System and method utilizing magnetic steering for placement of a catheter within brain tissue for laser ablation

Abstract

Systems and methods herein involve placement of an elongated body structure (e.g., catheter) having a therapeutic optical fiber within brain tissue of a subject to enable delivery of laser emissions for therapeutic effect. The body structure is steered along non-linear trajectories within the brain tissue, including magnetic steering (e.g., pulling) via a magnetic field source external to the subject and including linear actuation (e.g., pushing) via an actuator outside the subject. A fiber optic shape sensor is arranged within the body structure. The therapeutic optical fiber is configured to be coupled to a laser to permit laser emissions to be delivered through a photonic output end thereof to one or more areas of the brain tissue.

Description

SYSTEM AND METHOD UTILIZING MAGNETIC STEERING FOR PLACEMENT OF CATHETER BEARING OPTICAL FIBERS WITHIN BRAIN TISSUE FOR LASER ABLATIONCross-Reference to Related Applications)

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 707,502 filed on October 15, 2024, wherein the entire contents of the foregoing application are hereby incorporated by reference herein.Technical Field

[0002] This disclosure relates to a system and method utilizing magnetic steering for placement of a catheter bearing at least one optical fiber within brain tissue of a subject to permit delivery of laser emissions to the brain tissue for laser ablation.Background

[0003] Various neurological disorders involve mesial temporal lobe structures of the brain, such as the hippocampus, amygdala, entorhinal cortex, and other areas, and may not be adequately treated with pharmaceuticals. For example, Drug-Resistant Epilepsy (DRE) affects a significant number of patients who do not respond adequately to conventional anti-epileptic drugs. According to the CDC, approximately 3.4 million people in the U.S. live with active epilepsy, 30% of whom continue to suffer from seizures that are refractory to medications. Stereotactic Laser Ablation of the Hippocampus (SLAH) has emerged as a minimally invasive surgical option to target epileptic foci within the brain, particularly in cases of temporal lobe epilepsy. SLAH is a procedure that destroys lesions (i.e., tissue that has suffered damage through injury or disease) in the brain that cause seizures. According to such a procedure, a laser fiber is pushed in from the cortical surface and placed into the area of the brain causing seizures (i.e., a pathologic target) with computer-assisted stereotactic guidance. Laser energy is supplied through the fiber to effectuate precise destruction of soft tissue. However, current methods for implanting SLAH laser fibers rely on linear trajectories and manual navigation, which limit the ability to reach certain regions of the hippocampus accurately and safely. Additionally, complete ablation of both the amygdala and hippocampus has been show to correlate with improved seizure outcomes. Given the anatomical intricacies of target structures particularly the hippocampal head and amygdala, which deviate medially from the hippocampal body's long axis, laser fiber deployment often requires two separate trajectories.Each trajectory brings the risk of hemorrhage due to vascular damage, especially to vessels near the targeted structures within the superficial cortical areas.

[0004] Another therapeutic surgical procedure for addressing medically refractory epilepsy, particularly in patents who do not respond to anti-seizure medications, is corpus callostomy. This procedure involves making severing the corpus callosum, which is a band of nerve fibers that connects the right and left hemispheres of the brain. Severing this connection may help prevent seizure activity from spreading between the two sides of the brain, thereby reducing the severity and frequency of seizures. Although laser corpus callostomy has been investigated, a large number of linear trajectories (e.g., up to five trajectories) using conventional methods have been required to successfully ablate the full extent of the complex corpus callosum. This significantly elevates the risk of complications, since the risk of hemorrhage from damaging intracranial vessels is directly proportional to the number of passes through brain parenchyma, with each trajectory increasing the risk of intracranial hemorrhage by approximately 1 percent.

[0005] Need exists to enhance clinical outcomes and procedural safety of ablation therapies for treatment neuropsychiatric disorders.Summary

[0006] Aspects of the present disclosure relate to a system and method for precise placement of a catheter bearing at least one therapeutic optical fiber within brain tissue of a subject to enable delivery of laser emissions to the brain tissue for therapeutic effect. Such placement may involve transit of a steerable assembly having a catheter embodied in an elongated body structure over non-linear trajectories within the brain tissue, including magnetic steering via a magnetic field source located outside the subject interacting with a premagnetized material of the steerable assembly, and including a linear actuator (also located outside the subject) coupled with the elongated body structure and configured to advance at least a portion of the elongated body structure within the brain tissue. A fiber optic shape sensor is arranged within the elongated body structure. The therapeutic optical fiber is configured to be coupled to a laser (also located outside the subject) to permit laser emissions to be delivered through a photonic output end of the therapeutic optical fiber to one or more areas of the brain tissue.

[0007] In one aspect, the disclosure relates to a system for placement of a therapeutic optical fiber within brain tissue to enable delivery of laser emissions, the system comprising: at least one magnetic field source; a steerable assembly that comprises: an elongated body structure having a proximal end and a distal end, the therapeutic optical fiber extending within theelongated body structure to a photonic output end proximate to the distal end of the elongated body structure, a premagnetized material arranged closer to the distal end than to the proximal end of the elongated body structure, and a fiber optic shape sensor within the elongated body structure; and a linear actuator coupled to the elongated body structure at a position closer to the proximal end than to the distal end of the elongated body structure, the linear actuator being configured to advance at least a portion of the elongated body structure within the brain tissue; wherein the at least one magnetic field source is configured to interact with the premagnetized material to effectuate steering of the distal end of the elongated body structure when the distal end is arranged within the brain tissue; and wherein the therapeutic optical fiber is configured to be coupled to a laser to permit laser emissions to be delivered through the photonic output end to one or more areas of the brain tissue.

[0008] In certain embodiments, the system further comprises at least one robotic arm configured to move the at least one magnetic field source.

[0009] In certain embodiments, the premagnetized material comprises at least one of a permanent magnet, a ferromagnetic material, or an electromagnet.

[0010] In certain embodiments, the premagnetized material is arranged within an interior of the elongated body structure.

[0011] In certain embodiments, the premagnetized material is configured to be removed from the interior of the elongated body structure while the at least a portion of the elongated body structure is arranged within the brain tissue.

[0012] In certain embodiments, the fiber optic shape sensor comprises one or more optical frequency domain reflectometry (OFDR) sensors.

[0013] In certain embodiments, the fiber optic shape sensor comprises one or more fiber Bragg grating (FBG) sensors.

[0014] In certain embodiments, the system further comprises at least one processor configured to control operation of at least one magnetic field source, the steerable assembly, and the linear actuator.

