Enhanced planning and visualization of curved instrument paths and their applications

Abstract

Exemplary methods and systems for curved path trajectories that can be used with bendable medical devices are provided. The curved path can include straight and curved cascading arc segments. The method and system can provide planning, visualization, and treatment of, for example, temporal lobe epilepsy (TLE) using laser interstitial thermal therapy (LITT) or tumors treated using ablation. Using the curved path, the surgeon can create an interventional plan that avoids critical structures and covers more target volume for treatment / diagnosis than a straight path.

Description

[0001] Cross-references to related patent applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 959,095, filed in the U.S. Patent and Trademark Office on January 9, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0003] U.S. Government Rights

[0004] This invention may have been made while performing work under NIH Grants P41-EB015898 and R01-EB027134. The government may have rights in this invention. Technical Field

[0005] The present disclosure relates generally to medical systems having software and devices, and more particularly to computer-assisted systems having bending devices applicable for guiding interventional tools and instruments, such as catheters and ablation probes. Background Art

[0006] Minimally invasive interventions have gained widespread adoption in many medical fields. For example, in neurosurgery, laser interstitial thermal therapy (LITT) has been associated with cost-appropriate improvements in survival, the ability to treat deep and otherwise surgically inaccessible lesions during brain surgery. In addition, because LITT bypasses the blood-brain barrier, it has shown promise in targeted drug delivery. Specifically, in epilepsy, LITT is now a first-line surgical option for pediatric hypothalamic hamartomas and is accepted as an upfront surgical option for mesial epilepsy.

[0007] LITT is a minimally invasive treatment technique that includes tumor ablation, radiation necrosis, and treatment of epilepsy. LITT uses a catheter with a semiconductor laser tip that is stereotactically placed inside the brain via a 2-3mm diameter cannula. The cannula passes through the skull and brain parenchyma and follows a linear path to the target lesion. The laser emits energy at its tip to ablate the area of ​​interest at the target location. Ablation can be performed with the help of magnetic resonance thermometry (MRT), which uses a gradient echo sequence to provide the surgeon with real-time feedback on the temperature of the ablation zone.

[0008] Because LITT is minimally invasive, it allows for a quicker recovery and less morbidity than open surgery. However, the success rate of LITT in treating patients with temporal lobe epilepsy (TLE) is only 50%, much lower than the 80% success rate of temporal lobectomy. This is thought to be due to the fact that the straight path of the inserted cannula does not allow access to the entire amygdala and hippocampus with a single insertion, thus allowing only partial ablation of these structures.

[0009] Therefore, a curved trajectory is needed, both for planning software and for guiding LITT. There are various planning software options. For example, U.S. Patent No. 9,818,231 discloses visualization software for intervention. The software displays a curved path and an anatomical item. The curved path is represented as a spline curve and includes points along the path, and the distances between the anatomical item and these points are determined.

[0010] However, this and similar techniques still have significant limitations. For example, while the curved path in U.S. Pat. No. 9,818,231 provides information to the patient and informs the clinician during surgery, it represents the trajectory as a smooth curve such as a spline. It is unlikely that any actual insertion path of the inserted instrument or the instrument shape itself will exactly follow this spline curve. Therefore, any plan generated using this software cannot inherently represent the actual path of a real intervention and thus be used to avoid errors during insertion.

[0011]

[0006] Therefore, there is a need to provide systems and methods for curved trajectories and use thereof that more closely correspond to insertion paths that can be used for devices that guide interventional tools and instruments (e.g., catheters) along curved trajectories during surgical interventions (e.g., LITT). Summary of the invention

[0012] According to at least one embodiment of the present invention, a planning and visualization method is provided, comprising: identifying an entry point and a target volume in a medical image; defining a preliminary curved path between the entry point and the target volume based on geometric elements (e.g., a centerline) of the target volume, wherein the preliminary curved path comprises at least two segments, wherein at least one of the at least two segments is an arc segment; modifying the preliminary curved path based on user input to form a surgical curved path; wherein at least one of the preliminary curved path and the surgical curved path is constrained by physical parameters of a surgical robot; and displaying at least one of the preliminary curved path and the surgical curved path, and displaying the target volume.

[0013] In some embodiments, there are two or more cascaded arc segments and at least one straight segment in the initial and / or surgical curved path, the straight segment cascaded between the arc segments and the entry point. One or both of the preliminary curved path and the surgical curved path can be constrained by physical parameters of the surgical robot. Visualization can include displaying two or more of the following separately or overlapping on each other or on the medical image: the preliminary curved path, the surgical curved path, the target volume, the geometric elements, and the distance between the (multiple) curved paths to the boundaries of the target volume.

[0014] According to other embodiments, a system for planning and visualizing a curved path is provided, comprising: a computer-implemented planning and visualization subsystem configured to: identify an entry point and a target volume in a medical image; define a preliminary curved path between the entry point and the target volume based on geometric elements of the target volume, wherein the preliminary curved path comprises at least two segments, wherein at least one of the at least two segments is an arc segment; accept user input to modify the preliminary curved path and form a surgical curved path; wherein at least one of the preliminary curved path and the surgical curved path is constrained by physical parameters of a surgical robot; and display at least one of the preliminary curved path and the surgical curved path, and display the target volume.

[0015] According to other embodiments, a medical planning and implementation system is provided, comprising: a computer-implemented planning and visualization subsystem configured to perform the method described herein, and a surgical robot comprising two or more curved segments, wherein the arc length of two or more arc segments is substantially the same as the length of the two or more curved segments.

[0016] In other embodiments, a method for treating a patient with temporal lobe epilepsy (TLE) is provided, comprising: identifying an entry point in a medical image of the patient; defining a preliminary curved path between the entry point and geometric elements of the amygdala and hippocampus, wherein the preliminary curved path comprises at least two segments, wherein at least one of the at least two segments is an arc segment; modifying the preliminary curved path based on user input to form a surgical curved path; wherein at least one of the preliminary curved path and the surgical curved path is constrained by physical parameters of a surgical robot; displaying at least one of the preliminary curved path and the surgical curved path and displaying a target volume; and providing laser interstitial thermal therapy (LITT) to the patient using a surgical robot comprising two or more curved segments, wherein the LITT is provided substantially along the surgical curved path.

[0017] These and other objects, features and advantages of the present disclosure will become apparent when the following detailed description of exemplary embodiments of the present disclosure is read in conjunction with the accompanying drawings and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other objects, features, and advantages of the present disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings which show illustrative embodiments of the present disclosure.

[0019] Figure 1 A display of enhanced planning software for brain interventions according to a first embodiment of the present invention is shown.

