Device for safely sectioning biological tissue

Abstract

The present invention relates to a device for sectioning biological tissue during a surgical intervention and the use of said device. In particular, the sectioning is performed safely by a laser without penalizing its operating speed. The device combines information about the laser, about the tissue and about the user to implement safety measures.

Description

Technical Field

[0001] The present invention relates to an apparatus for sectioning biological tissue during a surgical intervention and to the use of such an apparatus. Specifically, the sectioning is performed safely by a laser without disadvantaging its operating speed. The apparatus combines information about the laser, information about the tissue, and information about the user in order to take safety measures.

Background Art

[0002] In surgical applications, laser-based devices present significant advantages over conventional mechanical tools such as surgical blades, saws, drills, or piezoelectric tools. Among these advantages, precision, sectioning in any geometric shape, lack of vibration, better tissue recovery, and lack of contact stand out. However, the lack of contact has the drawback of losing tactile feedback and thereby losing control over the depth of the sectioning.

[0003] With mechanical instruments conventionally used in surgery, the surgeon receives this tactile feedback and can always control the depth of the sectioning being performed. Thus, the operation of the mechanical tool is always spatially limited, and as a result, the tool modifies only the parts that are physically in contact. In contrast, with a laser-based device, the laser propagates linearly and can act on the tissue without the contact and control that limit sectioning, i.e., the laser has no point of operation but rather a direction of operation. Thus, there are obvious problems in ensuring the safety of laser sectioning for surgical applications.

[0004] Some of the solutions proposed for this problem in the state of the art attempt to estimate how far the laser can penetrate based on the measurement of the surface of the tissue to be sectioned. In this type of solution, the process is carried out by interleaving the measurement of the surface of the tissue with the sectioning of the tissue in an iterative verification process. This has a significant drawback with respect to the total duration of the sectioning procedure, and these solutions are not feasible in actual surgery.

[0005] Furthermore, in some of these solutions, the sectioning of the tissue is carried out at a single point, the sectioning is advanced at the aforementioned position until the end is reached, and the movement to the next sectioning position is carried out only when the previous sectioning position is completed. This has the drawback that the measurement of the surface of the tissue can become extremely difficult in deep and narrow individual holes or when there are irregular or angled shapes on the surface.

[0006] Furthermore, these solutions present another series of drawbacks that do not guarantee the safety in tissue sectioning, since they do not define the first region where one or more tissues are well sectioned, or do not define at all the ends of the tissues to be sectioned, or do so with little accuracy, or only for tissues with specific characteristics (e.g., hard tissues), in which case additional image processing techniques are required or the application of the solution to very specific surgeries is restricted. Definition of a safety mechanism for tissue sectioning These limitations in the definition of a safety mechanism for tissue sectioning can lead to inappropriate sectioning and thus an unsatisfactory surgery. SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION

[0007] The present invention proposes a solution to the aforementioned problem by means of the living tissue sectioning device according to claim 1 and the use of the device according to claim 31. The dependent claims define preferred embodiments of the present invention.

Means for Solving the Problem

[0008] A first aspect of the invention is a biological tissue sectioning device, a laser emitter adapted to section biological tissue within a region, a controller communicating with the laser emitter and adapted to activate and deactivate the laser emitter, an optical module adapted to determine the surface of the tissue in the region in an operating mode, a central processing unit communicating with the controller and the optical module, defining a predefined sectioning depth of the laser emitter, defining at least one reference plane, the shape of the surface of the tissue in the region, the shape of at least one reference plane below which sectioning is prohibited, generating a numerical model of the region including at least the direction of the laser beam in which the laser emitter is oriented, In the numerical model, if a position corresponding to a point on the straight line representing the laser beam and separated by a distance equal to the sectioning depth from the intersection of the same straight line and the surface of the tissue is outside the prohibited region and is any part of the tissue in the region where sectioning is prohibited, activating the laser emitter, a central processing unit adapted to An apparatus comprising.

[0009] This first aspect of the invention defines a biological tissue sectioning device that can ensure safety during sectioning without including the speed of the procedure. In one example, the device according to the invention sections biological bone tissue with a volume of 10×10×10 cubic millimeters in the range of 50 to 400 seconds.

[0010] This sectioning device is equipped with a laser emitter, i.e., a laser beam or simply a laser, and communicates with a controller for activating or deactivating it. Preferably, this laser emitter is of the Er:YAG type with a typical emission wavelength of 2940 nanometers. To ensure safety during sectioning, the surface of the tissue to be sectioned must be known, and thus the sectioning device further comprises an optical module. The optical module is based on, for example, an optical coherence tomography system, or structured light, or optical topological techniques including a stereo pair, or hybrid techniques including, for example, a photoacoustic tomography system. Furthermore, the optical module comprises computing means capable of identifying the shape of the surface of the tissue based on measurements performed by the optical system or the photoacoustic system.

[0011] Furthermore, the sectioning device comprises a central processing unit that communicates with the controller and the optical module. Throughout this specification, the central processing unit is understood to mean a device capable of receiving and transmitting data and of processing that data. In a preferred example, the central processing unit is a processor or a microprocessor.

[0012] On the other hand, this central processing unit defines a pre-established sectioning depth of the laser emitter, where the sectioning depth is understood to mean the depth at which the laser can perform sectioning, measured from the position of the intersection of the line defining the laser and the biological tissue. Preferably, the sectioning depth of the laser emitter ranges from 50 micrometers to 200 micrometers.

[0013] On the other hand, the central processing unit defines at least one reference plane below which sectioning is not allowed. The one or more reference planes are defined considering different criteria such as the boundary of the end of the tissue, the boundary of the start of the tissue, a pre-established maximum depth, or a pre-established maximum flatness level. Further, the reference plane is dynamic, i.e., throughout the surgical intervention, new reference planes can be added and existing reference planes can be modified and / or removed.

[0014] The shape of these reference planes, as well as the shape of the surface of the tissue determined by the optical module, are imported into the numerical model generated by the central processing unit. Surfaces corresponding to physical entities obtained by a measuring device such as the surface of the tissue, or virtual surfaces such as reference planes that can be defined, for example, by the user, can be represented in the aforementioned numerical model. Further, the numerical model includes the direction of the laser beam to which the laser is oriented. The numerical model enables the determination of intersections and / or conditions based on what decisions can be made. In a preferred example, the numerical model is computationally depicted by a data structure that enables at least the definition of regions and geometric entities related to the surface and the operating line of the laser.

[0015] This numerical model enables the determination of whether the laser must be activated depending on whether safety criteria based on one or more defined reference planes are met. As a result of the numerical model, the position of the points of the straight line representing the laser beam, separated by a distance equal to the sectioning depth from the intersection of the same straight line with the surface of the tissue, is determined. The central processing unit then evaluates whether the aforementioned position is located in a prohibited region, where the prohibited region is understood to mean any part of the tissue in the region where sectioning is prohibited. Specifically, the prohibited region is a tissue region existing below one of the reference planes.

[0016] This prevents the laser from sectioning tissue or a portion of the tissue in areas that are not the surgical target. These safety measures are essential, especially when non-target tissues such as nerves, dura mater, or blood vessels are particularly important.

[0017] If there are multiple reference planes, it should be pointed out that these planes must be considered jointly, that is, the activation and deactivation of the laser depend simultaneously on all of these surfaces. Therefore, if one of the reference planes does not meet the laser activation criteria, the central processing unit will not activate the laser even if the remaining reference planes meet the activation criteria.

[0018] Therefore, with the device according to the first aspect of the invention, the central processing unit controls the activation of the laser to omit the prohibited area and continue the process without delay in the remaining area. Thereby, the laser can always be ready but can act only on the areas where the treatment has to be applied.