[0015] In certain embodiments, the system further comprises one or more magnetic field sensors, wherein the at least one processor is configured to control movement and / or activation of the at least one magnetic field source responsive to outputs of the one or more magnetic field sensors.

[0016] In certain embodiments, the at least one processor is configured to control the at least one magnetic field source and the linear actuator without user intervention.

[0017] In certain embodiments, the system further comprises a user input device controllable by user manipulation, wherein the magnetic field source and the linear actuator are configured to be operated responsive to outputs of the user input device.

[0018] In another aspect, the disclosure relates to a method for delivering laser emissions to brain tissue using a system as disclosed herein, the method comprising: moving the at least one magnetic field source to effectuate steering of the distal end of the elongated body structure and advancing the elongated body structure within the brain tissue using the linear actuator to position the photonic output end at a desired location within the brain tissue; and operating the laser to deliver laser emissions through the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue.

[0019] In certain embodiments, the operating of the laser to deliver laser emissions through the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue comprises Stereotactic Laser Ablation of the Hippocampus (SLAH).

[0020] In certain embodiments, the operating of the laser to deliver laser emissions through the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue comprises performing corpus callostomy.

[0021] In certain embodiments, the moving of the at least one magnetic field source comprises moving the at least one magnetic field source using at least one robotic arm.

[0022] In certain embodiments, one or more magnetic field sensors are provided, and the method further comprises controlling movement and / or activation of the at least one magnetic field source responsive to outputs of the one or more magnetic field sensors.

[0023] In certain embodiments, the method further comprises utilizing three-dimensional trajectory information and a three-dimensional model of the brain tissue to control movement the at least one magnetic field source and advancement of the elongated body structure within the brain tissue.

[0024] In another aspect, any two or more features of aspects and / or embodiments disclosed herein may be combined for additional advantage.Brief Description of Drawings

[0025] FIG. 1 is a schematic diagram showing interconnections between components of a system for utilizing magnetic steering for placement of a steerable assembly including an elongated body structure (e.g., catheter) and at least one therapeutic optical fiber within brain tissue of a subject, to permit delivery of laser emissions to the brain tissue for laser ablation according to one embodiment.

[0026] FIG. 2 is a perspective view of a robotic arm incorporating magnets to serve as an end effector to effectuate steering of an elongated body of a steerable assembly incorporating at least one optical fiber to permit delivery of laser emissions to the brain tissue for laser ablation according to one embodiment.

[0027] FIG. 3 is a schematic side view illustration of a portion of a fiber Bragg grating sensor that may be utilized for determining position of a steerable assembly incorporating at least one therapeutic optical fiber to permit delivery of laser emissions to the brain tissue for laser ablation according to one embodiment.

[0028] FIG. 4 is a perspective view of robot arm carrying permanent magnets and an elongated body including a fiber optic shape sensor as part of a steerable assembly incorporating at least one optical fiber to permit delivery of laser emissions to the brain tissue for laser ablation according to one embodiment, with inset images of a display showing side and top views of brain tissue with a steerable assembly therein.

[0029] FIG. 5 shows multiple images of brain tissue including portions subject to being laser ablated according to devices and methods disclosed herein, with left and right frames showing superimposed first and second straight trajectories as well as a superimposed third curved trajectory for a steerable assembly as disclosed herein, and with a center magnified frame showing a portion of a steerable assembly therein, according to one embodiment.

[0030] FIG. 6 is a plot of force versus displacement showing forces needed for puncturing and moving through brain tissue, for lumens (e.g., catheters) having diameters ranging from 7. 5 to 100 microns.

[0031] FIG. 7 is a plot of magnetic pulling force (in Nm) applied to two 15 kg cubic external magnetic on cylindrical internal magnets of diameters 0.5 to 1.5 mm at different distances ranging from 100 to 200 mm.

[0032] FIG. 8 is a hybrid point to point and path diagram for controlling a steerable assembly having an internal premagnetized material using magnetic steering and avoiding back-tracking according to one embodiment.

[0033] FIG. 9 is a block diagram for a closed-loop control system for steering of an intracranial magnetically steerable assembly according to one embodiment.

[0034] FIG. 10 is a plot of path (Y mm vs. X mm) for manipulation of an elongated body structure having a FOSS sensor and internal magnets through three different curvatures in a stiff phantom gel, tracked using a fiber Bragg grating system.

[0035] FIG. 11 is a plot of path (Y mm vs. X mm) for manipulation of an elongated body having a FOSS sensor and internal magnets through three different curvatures in a soft phantom gel, tracked using a fiber Bragg grating system.

[0036] FIG. 12 provides plots of force (g) versus time (sec) depicting penetration transients and cumulative drag forces on a 3-mm diameter catheter moved through 0.6 agarose gel by a motor-drive force gauge inserted at a rate of 0.33 mm per second, with a mean data plot presented along with upper and lower values of standard deviations of the data.

[0037] FIG. 13 provides plots of force (g) versus time (sec) depicting penetration transients and cumulative drag forces on a 3-mm diameter catheter moved through porcine brain tissue by a motor-drive force gauge inserted at a rate of 0.33 mm per second, with a mean data plot presented along with upper and lower values of standard deviations of the data.

[0038] FIG. 14A is a top plan view of the path of a magnetically steerable assembly superimposed on a preoperative MRI / CT image of a human brain.

[0039] FIG. 14B is a perspective view of the path of a magnetically steerable assembly superimposed on a three-dimensional image of a cadaver head.

[0040] FIG. 14C-14D provide rear elevational and left side elevational views, respectively, of the items of FIG. 14 A.

[0041] FIG. 15 A is a top plan view of the path of a magnetically steerable assembly including FOSS sensors superimposed on a preoperative MRI / CT image of a cadaver brain

[0042] FIG. 15B is a perspective view of the path of a magnetically steerable assembly including FOSS sensors superimposed on a three-dimensional image of a cadaver head.

[0043] FIG. 15C-15D provide rear elevational and left side elevational views, respectively, of the items of FIG. 15 A.

[0044] FIG. 16 is a plot of measured insertion force versus displacement within a cadaver brain of the magnetically steerable assembly of FIG. 15 A.

[0045] FIG. 17 is a plot of steerable assembly deflection in two dimensions according to PyElastica-based simulations measurements of steerable assembly deflection under gravity alone and under combined gravity plus magnetic field conditions.

