Needle Steering Research Articles

In Vivo Feasibility Study: Evaluating Autonomous Data-Driven Robotic Needle Trajectory Correction in MRI-Guided Transperineal Procedures.

This study addresses the targeting challenges in MRI-guided transperineal needle placement for prostate cancer (PCa) diagnosis and treatment, a procedure where accuracy is crucial for effective outcomes. We introduce a parameter-agnostic trajectory correction approach incorporating a data-driven closed-loop strategy by radial displacement and an FBG-based shape sensing to enable autonomous needle steering. In an animal study designed to emulate clinical complexity and assess MRI compatibility through a PCa mock biopsy procedure, our approach demonstrated a significant improvement in targeting accuracy (p<0.05), with mean target error of only 2.2 ± 1.9 mm on first insertion attempts, without needle reinsertions. To the best of our knowledge, this work represents the first in vivo evaluation of robotic needle steering with FBG-sensor feedback, marking a significant step towards its clinical translation.

A fabrication strategy for millimeter-scale, self-sensing soft-rigid hybrid robots.

Soft robots typically involve manual assembly of core hardware components like actuators, sensors, and controllers. This increases fabrication time and reduces consistency, especially in small-scale soft robots. We present a scalable monolithic fabrication method for millimeter-scale soft-rigid hybrid robots, simplifying the integration of core hardware components. Actuation is provided by soft-foldable polytetrafluoroethylene film-based actuators powered by ionic fluid injection. The desired motion is encoded by integrating a mechanical controller, comprised of rigid-flexible materials. The robot's motion can be self-sensed using an ionic resistive sensor by detecting electrical resistance changes across its body. Our approach is demonstrated by fabricating three distinct soft-rigid hybrid robotic modules, each with unique degrees of freedom: translational, bending, and roto-translational motions. These modules connect to form a soft-rigid hybrid continuum robot with real-time shape-sensing capabilities. We showcase the robot's capabilities by performing object pick-and-place, needle steering and tissue puncturing, and optical fiber steering tasks.

Automatic Path-Planning Techniques for Minimally Invasive Stereotactic Neurosurgical Procedures-A Systematic Review.

This review systematically examines the recent research from the past decade on diverse path-planning algorithms tailored for stereotactic neurosurgery applications. Our comprehensive investigation involved a thorough search of scholarly papers from Google Scholar, PubMed, IEEE Xplore, and Scopus, utilizing stringent inclusion and exclusion criteria. The screening and selection process was meticulously conducted by a multidisciplinary team comprising three medical students, robotic experts with specialized knowledge in path-planning techniques and medical robotics, and a board-certified neurosurgeon. Each selected paper was reviewed in detail, and the findings were synthesized and reported in this review. The paper is organized around three different types of intervention tools: straight needles, steerable needles, and concentric tube robots. We provide an in-depth analysis of various path-planning algorithms applicable to both single and multi-target scenarios. Multi-target planning techniques are only discussed for straight tools as there is no published work on multi-target planning for steerable needles and concentric tube robots. Additionally, we discuss the imaging modalities employed, the critical anatomical structures considered during path planning, and the current status of research regarding its translation to clinical human studies. To the best of our knowledge and as a conclusion from this systematic review, this is the first review paper published in the last decade that reports various path-planning techniques for different types of tools for minimally invasive neurosurgical applications. Furthermore, this review outlines future trends and identifies existing technology gaps within the field. By highlighting these aspects, we aim to provide a comprehensive overview that can guide future research and development in path planning for stereotactic neurosurgery, ultimately contributing to the advancement of safer and more effective neurosurgical procedures.

Autonomous Soft-Tissue Needle Steering Using Reinforcement Learning Guided by Human Input

Soft-tissue needle steering, where a deformable needle is inserted into the tissue to guide its tip to a desired position, is a common minimally invasive surgery (MIS) procedure. The diverse types of needles and complex tissue dynamics limit the use of existing approaches that utilize models of the needle and the tissue for automating the task. In this work, we employ a data-driven approach using deep reinforcement learning (DRL) to achieve autonomous needle steering by viewing it as a multi-goal reinforcement learning problem. Human interventions are incorporated during training to accelerate learning and reduce catastrophic failures. Generative adversarial imitation learning (GAIL) is combined with regular DRL by utilizing a hindsight relabeling scheme for human interventions to encourage the agent to imitate human behavior. To emulate the sim-to-real process, an agent is first trained in a simplistic simulation environment for needle steering and then transferred to a sophisticated one considered as the real world with fine-tuning (sim-to-sim). Experimental results show that with human interventions, the proposed method outperforms the other compared DRL approaches and can achieve good performance with only 2,000 training steps in the complex simulation environment, achieving an average return comparable to that of a 55,000-step agent trained from scratch.