[0019] The execution of sectioning and measurement by the optical module is continuously carried out in a coordinated and independent manner by the central processing unit. The aforementioned device updates the information received from the optical module to dynamically determine the surface of the tissue again during the sectioning procedure.

[0020] Accordingly, the present invention proposes that the laser and the optical module act simultaneously, and this feature is contrary to the teachings of the prior art. Since the laser affects the tissue that deteriorates the measurements performed by the optical module, the tendency so far has been to prevent their simultaneous use. For example, laser sectioning results in the appearance of smoke, bone dust, vibrations, or sparks that change the measurements of the optical module. Furthermore, continuously or periodically applying mist, perfusion, blowing, suction, or any combination of these operations to ensure cooling and cleaning of the surgical area can also cause interference with the measurements performed by the optical module. However, the device of the present invention only needs to determine the surface of the tissue, and this determination remains robust even in the presence of an operative sectioning laser as well as cleaning and cooling fluids. Thus, the influence of the changes caused by the operation of the laser on the measurements of the optical module does not prevent the reliable identification of the shape of the tissue surface, and advantageously, the number of treatments is significantly reduced.

[0021] In one embodiment, the central processing unit is further configured to stop the laser emitter if, in the numerical model, at least one of the positions of the points of the straight line representing the laser beam located between the intersection of the aforementioned straight line and the tissue surface and the addition of a distance equal to the sectioning depth at the intersection coincides with the position of at least one point of the prohibited area.

[0022] In this embodiment, the central processing unit estimates the position of the segment of the points of the straight line representing the laser beam according to the numerical model, checks whether at least one of the points of the segment is within the prohibited area, and in that case, stops the laser. Otherwise, the central processing unit activates the laser.

[0023] This segment includes the intersection of the straight line representing the laser beam having the tissue surface and the point located between the addition of a distance equal to the sectioning depth at the intersection.

[0024] In one embodiment, the central processing unit is further configured to stop the laser emitter when, in the numerical model, none of the positions of the points on the straight line representing the laser beam coincide with the positions of the points on the surface of the tissue.

[0025] For safety, the central processing unit stops the laser when the laser does not intersect the surface of the target tissue at a particular position. For example, if the laser is accidentally positioned outside the surgical area, it will not collide with the target tissue when activated and may damage other tissues of the patient that should not be treated or even harm medical staff.

[0026] For example, the option that the device was pre - turned on, the patient was not yet positioned on the operating table, or simply a failure occurred in the optical module, so the optical module did not detect the tissue is also considered in this embodiment. In such a situation, laser sectioning must be stopped to prevent accidents.

[0027] In one embodiment, at least one reference plane is a boundary surface defining an end of the tissue in the region, or a boundary surface defining a starting portion of a different tissue, the surface of which is a different tissue from the tissue in the region determined by the optical module and the different tissue is located deeper than the tissue in the region, or a boundary surface defining an end of a different tissue, the surface of which is a different tissue from the tissue in the region determined by the optical module and the different tissue is located deeper than the tissue in the region, or any combination of the above.

[0028] As described above, one or more reference planes are defined considering different criteria. In this embodiment, regardless of whether the tissue is the tissue whose surface is determined by the optical module, called the main tissue, or the tissue adjacent to it, the reference plane is a boundary surface defining the end or starting portion of the tissue.

[0029] For example, in spinal surgery, the area where the laser performs the sectioning includes a mixture of tissues consisting of at least one vertebra, soft tissue, blood vessels, and other adjacent or underlying structures such as the dura mater that protects the dural sac surrounding the spinal cord and spinal nerves. In this case, at the start of the surgery, the main tissue can be the vertebra whose surface is determined by the optical module. A possible reference plane is the end of the vertebra. Alternatively or simultaneously, the reference plane or other reference planes can be the surface that defines the start or end of any soft tissue or nerve adjacent to the vertebra. At another, more advanced stage of the surgery, the main tissue can be the ligamentum flavum, and a possible reference plane is the end of the ligamentum flavum or the start of the dural sac.

[0030] The central processing unit defines these boundary surfaces based on the information received about the anatomical structures present in the surgical field. The aforementioned information can result from preoperative images, and / or intraoperative images, and / or measurements made by the optical module.

[0031] In one embodiment, at least one reference plane is determined by preoperative images, preferably by magnetic resonance images, computed tomography images, or fluoroscopic images.

[0032] The anatomical structure of the patient in need of surgery is known as a result of one or more medical imaging techniques typically performed before and / or during the surgery, typically magnetic resonance, computed tomography, or fluoroscopy. This planning can show, for example, that there is no need to treat specific elements of the volume because they may belong to important structures such as the dural sac, nerves, or blood vessels.

[0033] This image is processed and segmented to define only the volume of the main tissue of the subject. As a result, the boundaries between the main tissue and the adjacent tissues are properly distinguished, and this information is converted by the central processing unit into at least one reference plane.

[0034] Alternatively, or to supplement the prior information, the optical module can also determine one or more surfaces that define the tissue relative to each other, such that the central processing unit can define a reference plane.

[0035] Using one or more of the aforementioned reference planes, one or more tissues that can be sectioned by a laser are defined from those that cannot be sectioned, thereby ensuring the safety of the sectioning.

[0036] In one embodiment, at least one reference plane determined by the preoperative image is a boundary surface that defines the end of the bone tissue of the region.

[0037] In certain types of surgeries such as the aforementioned spinal surgery, the target tissue is bone. Specifically, osteotomy or bone removal for laminectomy and laminotomy are common steps in decompression and stabilization procedures. The preoperative image can visualize the boundaries of this type of tissue relative to adjacent tissues such as soft tissues like the ligamentum flavum, the dural sac, and nerves.

[0038] Therefore, considering that only sectioning of the vertebrae is required in this type of procedure, the definition of the reference plane as the boundary surface that defines the end of the vertebra is a reliable safety criterion to prevent adjacent tissues from being affected by the sectioning.

[0039] After osteotomy of one or more parts of the vertebrae, another common step in the aforementioned spinal surgery is the removal of soft tissue located between the bone and the dural sac, typically the ligamentum flavum, for the purpose of decompressing the nerves, removing spinal stenosis, and releasing them from the pressure source causing pain. In this procedure, the end of the ligamentum flavum, the surface of the dural sac, or any other combination of the initial or final surfaces of the tissues present in the anatomical region of interest can be used as the reference plane.

[0040] In one embodiment, at least one reference plane is a flat plane that is essentially parallel to the focal plane of the laser emitter and / or the focal plane of the optical module.

[0041] In this embodiment, at least one of the reference planes or the reference plane is a flat plane that defines the maximum allowable sectioning level. This surface is substantially flat and parallel to the focal plane, whether it is the focal plane of the laser or the focal plane of the optical module. Preferably, both focal planes coincide with each other. Throughout this specification, the focal plane is understood to mean a plane perpendicular to the optical axis where the laser emitter and / or the optical module reach their optimal spatial resolution or focus.

[0042] Preferably, this maximum level is selected by the surgeon and received by a central processing unit that converts the information into the reference plane. Furthermore, this maximum level can be dynamic, i.e., its depth can be gradually updated as the surgical intervention progresses. Throughout this specification, when the term surgeon is mentioned, it can be understood to mean any user authorized to intervene in the surgery or medical staff.

[0043] Preferably, the sectioning laser gradually sweeps the biological tissue until the surface is leveled, taking into account the tolerance range considered to have successfully leveled the surface. For safety reasons, this progression and leveling in tissue sectioning are always performed without penetrating the defined flat plane. According to this operating mode, the laser beam acts more frequently on points of the surface with a higher height.

[0044] Furthermore, this type of reference plane provides several related technical advantages resulting from the fact that both the sectioning laser and the optical module have a focal plane where the measurement is optimal.