[0046] FIG. 18 is a schematic diagram of a generalized representation of a computer system that can be included as one or more components of a system or method utilizing magnetic steering and linear actuation for placement of at least one optical fiber within brain tissue of a subject to permit delivery of laser emissions to the brain tissue according to one or more embodiments.Detailed Description

[0047] In one or more aspects, the present disclosure relates to a system and method for precise placement of a catheter bearing at least one therapeutic optical fiber within brain tissue of a subject to enable delivery of laser emissions to the brain tissue for therapeutic effect. Such placement may involve transit of a steerable assembly having a catheter embodied in an elongated body structure over non-linear traj ectories within the brain tissue, including magnetic steering via a magnetic field source located outside the subject interacting with a premagnetized material of the steerable assembly, and including a linear actuator (also located outside the subject) coupled with the elongated body structure and configured to advance at least a portion of the elongated body structure within the brain tissue. A fiber optic shape sensor is arranged within the elongated body structure. The therapeutic optical fiber is configured to be coupled to a laser (also located outside the subject) to permit laser emissions to be delivered through a photonic output end of the therapeutic optical fiber to one or more areas of the brain tissue.

[0048] In certain embodiments, systems and methods disclosed herein enable precise three- dimensional placement of a catheter bearing one or more therapeutic optical fibers in brain tissue to perform Stereotactic Laser Ablation of the Hippocampus (SLAH) in patients with Drug-Resistant Epilepsy (DRE). This system uses magnetic steering to accurately guide laser fibers borne by a catheter having a flexible elongated body structure through complex brain structures, minimizing damage to surrounding tissues and enhancing the safety and efficacy of the SLAH procedure. Magnetic steering may be aided by linear actuation (e.g., pushing) of the elongated body structure. This technology enables flexible, non-linear trajectories that surpass the limitations of existing manual or linear placement methods, which reduces the risk of injury to critical brain structures, enhancing patient safety during the outcome.

[0049] In certain embodiments, the premagnetized material comprises at least one of a permanent magnet, a ferromagnetic material, and an electromagnet. In certain embodiments, the premagnetized material comprises multiple strategically placed premagnetized material regions within an elongated body structure.

[0050] In certain embodiments, the premagnetized material is arranged within an interior of the elongated body structure. In certain embodiments, the premagnetized material is configured to be removed from the interior of the elongated body structure while the at least a portion of the elongated body structure is arranged within the brain tissue. For example, a premagnetized material may be selectively withdrawn through a passage defined in the elongated body structure.

[0051] The fiber optic shape sensor serves as a tracking apparatus for the elongated body structure to achieve accurate and flexible navigation within brain tissue of a subject, and provides feedback on position and orientation of the elongated body structure relative to anatomical structures of the brain tissue. In certain embodiments, the fiber optic shape sensor comprises one or more fiber Bragg grating (FBG) sensors. In certain embodiments, the fiber optic shape sensor comprises one or more optical frequency domain reflectometry (OFDR) sensors. OFDR can measure strain and temperature variations along a fiber's length in a distributed manner, thus enabling the reconstruction of complex shapes with higher accuracy. In certain embodiments, real-time tracking data provided by fiber optic shape sensing may be integrated with pre-operative MRI images to minimize the need for invasive live imaging (such as X-ray, MRI, and ultrasound imaging) with its attendant limitations (e.g., radiation exposure, insufficient temporal resolution, and / or incompatibility with magnetic objects).

[0052] In certain embodiments, the system comprises at least one robotic arm configured to move the at least one magnetic field source. In certain embodiments, the at least one robotic arm comprises a six-degree-of-freedom (6-DOF) robotic arm that supports a plurality of magnets to enable application of precise magnetic fields and gradients to steer the elongated body along non-linear trajectories.

[0053] As noted above, a linear actuator is provided (i.e., to perform mechanical pushing of an elongated body structure) in addition to a magnetic steering system, wherein the resulting dual-control approach (mechanical pushing and magnetic steering) allows an elongated body structure to be navigated through complex, curved pathways within brain tissue to reach specific target regions (e.g., of the hippocampus). The mechanical pushing beneficially allows an elongated body structure to be advanced through brain tissue that would be difficult to penetrate with magnetic pulling alone. As the elongated body structure is pushed forward, the external magnetic field generator may be dynamically repositioned in three-dimensional space to generated controlled magnetic fields, thereby exerting torques on premagnetized material(s) of the elongated body structure, to continuously align them with the desired trajectory and enable directional control in three dimensions. The integration of magnetic manipulation and real-time tracking enhances the precision of therapeutic delivery of laser emissions to ensure that a laser fiber is accurately guided to target tissues (e.g., epileptogenic foci) while reducing or minimizing the risk of collateral damage to surrounding healthy tissues.

[0054] In another aspect, the disclosure relates to a method for delivering laser emissions to brain tissue utilizing a system as disclosed herein. The method comprises moving at least one magnetic field source to effectuate steering of the distal end of the elongated body structureand advancing the elongated body structure within the brain tissue using the linear actuator to position the photonic output end at a desired location within the brain tissue. The method further comprises operating a laser (e.g., located outside a subject) coupled with the therapeutic optical fiber to deliver laser emissions thro ugh the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue, such as by performing laser ablation.

[0055] FIG. 1 schematically illustrates components of a system for placement, within brain tissue 110, of an elongated body structure 150 (such as a catheter) bearing at least one therapeutic optical fiber 172 to enable delivery of laser emissions (e.g., for laser ablation) according to one embodiment. At lower left, a surgical instrument including the elongated body structure 150 extends through an opening or incision 111 and is positioned within tissue (e.g., brain tissue) 110 of a human body or other animal body. The elongated body structure 150 terminates at a distal end 180 including a tip portion 181 within the brain tissue 110, with the distal end 180 coinciding with a photonic output end 180 of the therapeutic optical fiber 172. The elongated body 150 structure further comprises at least one premagnetized material 156 proximate to the distal end 180 (e.g., closer to the distal end 180 than to a proximal end 182 thereof). The system further includes a fiber optic shape sensor (FOSS) 161 received by the elongated body structure 150. In certain embodiments, the fiber optic shape sensor 161 may include one or more optical frequency domain reflectometry (OFDR) sensors, or one or more fiber Bragg grating (FBG) sensors, associated with an optical fiber (e.g., a sensory fiber differing from the above-mentioned therapeutic optical fiber 172 configured to deliver laser emissions).