[0020] Fig. 2(A) and Fig. 2(B) are diagrams showing arc segments 2 and their arc parameters. An arc segment is a circular arc with connection points 4 at both ends (Fig. 2(A)). The arc segment 2 is located on plane A in the XYZ coordinate system, with an angle u, the origin at one of the connection points, and the Z direction being the tangent of the arc segment 2. Angle u is one of the arc parameters and is called the bending plane.

[0021] 3(A) and 3(B) show a flexible catheter subsystem according to a second embodiment of the present invention.

[0022] Figure 3(C) is a graph showing three arc segments and one straight segment between the distal and proximal ends. Figure 3(D) shows a similar curve, but within the model of a robotic catheter model.

[0023] 4(A)-4(P) are screen shots of various embodiments of using a planning system for laser ablation therapy showing an exemplary LTE case with segmented amygdala, hippocampus, blood vessels, ventricles, optic tracts, optic chiasm, optic nerves, and brainstem.

[0024] 5(A)-5(D) are screen shots of an embodiment of a planning system for a tumor case with segmented tumor, ventricles, brainstem, functional language areas (via fMRI), and white matter tracts (via dMRI).

[0025] 6(A)-6(H) show three views of a linear pathway designed by a neurosurgery resident.

[0026] Figure 7 The actual path used to reach the amygdala and hippocampus during surgery for treating MTLE is shown following the planning stages shown in FIGS. 6(A)-6(H).

[0027] Figure 8(A)-8(C) 8(A) and TLE1 left (Fig. 8(B)) for temporal lobe epilepsy in the amygdala and hippocampus. Figure 7 The tumor coverage is shown in Figure 8(C).

[0028] Figure 9(A) shows a schematic diagram of an embodiment of a computer that can be used with one or more embodiments of at least one device, system, method and / or storage medium of the present invention. Figure 9(B) shows a schematic diagram of another embodiment of a computer that can be used with one or more embodiments of at least one device, system, method and / or storage medium of the present invention according to one or more aspects of the present disclosure.

[0029] Throughout the drawings, unless otherwise indicated, the same reference numerals and characters are used to represent the same features, elements, components or parts of the illustrated embodiments. In addition, although the present disclosure will now be described in detail with reference to the accompanying drawings, it is done in conjunction with illustrative exemplary embodiments. It is intended that changes and modifications may be made to the described exemplary embodiments without departing from the true scope and spirit of the present disclosure as defined by the appended claims. DETAILED DESCRIPTION

[0030] The planning software provides the physician with visual information for the intervention. The display for one particular embodiment includes different views ( Figure 1 ) and the control panel for intervention planning ( Figure 1 on the left side of the ).

[0031] The software can display medical images in a window. In this particular embodiment, the software displays MRI images of the brain.

[0032] The operator can identify the target volume by segmenting specific portions of the MRI image. Figure 1 In the embodiment, the software segments the amygdala, hippocampus, blood vessels, ventricles, optic tracts, optic chiasm, optic nerves, and brainstem, and overlays the models of these segmented anatomical structures with the MRI image by using colored lines. Specifically, in this embodiment, the models of the amygdala 5 and hippocampus 6 are the target volumes of anatomical structures that are ablated in LITT surgery. The operator can also identify volumes to be avoided, which can be models of blood vessels, ventricles, optic tracts, optic chiasm, optic nerves, and brainstem.

[0033] In some embodiments, the target volume is the volume of the three-dimensional model of the anatomical object. For example, the entire hippocampus may be the target volume and be the target of ablation. In other embodiments, the target volume may be smaller than the volume of the three-dimensional anatomical object, and in yet other embodiments, the target volume may be larger than the volume of the anatomical object (e.g., the object and the remainder).

[0034] The operator may also identify entry point 3, which may be the entry point for the ablation instrument through the skull.

[0035] By using the segmented anatomy and entry points3, physicians can simulate insertion and removal paths while visualizing medical images, target volumes, and measurements of distances to structures to be avoided and how much of the target volume is reachable to explore the optimal path.

[0036] These simulated insertion and removal paths are directed through a target volume, which may be defined as a specific region or point of interest, or, more interestingly for some embodiments, an entire volume, such as the entire amygdala or hippocampus, or an entire tumor. Thus, during this planning step, information about how much of the target volume is accessible may be indicated visually, or calculated and presented numerically, to aid in the optimization process.

[0037] The path comprises a proximal straight segment 1, arc segments 2a, 2b and 2c. These segments are connected in cascade with connection points 4a, 4b, 4c and 4d.

[0038] Using the curved path, the physician can find the best path to cover the target volume in the model including the complex longitudinal shapes of the amygdala 5 and hippocampus 6. In addition, the physician can also find a path to avoid critical anatomical structures by using the coverage model together with the MRI images.

[0039] The arc segments 2a, 2b, 2c comprise circular arcs with their own arc parameters including 1) arc length, 2) radius of curvature or bending angle, and 3) bending surface.

[0040] In some other embodiments, the arc segment is an arc segment of a differentiable curve rather than an arc. Thus, the arc segment can be an arc segment of an ellipse. In other embodiments, the arc segment can be a parabola or a double curved arc segment to adjust the friction difference between the proximal and distal ends of a curved segment in a bendable catheter, for example. As understood herein, an arc segment that is a circular arc segment or a differentiable curve arc segment has a radius of curvature or a bending angle greater than zero. Preferably, the arc segment has a radius of curvature less than 10 cm.

[0041] In some embodiments, the optimal path will be defined as described herein. In other embodiments, the optimal path may be defined, for example, by a surgeon using a planning system and a catheter described herein. In other embodiments, more objective parameters for the optimal path may be planned based on target areas and critical structures to be avoided and other parameters that are shown to be related to patient outcomes. In other embodiments, the optimal curved path may be automatically designed, for example, after the work described below: M. Pinzi, S. Galvan, and YBF Rodriguez, Int J Comput Assist Radiol Surg, vol. 14, no. 4, pp. 659-670, April 2019; A. Hong et al., Int J Med Robot, vol. 15, no. 4, pp. e1998, August 2019 and / or J. Granna, A. Nabavi, and J. Burgner-Kahrs, Int J Comput Assist Radiol Surg, vol. 14, no. 4, pp. 335-344, February 2019.

[0042] Figures 2(A) and 2(B) explain arc segment 2 and its arc parameters. An arc segment is a circular arc with connection points 4 and 5 at the ends (Figure 2(A)). The arc segment 2 is located on plane A in the XYZ coordinate system, with an angle u, the origin at one of the connection points, and the Z direction being the tangent of the arc segment 2 at the connection point. Angle u is one of the arc parameters and is called the bending plane.