[0045] On the one hand, when the tissue of the region is leveled, any height irregularities that may reduce the measurement or create shadow regions can be optimally focused without, and thereby the measurement of the surface of the sample can be performed under the most favorable conditions, so that the measured values of the optical module are obtained under favorable conditions. Further, the leveling of the tissue also enables the laser to be optimally focused on the tissue and encounter a surface without obstacles, which converts to more efficient sectioning. Finally, providing a leveled sectioning region, while not being a part of the surgery itself, facilitates other operations that are strictly necessary for the success of the surgery, such as performing cleaning during the surgery to keep the surgical field clean and preventing thermal damage.

[0046] In one embodiment, at least one reference plane is a surface having a maximum depth determined from the surface of the tissue.

[0047] In this embodiment, one of the reference planes or the reference planes is a surface having a depth that indicates the maximum allowable sectioning depth for each point with respect to the surface of the tissue determined by the optical module.

[0048] This surface having a depth can be defined with respect to the surface of the tissue in the region initially determined by the optical module or at any other point during the surgery when the surface of the tissue is updated.

[0049] Advantageously, this type of reference plane constitutes a safety means of the device that prevents the tissue from being sectioned at a depth deeper than the depth defined by the central processing unit, thereby preventing the sectioning of tissue other than the target tissue.

[0050] In one embodiment, at least one reference plane is a boundary surface that defines the end of the tissue in the region, and / or a boundary surface that defines the start of a different tissue, the surface of which is a different tissue with respect to the tissue in the region determined by the optical module and the different tissue is located deeper than the tissue in the region, and / or A boundary surface defining an end of a different tissue, the surface of which is a different tissue from the tissue of the region determined by the optical module, and the different tissue is located deeper than the tissue of the region, and / or A flat surface essentially parallel to the focal plane of the laser emitter and / or the focal plane of the optical module, and / or A surface having a maximum depth determined from the surface of the tissue.

[0051] The reference plane can be an individual surface by any of the surfaces defined in the foregoing embodiments, or a set of reference planes that must be considered simultaneously. Thus, the device according to the present invention contemplates a wide variety of safety options that can be adapted to each specific surgery.

[0052] In one embodiment, the central processing unit defines at least one reference plane having a safety margin.

[0053] Despite the fact that laser-based sectioning is much more accurate than sectioning with conventional surgical instruments, the device of the present invention contemplates that all reference planes have a safety margin for further enhancing the safety of the method and always preventing the sectioning of non-target tissue.

[0054] Furthermore, the safety margin can be dynamic, i.e., it can change gradually through a surgical intervention.

[0055] The safety margin is understood to mean a pre-established distance such that the point that determines whether the laser beam should not exceed the reference plane is separated from the point where it reaches the reference plane by a pre-established distance so as to prevent reaching the reference plane. In this case, the safety margin corresponds to taking into account that the reference plane has approached the radiation source by a pre-established distance.

[0056] In one embodiment, the central processing unit comprises input means for inputting the definition of the safety margin of at least one reference plane.

[0057] The margins can be selected by the surgeon or healthcare professional performing the surgery, who transmits the values of these margins to the central processing unit via the input means. The central processing unit then defines or updates one or more reference planes taking into account the aforementioned margins within the numerical model.

[0058] In one embodiment, the optical module comprises an optical coherence tomography (OCT) system.

[0059] Throughout this document, an OCT system is understood to mean an optical system that can determine the volume of a region of biological tissue to be sectioned by illuminating the region with a partially coherent light source, typically a superluminescent diode or a scanning light source. Based on this information obtained by the OCT system, the optical module identifies the surface of the target or main tissue.

[0060] In one embodiment, the optical coherence tomography system is a polarization-sensitive optical coherence tomography (PS-OCT) system.

[0061] More specifically, in this embodiment, an OCT system of the optical module that is a polarization-sensitive optical coherence tomography (PS-OCT) system is contemplated. This type of system is characterized in that its measurements take into account that the polarization state of the light reflected by the tissue can be altered.

[0062] Advantageously, this type of system performs post-processing of the light reflected by the tissue, providing highly robust measurements, so that the reflectance or intensity signal no longer responds to polarization fluctuations caused by the tissue and provides optimal contrast regardless of the polarization effects generated in the tissue. Thereby, the surface of the tissue can be determined robustly. Furthermore, tissues that cannot be distinguished by OCT can be accurately distinguished using PS-OCT considering their different responses to polarization, thereby identifying prohibited areas that would otherwise not have been identified.

[0063] As described above, preferably, the sectioning laser sweeps gradually across the biological tissue until the surface is horizontal. Under these circumstances, an optical module system, such as a PS-OCT system, can place the tissue in the focal plane of the system due to the flattening of the surface, and thus perform measurements under optimal conditions. Similarly, the laser emitter operates under optimal conditions when the flattened surface of the tissue is located in its focal plane.

[0064] In one embodiment, the optical module is of a structured light type, a stereo pair type, or a photoacoustic tomography type system.

[0065] Instead of OCT and PS-OCT systems, the optical module may comprise another type of optical system (structured light or stereo pair) or a photoacoustic system (photoacoustic tomography) as described above.

[0066] Specifically, a structured light system irradiates the tissue typically using infrared light with a projector that creates a spatial pattern, such as a checkerboard pattern. Since the light pattern deforms according to the shape of the surface, if the pattern on the plane is known, the shape of the surface can be inferred from the imaging of the deformed pattern.

[0067] A stereo pair system typically irradiates the tissue with an infrared light source and reconstructs the volume of the tissue by stereoscopic techniques.

[0068] Next, a photoacoustic tomography system irradiates the tissue with a laser and performs measurements with an ultrasonic transducer.

[0069] In one embodiment, the laser emitter comprises a scanner that enables the direction of the beam to be changed so as to direct the beam at different points in the region.

[0070] This scanner enables the laser to sweep across a pre-defined scanning area or pattern. Preferably, the aforementioned pattern is uniform. In one example, from the perspective of the surgeon performing the surgery, the pattern is created from the left side to the right side of the surgeon and from top to bottom.

[0071] Solutions are known in the state of the art where the sectioning is specifically established at each position so that the laser does not proceed to the next position until the sectioning at one position is completed. However, in the context of the present invention, this type of solution is not optimal for the operation of the optical module because its measurements become extremely difficult and even impossible in deep and narrow individual holes or when complex angles or shapes exist on the surface of the tissue. Therefore, progressing gradually across the entire area rather than at a single point facilitates the measurement of the optical module and thus the definition of the surface of the tissue throughout the surgery. Furthermore, it facilitates the visualization of the surgical field by the surgeon, gradually reaches the stages of the surgery closest to the important tissues, approaches them simultaneously, and can improve safety.

[0072] During a process that is executed repeatedly and continuously, the laser may interact with areas that do not need to be processed. That is, what is referred to above as the prohibited area. Preferably, in such a situation, the scanner is able to omit the prohibited area and redirect the laser towards the area having the target tissue. As a result, the laser is not cooled and can continue the sectioning procedure under optimal conditions without delay, minimizing the time required to perform the sectioning.

[0073] Alternatively, the scanner enables the laser to continue a pre-defined pattern by sweeping across the prohibited area, but the central processing unit prevents the laser from being activated, thereby preventing the non-target tissue from being sectioned.

[0074] In one embodiment, the central processing unit is adapted to perform a continuous scan of the laser beam emitted by the laser emitter over an area until it reaches at least one reference plane.

[0075] In this embodiment, the central processing unit enables the scanning of the laser until it reaches the reference plane or one of the reference planes.

[0076] For example, if the reference plane is a flat surface that defines the maximum sectioning level, the central processing unit enables the defined scanning of the laser until it reaches that maximum level. At this point, when the depth of the level is increased, the central processing unit proceeds to resume the scanning of the laser.