[0056] One or more magnetic field sources that may comprise one or more robotic actuators 114 (e.g., robotic arms, such as 6-degree-of-freedom (6DOF) robotic arms) are arranged external to the body comprising the brain tissue 110 to apply at least one magnetic field to interact with the premagnetized material 156 of the elongated body structure 150 to effectuate steering of the elongated body structure 150. In certain embodiments, a UR16e robotic arm may be used. In certain embodiments, multiple robotic actuators 114 may be provided. Each robotic actuator 114 may be controlled by a motor driver 116 and a processor 130 (e.g., integrated with a microcomputer in certain embodiments), wherein one or more intermediately arranged motor signal converters 117 may also be provided. Desired poses of each robotic actuator 114 may be calculated by the processor 130 and supplied to the motor driver 116 to control movement of the robotic actuator 114. Movement of one or more magnetic end effectors 112A, 112B (which may be embodied in permanent magnet materials, ferromagnetic materials, or electromagnets) may effectuate steering of the elongated body structure 150 whenpresent within tissue (e.g., brain tissue) 110 of an animal (e.g., human) body. In certain embodiments, magnetic end effectors 112A, 112B may be mounted on separate support arms 115A, 115B and spaced apart from one another.

[0057] In certain embodiments, a user input device 119 controllable by user manipulation may be arranged to permit control of the magnetic field source(s) 114 as well as a linear actuator 152 to achieve a desired trajectory of the elongated body structure 150 for positioning the photonic output end 180 at a desired location within the brain tissue 110. One or more feedback actuators 118 are configured to supply haptic feedback to a user (e.g., surgeon or other medical professional) through the user input device 119, wherein such haptic feedback may be proportional to one or more of magnetic field strength, magnetic field direction, etc.). One example of a user input device 119 is a joystick, which may be provided in single or dual forms, optionally augmented with various items such as triggers, buttons, dials, and the like. In certain embodiments, movement and / or activation of at least one magnetic field source 114 may be controlled responsive to one or more of detected magnetic field strength and detected magnetic field direction, which may be detected by one or more magnetic field sensors 121.

[0058] In certain embodiments, the magnetic field source(s) 114 and linear actuator 152 may be robotically controlled without user intervention to achieve a desired trajectory of the elongated body structure 150 for positioning photonic output ends of one or more therapeutic optical fibers 172 at desired location(s) within brain tissue 110.

[0059] A linear actuator 152 is provided to control advancement of the elongated body structure 150 into and within tissue 110 (e.g., brain tissue) of the human or other animal body. A data acquisition device 136 sends control inputs to a linear actuator driver 151 that supplies power to the linear actuator 152 which is coupled with the elongated body structure 150. Operation of the linear actuator 152 is controlled together with the at least one magnetic field source 114 to cause the elongated body structure 150 to move along a desired non-linear trajectory within the tissue 110. In certain embodiments, signals provided to and / or obtained from the linear actuator 152 may be indicative of advancement of the elongated body structure 150 into the tissue 110, and may be used (together with signals from a fiber optic shape sensor 161 and associated FOSS driver / detector 160 as described herein) to determine position of the elongated body structure 152 within the tissue 110.

[0060] With continued reference to FIG. 1, in certain embodiments, position of the elongated body structure 150 of the surgical instrument within tissue 110 (e.g., brain tissue) may be estimated without continuous imaging techniques. In certain embodiments, one or more fiber optic shape sensors 161 may be provided in or on the elongated body structure 150 and insertedinto brain tissue 110. Light signals may be supplied to a sensing optical fiber by a FOSS driver / detector 160 arranged external to the tissue of the human or other animal body 110. Reflected light signals received by the FOSS driver / detector 160 may be used to determine one or more of force, strain, or shape of the fiber optic shape sensor(s) 161 associated with the elongated body structure 150, and thereby used (e.g., in conjunction with signals provided to and / or received from the linear actuator 152) to determine orientation and position of the elongated body structure 150. In certain embodiments, FOSS sensors (e.g., one or more optical fibers with multiple sensing regions 164) may be secured to the elongated body structure 150 with a biodegradable polymer such as PEO or another adhesive or wax. In certain embodiments, fragile optical fibers of FOSS sensors 161 may be safeguarded by encasement in stress-dissipating Teflon or Nitinol tubes. In certain embodiments, temperature-induced reading variances may be mitigated through insulation and signal-processing compensation techniques. Implementing these strategies may significantly enhance robustness and accuracy of FOSS sensors 161, such as FBG or OFDR sensors.

[0061] In certain embodiments, a three-dimensional (3D) model of brain tissue (and / or other tissue) of a human or other animal body is generated before a steerable assembly as described herein (e.g., including an elongated body structure 150) is supplied to tissue 110 of the human or other animal body. Such a 3D model may be generated by any suitable imaging device 123, such as a MRI, CT, ultrasound, fluoroscopy, or other imaging device. The 3D model, optionally received via a network interface 144 and / or generated from 3D model input data 142 as part of a 3D model interaction subsystem 141, may be stored to memory 146 accessible to at least one processor 130, in preparation for receiving 3D trajectory information of a steerable assembly (including the elongated body structure 150) for superimposition onto the 3D model. The 3D model may be viewable via a display 148. The 3D trajectory information may be determined by directly by imaging, or inferentially from a detected length of insertion of the elongated body structure 150 into the tissue 110, in combination with a recorded directionality of a magnetic field applied (by magnetic effectors 112A, 112B) to a premagnetized material 156 (e.g., proximate to tip portion 181) associated with the elongated body structure 150 that may be part of a surgical instrument.

[0062] In certain embodiments, recording of directionality of one or more magnetic fields supplied by one or more magnetic field sources 112A, 112B comprises recording control signals supplied motor drivers 116 coupled with the robotic manipulator 114 configured to adjust position of magnetic end effectors 112A, 112B configured to apply one or more magnetic fields to a premagnetized material 156 of the elongated body structure 150. Restated,the recording of directionality of the magnetic field may comprise recording control signals supplied to robot arm 114. In certain embodiments, recording of directionality of the magnetic field may comprise, or be supplemented by, collected signals received from one or more magnetic field sensors 121. In certain embodiments, one or more magnetic field sensors 121 may be positioned proximate to the tissue 110 into which the elongated body structure 150 is inserted.

[0063] In certain embodiments, the system 100 may be configured to receive signals for linear translation / insertion of an elongated body structure 150 (for determining insertion depth of the elongated body structure 150), receive signals for movement of a robotic actuator (for determining magnetic field direction), and process the signals for forwarding to a computer processor (e.g., 130) for superimposition of a 3D trajectory of the elongated body structure 150 on a previously generated 3D model of tissue 110 (e.g., brain tissue) into which the elongated body structure 150 is inserted. By superimposing FOSS sensor data onto pre-operative MRI, CT, and / or CAT scans of the brain, dynamic visualization (e.g., using display 148) of placement of an elongated body within brain tissue 110 is enabled.