[0043] On plane A, arc segment 2 has a length of s and a radius of curvature of r. In FIG2(B), arrow C indicates the orientation vector of arc segment 2 at connection point 5. Arc length s and radius of curvature r are arc parameters. In addition, Figure 1 The arc segments 2a, 2b, 2c in the embodiment are configured to have independent arc parameters respectively, instead of having a common curvature radius r, arc length and bending angle t. However, at the connection points between adjacent arc segments, the tangents of the adjacent arc segments are the same to maintain curvature continuity.

[0044] The operator can use the arc segments 2a, 2b and 2c ( Figure 1 )'s control panels 7, 8, 9 in the software to change these arc parameters and multiple curved paths for brain intervention can be explored and identified.

[0045] In various embodiments, the curved path does not include a proximal straight segment 1. In this embodiment, the curved path includes only an arc segment 2 from the entry point 3 to the target volumes 5 and 6.

[0046] Although FIG. 2(A) and FIG. 2(B) show a single arc segment, other embodiments are shown in FIG. 3(A) and FIG. 3(B), which describe an exemplary flexible catheter subsystem. The flexible catheter subsystem forms an interventional system in conjunction with the planning software described above. The flexible catheter subsystem includes a flexible catheter 10 and a control handle 11.

[0047] The control handle 11 includes a bending device for bending the bending section in the bendable catheter 10. The bending device may be a motor or a mechanical structure configured to transmit force from an operator.

[0048] The bendable catheter includes three curved segments 12, 13, 14 and a proximal segment 19. The three curved segments 12, 13, 14 can be bent in three dimensions using a control handle 11. The proximal segment 19 can be passively flexible or straight and rigid. In some embodiments, each curved segment has two or three guidewires that provide push-pull actuation of the bendable segment using the control handle 11. In some embodiments, the proximal segment 19 is passive because there are no tendons or guidewires to control the orientation of the segment. However, there is a certain flexibility in the segment that allows the segment to move to reduce friction within the bendable device and / or to better follow their direction when the curved segments are manipulated within the lumen.

[0049] Specifically, in this embodiment, the software has a fixed parameter of arc length s corresponding to the length of the curved segment. In addition, when the flexible catheter 10 includes a maximum bendable radius of curvature, the software can automatically limit the radius of curvature to the maximum bendable radius of curvature during the planning process, so that the physician can exclude infeasible interventional planning.

[0050] In other similar embodiments, the bendable catheter subsystem may have, for example, 2, 4, 5, 6 or more bendable segments, rather than having three bendable segments 12, 13 and 14 and a proximal segment 19. Additional bendable segments may be provided to provide greater flexibility and the ability to navigate tortuous paths. Although the bendable catheter subsystem shown in FIG. 3 (A) and FIG. 3 (B) is designed to have a small outer diameter, such as that preferred by brain surgery, other embodiments are not limited to having a small diameter, and additional control wires may be added based on the catheter as described above, thereby adding bendable segments. Similarly, other configurations of the bendable catheter subsystem may be used with more or fewer bendable segments, or with additional inflexible segments or passive segments.

[0051] Because the curved segments (three provided, or more or fewer where appropriate) can each be approximated by an arc of a circle, the software can create a feasible and accurate path that an actual flexible catheter can follow.

[0052] In use, the bendable catheter subsystem can be steered by, for example, independently bending bendable segment 12 and bendable segment 13 and bending bendable segment 14. Thus, in the planning stage, a tortuous path comprising three cascaded arc segments, wherein the lengths of the arc segments correspond to the lengths of bendable segments 12, 13 and 14 and the straight segment (which corresponds to segment 19), provides a useful planning trajectory that the bendable catheter subsystem can follow during surgical interventions such as LITT or tumor ablation therapy.

[0053] In some embodiments, the flexible catheter subsystem is described by one or more of: U.S. Patent Publications 2015 / 0088161; 2018 / 0192854; 2018 / 0296800; 2018 / 0310804; 2018 / 0243900; 2018 / 0311006; 2019 / 0015978 and 2019 / 010546 and PCT Publication WO2018204202, each of which is incorporated herein by reference in its entirety.

[0054] Demonstration research

[0055] Laser ablation systems for LTE and other neurosurgical applications are available and include Visualase (Medtronic) and NeuroBlate (Monteris). Both systems use a linear cannula to access the brain lesion with one channel in the cannula dedicated to the laser fiber and a second channel for the cooling system. The insertion path is generally planned in a 2D cross-section on the preoperative MRI. The insertion path is typically designed preoperatively by placing one path endpoint inside the target volume and one path endpoint on the skull surface. The entire path can be viewed relative to the target volume and other brain structures of interest by scrolling through the 2D cross-section of the MRI image in traditional axial / sagittal / coronal views or in orthogonal views aligned (inline) with the path and perpendicular to the path. The path can also be viewed in a 3D view as a cylinder relative to the segmented structure of interest. Figure 1A custom path planning system for straight path insertion is shown, which was implemented as a Python module in the 3D slicer in this study. The surgeon adjusts the path endpoints to find a path that covers as much of the target lesion (e.g., amygdala and hippocampus for LTE, or tumor for tumor ablation) as possible while avoiding critical structures (e.g., vessels, ventricles, optic tracts, etc.). Unfortunately, due to the geometric complexity of brain structures and the shape of the lesion, a single laser insertion may not be able to cover the entire lesion while avoiding critical structures for this straight path insertion geometry. When considering multiple insertions, the surgeon must balance optimal treatment and risk of bleeding or functional deficits. The path can be edited and viewed in traditional axial / sagittal / coronal views or inline / perpendicular views. Endpoints can be selected and dragged in 2D or 3D.

[0056] Curved insertion path

[0057] The current embodiments provide curved insertion paths and may also include a bendable catheter subsystem such as that described in FIG. 3(A) and FIG. 3(B). These curved insertion paths facilitate better access to brain lesions via LITT and better avoidance of critical structures during laser insertion into the brain. Furthermore, the use of planning software that provides arc segments to define curved trajectories more closely corresponds to the actual motion and position of the bendable catheter subsystem compared to more general curved trajectories.

[0058] The curved insertion path includes one or more cascading arcs. (e.g., cascading arcs between points C0 and C1; C1 and C2; and C2 and C3 in Figure 3(C). The curved insertion path may also include a straight segment as shown between points C3 and C4 in Figure 3(C). In some preferred embodiments, a straight segment is used from the skull entry point to a point at or near the target area (e.g., a brain lesion), and then two or more cascading arcs provide a path through the lesion. This can be seen in Figure 3(D), which provides three cascading arcs and a longer straight segment extending from the entry point to C4 in Figure 3(D).