[0077] In another example, if the reference plane is a boundary surface that defines the end of a bone, the central processing unit enables the scanning of the laser until it reaches the end face of the bone. In a more specific example where a safety margin is further imposed, the central processing unit enables the scanning of the laser until the remaining thickness equal to the safety margin remains across the entire bone.

[0078] In one embodiment, the optical module comprises a light source and a scanner that enables changing the direction of the light source so as to direct the light source to different points in the area.

[0079] In this embodiment, the optical module comprises an OCT system, a PS - OCT system, or a photoacoustic tomography system comprising a light source. To scan the target area, the optical module further comprises a scanner that enables focusing the aforementioned light source at different points in the area.

[0080] Advantageously, as sectioning progresses during surgery, the light source of the optical module focuses on the points of the tissue where the surface is located so that the central processing unit can accurately re - define the new surface in the numerical model.

[0081] In one embodiment, the central processing unit is adapted to perform a continuous scan of the light source of the optical module over an area.

[0082] In this more specific embodiment, the central processing unit controls the scanning of the aforementioned light source.

[0083] In one embodiment, the control of the scanning established by the laser emitter and the scanning established by the optical module are independent.

[0084] The laser emitter scanning and the optical module scanning are controlled by the central processing unit, but both scans are independent of each other. Therefore, the parameters defining each of the aforementioned scans, such as speed, are completely independent of each other, so the aforementioned scans can be stopped or changed without being affected by other scans.

[0085] The scanning by the optical module may require a lower scanning frequency, for example, so that the information regarding the tissue is appropriately updated.

[0086] In one embodiment, the scanning of the light source of the optical module over the area is after a pre-established period has elapsed, before the activation or deactivation of the laser emitter by the central processing unit, is performed when a deterioration criterion selected from is met.

[0087] As described above, since the sectioning path and measurement of the optical module are performed independently, they do not need to be in a straight line with each other.

[0088] The optical module performs measurements continuously, but there is a possibility that an error may occur when the module scans the target area, or that the measurement may be performed at a point when it is overly long. Therefore, the information on which the numerical model is based at a given point in time may be outdated, which may cause the tissue to be sectioned incorrectly and put the surgery at risk.

[0089] To prevent such situations, the device provides an update of the measurements made by the optical module in critical situations, especially when a previously predefined period has elapsed, thereby preventing any problems when refreshing the execution of the measurements and before the central processing unit starts or stops the laser emitter, and as a result, ensuring that the tissue in which the information is updated in the numerical model is sectioned or not sectioned.

[0090] In one embodiment of the numerical model generated by the central processing unit, at least one flat surface is gradually established at a plurality of depth levels with respect to the focal plane of the laser emitter and / or the focal plane of the optical module such that when the surface of the tissue descends to the depth of the aforementioned flat surface as a result of the action of the laser of the laser emitter, at least one flat surface changes to a greater depth.

[0091] If at least one of the reference planes is a focal plane, i.e., a flat surface parallel to the focal plane of the laser emitter and / or the focal plane of the optical module, the plane is defined at a specific depth. This depth can gradually progress when the laser reaches the flat surface defined for a given time so that the flat surface is updated to a greater depth than the previous one.

[0092] Therefore, define a plurality of levels of different depths at which sectioning can be gradually performed in a secure segment.

[0093] The plurality of levels can be fixed, i.e., predefined before starting the operation, or dynamic, i.e., the flat surface is gradually updated as the operation progresses. In a particular example, the difference in depth between consecutive levels is constant. In another example, the difference in depth between consecutive levels is variable. In another example, the surgeon determines the new depth of the flat surface during the operation, converts the information to the new updated flat surface, and enters the value via an input means within the central processing unit that assigns it to the numerical model.

[0094] In one embodiment, the central processing unit comprises input means for inputting the definition of at least one reference plane assigned to the numerical model.

[0095] Throughout this document, it is mentioned that a surgeon or medical staff can make different decisions regarding the reference plane before and during a surgical intervention. These decisions must be considered by a central processing unit that analyzes the received information, uses it to define the reference plane, and assigns the reference plane to the numerical model.

[0096] Preferably, the input means is constituted by an interface that enables interaction between the central processing unit and the surgeon, medical staff, or user.

[0097] In one embodiment, the central processing unit comprises input means for inputting the definition of an area to be avoided, the shape of which is assigned to the numerical model, and the central processing unit is further configured to stop the laser emitter in the numerical model when at least one of the positions of the points of the straight line representing the laser beam located between the intersection of the aforementioned straight line and the surface of the tissue and the addition of a distance equal to the sectioning depth at the intersection coincides with the position of at least one point of the area to be avoided.

[0098] In addition to the prohibited area, for safety reasons, the user, surgeon, or medical staff can determine other types of specific areas that cannot be sectioned with a laser before or during the surgery, for example, when the presence of an important structure not within the prohibited area is identified during the surgery.

[0099] In these situations, the central processing unit comprises additional input means by which the user can define the area to be avoided, and the area to be avoided is understood to mean a specific area that cannot be sectioned with a laser. Preferably, these input means are interfaces.

[0100] In a preferred example, the area to be avoided is defined within the plan view of the surgical field, and thus, at any depth, sectioning is prohibited at all points of "x" and "y" belonging to the area whose coordinates are defined. The "x" and "y" coordinates must be generally interpreted as the coordinates by which a specific point on the surface is identified, regardless of the method by which the surface is parameterized. In a specific example where a Cartesian coordinate system is used, the "x" and "y" coordinates correspond to the x-axis and y-axis.

[0101] This information is received by a central processing unit involved in processing the information to assign the shape of the area to be avoided to a numerical model. Further, the central processing unit is configured to stop the laser emitter if its beam enters the area to be avoided according to the established sectioning depth.

[0102] In one embodiment, the device comprises a surgical field display means, preferably a screen showing an RGB video image.

[0103] In order to always provide visual information to the user during a surgical intervention, the device comprises these display means. In a preferred example, the display means is a screen or monitor that shows the surgeon a video image of the surgical field in a plan view, particularly an RGB image. The RGB image should be understood to mean an image whose color can be defined by the standard RGB color model.

[0104] Furthermore, the display means advantageously helps the user or surgeon to select the area to be avoided if considered necessary. That area to be avoided is drawn by the user in the context of the image shown on the display means, preferably an RGB video showing the surgical field in a plan view. In these cases, at all points of "x" and "y" whose coordinates belong to the area defined from the image shown on the display means, sectioning at any depth is prohibited.

[0105] In one embodiment, the surgical field display means further shows information regarding the distance from each point on the surface of the tissue to at least one reference plane.

[0106] In this embodiment, in order to have an additional source of visual information regarding the approach towards the surgical target, the surgeon is informed of the distance from each point on the surface of the tissue to the reference plane. If there are multiple reference planes, the distance to the reference plane closest to each point is calculated. This additional information is attached to the image shown on the surgical field display means.

[0107] The central processing unit calculates the distance according to a numerical model and indicates the distance via the surgical field display means.

[0108] In one embodiment, the central processing unit is further configured such that, during the sectioning process while the laser emitter scans a set of points in the region, each time a series of points reaches a point where the emission of the laser emitter is blocked, the laser emitter is positioned at the next point where emission is permitted without stopping the emission of the laser beam.

[0109] To prevent a delay in the treatment, when the laser of the device hits a point where sectioning should not be performed, the central processing unit redirects the laser towards another region containing the target tissue, i.e., towards another region where sectioning must be performed. Preferably, the laser is redirected by a scanner included in the optical module.

[0110] According to this embodiment, advantageously, not only is the time when the laser stops avoided, but rather, by skipping to another point where the laser can continue to operate, the laser is not cooled and remains under optimal operating conditions.