Dosimetric benefits and preclinical performance of steerable needles in HDR prostate brachytherapy

Prostate cancer patients with an enlarged prostate and/or excessive pubic arch interference (PAI) are generally considered non-eligible for high-dose-rate (HDR) brachytherapy (BT). Steerable needles have been developed to make these patients eligible again. This study aims to validate the dosimetric impact and performance of steerable needles within the conventional clinical setting.HDR BT treatment plans were generated, needle implantations were performed in a prostate phantom, with prostate volume > 55 cm3 and excessive PAI of 10 mm, and pre- and post-implant dosimetry were compared considering the dosimetric constraints: prostate V100 > 95 % (13.50 Gy), urethra D0.1cm3 < 115 % (15.53 Gy) and rectum D1cm3 < 75 % (10.13 Gy).The inclusion of steerable needles resulted in a notable enhancement of the dose distribution and prostate V100 compared to treatment plans exclusively employing rigid needles to address PAI. Furthermore, the steerable needle plan demonstrated better agreement between pre- and post-implant dosimetry (prostate V100: 96.24 % vs. 93.74 %) compared to the rigid needle plans (79.13 % vs. 72.86 % and 87.70 % vs. 81.76 %), with no major changes in the clinical workflow and no changes in the clinical set-up.The steerable needle approach allows for more flexibility in needle positioning, ensuring a highly conformal dose distribution, and hence, HDR BT is a feasible treatment option again for prostate cancer patients with an enlarged prostate and/or excessive PAI.

A Survey of Needle Steering Approaches in Minimally Invasive Surgery.

In virtue of a curved insertion path inside tissues, needle steering techniques have revealed the potential with the assistance of medical robots and images. The superiority of this technique has been preliminarily verified with several maneuvers: target realignment, obstacle circumvention, and multi-target access. However, the momentum of needle steering approaches in the past decade leads to an open question-"How to choose an applicable needle steering approach for a specific clinical application?" This survey discusses this question in terms of design choices and clinical considerations, respectively. In view of design choices, this survey proposes a hierarchical taxonomy of current needle steering approaches. Needle steering approaches of different manipulations and designs are classified to systematically review the design choices and their influences on clinical treatments. In view of clinical consideration, this survey discusses the steerability and acceptability of the current needle steering approaches. On this basis, the pros and cons of the current needle steering approaches are weighed and their suitable applications are summarized. At last, this survey concluded with an outlook of the needle steering techniques, including the potential clinical applications and future developments in mechanical design.

Magnetic needle steering control using Lyapunov redesign

Using steerable needles to enable course correction and curved trajectories can improve surgical outcomes in numerous clinical interventions including electrode placement for deep brain stimulation. In this work, a physically motivated kinematic model for an actively steered magnetic-tipped needle is used in closed-loop control to perform insertion trajectories. The applied control law is derived using the Lyapunov redesign. Simulation results show this control method to be accurate for a wide range of conditions including randomized target trajectories. Control is performed experimentally in a brain tissue phantom for both initial position offset recovery and curved trajectories. Converged error results average 0.52 mm from target trajectory. Simulation results demonstrate the robustness of the control implementation, while experimental results exceed the accuracy required for the target application, encouraging future use in a clinical setting. Beyond needle insertion, this work has implications in general vehicle steering, as this model and control can apply to systems with similar kinematics such as boats and wheeled vehicles that could benefit from a relaxed slip constraint.

