LASER DEVICE AND TISSUE CHARACTERIZING METHOD

Abstract

A laser device (100) has an ablation laser source (401) adapted to provide an ablating laser beam (402; 402i) for ablating a target tissue (120). It further comprises a plume analyzing arrangement (250) adapted to identify and/or quantify substances in the debris of the plume (110) generated by the ablating laser beam (402) ablating the target tissue (120) particularly substances being biomarkers of the ablated target tissue (120).

Claims

1. A laser device with an ablation laser source adapted to provide an ablating laser beam for ablating a target tissue the laser device comprising: a plume analyzing arrangement adapted to identify and/or quantify at least one substance in debris of a plume generated by the ablating laser beam ablating the target tissue particularly a substance being a biomarker of the ablated target tissue.

2. The laser device of claim 1, wherein the plume analyzing arrangement comprises a laser spectroscope.

3. The laser device of claim 2, comprising a beam mixing structure, wherein the plume analyzing arrangement has an analysis laser source adapted to provide an analyzing laser beam, and the beam mixing structure is adapted to redirect the ablating laser beam of the ablation laser source and/or the analyzing laser beam of the analysis laser source such that an optical axis of the ablating laser beam is parallel to an optical axis of the analyzing laser beam.

4. The laser device of claim 3, comprising a movable scanner mirror positioned after the beam mixing structure, wherein the scanner mirror is arranged to direct the analyzing laser beam and the ablating laser beam when having parallel optical axes.

5. The laser device of claim 2, wherein the laser spectroscope comprises a laser induced fluorescence spectroscope, a coherent anti Stokes Raman scattering spectroscope, a laser photo-acoustic spectroscope, a laser induced breakdown spectroscope, a resonance-enhanced multi-photon ionization spectroscope or an elastic scattering spectroscope.

6. The laser device of claim 1, wherein the plume analyzing arrangement comprises a mass spectrometer.

7. The laser device of claim 6, wherein the plume analyzing arrangement comprises a debris gathering unit arranged to collect debris of the plume generated by the ablating laser beam when ablating the target tissue wherein the debris gathering unit is connected to the mass spectrometer.

8. The laser device of claim 7, wherein the debris gathering unit of the plume analyzing arrangement comprises an aspirating mouthpiece.

9. The laser device of claim 7, wherein the debris gathering unit of the plume analyzing arrangement comprises a pump unit adapted to forward the debris to the mass spectrometer.

10. The laser device of claim 7, wherein the debris gathering unit of the plume analyzing arrangement comprises an electrical field generator to collect the debris of the plume.

11. The laser device of claim 1, wherein the plume analyzing arrangement comprises a processing unit adapted to evaluate measurement data of the at least one substance in the debris of the plume generated by the ablating laser beam ablating the target tissue.

12. The laser device of claim 1, comprising a camera adapted to capture an image of the target tissue.

13. The laser device of claim 1, wherein the plume analyzing arrangement is adapted to three-dimensionally localize the origin of the plume.

14. The laser device of claim 13, wherein the plume analyzing arrangement is adapted to augment the image captured by the camera with information derived from the substance in the debris of the plume.

15. The laser device of claim 12, comprising a processing unit adapted to identify a movement of the target tissue relative to the laser source on the captured image and to correct a position of the laser source in accordance with the identified movement of the target tissue.

16. The laser device of claim 1, wherein the ablation laser source is three-dimensionally movable, particularly, relative to the target tissue.

17. A tissue characterizing method comprising: providing an ablating laser beam to a target tissue wherein the ablating laser beam ablates the target tissue such that a plume comprising debris of the target tissue is generated; and identifying and/or quantifying at least one substance in the debris of the plume generated by the laser beam ablating the target tissue.

18. The tissue characterizing method of claim 17, wherein the at least one substance in the debris of the plume generated by the laser beam ablating the target tissue is identified or detected by a laser spectroscope.

19. The tissue characterizing method of claim 17, the at least one substance in the debris of the plume generated by the laser beam ablating the target tissue is identified by a structure comprising a mass spectrometer, an ion mobility device or an emission light spectrometer.