[0111] Alternatively, the central processing unit instructs the laser emitter to sweep all the points in the region, but enables its activation only at points where sectioning is possible.

[0112] In one embodiment, the central processing unit is further configured to define a function representing a scalar representing the temperature level within a set of points in a region having a specific pattern. The function first takes a pre-established reference value, Each time the laser emitter collides with a point in the pattern, the function increases by a first pre-established increment value at that point, The values of all points are reduced by a second pre-established increment value every pre-established period, For each point in the pattern, if it exceeds a pre-established threshold value, the aforementioned point is assigned to the numerical model as a point where sectioning is not allowed as long as it remains above the aforementioned threshold value.

[0113] If the size of the sectioning area is very small, the laser can act on these areas almost continuously, resulting in a situation where these areas are thermally damaged. Therefore, the process can start within a wide operating range, but larger and larger prohibited areas, and optionally areas to be avoided, may occur during sectioning. Therefore, the area where sectioning is performed becomes smaller and smaller, the laser passes through this area more frequently, increasing the output per unit of the surface in the process. When this power exceeds a specific threshold, the tissue begins to suffer thermal burns.

[0114] In the prior art, in order to prevent laser sectioning from causing any thermal damage due to tissue heating, it is necessary to cool the sectioning area by perfusion or mist. As a result, the tendency has been to not use the laser emitter and the optical module simultaneously, but rather to perform tissue sectioning and optical module measurement alternately. However, as described throughout this specification, the present invention contemplates the simultaneous use of a laser and an optical module in one embodiment.

[0115] The device according to this embodiment is intended to adjust the output per unit area of the laser so that it does not exceed a predefined threshold. This threshold can be a dynamic threshold or can change gradually through surgical intervention. In one example, the user, surgeon, or healthcare provider selects the threshold at a given point in the surgery and preferably inputs the threshold via the input means of the central processing unit, which is an interface.

[0116] This thermal protection is based on a simplified tissue temperature model that takes into account the heating and cooling of the tissue at each point having the number of laser pulses allowed per unit time.

[0117] In this model, a scalar reflecting the temperature of the point of the tissue is defined. Each time the laser is fired, this scalar increases by a certain increment, and when it exceeds a predetermined threshold, the numerical model anticipates that the sectioning is not allowed at the aforementioned point as long as the relevant temperature scalar remains above the threshold.

[0118] As described above, since the model also anticipates tissue cooling, the scalar decreases by a fixed amount (equal to or different from the fixed increment) at each point of the tissue when a predetermined period has elapsed. This period can be a fixed or dynamic period during the surgery. Further, it can be selected at a given point in the surgery by the surgeon or healthcare provider who inputs the value to the central processing unit via the input means, preferably an interface.

[0119] In one embodiment, the central processing unit is further configured such that during the sectioning process while the laser emitter scans a set of points in the region, points with a smaller sectioning depth than others are prioritized in the scanning sequence to compensate for the sectioning depth.

[0120] As described above, one way to laser section a target area can be performed by a control mode that adjusts the firing of the laser to achieve a section with a always flat bottom. Thus, during the sectioning process, there are areas that are deeper than other areas.

[0121] To achieve the goal of flattening the bottom of the section, in this embodiment, it is conceivable that the central processing unit is configured to prioritize shallower points so as to stop the laser at deeper points or areas and start the laser at more superficial points or areas. According to another embodiment, the skip from one point to another is performed without stopping the laser, but strikes those points with a higher height more often. In this way, the surface layer area becomes deeper and deeper, while the deep area remains unchanged until all points reach the same level.

[0122] In one embodiment, the central processing unit comprises means for stopping the emission of the laser emitter adapted to stop the emission of the laser emitter when operating.

[0123] The device of the present invention also contemplates options for stopping the firing of the laser under any circumstances, even if other safety criteria defined above are not met.

[0124] For this purpose, the central processing unit preferably receives externally a stop command issued by a user or a surgeon. Advantageously, if for any reason the medical staff considers that the sectioning must be stopped, the safety of the sectioning is guaranteed.

[0125] In one embodiment, the device further comprises a fluid management unit adapted to provide a flow of gas, or liquid, or a mist having liquid particles in the gas, within the area including the area of the biological tissue on which the laser emitter acts in the operating mode.

[0126] Tissue sectioned by the device tends to bleed continuously, and the sectioning operation itself also continuously generates particles and solid residues that must be removed from the laser activation area.

[0127] In this embodiment, in addition to laser sectioning, the device has a cleaning ability. To this end, it comprises a fluid management unit that provides a flow of gas, liquid, or mist that can entrain unwanted elements present in the area including the area of tissue sectioned by the laser emitter.

[0128] Preferably, the flow of gas or liquid or mist is provided through a conduit connecting the fluid management unit to the surgical area.

[0129] Advantageously, on the one hand, the laser can act on a tissue area that does not contain blood and / or unwanted particles that could affect sectioning accuracy, and on the other hand, the accuracy of the measurements of the optical module is not affected, and the actual surface of the target tissue can be determined without including these unwanted elements.

[0130] A second aspect of the invention provides for the use of the device of the first aspect in minimally invasive robot-assisted surgical procedures.

[0131] These and other features and advantages of the invention will become more apparent from the following detailed description of the preferred embodiments given by way of illustration and not limitation with reference to the accompanying drawings.

Brief Description of the Drawings

[0132]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0133] Figure 1 shows an overall view of a biological tissue sectioning device for sectioning the biological tissue shown in this figure by parallel lines. The device includes a laser emitter (1) configured to section the aforementioned tissue in the area (R), and its activation and stop are instructed by a controller (2).

[0134] In one embodiment, the laser emitter (1) includes a scanner that enables changing the direction of the beam so as to direct the beam to different points in the area (R).

[0135] The device further includes an optical module (3) capable of detecting the surface (S) of the tissue in the area (R). Preferably, the optical module (3) includes an optical or photoacoustic system that performs a series of measurements that are subsequently processed by computational means to determine the surface (S) of the tissue.

[0136] In a preferred example, the optical module (3) includes an optical coherence tomography (OCT) system that can be a polarization-sensitive optical coherence tomography (PS-OCT) system. Another example of the optical system of the optical module (3) is structured light or a stereo pair type. Another example of the photoacoustic system of the optical module (3) is a photoacoustic tomography system.

[0137] In one embodiment, the optical module (3) further includes a light source and a scanner that enables changing the direction of the light source so as to direct the light source to different points in the area (R).

[0138] The device further comprises a central processing unit (5) that communicates with a controller (2) and an optical module (3). On the one hand, it sends commands to the controller (2) to start and stop the laser, and on the other hand, it receives information from the optical module (3) and processes it. The central processing unit (5) generates a numerical model (NM) of the region (R) that includes at least the shape of the surface (S) of the region (R) determined by the optical module (3), the direction of the laser beam towards which the laser emitter (1) is oriented, and the shape of one or more reference surfaces (RS).

[0139] One or more reference surfaces (RS) are defined by the processing device (5) itself. These surfaces (RS) define the surface of a prohibited region of tissue where sectioning is prohibited for several reasons, for example, because they contain important tissues such as nerves or blood vessels.

[0140] Furthermore, the central processing unit (5) defines the sectioning depth (d) of the laser emitter (1) that can be fixed or changed throughout the surgical intervention. Preferably, the sectioning depth (d) can be selected.

[0141] Based on the generated numerical model (NM), the central processing unit (5) estimates the position of the point on the straight line representing the laser beam that is spaced from the intersection of the straight line and the surface (S) of the tissue by a distance equal to the sectioning depth (d). If the estimated position indicates that the point is located outside the prohibited region, the central processing unit (5) activates the laser emitter (1) via the controller (2). In contrast, if the aforementioned point is within the prohibited region, the central processing unit stops the laser emitter.