[0064] In certain embodiments, a condition indicative of heart rate, respiration rate, and / or respiration amplitude of a human and / or animal body may be sensed (e.g., chest sensors, respiration sensors, radar-based sensors, or the like) and responsive to the sensing, a 3D model of the body containing the tissue 110 (storable in memory 146) may be updated, and / or position of the magnetic end effector(s) 114 may be adjusted. In certain embodiments, the foregoing scheme may be used to update end effector position (e.g., maintain constant distance between the tissue 110 and the magnetic end effector(s) 114) so that a desired (e.g., constant) magnetic force is applied on the premagnetized material 156 associated with the elongated body structure 150.

[0065] In certain embodiments, a laser driver 170 configured to generate laser emissions is coupled with a therapeutic optical fiber 172 that extends in or on the elongated body structure 150 to transmit laser emissions to a photonic output end 180 coinciding with a distal end of the elongated body structure 150. When the elongated body structure is placed at a desired position within brain tissue 110, laser emissions may be emitted through the photonic output end 180 to interact with (e.g., ablate) desired portions of brain tissue 110 (including, but not limited to, mesial temporal lobe structures such as the hippocampus, amygdala, entorhinal cortex) to provide therapeutic effect. In certain embodiments, the laser ablation is performed on the hippocampus (e.g., in the form of Stereotactic Laser Ablation of the Hippocampus (SLAH)) to treat drug-resistant epilepsy and / or other conditions. In certain embodiments, multiple laserdrivers 170 and multiple therapeutic optical fibers 172 may be provided, with each laser driver 170 coupled to a corresponding therapeutic optical fiber 172, to permit laser emissions to be delivered to multiple brain tissue locations without requiring movement of the elongated body structure 150 between steps of impinging laser treatment on the multiple brain tissue locations.

[0066] As noted previously, a premagnetized material 156 (which may be arranged as a single premagnetized body, or arranged as multiple premagnetized bodies that are spaced apart or contacting one another) is associated with the elongated body structure at one or more locations proximate to a distal end 180 thereof. In certain embodiments, the premagnetized material 156 is arranged within the elongated body structure to permit the elongated body structure 150 to be steered to a desired location within brain tissue 110, but the premagnetized material 156 is configured to be removed from the elongated body structure 150 while the elongated body structure 150 remains within the brain tissue 111, such as to permit imaging (e.g., via MRI) of the brain tissue 111 with the elongated body structure 150 received therein. In certain embodiments, the premagnetized material 156 may be weakly adhered to an interior of the elongated body (e.g., with a biodegradable polymer such as polyethylene oxide (PEO), or another adhesive and / or wax material), and one or more tethers (e.g., wires and / or filaments) may be coupled with the premagnetized material 156 to permit the premagnetized material 156 to be extracted or otherwise removed from the elongated body structure 150 by pulling the premagnetized material 156 through a passage of the elongated body structure 150. In certain embodiments, premagnetized material 156 may be secured to an elongated body structure 150 using heat shrink tubing and biodegradable polymers. In certain embodiments, a premagnetized material 156 and a FOSS sensor 161 may be positioned sequentially within a single heat shrink tube that is inserted into a hollow tube or sheath that forms the elongated body structure 150.

[0067] As shown in FIG. 1, one or more additional sensors 134 (e.g., for sensing temperature, sensing pressure, capturing images, etc.) may be associated with the elongated body structure 150 to provide additional information useful for ascertaining position and / or controlling delivery of laser emissions.

[0068] In certain embodiments, the elongated body structure 150 may utilize a Medtronic Visualase therapeutic laser catheter (1.65 mm OD, 0.4 mm ID, and typically utilizing a stylet for linear insertion) modified to receive both a FOSS sensor (fiber) 161 and one or more internal magnets (premagnetized material 156), with the FOSS sensor fiber and internal magnets being assembled using heat shrink tubing and secured within the lumen of the therapeutic laser catheter using biodegradable polyethylene oxide (PEO). Preliminary phantom and cadaverstudies have demonstrated that the resulting elongated body structure 150 retains sufficient stiffness for mechanical insertion while remaining flexible enough to enable magnetic steering. After the elongated body structure is accurately placed in tissue, the FOSS-magnet assembly may be removed by pulling on the heat shrink tubing once the PEO dissolves, leaving the implanted laser catheter in place for post-operative MRI and long-term therapy.

[0069] FIG. 2 is a perspective view of a robotic arm 214 incorporating magnets 213-1, 213- 2 (e.g., permanent magnets or electromagnets) to serve as an end effector 212 to effectuate movement of a steerable assembly including an elongated body structure incorporating a premagnetized material within tissue of a human or other animal body according to certain embodiments. In certain embodiments, the magnets 213-1, 213-2 may be, or may be controlled to be, of the same polarity or opposing polarities. The robotic arm 214 is mountable to a support surface 220 and includes multiple joints 225-229 to provide numerous degrees of freedom for movement of the robotic arm 214 relative to tissue (e.g., brain tissue) of a human or other animal body (not shown) in order to effectuate movement of an elongated body structure of a steerable assembly as described herein within the tissue.

[0070] FIG. 3 is a schematic side view illustration of a portion of a fiber Bragg grating (FBG) sensor 262 (representing one example of a fiber optic shape sensor) that may be utilized with components for determining position of a steerable assembly as described herein within tissue (e.g., brain tissue) of an animal body according to certain embodiments. The FBG sensor 262 is embodied in a sensing optical fiber 261 having a core 263 surrounded by cladding 265. A portion of the core 263 constitutes an index modulation region 264 in which an index of refraction of glass material of the core 263 periodically varies. When an input signal 266A (having a propagating core mode) is transmitted through the core 263 and reaches the index modulation region 264, one spectral portion of the input signal is reflected to produce a reflected signal 266C, while another spectral portion is transmitted through the index modulation region 264 to provide a transmitted signal 266B. The reflected signal 266C may be detected by a light detector associated with a FBG driver / detector unit (not shown), and analyzed to determine one or more of force, strain, or shape experienced by the FBG sensor 262. In certain embodiments, one or more FBG sensors may be arranged in or on an elongated body structure of a steerable assembly, wherein an index modulation region may be provided proximate to a distal end of the elongated body structure.

