in which:

[0078] FIG. 1 shows a setup of an embodiment of a laser ablating device according to the invention;

[0079] FIG. 2 shows details of a beam configurator of the laser ablating device of FIG. 1;

[0080] FIG. 3 shows a course of an embodiment of operating and cutting methods according to the invention; and

[0081] FIG. 4 shows operation of the laser ablating device of FIG. 1 in the method of FIG. 3.

DESCRIPTION OF EMBODIMENTS

[0082] In the following description certain terms are used for reasons of convenience and are not intended to limit the invention. The terms right, left, up, down, under and above refer to directions in the figures. The terminology comprises the explicitly mentioned terms as well as their derivations and terms with a similar meaning. Also, spatially relative terms, such as beneath, below, lower, above, upper, proximal, distal, and the like, may be used to describe one element's or feature's relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions and orientations of the nozzle device in use or operation in addition to the position and orientation shown in the figures. For example, if the device or a specific part thereof in the figures is turned over, elements described as below or beneath other elements or features would then be above or over the other elements or features. Thus, the exemplary term below can encompass both positions and orientations of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along and around various axes include various special device positions and orientations.

[0083] To avoid repetition in the figures and the descriptions of the various aspects and illustrative embodiments, it should be understood that many features are common to many aspects and embodiments. Omission of an aspect from a description or figure does not imply that the aspect is missing from embodiments that incorporate that aspect. Instead, the aspect may have been omitted for clarity and to avoid prolix description.

[0084] In this context, the following applies to the rest of this description: If, in order to clarify the drawings, a figure contains reference signs which are not explained in the directly associated part of the description, then it is referred to previous or following description sections. Further, for reason of lucidity, if in a drawing not all features of a part are provided with reference signs it is referred to other drawings showing the same part. Like numbers in two or more figures represent the same or similar elements.

[0085] FIG. 1 shows a schematic illustration of an embodiment of a laser ablating device 1 according to the invention. The laser ablating device 1 comprises an OCT laser source 11 as imaging laser source, a cutting laser source 12, an aiming laser source 15 and a controlling unit 14. The OCT laser source 11 is arranged to provide an imaging laser beam 111 covering a broadband spectral region of 50 nm. The cutting laser source 12 is arranged to provide a pulsed cutting laser beam 121 which is capable of ablating tissue of a bone 2. The aiming laser source 15 is arranged to provide an aiming laser beam 151 of visible light.

[0086] The laser ablating device 1 further comprises a beam configurator 13 which is arranged to collect the imaging laser beam 111, the cutting laser beam 121 and the aiming laser beam 151 and to combine them to a composite laser beam 131. The composite laser beam 131 is provided to the bone 2. In particular, it is driven along an osteotomic line 21 preoperatively defined on the bone 2 or on an image thereof. For driving the composite laser beam 131 along the osteotomic line 21, on one hand the beam configurator 13 has respective guiding means as explained in more detail below in connection with FIG. 2. On the other hand the laser ablating device 1 is mounted to a robotic arm 31 of an actuating support system 3 which allows for precisely moving the laser ablating device 1 to a greater extent than possible by the guiding means of the beam configurator 13.

[0087] The actuating support system 3 further comprises a navigator 32 and a user interface 33. The user interface 33 is arranged to allow a user or operator to interact with the controlling unit 14 of the laser ablating device 1.

[0088] The controlling unit 14 comprises a number of interfaces for communicating with other components within or outside the laser ablation device 1. In particular, via these interfaces it is connected to the robotic arm 31, the navigator 32, the user interface 33, the cutting laser source 12, the OCT laser source 11, the aiming laser source 15, the beam configurator 13, a cooling nozzle 16 and an infrared (IR) camera 17 as temperature sensor.

[0089] The controlling unit 14 is adapted or arranged and configured to perform a plurality of tasks when operating the laser ablating device 1. It evaluates the reflection of the imaging laser beam 111 between two subsequent pulses of the cutting laser beam 121 and as can be seen in more detail in in FIG. 4 below immediately after each pulse of the cutting laser beam 121. By evaluating this reflection the controlling unit 14 derives information about the effect of the pulse of the cutting laser beam 121 such as a transversal cross section of the ablated tissue. Depending on this information the controlling unit adjusts cutting laser source 12 such that the next pulse of cutting laser bream 121 fits to the actual situation at the tissue. Such adjustment may comprise changing the power of the cutting laser beam 121, changing its repetition rate, changing its beam shape and the like.

[0090] The cooling nozzle 16 is adapted to spray a cooling medium towards the bone 2 at a spot where the composite laser beam 131 hits the tissue of the bone 2, i.e. at the osteotomic line 21. The cooling medium can particularly be a preferably sterile liquid such as water combined with a gas such as air. Thereby, cooling can be adjusted by the controlling unit 14 by adjusting the composition, the conditions and the direction of the spray generated by the nozzle 16.