[0059] Research

[0060] Retrospective data from four patients with epilepsy and one patient with a deep brain tumor were used for the study. Four clinicians planned conventional straight insertion paths for the left and right sides of LTE patients and tumor cases (a total of nine paths per clinician). Two technologists manually planned optimal curved insertion paths for the same cases using an enhanced version of the path planning system. The differences between the straight and curved insertion paths were analyzed to quantify the advantages of the curved insertion paths over the straight ones. The insertion paths were evaluated based on the percentage of lesion coverage and the distance from the path to the closest critical structure.

[0061] This retrospective study included five patients who underwent LITT at Brigham and Women's Hospital in 2019. Table 1 shows the image data available for each patient, which includes the target volumes and image data available for the cases in this study. Images were acquired for clinical indications and therefore were not consistent across the study. Target structures (i.e., left and right amygdala and hippocampus for each LTE patient and brain tumor for tumor patients) and critical structures to be avoided (e.g., vessels, ventricles, optic tracts) were segmented using BrainLAB ElementsSegmentation Cranial software. The atlas-based automatic segmentation in this system provides accurately labeled structures from several MRI protocols [J.F. Daisne and A. Blumhofer, Radiat Oncol, vol. 8, pp. 154, June 26, 2013]. The segmentation was then exported to 3D Slicer and the 3D Slicer Segmentation Editor module was used to create a closed surface mesh [C. Pinter, A. Lasso, and G. Fichtinger, ComputMethods Programs Biomed, vol. 171, pp. 19-26, April 2019]. The segmented objects were displayed in the 3D scene and in 3 cross-sectional 2D views. Representative cross-sections and reconstructed 3D models of the relevant structures (target lesions and critical structures to avoid) for each case are shown in Figures 4(A)-4(P) and 5(A)-5(D).

[0062] Table 1

[0063] Case Target area Available preoperative image data LTE1 Amygdala / Hippocampus MRA, MRI T1 with / without contrast LTE2 Amygdala / Hippocampus MRI T2 for non-enhancing lesions LTE3 Amygdala / Hippocampus MRI T1 using gadolinium LTE4 Amygdala / Hippocampus MRI T1 with / without contrast BT1 Tumor MRI T1 and T2

[0064] Path Planning System

[0065] For this example, an exemplary custom 3D slicer module in Python was used to create a planning system for neurosurgeons to plan insertion paths. The module includes an interactive graphical user interface (GUI) that provides tools for displaying cross-sectional images and 3D models and for planning insertion paths ( Figure 1and Figure 4). The path is designed by placing a pair of landmarks on the skull corresponding to the laser tip and entry point, and the line connecting these two points defines the insertion path of the LITT's cannula. A 2.5mm radius cylinder representing the cannula is placed along the path, and a 2.5mm radius sphere is placed at the laser tip to represent the ablation zone. The radii of the cannula and ablation zone can be adjusted via the GUI. The user can edit the laser tip and entry point positions in axial, sagittal, and coronal views, as well as in 3D views. 2D cross-sections can be viewed in conventional axial / sagittal / coronal views or in views perpendicular and parallel to the insertion path. The insertion path can be edited in any 2D view by selecting and dragging the ellipse representing the intersection between the cylinder and the current slice. This action then recalculates the path entry point so that it remains on the skull surface.

[0066] Enhanced path planning system for curved insertion paths

[0067] The enhanced planning system incorporates wire-driven multi-segment surgical robot constraints, such as the surgical robot described below: [Y. Gao, K. Takagi, T. Kato, N. Shono and N. Hata, IEEE Trans Biomed Eng, April 29, 2019]. The exemplary robot consists of a 3.5 mm diameter Nitanol catheter that is regularly cut to create flexible segments. Each segment is linked to its adjacent segments using rigid segments, allowing the segments to bend in different planes. The curved segments form a roughly circular arc of fixed length and maximum curvature. The push-pull guidewires responsible for the bending of the robot are inserted into regularly distributed guidewire rails in the tube wall. Each segment has a guidewire rail, each of which is fixed at the distal end of its segment. The guidewires are connected to a drive system with a motor for each guidewire. The robot uses a Follow-the-Leader motion algorithm to minimize tension on brain tissue during insertion. The catheter has an inner channel with a diameter of 2.5 mm that can be used to accommodate a fiber laser for LITT. In other embodiments, other surgical robots may be used instead, and these system constraints may be incorporated into the enhanced planning system described herein. Other wire-driven multi-segment surgical robots may be described below: U.S. Patent Publications 2015 / 0088161; 2018 / 0192854; 2018 / 0296800; 2018 / 0310804; 2018 / 0243900; 2018 / 0311006; 2019 / 0015978 and 2019 / 010546 and PCT Publication WO2018204202.

[0068] In order to simulate the constraints of the robot, the path planning system provided herein allows the user to design a path consisting of multiple straight segments and curved segments. Each segment can form an arc constrained to a single plane. The number of segments and the length and maximum curvature of each segment are customized in the GUI. The tangent at two continuous cross-section intersections is constrained to have equal size, so the path is continuous. Plan the path by editing the segmentation parameters and dragging the segmentation endpoints in a 2D cross-sectional view or a 3D view. In certain embodiments, the path is designed by drawing a path freehand in 2D, then running a custom algorithm to locate the segmentation endpoints and the curved plane to best fit the freehand path. Then, the resulting path can be edited by dragging the segmentation endpoints.

[0069] The system is useful but may not be preferred for non-skilled clinicians. The added complexity of moving segment endpoints in 3D and the fact that 3D curves cannot be visualized in a single 2D cross section necessitates visualization and manipulation in a 3D view, something some clinical users are not comfortable with. To this end, in this preliminary study, skilled users planned optimal curved paths to be compared with straight paths.

[0070] Straight line path planning

[0071] Four clinicians with experience planning multiple LITT cases using commercial software participated in this study, including a neurosurgery resident, two neurosurgery fellows, and a neurosurgery postdoctoral fellow. Each clinician was asked to plan a conventional linear insertion path for each side of LTE patients (8 trajectories per clinician) and oncology cases using the linear path planning system described above.

[0072] After an introduction to the 3D slicer controls and features available in the linear path planning system, clinicians were free to interact with each case. Clinicians were asked to express their thoughts during the planning process, allowing us to better understand their priorities and the structures they were trying to avoid. For each trajectory, the endpoints were saved for later intra-operator comparison and path quality assessment.

[0073] Curved path planning

[0074] Two technologists used an enhanced version of the path planning system to manually design the optimal curved insertion path for the same cases used for the straight path planning. The user was able to vary the number, length, and maximum curvature of each segment to achieve the optimal path. Based on clinical user feedback regarding their priorities for targeting and the structures they were trying to avoid, two approaches for the curved path were considered: (1) a straight approach from the skull followed by a curved insertion to the target structure and (2) a curved approach and insertion to the target structure.