20. The tissue characterizing method of claim 17, comprising evaluating measurement data of the at least one substance in the debris of the plume generated by the laser beam ablating the target tissue.

21. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The laser device and tissue characterizing method according to the invention are described in more detail herein below by way of exemplary embodiments and with reference to the attached drawings, in which:

[0081] FIG. 1 shows a setup of a first embodiment of a laser device according to the invention suitable for performing an embodiment of a tissue characterizing method according to the invention;

[0082] FIG. 2 shows a laser spectroscope of the laser device of FIG. 1;

[0083] FIG. 3 shows a beam mixing structure of the laser device of FIG. 1;

[0084] FIG. 4 shows a robotic laser system comprising the laser device of FIG. 1 in operation where the robotic laser system can reach any position on a three dimensional surface of a patient within a correct angle (laser surface and distance); and

[0085] FIG. 5 shows a beam mixing structure of a second embodiment of a laser device according to the invention.

DESCRIPTION OF EMBODIMENTS

[0086] 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 devices in use or operation in addition to the position and orientation shown in the figures. For example, if a device 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 devices 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.

[0087] 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. 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.

[0088] FIG. 1 shows a first embodiment of a laser device 100 according to the invention, e.g. embedded into a cold ablation robotic laser osteotome (CARLO). The laser device 100 comprises an ablation laser source 401 adapted to provide an ablating laser beam 402 for ablating a bone 120 as target tissue. It is further equipped with a beam mixing structure 470 and an analysis laser source 403 arranged to provide an analyzing laser beam 404 at a more or less single wavelength to record the disperse spectra or at a wavelength tuned to record excitation spectra. The beam mixing structure 470 is embodied to mix the ablating laser beam 402 and the analyzing laser beam 404 to a composite laser beam 400 as described in more detail below in connection with FIG. 3.

[0089] The laser device 100 further comprises a plume analyzing arrangement 250 with a mass spectrometer 300, a debris gathering unit 350, a microphone 310 and a laser spectroscope 200. The plume analyzing arrangement 250 is embodied to identify and to quantify substances in the debris of a plume 110 generated by the composite laser beam 400 ablating the bone 120 along a predefined osteotomic line 130 after being focused by a beam focusing optics 420.

[0090] In use of the laser device 100, the ablating laser beam 402 mixed together with the analyzing laser beam 404 to the composite laser beam 400 passes a dichromatic mirror 410 of the plume analyzing arrangement 250 and is provided to the bone 120 via the beam focusing optics 420. Thereby, the plume 110 comprising debris of the ablated bone tissue is generated. A specific portion of the analyzing laser beam 404 contained in the composite laser beam 400 is reflected by the debris of the plume 110. This reflected light 450 travels more or less in an opposite direction than the composite laser beam 400 away from the bone 120. Thereby, it hits the dichromatic mirror 410 which redirects the reflected light 450 towards the laser spectroscope 200. There, substances of the debris of the plume 110 are identified and/or at least the spectra are recorded.

[0091] Simultaneously, the debris of the plume 110 generated by the composite laser beam 400 is collected or sucked by an aspirating mouthpiece 351 of the debris gathering unit 350 and forwarded to the mass spectrometer 300 by means of a pump. There, the debris is analyzed by using acoustic signals sensed by the microphone 310. Like this, substances of the debris are identified.

[0092] Further, a processing unit 500 equipped with suitable interfaces is connected to the various components of the laser device 100. The processing unit 500 adjusts the laser sources 401, 403 and evaluates the measurement results of the microphone 310, the mass spectrometer 300 and the laser spectroscope 200.

[0093] As shown in FIG. 2 laser spectroscope 200 comprises a light focusing optics 421 which focuses the reflected light 450 redirected by the dichromatic mirror 410. The focused reflected light is provided to a monochromator 210 which is associated to a light detector 230 which can be a photomultiplier, a photodiode, a charged-coupled device or a similar device.