[0091] The IR camera 17 is also directed towards the bone 2 at a spot where the composite laser beam 131 hits the tissue of the bone 2, i.e. at the osteotomic line 21. Thereby, it constantly measures the temperature of the tissue while being ablated. In case the temperature exceeds a specific threshold such as, e.g., 45 C. the controlling unit 14 interrupts the provision of the cutting laser beam 121 until the tissue is sufficiently cooled again.

[0092] In FIG. 2 the beam configurator 13 of the laser ablating device 1 is shown in more detail. It is equipped with a parabolic mirror 133 as scanner mirror and an optomechanical system 132 as beam mixing structure comprising a mirror 1321, a first dichroic mirror 1322 and a second dichroic mirror 1323. The mirror 1321 is arranged to redirect the aiming laser beam 151 to the back side of the first dichroic mirror 1322. The first dichroic mirror 1322 is transparent for the aiming laser beam 151 and redirects the imaging laser beam 111 into the same direction as the aiming laser beam 151 towards the back side of the second dichroic mirror 1323. The second dichroic mirror 1323 is transparent for the aiming laser beam 151 and the imaging laser beam 111. It redirects the cutting laser beam 121 into the same direction as the aiming laser beam 151 and the imaging laser beam 111 towards the parabolic mirror 133.

[0093] At this stage the optical axes of the aiming laser beam 151, the imaging laser beam 111 and the cutting laser beam 121 are parallel or coaxial such that together they form the composite laser beam 131. The parabolic mirror 133 is movable and adjustable by the controlling unit 14. Like this, it focusses and directs the composite laser beam 131 via an out-coupling window 134 precisely along the osteotomic line 21 to the bone 2. Thus, it establishes the guiding means of the beam configurator 13.

[0094] FIG. 3 shows a workflow of operation of the laser ablating device 1. Start is the setup of the cutting execution and their parameters which requires a user input from the external higher level system 3A such as via the user interface 33. In a second step the cutting design is loaded to the controlling unit 14 from external 1A and the controlling unit 14 plans the first cutting laser pulse 1 B which is followed by defining the cutting parameters 1C. Prior the first cutting laser beam pulse the controlling unit 14 sets the beam configurator 13 according the planned position 1D. Then the laser ablation is executed by providing a pulse of the cutting laser beam 121 pulse 1E. Depending on configuration the imaging laser beam 111 measurement is acquired 1F before and/or after the cutting laser beam pulse 1E. Directly after the acquisition this reflection is evaluated by the controlling unit 14 1G and the cutting execution is updated by planning the next cutting laser beam pulse 11B. Depending on the use of external actuators and/or tracking systems this step requires interaction with external components 3B or not.

[0095] In FIG. 4 graphs of indexes I.sub.121, I.sub.133, I.sub.111 representing actions of the cutting laser source 12, the parabolic mirror 133 and the OCT laser source 111 are shown. Thereby, it can be seen that immediately after a cutting laser beam 121 pulse is provided (represented by index I.sub.121) the parabolic mirror 133 is moved (represented by index I.sub.133) such that the location of the bone 2 where tissue is ablated is scanned. Thereby, the OCT laser beam 111 which is constantly provided allows for generating a cross sectional image of the cut of the bone 2 (represented by index I.sub.111). From this image at least the depth is derived by the controlling unit 14 and conclusions are drawn for adapting the next cutting laser beam 121 pulse if appropriate.

[0096] This description and the accompanying drawings that illustrate aspects and embodiments of the present invention should not be taken as limiting-the claims defining the protected invention. In other words, while the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the spirit and scope of this description and the claims. In some instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the invention. Thus, it will be understood that changes and modifications may be made by those of ordinary skill within the scope and spirit of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below.

[0097] The disclosure also covers all further features shown in the Figs. individually although they may not have been described in the afore or following description. Also, single alternatives of the embodiments described in the figures and the description and single alternatives of features thereof can be disclaimed from the subject matter of the invention or from disclosed subject matter. The disclosure comprises subject matter consisting of the features defined in the claims or the exemplary embodiments as well as subject matter comprising said features.

[0098] Furthermore, in the claims the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. A single unit or step may fulfil the functions of several features recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. The terms essentially, about, approximately and the like in connection with an attribute or a value particularly also define exactly the attribute or exactly the value, respectively. The term about in the context of a given numerate value or range refers to a value or range that is, e.g., within 20%, within 10%, within 5%, or within 2% of the given value or range. Components described as coupled or connected may be electrically or mechanically directly coupled, or they may be indirectly coupled via one or more intermediate components. Any reference signs in the claims should not be construed as limiting the scope. [0099] 1-57. (canceled)