[0075] Path evaluation

[0076] For this exemplary study, path quality was assessed based on two metrics:

[0077] (1) How much of the lesion is covered by the planned insertion path. In this study, coverage assumed a 1-cm radius of laser ablation around the laser tip and that the laser could be fired at multiple locations during retraction, thereby achieving a maximum cylindrical ablation zone of 1 cm along the path.

[0078] (2) How closely the planned insertion path approached nearby structures, as judged by the clinicians and two senior neurosurgeons in this study. In this study, each insertion path was sampled at 1-mm intervals along its entire length, and the distance to nearby key structures was measured. Key structures in LTE include segmented ventricles, vessels, corrugations, optic tracts, chiasm, and brainstem. Key structures in brain tumors include vessels, ventricles, functional MRI (fMRI)-defined language areas, and diffusion tensor imaging (dMRI)-defined splenium, inferior longitudinal fasciculus, and inferior fronto-occipital white matter tracts (see Figure 3).

[0079] To compare quality, we must define metrics to measure coverage and safety. For coverage, we segmented the voxels of the target structure, here the amygdala is green and the hippocampus is pink. We defined the ablation zone as the volume of the target structure that lies within a specified distance from the insertion path. We defined target coverage as the percentage of target voxels that lie within the ablation zone. We measured target coverage at 5mm and 10mm distances from the insertion path. These distances represent the typical ablation radius range for LITT.

[0080] For safety, we calculated the distance field of each critical structure that the insertion path was to avoid. We then sampled the distance to each critical structure at 1mm intervals along the insertion path. We recorded the minimum distance from the insertion path to each critical structure and the length of the path that was within 5mm and 10mm of each critical structure.

[0081] These simple measurements are not perfect measures of coverage or safety, and they ignore multiple factors. However, they provide some understanding, and both can be calculated in real time to provide immediate feedback when designing the insertion path.

[0082] A straight path planned by each clinician and a curved path according to an embodiment disclosed herein were defined by a technical expert for each of the nine cases. The study found that the curved path provided improvements compared to the straight path. For example, the curved path achieved better lesion coverage with a smaller ablation radius.

[0083] Figures 6(A)-6(H) show the linear pathways designed by the neurosurgery resident and the actual pathways used during surgery to reach the amygdala and hippocampus for MTLE. We observed relatively little variation in these pathways, likely because in the case of MTLE, the entry and target points are highly constrained by the shape and location of the target and surrounding critical structures. In contrast, Figure 7 The paths to the tumor shown in show more variation. In this case, the pathways approaching the target tumor are less constrained. In addition, because the tumor is curved in two dimensions, it is not possible to reach the entire tumor with a single straight insertion path. Therefore, clinicians use different strategies to try to reach as much of the tumor as possible to optimize coverage.

[0084] Path Planning Basics

[0085] In order to optimize the system and minimize the time and technical skills involved in path planning of the curved path, a preliminary curved path can be provided. This preliminary curved path (which may include straight segments and include one or more, or two or more cascaded arcs) can be modified by the clinician to provide a planned path. Therefore, in some embodiments, to create a preliminary curved path, geometric elements are used to define a path to a target area (e.g., amygdala, hippocampus or other organ) and defined or used as part of an initial suggested path.

[0086] The geometric element can be, for example, a centerline, a surface, a distance field, or a label map. In one embodiment, the geometric element is the centerline of the target area. For example, the target volume (e.g., a combination of the amygdala and the hippocampus) can be determined by segmenting the target structure. The centerline of the target volume can then be determined to specify an initial proposed path (preliminary curved path). In addition, the minimum and maximum distances from the centerline to the target volume boundary can be defined at each point along the centerline to provide boundaries for the initial ablation radius at each point.

[0087] In this embodiment, assuming that the laser ablates a spherical volume of tissue around its tip location, the centerline of the target volume provides a reasonable path for accessing as much of the target volume as possible. Because the shape of the target volume and its centerline can have complex curvatures in 3 dimensions, providing this initial suggested path with a simple GUI that enables the surgeon to make minor modifications to the initial suggested path can greatly simplify the task of defining the optimal curved path.

[0088] In some embodiments, a preliminary curved path is calculated based on the cascade arc structure and the physical parameters of a surgical robot, such as a multi-segment surgical robot driven by a wire as shown in FIG. 3 (B) and described herein. The surgical robot predefines the length of each of the segments 12, 13, 14, and 19, the maximum curvature, and the diameter of each segment in the robot. The specific surgical robot used in the surgical operation can be used to constrain the limitations of the preliminary curved path, making surgical reproduction of the path possible. In some embodiments, the preliminary curved path constraints are more restrictive than those allowed by the surgical robot. For example, it may be preferred to limit the potential arc curvature to a percentage of the maximum curvature of the preliminary curved path (e.g., 70%, 80%, 90%) to provide a less stringent initial route, and to be able to adjust the path with an increased curvature at the instruction of the clinician, and still within the constraints of the physical parameters of the surgical robot. The constraints may be a single type of physical parameter (e.g., the maximum curvature of various arc segments), or may be two or more physical parameters (e.g., the maximum curvature and length of various arc segments).

[0089] The number of straight segments (if any) and the number of cascading arcs can be fixed based on the surgical robot to be used, or the clinician can be allowed to adjust them. For example, there may be two arcs and a straight segment, or there may be three arcs and a straight segment. In other embodiments, four or five arcs may be used. In other embodiments, the segmentation may include an arc, a straight segment, and then another arc segment. Each arc segment may form an arc constrained to a single plane. The number of segments and the length and maximum curvature of each segment are customized in the GUI. The tangents at the intersection of two consecutive segments are constrained to be of equal size so that the path is continuous.

[0090] A preliminary curved path can be automatically calculated based on geometric elements and optionally physical parameters of the surgical robot, such as a centerline of a target structure. In another example, the automated method can determine a collection of arcs and straight segments that approximate the centerline. In a third example, the automated method can incorporate additional constraints or goals, including geometric constraints of the surgical robot or distances from the curved path to structures to be avoided.

[0091] In other embodiments, the preliminary curved path is semi-automatically created, for example by providing an initial proposed path in the planning system and a GUI that enables the clinician to modify the initial proposed path. The planning system can provide a visualization of the path, the target volume, the segmented structures to be avoided, and a measurement of the distance to the structures to be avoided and how much of the target volume is reachable in the context of the medical image.