[0142] Alternatively or additionally, based on the generated numerical model (NM), the central processing unit (5) estimates the position of a point of the straight line representing the laser beam, positioned at a distance equal to the sectioning depth (d) from the intersection of the straight line and the surface (S) of the tissue added to the intersection. If the estimated position of the aforementioned point does not coincide with a point of the prohibited area, the central processing unit (5) activates the laser emitter (1) via the controller (2), and in contrast, if at least one of the points coincides with at least one point of the prohibited area, the central processing unit stops the laser emitter.

[0143] The central processing unit (5) defines one or more reference planes (RS) based on several criteria.

[0144] Criterion 1: The boundary surface defining the start or end of the tissue. This tissue can be the tissue whose surface (S) is determined by the optical module (3), i.e., the main tissue or the tissue adjacent thereto.

[0145] Criterion 2: A flat surface essentially parallel to the focal plane of the laser emitter (1) and / or the focal plane of the optical module (3) establishing the maximum sectioning level.

[0146] Criterion 3: A surface having a maximum depth estimated point-by-point from the surface (S) of the tissue determined by the optical module (3).

[0147] These reference planes (RS) can be dynamic planes, i.e., they can change throughout the surgical intervention. For example, the flat surface establishing the maximum sectioning level at the start of the operation can be updated to a greater depth as the sectioning progresses. In another example, since the surface (S) of the tissue changes gradually throughout the operation, different surfaces with maximum depth can be gradually defined.

[0148] The central processing unit (5) defines these reference planes (RS) based on preoperative information, measurements of the optical module (3) itself, and / or decisions made by medical staff. Once the aforementioned reference planes are defined, they are assigned to the generated numerical model (NM).

[0149] Furthermore, in order to enhance safety during sectioning, the device is intended to include a safety margin that can be fixed or that varies throughout the surgical intervention, to the aforementioned reference plane (RS). Preferably, the central processing unit (5) comprises input means for entering the definition of the safety margin, and the medical staff is responsible for entering the margin via the interface.

[0150] Figure 2 shows an exemplary surface (S) of the tissue of the region (R) determined by the optical module (3) and three reference planes (RS1 - RS3) defined according to three different criteria.

[0151] The reference plane RS1 is a surface that defines the end of the main tissue, for example, the end of a vertebra in spinal surgery. In this example of Figure 2, the central processing unit (5) defines this surface RS1 and assigns it to the numerical model (NM) based on preoperative images such as those obtained by magnetic resonance, computed tomography, or fluoroscopy. In an alternative example, the central processing unit (5) defines this surface RS1 and assigns it to the numerical model (NM) based on measurements performed by the optical or photoacoustic system of the optical module (3).

[0152] The reference plane RS2 is a flat surface having a maximum level. In this example of Figure 2, the depth of this reference plane RS2 is defined by the surgeon at the start of the surgery. The value of the depth determined by the surgeon is received by the central processing unit (5) via the interface, and the device (5) then processes the information to define the reference plane RS2 and assigns it to the numerical model (NM).

[0153] The reference plane RS3 is a surface having a maximum depth defined point by point with respect to the surface (S) of the tissue determined at the start of the surgical intervention by the optical module (3). The central processing unit (5) receives the surface (S) of the tissue from the optical module (3), processes the information, defines a surface having the maximum depth RS3, and assigns it to the numerical model (NM).

[0154] Furthermore, the reference planes RS2 and RS3 change gradually through the surgical intervention. On the one hand, the surgeon can input, via the interface, a new value of the depth of the new flat surface RS2, which is then processed by the central processing unit (5), define the surface, and assign it to the numerical model (NM). Furthermore, taking into account the development of the surface (S) of the tissue as the sectioning procedure progresses, the central processing unit (5) can define a new surface having the maximum depth RS3 as it gradually receives updates regarding the surface (S) of the tissue from the optical module (3), and subsequently assign the new surface having the maximum depth RS3 to the numerical model (NM).

[0155] Additionally, FIG. 2 shows a series of points (P1 to P4) on the tissue where the laser beam hits, and the central processing unit (5) serves to determine whether it is necessary to activate the laser in each case. To do so, as described above, the central processing unit (5) estimates the position of the point on the straight line representing the laser beam, which is separated by a distance equal to the sectioning depth (d) from the intersection of the straight line and the surface (S) of the tissue. The aforementioned point is denoted by x in the figure. It is understood that the point is separated from the intersection in the opposite direction of the laser beam source, i.e., a point located within the tissue. If the estimated position indicates that the point is located outside the prohibited region, i.e., the region below one of the reference planes (RS1 to RS3), the central processing unit (5) activates the laser emitter (1) via the controller (2), and in contrast, if the aforementioned point is within the prohibited region, the central processing unit stops the laser emitter.

[0156] Instead, the central processing unit (5) estimates the position of a point on the straight line representing the laser beam that is included between the intersection of the straight line and the surface (S) of the tissue and a point obtained by adding a distance equal to the sectioning depth (d) to the intersection. When the estimated position indicates that the entire segment is located outside the prohibited region, i.e., outside the region below one of the reference planes (RS1 to RS3), the central processing unit (5) activates the laser emitter (1) via the controller (2). In contrast, when the segment is at least partially within the prohibited region, the central processing unit stops the laser emitter.

[0157] The state of the laser (1) at each of the aforementioned points in FIG. 2 will be described below. Point P1: Since all points are outside the prohibited region, the laser is activated. Point P2: Since the point is within the prohibited region defined by the plane RS2, the laser is stopped. Point P3: Since all points are outside the prohibited region, the laser is activated. Point P4: Since the point is within the prohibited region defined by the plane RS1, the laser is stopped.

[0158] In one example, the central processing unit (5) of the device described in either FIG. 1 or FIG. 2 is further adapted to perform a continuous scan of the light source of the optical module (3) across the region (R).

[0159] The central processing unit (5) controls the scanner to enable the light source of the optical module (3) to sweep across the region (R) while performing a continuous scan. As a result, the measured values, and using them, the surface (S) of the tissue is gradually updated in the numerical model (NM).

[0160] In a more specific example, this scan by the light source is after an established period has elapsed, before the activation or deactivation of the laser emitter (1) by the central processing unit (5), is performed when a measurement aging criterion selected from

[0161] By imposing these aging criteria, the device ensures that the measurement values of the optical module (3) are gradually updated at least every predefined period and / or each time the laser changes from the off state to the on state (or vice versa).

[0162] In one example, the central processing unit (5) is adapted to perform a continuous scan of the laser beam emitted by the laser emitter (1) over the region (R) until it reaches at least one reference plane (RS). In a particular example, the control of the scan established by the laser emitter (1) and the scan established by the optical module (3) are independent.

[0163] This scan is performed according to a predefined scan pattern. Preferably, the aforementioned pattern is uniform. In one example, from the perspective of the surgeon performing the surgery, the pattern is made from the left side to the right side and from top to bottom of the surgeon.

[0164] During a process that is executed iteratively and continuously, the laser (1) may interact with areas that do not need to be processed, i.e., areas that are referred to as prohibited areas above.

[0165] In a preferred example, the central processing unit (5) is further configured such that during the sectioning process while the laser emitter (1) scans a set of points in the region (R), each time a series of points reaches a point where the emission of the laser emitter (1) is blocked, the laser emitter is positioned at the next point where emission is permitted without stopping the emission of the laser beam.

[0166] That is, the central processing unit (5) controls the laser to skip the prohibited area, so that the process is completed without delay. The laser can redirect towards areas not prohibited by the scanner of the optical module (3).

[0167] In addition to the obvious speed achieved by this method, the laser is not stopped and thus not cooled, further providing the advantage of always operating under optimal conditions.

[0168] Alternatively, the central processing unit (5) can command the laser to continue scanning a predetermined pattern by sweeping across a prohibited area while preventing the laser (1) from being activated across that area.