[0071] As an alternative to using FBG sensors, OFDR sensors may be used in certain embodiments. Performance issues with OFDR often arise from complications within a tunable laser source (TLS) and the interferometer, including nonlinear tuning of the TLS and thepolarization-induced fading in the interferometer. To enhance performance of OFDR, solutions like improving TLS tuning linearity, compensating for nonlinear phase noise, and employing polarization diversity detection have been explored. In certain embodiments, a frequency-sampling method may be utilized, in which sampling occurs at consistent frequency intervals, offering a robust solution for counteracting nonlinear tuning within the sensing range. This method, paired with random optical gratings by ultraviolet laser exposure, may markedly boost signal -to-noise ratio, thereby enhancing sensing accuracy.

[0072] FIG. 4 is a perspective view of robot arm 214 mounted on a rolling cart 220, with the robot arm 214 including first and second arms 215 A, 215B (forming a fork-like projection) that support opposing first and second permanent magnets 212A, 212B arranged to be positioned on either side of brain tissue 110 of a patient supported by a horizontal platform 109. FIG. 4 further shows a steerable assembly 262 extending through an incision 211 to be inserted into the brain tissue 110, with the steerable assembly 262 including an elongated body structure (e.g., a catheter) bearing at least one fiber optic shape sensor and at least one therapeutic optical fiber to permit delivery of laser emissions to the brain tissue 110 for laser ablation according to one embodiment. At least one driving apparatus 260 may supply laser pulses to the therapeutic optical fibers and may send / receive signals for operation of the at least one fiber optic shape sensor. FIG. 4 further includes two inset images of a display 248 showing side and top views of brain tissue with the elongated body structure 150 of a steerable assembly therein.

[0073] FIG. 5 provides multiple images of brain tissue including portions subject to being laser ablated according to devices and method disclosed herein. A first frame at left shows first, second, and third trajectories 101-103 superimposed over brain tissue, with the first and second trajectories 101, 102 being straight and corresponding to multiple insertions that would be required to fully ablate the hippocampus and amygdala according to traditional approaches involving straight-path laser catheter insertion. The first frame further includes a curved third trajectory 103 attainable with devices and methods disclosed herein by which both the hippocampus and amygdala may be ablated using a steerable laser catheter having a fiber optic shape sensor. With continued reference to FIG. 5, a second frame at far right shows the same three trajectories superimposed on brain tissue as illustrated in the first frame at left, and a magnified portion of the right frame is shown at center with an elongated body structure 150 of a steerable assembly arranged in a curved configuration, the elongated body structure 150 having an associated tip portion 181 and a therapeutic optical fiber 172 couplable to a laser source and being configured to laser ablate brain tissue.

[0074] Using COMSOL multiphysics simulations, the inventors have established the feasibility of deploying Neodymium Iron Boride (NeFeB) magnets, coated with biocompatible parylene C, for puncturing and navigating through brain tissues. The simulations confirm that magnets of sizes suitable to performance of the methods described herein can generate sufficient force for performing intricate intracranial operations. In certain embodiments, an elongated body (e.g., a catheter) of a steerable assembly as disclosed herein includes a premagnetized material arranged therein (e.g., premagnetized material 156 within elongated body 150 in FIG. 1), optionally secured to the elongated body with a biodegradable polymer such as polyethylene oxide (PEO). In certain embodiments, external magnets (arranged outside a body of a subject to be treated, such as magnets 112 A, 112B in FIG. 1 or 212A, 212B in FIG. 2) may be controlled with a UR30 robotic arm configured to carry a payload of 30 kg with a repeatability of 100 microns.

[0075] FIG. 6 is a plot of force versus displacement showing forces needed for puncturing and moving through brain tissue for catheters having diameters ranging from 7.5 to 100 microns. As shown, a large magnitude force is required to effectuate puncture (at displacement values roughly between 0.2 and 0.5 mm), then force is reduced for initial displacements after puncture, but force steadily increases as displacement is increased thereafter.

[0076] FIG. 7 is a plot of magnetic pulling force (in Nm) applied to two 15 kg cubic external magnetic on cylindrical internal magnets of diameters 0.5 to 1.5 mm at different distances ranging from 100 to 200 mm. As shown, pulling force increases with increasing internal magnet size, but decreases with increasing distance between internal and external magnets.

[0077] FIG. 8 is a hybrid point-to-point and path diagram for controlling a steerable assembly having an internal magnet using magnetic steering and avoiding back-tracking according to one embodiment. A reference path 201 is shown in dashed lines, with multiple points Pi, Pi-i, Pi, Pi+i, Pi+2, and Pnarranged thereon, wherein point Pi+2 coincides with a target point Ptarget. An actual path 202 traversed by a tip portion 181 of an elongated body structure (not shown) is depicted as a solid line. The tip portion 181 is subjected to magnetic steering using a system as described herein to extend through the target point Ptarget. In certain embodiments, the reference path 201 is predefined according to a surgical plan, and advancement of the tip portion 181 of an elongated body structure through brain tissue is motivated by combined operation of a linear actuator (e.g., 152 in FIG. 1) and a movable magnetic field source (e.g., robotic arm 114 and associated premagnetized materials 112A, 112B in FIG. 1).

[0078] FIG. 9 is a block diagram for a closed-loop control system for steering of an intracranial magnetically steerable assembly according to one embodiment. The closed-loopcontrol system, which draws on nonholonomic system models, integrates feed-forward and feedback elements. Real-time FOSS sensor feedback may be used to guide adjustments that improve accuracy and safety of the steering system. According to the block diagram of FIG. 9, pre-planned trajectory is input in Cartesian coordinates, from which the control system calculates the desired state and control inputs. Real-time FOSS sensor data captures the elongated body’s pose within the brain tissue, feeding back into the control loop for continuous trajectory correction. FIG. 9 includes multiple functional blocks. At left, one block 302 includes trajectory transformation, from which a feedforward component block 304 is derived, wherein an output of the trajectory information block 302 (as well as output of a state transformation block 308) is supplied to a feedback component block 306. Outputs of the feedforward component block 304 and the feedback component block 306 utilized by inverse of input transformation block 301 that supplies an output signal to magnetic system block 312 according to which a magnetic steering system 314 (e.g., including magnetic field generating block 314 that cooperates with internal magnet-brain tissue interaction block 316), wherein optical frequency domain reflectometry (OFDR) localization block 318 (incorporating a fiber optic shape sensor) cooperates with various other blocks (e.g., the magnetic system block 314, the inverse of input transformation block 310, and the state transformation block 308).