[0092] In some embodiments, starting with a preliminary curved path is advantageous because if a clinician were to create a surgical curved path without this initial pre-path, refinement of the path would be constrained in multiple dimensions and require a significant skill set or time to create the path.

[0093] After the preliminary curved path is calculated, the path can be presented to the clinician and the clinician is given the option to modify the path to create a surgical curved path. Modification of the preliminary curved path can be constrained to limit the surgical curved path based on physical parameters of a surgical robot (such as the wire-driven multi-segment surgical robot shown in FIG. 3(B) and described herein). The surgical robot has a predefined length for each segment 12, 13, 14, and 19 in the robot and a maximum curvature for each segment, and these physical parameters can be used to constrain the preliminary curved path and / or the surgical curved path.

[0094] Although both the initial curved path and the surgical curved path can be constrained based on the physical parameters of the surgical robot, at least one of the curved paths must be constrained in this way. The physical parameters of the specified surgical robot to be used in the surgical operation can be used to constrain one or two curved paths so that the reproduction of the path during the surgical operation is optimized or at least possible. At least one of the preliminary curved path and the surgical curved path can be constrained at any point in the process. For example, it can occur after defining the centerline (or other geometric parameters), after the clinician modifies the preliminary path to the surgical path, or during the formation of the preliminary path and / or the surgical path at the same time. For the surgical curved path, the user's allowable modifications can be constrained based on the physical parameters of the surgical robot. Alternatively, fewer constraints can be imposed on user modifications, and additional steps of adjusting the surgical curved path to adapt to the constraints of the surgical robot can occur after the user makes (multiple) modifications. This can also be an iterative process between user modifications and review and / or adding constraints based on physical parameters. In addition, in some embodiments, one or more physical parameters can be used to constrain user modifications, and (multiple) other physical parameters can be included at different times during the process.

[0095] In embodiments where only the preliminary curved path is constrained by the physical parameters of the surgical robot, parameters may be provided to the clinician to describe how far adjustments used to create the surgical curved path deviate the plan from the optimal performance of the surgical robot. The optimal performance may be, for example, the actual limitations of the surgical robot, or, for example, a percentage of that performance (e.g., 90% of the maximum curvature available in an arc segment).

[0096] Treatments for the amygdala and hippocampus

[0097] In some embodiments, a method of treating temporal lobe epilepsy (TLE) is provided in which the amygdala and hippocampus are targeted using a curved trajectory and then treated using LITT therapy. Although treatments for TLE are known, the present invention provides a minimally invasive treatment. The curved path provides access to the entire amygdala and hippocampus with a single insertion of a bendable device, so that the entire necessary area can be ablated using LITT therapy. The curved path also allows for avoiding critical structures between the entry point and the amygdala and hippocampus.

[0098] Curved paths have been found to perform consistently better than straight-path MTLE and tumor ablation in the amygdala and hippocampus. Curved paths provide better lesion coverage with a smaller ablation radius, thus potentially causing less damage to surrounding tissue.

[0099] Software-related disclosures

[0100] FIG9(A) provides various components of a computer system 1200. The computer system 1200 may include a central processing unit ("CPU") 1201, a ROM 1202, a RAM 1203, a communication interface 1205, a hard disk (and / or other storage device) 1204, a screen (or a monitor interface) 1209, a keyboard (or an input interface; in addition to a keyboard, a mouse or other input device may also be included) 1210, and a bus or other connection line (e.g., a connection line 1213) between one or more of the aforementioned components (e.g., as shown in FIG9). In addition, the computer system 1200 may include one or more of the aforementioned components. For example, computer system 1200 may include CPU 1201, RAM 1203, input / output (I / O) interfaces (such as communication interface 1205), and a bus (which may include one or more lines 1213 as a communication system between components of computer system 1200; in one or more embodiments, computer system 1200 and at least its CPU 1201 may communicate with one or more components or devices or systems using one or more components via one or more lines 1213, such as, but not limited to, system 100, system 100', system 100", and / or system 100'" discussed above), and one or more other computer systems 1200 may include one or more combinations of the other aforementioned components. CPU 1201 is configured to read and execute computer-executable instructions stored in a storage medium. Computer-executable instructions may include instructions for performing the methods and / or calculations described herein. Computer system 1200 may include one or more additional processors in addition to CPU 1201, and such processors including CPU 1201 may be used to control and / or manufacture devices, systems, or storage media for use therewith or with the software, planning systems, and flexible catheter subsystems discussed herein. System 1200 may also include one or more processors connected via a network connection (e.g., via network 1206). CPU 1201 and any additional processors being used by system 1200 may be located in the same telecommunications network or in different telecommunications networks (e.g., the execution, manufacture, control, and / or use of the technology(s) may be controlled remotely).

[0101] The I / O or communication interface 1205 provides a communication interface to input and output devices, which may include an imaging system or an imaging database, such as for an MRI imaging system, communication cables and networks (wired or wireless), a keyboard 1210, a mouse (e.g., see mouse 1211 shown in FIG. 9(B) ), a touch screen or screen 1209, a light pen, etc. A monitor interface or screen 1209 provides a communication interface thereto.

[0102] Any method and / or data of the present disclosure, such as methods for planning, using and / or manufacturing devices, systems or storage media for use therewith and / or methods for planning systems, software and control of flexible catheter subsystems, as discussed herein, can be stored on a computer-readable storage medium. Commonly used computer-readable and / or writable storage media, such as but not limited to one or more of the following: hard disk (e.g., hard disk 1204, magnetic disk, etc.), flash memory, CD, optical disk (e.g., compact disk ("CD"), digital versatile disk ("DVD"), Blu-ray TM Disks, etc.), magneto-optical disks, random access memories ("RAM") (such as RAM 1203), DRAM, read-only memories ("ROM"), storage devices of distributed computing systems, memory cards, etc. (e.g., other semiconductor memories, such as but not limited to non-volatile memory cards, solid-state drives (SSDs) (see SSD 1207 in FIG. 9(B)), SRAM, etc.), optional combinations thereof, servers / databases, etc., which can be used to enable a processor, such as the processor or CPU 1201 of the aforementioned computer system 1200, to perform the steps of the methods disclosed herein. The computer-readable storage medium may be a non-transitory computer-readable medium, and / or the computer-readable medium may include all computer-readable media, with the sole exception of transient propagation signals. The computer-readable storage medium may include a medium that stores information for a predetermined, limited or short (multiple) period of time and / or only in the presence of power, such as but not limited to random access memories (RAM), register memories, (multiple) processor caches, etc. The (multiple) embodiments of the present disclosure may also be implemented by a computer of a system or device, which reads and executes computer-executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be more completely referred to as a "non-transitory computer-readable storage medium") to perform the functions of one or more of the above-described embodiments, and / or includes one or more circuits (e.g., application-specific integrated circuits (ASICs)) for performing the functions of one or more of the above-described embodiments, as well as methods executed by a computer of a system or device, for example, by reading and executing computer-executable instructions from a storage medium to perform the functions of one or more of the above-described embodiments and / or controlling one or more circuits to perform the functions of one or more of the above-described embodiments.