[0169] In a preferred example, the sectioning laser gradually scans the biological tissue until the surface is leveled, taking into account an acceptable range within which it is considered to have succeeded in leveling the surface (S).

[0170] To achieve the purpose of leveling the bottom of the section, in one embodiment, the central processing unit (5) is further configured such that points where the sectioning depth is smaller than others are prioritized in the scanning sequence to compensate for the sectioning depth.

[0171] Accordingly, the central processing unit (5) prioritizes shallower points such that the laser is stopped at deeper points or regions and activated at more superficial points or regions. In this way, the surface layer region becomes deeper and deeper, while the deep region remains unchanged until all points reach the same level.

[0172] According to another embodiment, in order to maintain the operating conditions of the laser and prevent it from being cooled even when it stops, the laser remains activated but skips between higher points and avoids passing through points at lower heights.

[0173] This embodiment is shown in FIG. 3 which shows the positions of a set of points on the surface (S) of the tissue that the laser (1) hits. In this particular example, a flat reference surface (RS) is defined that defines the maximum sectioning level to be reached.

[0174] At point 1, the surface (S) of the tissue has reached the maximum sectioning level, while at points P2 to P4, it can be seen that the surface (S) is shallower. To achieve the purpose of flattening the section, the central processing unit (5) in this example prioritizes sectioning at point P4, followed by points P3 and P2. For safety reasons, this progression and flattening in tissue sectioning are always performed without invading a defined flat reference surface (RS).

[0175] This flat reference surface (RS) can be gradually established at multiple depth levels with respect to the focal plane of the laser emitter (1) and / or the focal plane of the optical module (3) such that when the entire surface (S) of the tissue drops to the depth of the aforementioned flat surface as a result of the action of the laser of the laser emitter (1), at least one flat surface changes to a deeper depth.

[0176] In one example, any of the reference surfaces (RS) can be defined by input means included in the central processing unit (5) for inputting the definition of at least one reference surface (RS), and the defined reference surface (RS) is then assigned to the numerical model (NM).

[0177] Additionally, in another example, the central processing unit (5) is provided with input means for inputting the definition of an area to be avoided (RA), and its shape is assigned to the numerical model (NM). The central processing unit (5) is further configured to stop the laser emitter (1) in the numerical model (NM) when at least one of the positions of the points of the aforementioned straight line representing the laser beam, which is the distance equal to the sectioning depth (d) added to the intersection of the straight line and the surface (S) of the tissue, coincides with the position of at least one point of the area to be avoided (RA).

[0178] In a specific example, the surgeon selects an area to be avoided (RA), preferably an RGB video image, shown through the surgical field display means for displaying the surgical field in a plan view. In an even more specific example, the central processing unit (5) calculates the distance between each point on the surface (S) of the tissue and the reference plane (RS) closest to each point, and superimposes information on the RGB image to show the aforementioned distance to the user via the surgical field display means. A specific way of showing depth-related information is the use of a color palette or depiction by levels that distinguish regions of different depths.

[0179] Both types of input means can be arranged at an interface that functions as an intermediary between the user and the central processing unit (5).

[0180] Figure 4 shows an example of a reference plane (RS) and an area to be avoided (RA) defined by the surgeon via the input means of the central processing unit (5), particularly the interface. The central processing unit (5) then assigns the surface and shape of the area to be avoided (RA) to a numerical model (NM).

[0181] Additionally, this Figure 4 shows the point P on the surface (S) where the laser beam (1) hits, which the central processing unit (5) has instructed to stop. As can be seen from the figure, according to the numerical model (NM), the set of points of the segment defined between the intersection of the straight line representing the laser beam and the surface (S) of the tissue, and the point obtained by adding a distance equal to the sectioning depth (d) to the intersection, is within the area to be avoided (RA). Therefore, considering that sectioning is prohibited in the area to be avoided (RA), the laser must stop at the aforementioned point P.

[0182] In one example, the central processing unit (5) is equipped with other safety mechanisms to prevent the laser from being activated in dangerous situations.

[0183] On the one hand, the central processing unit (5) comprises means for stopping the emission of the laser emitter (1), which is adapted to stop the emission of the laser emitter (1) when it is operating. These stopping means can be used at any time during the operation that the medical staff deems appropriate.

[0184] Furthermore, simultaneously or alternatively, the central processing unit (5) is further configured to stop the laser emitter (1) in the numerical model (NM) if any of the positions of the points of the straight line representing the laser beam do not coincide with the positions of the points of the surface (S) of the tissue. This means aims to prevent the laser from being activated to prevent the sectioning of important tissues and non-target tissues when the laser is not properly positioned above the surgical area (R) or when information about the actual surface (S) of the tissue is not available, for example, due to a failure of the optical module (3). This also constitutes a safety measure when the patient has not yet been positioned on the operating table.

[0185] Finally, FIG. 5 shows another safety measure of the device of the present invention, namely, the control of the laser output per unit of surface to prevent the tissue from being thermally damaged.

[0186] Therefore, the central processing unit (5) is further configured to define a function representing a scalar (X) representing the temperature level within a set of points in the region (R) having a specific pattern. The function initially takes a pre-established reference value, for example, 0. Each time the laser emitter (1) hits a point of the pattern, the function is increased by a first pre-established increment value (deltaX) at that point. The values of all points are reduced by a second pre-established increment value at each pre-established period. For each point of the pattern, if it exceeds a pre-established threshold value (Xth), the aforementioned point is assigned in the numerical model (NM) as a point where sectioning is not allowed as long as it remains above the aforementioned threshold value (Xth).

[0187] Thereby, the device adjusts the laser output per surface unit so as not to exceed a predetermined threshold value (Xth). This threshold value (Xth) can be a dynamic threshold value or can change gradually through surgical intervention. In one example, the user, surgeon, or medical staff selects the threshold value (Xth) at a given point in the surgery and preferably inputs the threshold value via the input means of the central processing unit (5) which is an interface. The pre-established period can be a fixed or dynamic period during the surgery. Further, it can be selected at a given point in the surgery by the user or medical staff who inputs a value to the central processing unit (5) via the input means. In this example, the surgeon selects a fixed period at the start of the surgery.

[0188] In one example, the device described in any of the figures further comprises a fluid management unit not shown in any of the aforementioned figures to provide the device with the ability to wash the surgical area (R). This unit is adapted to provide a flow of gas, liquid, or mist with liquid particles in the gas in the area including the area (R) of the living tissue on which the laser emitter (1) acts in the operating mode.

Claims

1. A biological tissue sectioning device, comprising: a laser emitter (1) adapted to section a biological tissue within a region (R); a controller (2) communicating with the laser emitter (1) and adapted to activate and deactivate the laser emitter (1); an optical module (3) adapted to determine a surface (S) of the tissue in the region (R) in an operating mode; a central processing unit (5) communicating with the controller (2) and the optical module (3), defining a pre-established sectioning depth (d) of the laser emitter (1), defining at least one reference plane (RS), the shape of the surface (S) of the tissue in the region (R), the shape of the at least one reference plane (RS) below which sectioning is prohibited, and the direction of a laser beam to which the laser emitter (1) is oriented, generating a numerical model (NM) of the region (R) at least including the above; in the numerical model (NM), when a position corresponding to a point on the straight line representing the laser beam and separated from the intersection of the same straight line and the surface (S) of the tissue by a distance equal to the sectioning depth (d) is located outside a prohibited region which is any part of the tissue in the region (R) where sectioning is prohibited, activating the laser emitter (1); a central processing unit (5) adapted as such; The device comprising the above.