[0094] The analyzing laser beam 404 is adapted to induce reflection or emission such as fluorescence or phosphorescence from the debris of the plume 110. Such emission or reflection advantageously propagates coaxially or parallel to composite laser bream 400. Thereby the reflected light 450 or excitation laser beam can be coming from a continuous wave (cw) or from a pulsed laser. If the excitation laser beam is from a cw laser beam the emission could be time-gated to select light right after the ablation laser pulse has reached the bone 120. If the excitation laser beam 450 is from a pulsed laser source it could be time synchronized in such a way that it arrives after a give short time interval to facilitate the discrimination of the emission in the laser spectrometer 200. When interested in the emission of the targeted surface of the osteotomic line 130 or surgical ablating trajectory the emission of the excitation laser beam 450 should be detected using time-gating methods just before the ablating laser reach the target when using a cw laser or, when using a pulsed laser source its pulse should arrive before the pulse of the ablating laser source 401.

[0095] FIG. 3 shows the beam mixing structure 470 of the laser device 100 in more detail. It is equipped with a further dichromatic mirror 415 which is transparent for the ablating laser beam 402 and reflective for the analysing laser beam 404. The further dichromatic mirror 415 redirects the analyzing laser beam 404 into the same direction as the ablating laser beam 402. The two laser beams 402, 404 now have parallel or coaxial optical axes and the composite laser beam 400 is generated.

[0096] In FIG. 4 the laser device 100 is shown implemented in a robotic laser system such as a CARLO. The laser device 100 and, particularly, its ablation laser source 401 and/or optical elements 410, 420 are mounted to a robotic structure such as a robotic arm. The robotic structure can provide movements in six degrees of freedom in a motion coordinate system 530. In particular, the robotic structure can allow for a movement along and about each of x-, y- and z-axes.

[0097] The laser device 100 comprises two cameras 540 adapted to capture an image of the target tissue 120 used for correct positioning and controlling of the position of the leaser beam during patient or target tissue 120 moving such as breathing. To be capable of recognizing smallest movements like breathing two cameras 540 are used. All recognized movements are corrected by a corresponding movement of the laser device 100. The target tissue 120 forms part of a patient 510 which is stationary positioned on a surgical bench 520. The processing unit 500 of the plume analyzing arrangement 250 is adapted to evaluate measurement data obtained of the debris of the plume 110 which is generated by the ablating laser beam 402 ablating the target tissue 120 of the patient 510. Thereby, the plume analyzing arrangement 250 is adapted to three-dimensionally localize the origin of the plume 110 and to augment images captured by the cameras 540 with information derived from debris of the plume 110.

[0098] FIG. 5 shows a section of a second embodiment of a laser device according to the invention. This laser device has an essentially identical setup as the laser device 100 described above. In contrast to the first embodiment of the laser device 100 the second laser device is embodied for CARS.

[0099] CARS requires two synchronized comparably fast laser pulses at two different wavelengths to generate the Raman response. In the second laser device the two wavelength excitation light 404i from a compact solid state fast laser is coupled to an optical fiber 240i and brought to the second laser device by the same fiber for its easy integration after proper collimation with a collimator 422i and added to the ablating laser beam 402i via a mirror 416i and a further dichromatic mirror 415i to form a composite laser beam 400i. The emission from debris in a plume is captured and analyzed preferably by the same arrangement as described above or, by means of an optical fiber close to the plume at the region of the excitation and directed to a light detector.

[0100] When CARS is used to obtain a two-dimensional microscopic CARS emission image of the surface of the ablated tissue the excitation light advantageously is scanned over the region of interest between the pulses of the ablating laser pulses by preferably by means of a scanner or by means of mounting the whole laser ablating device in e.g. a robot or an xyz linear scanner. The frequency of the ablating laser pulses 402i and those of the CARS laser 404i pulses are not necessarily the same. In the shown embodiment the CARS laser frequency is much higher implying that between two subsequent pulses of ablating laser pulses there will be several CARS excitation pulses which are used to improve the signal/noise ratio in the case the CARS laser is probing the particles in the plume or, to make two-dimensional scans if interested in recording the emission of the surface to reconstruct an image.

[0101] 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.

[0102] 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.

[0103] 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.