[0103] According to at least one aspect of the present disclosure, the methods, devices, systems and computer-readable storage media related to the processor (such as but not limited to the processor of the aforementioned computer 1200, the processor of the computer 1200', etc.) as described above can be implemented using appropriate hardware such as shown in the figure. The functions of one or more aspects of the present disclosure can be implemented using appropriate hardware such as shown in Figure 9 (A). Such hardware can be implemented using any known technology, such as standard digital circuits, any known processors that can be operated to execute software and / or firmware programs, one or more programmable digital devices or systems such as programmable read-only memories (PROMs), programmable array logic devices (PALs), etc. CPU 1201 (as shown in Figure 9 (A) or Figure 9 (B)) can also include the following and / or be composed of the following: one or more microprocessors, nanoprocessors, one or more graphics processing units ("GPUs"; also called visual processing units ("VPUs")), one or more field programmable gate arrays ("FPGAs") or other types of processing components (e.g., (multiple) application-specific integrated circuits (ASICs)). In addition, various aspects of the present disclosure may be implemented by software and / or (multiple) firmware programs, which may be stored in a suitable storage medium (e.g., a computer-readable storage medium, a hard drive, etc.) or multiple storage media (such as (multiple) floppy disks, (multiple) memory chips, etc.) for transportation and / or distribution. The computer may include a network of separate computers or separate processors to read and execute computer-executable instructions. The computer-executable instructions may be provided to the computer, for example, from a network or a storage medium.

[0104] As described above, the hardware structure of an alternative embodiment of a computer or console 1200' is shown in FIG9(B). The computer 1200' includes a central processing unit (CPU) 1201, a graphics processing unit (GPU) 1215, a random access memory (RAM) 1203, a network interface device 1212, an operation interface 1214 such as a universal serial bus (USB), and a memory such as a hard disk drive or a solid state drive (SSD) 1207. Preferably, the computer or console 1200' includes a display 1209. The computer 1200' can be connected to one or more other components of the system (e.g., system 100, system 100', system 100", system 100'", etc.) via the operation interface 1214 or the network interface 1212. For example, the computer 1200' can be connected to one or more actuators that control the movement of the flexible catheter subsystem. The operation interface 1214 is connected to an operation unit such as a mouse device 1211, a keyboard 1210, and a controller for the flexible catheter subsystem and / or a touch screen device. Computer 1200' may include two or more of each component. Alternatively, CPU 1201 or GPU 1215 may be replaced with a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or other processing unit, depending on the design of a computer such as computer 1200, computer 1200', etc.

[0105] The computer program is stored in the SSD 1207 , and the CPU 1201 loads the program onto the RAM 1203 and executes the instructions in the program to perform one or more of the processes described herein, as well as the basic input, output, calculation, memory write, and memory read processes.

[0106] A computer such as computer 1200, 1200' communicates with the imaging system, the planning system, and the flexible catheter subsystem, as well as one or more other components of the system (such as system 100, 100', 100", 100'", etc.) to perform planning and / or interventional treatment. A monitor or display 1209 displays the reconstructed image and may display other information about the imaging conditions or about the object to be imaged. A user interface is also provided for a user to operate the system (e.g., system 100, system 100', system 100", system 100'", etc.), and to navigate during planning or implementation, and to optionally modify, for example, an entry point, a target volume, or to modify a preliminary bending trajectory. An operation signal is input from an operation unit (e.g., such as, but not limited to, a mouse device 1211, a keyboard 1210, a touch pad device, etc.) into an operation interface 1214 in the computer 1200', and corresponding to the operation signal, the computer 1200' instructs the system (e.g., system 100, system 100', system 100", system 100'", etc.).

[0107] definition

[0108] When referring to the description, specific details are set forth in order to provide a thorough understanding of the disclosed examples. In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily lengthening the present disclosure.

[0109] It should be understood that if an element or component is referred to herein as being "on," "beside," "connected to," or "coupled to" another element or component, it may be directly on, beside, connected to, or coupled to the other element or component, or there may be intervening elements or components. Conversely, if an element is referred to as being "directly on," "directly beside," "directly connected to," or "directly coupled to" another element or component, there are no intervening elements or components. When used, the term "and / or" includes any and all combinations of one or more of the associated listed items (if so provided).

[0110] As shown in the various figures, spatially relative terms such as "below", "below", "beneath", "lower", "above", "upper", "proximal", "distal", etc. may be used herein to facilitate description of the relationship between one element or feature and another (multiple) element or feature. However, it should be understood that, in addition to the orientation shown in the drawings, the spatially relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the drawings is turned over, the elements described as "below" or "below" other elements or features will then be oriented to be "above" other elements or features. Therefore, relative spatial terms such as "below" can cover both the above and below orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein will be interpreted accordingly. Similarly, the relative spatial terms "proximal" and "distal" can also be interchanged where applicable.

[0111] As used herein, the term "about" means, for example, within 10%, within 5%, or less. In some embodiments, the term "about" may mean within a measurement error range.

[0112] The term first, second, third, etc. can be used herein to describe various elements, components, regions, parts and / or parts. It should be understood that these elements, components, regions, parts and / or parts should not be limited by these terms. These terms are only used to distinguish an element, component, region, part or part from another region, part or part. Therefore, without departing from the teaching of this article, the first element, component, region, part or part discussed below can be referred to as the second element, component, region, part or part.

[0113] The term "substantially" is intended to allow for deviations from the descriptor without negatively affecting the intended purpose. For example, deviations from the limitations of the clinician's ability to follow the planned path, and differences within manufacturing tolerances. Variations of less than 5% may be considered to be within the substantially identical range. The descriptors specified may be absolute values ​​(e.g., substantially spherical, substantially perpendicular, substantially concentric, etc.) or relative terms (e.g., substantially similar, substantially identical, etc.).

[0114] The terms used herein are only used to describe specific embodiments and are not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It should also be understood that when used in this specification, the terms "include" and / or "comprise" specify the presence of declared features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof that are not explicitly stated.

[0115] For the sake of clarity, specific terminology is employed in describing the example embodiments shown in the drawings. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner.