[0079] A two-phase experimental verification of the 3D magnetic steering system is now described. The above-described closed-loop control system is evaluated within brain phantom tissues (i.e., materials simulating brain tissue) to define paths. Preliminary results for manipulating an elongated body (e.g., catheter) having a FOSS sensor and internal magnets through various curvature in two distinct phantom gels are shown in FIGS. 10 and 11, with movement of the elongated body being guided by robotic arm -manipulated external magnets, with FOSS feedback driving the control algorithm. FIG. 10 is a plot of path (Y mm vs. X mm) for manipulation of a catheter (exemplifying an elongated body structure) equipped with a premagnetized material (along an exterior of the catheter) through three different curvatures (10.2 mm, 20.3 mm, and 30.5 mm) in a stiff phantom gel, tracked using a fiber Bragg grating system. FIG. 11 is a plot of path (Y mm vs. X mm) for manipulation of the magnet-equipped catheter of FIG. 10 through three different curvatures in a soft phantom gel, tracked using a fiber Bragg grating system. FIG. 11 also includes an inset view of an 8mm length distal tip portion of the magnet-equipped catheter, showing a premagnetized material embodied in three contacting tube-shaped bodies each having an outer diameter of 1 mm.

[0080] Further validation of the magnetic steering system may be obtained with experimentation. Trajectories may be planned based on pre-surgery MRI that visualizes boththe brain’s vasculature as well as the target structures Individual brain tissue areas to be treated may be segmented based on non-linear registrations of atlases with individual cadaver structural MR sequences. Trajectories may be planned with two primary considerations: (i) implant configuration non-linearly contoured to the target structures; and (ii) avoidance of vascular contact both en-route to the target structures as well as within the target structures.

[0081] After forming a burr hole in the skull of a subject (e.g., a non-human (porcine) head or cadaver head for testing purposes), a steerable assembly including an elongated body structure equipped with a FOSS sensors and a magnet, may be carefully inserted and magnetically navigated to the target region within the brain using a combination of motorized pushing via a linear actuator and magnetic steering. Specifically, for SLAH, the procedure may involve multiple stages of implant steering: initially from the cortical surface to the posterior entrance of the hippocampal body; then following the hippocampal body’s axis to reach the hippocampal head; from the lateral to the super-medial aspect of the hippocampal head; and extending anteriorly into the adjacent amygdala. For performing corpus callostomy, the elongated body structure may be steered from the cortical surface to the posterior body of the corpus callosum and then steered anteriorly along the curvilinear body until making a steep bend at the genu into the rostrum of the corpus callosum.

[0082] Interaction forces between the implanted elongated body structure and brain tissue may be recorded using a high-resolution load cell integrated into the elongated body structure insertion mechanism. The outcome of the steering process may be measured with respect to two benchmarks, namely: (1) post-surgery MRI to assess for vascular injury (as evidenced by contrast leakage outside the vasculature), and (2) post-surgery CT scans to verify position of the elongated body structure. Monitoring of the FOSS system may be performed at a 50-Hz frequency. One-tailed sample t-tests may be applied to the data to ensure that the mean tip placement error does not exceed 500 microns. A tip placement resolution of at least 500 microns at speeds of up to 5 mm per second may be attained.

[0083] FIG. 12 provides plots of force (g) versus time (sec) depicting penetration transients and cumulative drag forces on a 3-mm diameter catheter moved through 0.6 agarose gel (representing a phantom material for simulating brain tissue) by a motor-drive force gauge inserted at a rate of 0.33 mm per second, with a mean data plot presented along with upper and lower values of standard deviations of the data.

[0084] FIG. 13 provides plots of force (g) versus time (sec) depicting penetration transients and cumulative drag forces on a 3-mm diameter catheter moved through porcine brain tissueby a motor-drive force gauge inserted at a rate of 0.33 mm per second, with a mean data plot presented along with upper and lower values of standard deviations of the data.

[0085] FIG. 14A is a top plan view of the path of a magnetically steerable assembly 401 superimposed on a preoperative MRI / CT image of a cadaver brain 110, with FIGS. 14C and 14D providing rear elevational and left side elevational views, respectively, of the same items. FIG. 14B is a perspective view of the path of a magnetically steerable assembly 401 superimposed on a three-dimensional image of a cadaver head 110’. Tracked shape and position of the magnetically steerable assembly demonstrate the capability of three- dimensional steering within brain tissue. FIG. 15A is a top plan view of the path of another magnetically steerable assembly including FOSS sensors 401 superimposed on a preoperative MRI / CT image of a cadaver brain 110, with FIGS. 15C and 15D providing rear elevational and left side elevational views, respectively, of the same items. FIG. 15B is a perspective view of the path of a magnetically steerable assembly 401 superimposed on a three-dimensional image of a cadaver head 110’. In each of the foregoing figures, a liner actuator was used to push a steerable assembly while external magnets mounted to a robotic arm were used to pull and adjust directionality of the steerable assembly within brain tissue. An associated control system calculated required external magnet positions for each segment of the panned trajectory, and the robotic arm moved the external magnets accordingly to effectuate steering of the magnetically steerable assembly 401. Tracked shape and position of the magnetically steerable assemblies of FIGS. 14A to 15D demonstrate the capability of three-dimensional steering within brain tissue.

[0086] FIG. 16 is a plot of measured insertion force versus displacement within a cadaver brain of the magnetically steerable assembly 401 of FIG. 15A. Insertion speeds of 0.33 m / s and 1 mm / s, respectively, were used, with an initial insertion depth of 50 mm. individual points represent reference measurements in porcine brain tissue.

[0087] A physics-based model of the flexible elongated body structure (steerable assembly) was developed using the PyElastica simulation framework. Model parameters were calibrated using experimental data from two configurations involving a clamped tubular elongated body structure under (i) gravity alone and (ii) combined gravity and magnetic field conditions. FIG. 17 is a plot of steerable assembly deflection in two dimensions according to PyElastica-based simulations measurements of steerable assembly deflection under gravity alone and under combined gravity plus magnetic field conditions. This model enables predictive simulation of elongate body structure deformation during insertion, informing control strategies and helping optimize magnet positioning for accurate steering.

[0088] FIG. 18 is a schematic diagram of a generalized representation of a computer system 500 that can be included as one or more components of a system or method utilizing magnetic steering and linear actuation for placement of a catheter bearing at least one optical fiber within brain tissue of a subject to permit delivery of laser emissions to the brain tissue according to one or more embodiments. The computer system 500 may be adapted to execute instructions from a computer-readable medium to perform these and / or any of the functions or processing described herein.