2. The device according to claim 1, wherein the central processing unit (5) is further configured to deactivate the laser emitter (1) when at least one of the positions of a plurality of points on the straight line representing the laser beam in the numerical model (NM) is located between the intersection of the straight line and the surface (S) of the tissue and the position separated from the intersection by a distance equal to the sectioning depth (d) and coincides with the position of at least one point in the prohibited region.

3. The device according to any one of claims 1 to 2, wherein the central processing unit (5) is further configured to deactivate the laser emitter (1) when none of the positions of a plurality of points on the straight line representing the laser beam in the numerical model (NM) coincides with the position of a point on the surface (S) of the tissue.

4. The at least one reference plane (RS) is a first boundary surface defining an end of the tissue in the region (R), or A second boundary surface that defines a starting portion of a different tissue that is different from the tissue in the region (R) of the surface determined by the optical module (3) and is located deeper than the tissue in the region (R), or A third boundary surface that defines an end portion of a different tissue that is different from the tissue in the region (R) of the surface determined by the optical module (3) and is located deeper than the tissue in the region (R), or At least two combinations of the first boundary surface, the second boundary surface, and the third boundary surface The apparatus according to any one of claims 1 to 3.

5. The apparatus according to any one of claims 1 to 4, wherein the at least one reference surface (RS) includes a flat surface that is essentially parallel to the focal surface of the laser emitter (1) and / or the focal surface of the optical module (3).

6. The apparatus according to any one of claims 1 to 5, wherein the at least one reference surface (RS) includes a surface having a maximum depth determined from the surface (S) of the tissue.

7. The at least one reference surface (RS) is The first boundary surface that defines the end of the tissue in the region (R), A second boundary surface that defines a starting portion of a different tissue that is different from the tissue in the region (R) of the surface determined by the optical module (3) and is located deeper than the tissue in the region (R), A third boundary surface that defines an end portion of a different tissue that is different from the tissue in the region (R) of the surface determined by the optical module (3) and is located deeper than the tissue in the region (R), A flat surface that is essentially parallel to the focal surface of the laser emitter (1) and / or the focal surface of the optical module (3), A surface having a maximum depth determined from the surface (S) of the tissue, The apparatus according to any one of claims 1 to 3, including at least one of them.

8. The apparatus according to any one of claims 1 to 7, wherein the central processing unit (5) defines the at least one reference surface (RS) with a safety margin.

9. The apparatus according to any one of claims 1 to 8, wherein the optical module (3) comprises an optical coherence tomography OCT system.

10. The apparatus according to claim 9, wherein the optical coherence tomography OCT system is a polarization-sensitive optical coherence tomography PS-OCT system.

11. The optical module (3) is structured light type, or stereo pair type, or photoacoustic tomography type The apparatus according to any one of claims 1 to 8, comprising a system of.

12. The apparatus according to any one of claims 1 to 11, wherein the laser emitter (1) comprises a scanner capable of changing the direction of the beam so as to direct the beam to different points in the region (R).

13. The apparatus according to any one of claims 1 to 12, wherein the optical module (3) comprises a light source and a scanner capable of changing the direction of the light source so as to direct the light source to different points in the region (R).

14. The apparatus according to any one of claims 12 to 13, wherein the central processing unit (5) is adapted to perform a continuous scan of the laser beam emitted by the laser emitter (1) across the region (R) until reaching the at least one reference plane (RS).

15. The apparatus according to claim 13, wherein the central processing unit (5) is adapted to perform a continuous scan of the light source of the optical module (3) across the region (R).

16. The laser emitter (1) comprises a scanner capable of changing the direction of the beam so as to direct the beam to different points in the region (R), The optical module (3) comprises a light source and a scanner capable of changing the direction of the light source so as to direct the light source to different points in the region (R), The central processing unit (5) is adapted to perform a continuous scan of the laser beam emitted by the laser emitter (1) across the region (R) until reaching the at least one reference plane (RS), The central processing unit (5) is adapted to perform a continuous scan of the light source of the optical module (3) across the region (R), The control of the scan established by the laser emitter (1) and the scan established by the optical module (3) are independent. The apparatus according to claim 1.

17. The scan of the light source of the optical module (3) across the region (R) is after a pre-established period has elapsed, Before starting or stopping the laser emitter (1) by the central processing unit (5), The device according to claim 15, which is implemented when a spoilage criterion selected from is satisfied.

18. In the numerical model (NM) generated by the central processing unit (5), when the flat surface descends to the depth of the flat surface as a result of the action of the laser of the laser emitter (1) on the surface (S) of the tissue, the flat surface changes to a deeper depth. The device according to claim 5 or 7, which is gradually established at a plurality of depth levels with respect to the focal plane of the laser emitter (1) and / or the focal plane of the optical module (3).

19. The device according to any one of claims 1 to 18, wherein the central processing unit (5) comprises input means for inputting a definition of at least one reference plane (RS) assigned to the numerical model (NM).

20. The device according to claim 19, wherein the at least one reference plane (RS) is determined by preoperative images and / or intraoperative images, preferably by magnetic resonance images, computed tomography images, or fluoroscopic images.

21. The device according to claim 20, wherein the at least one reference plane (RS) determined by preoperative images and / or intraoperative images is an interface defining an end portion of the bone tissue in the region (R).

22. The central processing unit (5) comprises input means for inputting a definition of a region (RA) to be avoided, the shape of which is assigned to the numerical model (NM), The central processing unit (5) is configured such that in the numerical model (NM), at least one of the positions of a plurality of points of the straight line representing the laser beam located between the intersection of the straight line and the surface (S) of the tissue and the position spaced apart from the intersection by a distance equal to the sectioning depth (d) coincides with the position of at least one point of the region (RA) to be avoided. Further configured to stop the laser emitter (1), The device according to any one of claims 1 to 21.

23. The device according to any one of claims 1 to 22, comprising a surgical field display means, preferably a screen showing an RGB video image.

24. The apparatus according to claim 23, wherein the surgical field display means further shows information regarding the distance from each point on the surface (S) of the tissue to the at least one reference plane (RS).

25. The apparatus according to any one of claims 12 to 24, wherein the central processing unit (5) is further configured such that, during the sectioning process while the laser emitter (1) scans a set of a plurality of points in the region (R), each time a series of the plurality of points reaches a point where the radiation of the laser emitter (1) is blocked, the laser emitter is positioned at the next point where the radiation is permitted without stopping the emission of the laser beam.

26. The central processing unit (5) is further configured to define a function representing a scalar (X) representing the temperature level in a set of a plurality of points in the region (R) having a specific pattern, the function initially takes a pre-established reference value, each time the laser emitter (1) collides with a point of the pattern, the function is increased by a first pre-established increment value (deltaX) at that point, the values of the function for all the points are reduced by a second pre-established increment value at each pre-established period, for each point of the pattern, when the value of the function for the point exceeds a pre-established threshold value (Xth), the point is assigned to the numerical model (NM) as a point where sectioning is not permitted as long as the value of the function remains above the threshold value (Xth). The apparatus according to any one of claims 1 to 25.

27. The apparatus according to any one of claims 12 to 26, wherein the central processing unit (5) is further configured such that, during the sectioning process while the laser emitter (1) scans a set of a plurality of points in the region (R), points with a shallower sectioning depth than others are prioritized in the scanning sequence so as to compensate for the sectioning depth.

28. The apparatus according to claim 8, wherein the central processing unit (5) comprises input means for inputting the definition of the safety margin of the at least one reference plane (RS).

29. The apparatus according to any one of claims 1 to 28, wherein the central processing unit (5) comprises means for stopping the emission of the laser emitter (1) adapted to stop the emission of the laser emitter (1) when operating.

30. The device according to any one of claims 1 to 29, further comprising a fluid management unit adapted to provide a flow of gas, or liquid, or a mist having liquid particles in a gas within the region including the region (R) of the biological tissue on which the laser emitter (1) acts in the operating mode.

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