[0116] While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the present disclosure is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A planning and visualization method comprising: acquiring, by a processor, a location of an entry point and a target volume in a medical image; defining a preliminary curved path between the entry point and the target volume based on geometric elements of the target volume, wherein the preliminary curved path comprises at least two segments, wherein at least one of the at least two segments is an arc segment, and tangents at an intersection of two consecutive segments are constrained to have equal magnitudes so that the path is continuous; modifying the preliminary curved path based on user input to form a surgical curved path; wherein at least one of the preliminary curved path and the surgical curved path is constrained by physical parameters of a surgical robot; displaying a constrained preliminary curved path or a constrained surgical curved path; as well as The geometric elements are displayed while the user modifies the preliminary curved path.

2. The method of claim 1, wherein: At least one of the preliminary curved path and the surgical curved path includes one or more arc segments and at least one straight segment cascading between the one or more arc segments and the entry point.

3. The method of claim 2, wherein: The surgical curved path includes two or more cascaded arc segments and at least one straight segment.

4. The method of claim 2, wherein: The straight segment is cascaded between the arc segment and the entry point.

5. The method of claim 2, wherein: The preliminary curved path includes three or more cascaded arc segments and one straight segment cascaded between the arc segments and the entry point.

6. The method according to any one of claims 1 to 5, wherein: The preliminary curved path and the surgical curved path are constrained by physical parameters of the surgical robot.

7. The method according to any one of claims 1 to 5, wherein: The preliminary curved path is based on a centerline of the target volume.

8. The method of claim 1, wherein: Modifying the preliminary curved path to form the surgical curved path includes accepting user input to modify a radius of curvature or a bend angle of one or more arc segments.

9. The method of claim 8, wherein: The user input may include minor adjustments to the displayed preliminary curved path.

10. The method of claim 1, wherein: The surgical curved path and the target volume are displayed superimposed on the display of the medical image.

11. The method of claim 1, further comprising displaying minimum and / or maximum distances from the preliminary curved path or surgical curved path to a boundary of the target volume at multiple points along the preliminary curved path or surgical curved path.

12. The method of claim 1, wherein: The connection point between adjacent arcs includes a tangent line of the two adjacent arcs.

13. The method of claim 1, wherein: The arc segments are circular arc segments.

14. The method of claim 1, wherein: The target volume is a three-dimensional model of an anatomical object, the anatomical object being at least one of a tumor, an amygdala, a hippocampus, a blood vessel, a ventricle, an optic tract, an optic chiasm, an optic nerve, and a brainstem.

15. A system for planning and visualizing a curved path, comprising: The computer-implemented planning and visualization subsystem is configured to: Identifying entry points and target volumes in medical images; defining a preliminary curved path between the entry point and the target volume based on geometric elements of the target volume, wherein the preliminary curved path comprises at least two segments, wherein at least one of the at least two segments is an arc segment, the arc segment is defined in three-dimensional space by arc parameters, the arc parameters comprising at least two of the following: arc length, curvature radius, bending angle, and bending surface; accepting user input to modify the preliminary curved path and form a surgical curved path; wherein at least one of the preliminary curved path and the surgical curved path is constrained by physical parameters of a surgical robot; and A constrained preliminary curved path or a constrained surgical curved path is displayed.

16. The system of claim 15, wherein: At least one of the preliminary curved path and the surgical curved path includes one or more arc segments and at least one straight segment cascading between the one or more arc segments and the entry point.

17. The system of claim 15, wherein: The preliminary curved path and the surgical curved path are constrained by physical parameters of the surgical robot.

18. The system of any one of claims 15-17, wherein: The preliminary curved path is based on a centerline of the target volume.

19. The system of claim 15, wherein: The preliminary curved path and the target volume are displayed superimposed on the medical image.

20. The system of claim 19, wherein: The arc segments are defined in three-dimensional space using arc parameters, which include at least two of the following: arc length, curvature radius, bending angle, and bending surface.

21. The system of claim 15, wherein: The target volume is a three-dimensional model of an anatomical object, the anatomical object being at least one of a tumor, an amygdala, a hippocampus, a blood vessel, a ventricle, an optic tract, an optic chiasm, an optic nerve, a sulcus, and a brainstem.

22. The system of claim 15, further comprising a user interface configured to input user information for identifying the entry point and the target volume and modifying the preliminary curved path.

23. The system of claim 22, wherein: The planning and visualization subsystem is configured to revise at least one of the entry point, the target volume, and the preliminary curved path based on user input through the user interface.

24. A medical planning and implementation system, comprising: A computer-implemented planning and visualization subsystem configured to perform the method according to at least one of claims 1 to 14, and A surgical robot comprising at least a first bending segment and a second bending segment, The preliminary curved path includes at least a first arc segment and a second arc segment, and the arc length of the first arc segment corresponds to the first curved segment, and the arc length of the second arc segment corresponds to the second curved segment.

25. The medical planning and implementation system of claim 24, wherein: The preliminary curved path or surgical curved path includes two or more cascaded arc segments and at least one straight segment proximal to the two or more arc segments, and the surgical robot includes at least one straight proximal segment.

26. The medical planning and implementation system of claim 24, wherein: The preliminary curved path or the surgical curved path and the target volume are displayed superimposed on the medical image.

27. The medical planning and implementation system of claim 24, wherein: The target volume is a three-dimensional model of an anatomical object, the anatomical object being at least one of a tumor, an amygdala, a hippocampus, a blood vessel, a ventricle, an optic tract, an optic chiasm, an optic nerve, and a brainstem.

28. The medical planning and implementation system of claim 24, further comprising a user interface configured to input user information for identifying the entry point, the target volume, and modifying the preliminary curved path.

29. The medical planning and implementation system of claim 28, wherein: The planning and visualization subsystem is configured to revise at least one of the entry point and the target volume based on user input through the user interface.

30. A computer program product comprising computer executable instructions which, when executed, cause performance of operations comprising: obtaining a location of an entry point in a medical image of a patient; defining a preliminary curved path between the entry point and geometric elements of the amygdala and hippocampus, wherein the preliminary curved path comprises at least two segments, wherein at least one of the at least two segments is an arc segment; modifying the preliminary curved path based on user input to form a surgical curved path; wherein at least one of the preliminary curved path and the surgical curved path is constrained by physical parameters of a surgical robot; A constrained preliminary curved path or a constrained surgical curved path is displayed.

31. The computer program product of claim 30, wherein: The geometric elements are the center lines of the amygdala and hippocampus.

32. The computer program product of claim 30, wherein: The surgical curved path includes two or more cascading arcs and a straight segment.

33. The computer program product of claim 32, wherein: The lengths of the two or more curved segments of the surgical robot are substantially the same as the arc lengths of the two or more arc segments of the surgical curved path, and the surgical robot is used to provide laser interstitial thermal therapy (LITT) to the patient along the surgical curved path.

Images