[0089] The computer system 500 may include a set of instructions that may be executed to program and configure programmable digital signal processing circuits for supporting scaling of supported communications services. The computer system 500 may be connected (e.g., networked) to other machines in a local area network (LAN), an intranet, an extranet, or the Internet. While only a single device is illustrated, the term "device" shall also be taken to include any collection of devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. The computer system 500 may be a circuit or circuits included in an electronic board or card, such as a printed circuit board (PCB), a server, a personal computer, a desktop computer, a laptop computer, a personal digital assistant (PDA), a computing pad, a mobile device, or any other device, and may represent, for example, a server or a user's computer.

[0090] The computer system 500 in this embodiment includes a processing device or processor 502, a main memory 504 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM), etc.), and a static memory 506 (e.g., flash memory, static random access memory (SRAM), etc.), which may communicate with each other via a data bus 508. Alternatively, the processing device 502 may be connected to the main memory 504 and / or static memory 506 directly or via some other connectivity means. The processing device 502 may be a controller, and the main memory 504 or static memory 506 may be any type of memory.

[0091] The processing device 502 represents one or more general -purpose processing devices, such as a microprocessor, central processing unit (CPU), or the like. In certain embodiments, the processing device 502 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or other processors implementing a combination of instruction sets. The processing device 502 is configured to execute processing logic in instructions for performing the operations and steps discussed herein.

[0092] The computer system 500 may further include a network interface device 510. The computer system 500 may additionally include at least one input 512, configured to receive input and selections to be communicated to the computer system 500 when executing instructions. The computer system 500 also may include an output 514, including but not limited to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device (e.g., a keyboard), and / or a cursor control device (e.g., a mouse).

[0093] The computer system 500 may or may not include a data storage device that includes instructions 516 stored in a computer readable medium 518. The instructions 516 may also reside, completely or at least partially, within the main memory 504 and / or within the processing device 502 during execution thereof by the computer system 500, the main memory 504 and the processing device 502 also constituting computer readable medium. The instructions 516 may further be transmitted or received over a network 520 via the network interface device 510.

[0094] While the computer readable medium 518 is shown in an embodiment to be a single medium, the term "computer-readable medium" should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store the one or more sets of instructions. The term "computer readable medium" shall also be taken to include any medium that is capable of storing, encoding, or carrying a set of instructions for execution by the processing device and that cause the processing device to perform any one or more of the methodologies of the embodiments disclosed herein. The term "computer readable medium" shall accordingly be taken to include, but not be limited to, solid- state memories, an optical medium, and / or a magnetic medium.

[0095] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including" when used herein specify the presence of stated features, integers, actions, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and / or groups thereof.

[0096] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These termsare only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

[0097] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0098] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0099] It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the disclosure being set forth in the following claims.

[0100] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.

Claims

ClaimsWhat is claimed is:

1. A system for placement of a therapeutic optical fiber within brain tissue to enable delivery of laser emissions, the system comprising: at least one magnetic field source; a steerable assembly that comprises: an elongated body structure having a proximal end and a distal end, the therapeutic optical fiber extending within the elongated body structure to a photonic output end proximate to the distal end of the elongated body structure, a premagnetized material arranged closer to the distal end than to the proximal end of the elongated body structure, and a fiber optic shape sensor within the elongated body structure; and a linear actuator coupled to the elongated body structure at a position closer to the proximal end than to the distal end of the elongated body structure, the linear actuator being configured to advance at least a portion of the elongated body structure within the brain tissue; wherein the at least one magnetic field source is configured to interact with the premagnetized material to effectuate steering of the distal end of the elongated body structure when the distal end is arranged within the brain tissue; and wherein the therapeutic optical fiber is configured to be coupled to a laser to permit laser emissions to be delivered through the photonic output end to one or more areas of the brain tissue.

2. The system of claim 1, further comprising at least one robotic arm configured to move the at least one magnetic field source.

3. The system of claim 1, wherein the premagnetized material comprises at least one of a permanent magnet, a ferromagnetic material, or an electromagnet.

4. The system of claim 1, wherein the premagnetized material is arranged within an interior of the elongated body structure.

5. The system of any one of claims 1 to 4, wherein the premagnetized material is configured to be removed from the interior of the elongated body structure while the at least a portion of the elongated body structure is arranged within the brain tissue.

6. The system of any one of claims 1 to 4, wherein the fiber optic shape sensor comprises one or more optical frequency domain reflectometry (OFDR) sensors.

7. The system of any one of claims 1 to 4, wherein the fiber optic shape sensor comprises one or more fiber Bragg grating (FBG) sensors.

8. The system of any one of claims 1 to 4, further comprising at least one processor configured to control operation of at least one magnetic field source, the steerable assembly, and the linear actuator.

9. The system of claim 8, further comprising one or more magnetic field sensors, wherein the at least one processor is configured to control movement and / or activation of the at least one magnetic field source responsive to outputs of the one or more magnetic field sensors.

10. The system of claim 8, wherein the at least one processor is configured to control the at least one magnetic field source and the linear actuator without user intervention.

11. The system of any one of claims 1 to 4, further comprising a user input device controllable by user manipulation, wherein the magnetic field source and the linear actuator are configured to be operated responsive to outputs of the user input device.

12. A method for delivering laser emissions to brain tissue using the system of claim 1, the method comprising: moving the at least one magnetic field source to effectuate steering of the distal end of the elongated body structure and advancing the elongated body structure within the brain tissue using the linear actuator to position the photonic output end at a desired location within the brain tissue; and operating the laser to deliver laser emissions through the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue.

13. The method of claim 12, wherein the operating of the laser to deliver laser emissions through the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue comprises performing Stereotactic Laser Ablation of the Hippocampus (SLAH).

14. The method of claim 12, wherein the operating of the laser to deliver laser emissions through the therapeutic optical fiber and the photonic output end to interact with portions of the brain tissue comprises performing corpus callostomy.

15. The method of claim 12, wherein the moving of the at least one magnetic field source comprises moving the at least one magnetic field source using at least one robotic arm.

16. The method of claim 12, wherein one or more magnetic field sensors are provided, and wherein the method further comprises controlling movement and / or activation of the at least one magnetic field source responsive to outputs of the one or more magnetic field sensors.

17. The method of claim 12, further comprising using three-dimensional trajectory information and a three-dimensional model of the brain tissue to control movement the at least one magnetic field source and control advancement of the elongated body structure within the brain tissue.

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