Screw-Tip Soft Magnetically Steerable Needles

We present a new paradigm in steerable needles comprising flexible tubing with a screw tip and a permanent magnet near the tip. The needle is rotated at its proximal end as the primary mechanism of insertion, rather than being pushed, enabling the screw tip to pull itself through the tissue as it is steered via magnetic torque. Our design enables turns with tighter curvature than previous designs, and it circumvents a well-known problem with existing steerable needles: it is challenging to turn more than 90 degrees without inducing damage. We evaluate our needle via human-in-the-loop robot-assisted magnetic steering in a brain-simulating gel tissue phantom, wherein we achieve a radius of curvature of 29 mm with 210 degrees of turning for a needle with a functional lumen. In a needle without the lumen we achieve a minimum radius of curvature of 10.1 mm. We further evaluate the needle in ex-vivo ovine brain via open-loop steering. We characterize the steerability of the needles as a function of independent parameters. The results demonstrate a needle that promises significantly improved steerability and safety, particularly for use in delicate tissues that create the greatest challenges for existing designs.

Assessing Tissue Damage Around a Tape Spring Steerable Needle With Sharp Turn Radii.

Steerable needles are a novel technology that offers a wide range of uses in medical diagnostics and therapeutics. Currently, there exist several steerable needle designs in the literature, however, they are limited in their use by the number of possible turns, turn radius, and tissue damage. We introduce a novel design of a tape spring steerable needle, capable of multiple turns, that minimizes tissue damage. In this study, we measure the turning radius of our steerable needle in porcine liver tissue in vitro with ultrasound and estimate tissue damage in gel blocks using image analysis and 3D plaster casting. We were able to demonstrate our steerable needle's ability to steer through biological tissue, as well as introduce a novel method for estimating tissue damage. Our findings show that our needle design showed lower damage compared to similar designs in literature, as well as tissue stiffness being a protective factor against tissue damage.

Towards FBG-Based Shape Sensing and Sensor Drift for a Steerable Needle

Continuum manipulators contribute to promising improvements of minimally invasive surgical procedures due to their compliance, small size, and ability to navigate anatomical pathways. Feedback of the shape of such robots within the body is currently being researched through the use of fiber Bragg grating (FBG) sensors. As the size of the robot is reduced, placement of the sensors becomes increasingly challenging, often relying on glues and epoxies. In this article, a triplet of FBG fibers is used for shape sensing of a tendon driven continuum joint. Tests are performed to show the accuracy of reconstruction using this sensor both alone and incorporated in a tendon-driven continuum joint. A repeatable sensor drift was observed during prolonged deflection which caused an increase in error of up to 0.218 mm over a 10-min period. Results showed the effect of the repeated and sustained deflection on shape reconstruction under various deflection conditions and temperatures.

A Telescopic Tendon-Driven Needle Robot for Minimally Invasive Neurosurgery.

This paper presents the design, characterization, and testing of a steerable needle robot for minimally invasive neurosurgery. The robot consists of a rigid outer tube and two telescopic tendon-driven steerable tubes. Through the rotation, translation, and bending of individual tubes, this telescopic tendon-driven needle robot can perform dexterous motion and follow the path of the tip. We presented the design of the needle robot and its actuation system, modeling of the robotic kinematics, characterization of the robot motion, results of the open-loop kinematic control, and demonstration of the follow-the-leader motion. The position error of the robot tip is 0.92 mm, and follow-the-leader motion error is 1.1 mm. Due to its small footprint and unique motion ability, the robot has the potential to be manipulated inside human brain and used for minimally invasive neurosurgery.

Autonomous medical needle steering in vivo.

The use of needles to access sites within organs is fundamental to many interventional medical procedures both for diagnosis and treatment. Safely and accurately navigating a needle through living tissue to a target is currently often challenging or infeasible because of the presence of anatomical obstacles, high levels of uncertainty, and natural tissue motion. Medical robots capable of automating needle-based procedures have the potential to overcome these challenges and enable enhanced patient care and safety. However, autonomous navigation of a needle around obstacles to a predefined target in vivo has not been shown. Here, we introduce a medical robot that autonomously navigates a needle through living tissue around anatomical obstacles to a target in vivo. Our system leverages a laser-patterned highly flexible steerable needle capable of maneuvering along curvilinear trajectories. The autonomous robot accounts for anatomical obstacles, uncertainty in tissue/needle interaction, and respiratory motion using replanning, control, and safe insertion time windows. We applied the system to lung biopsy, which is critical for diagnosing lung cancer, the leading cause of cancer-related deaths in the United States. We demonstrated successful performance of our system in multiple in vivo porcine studies achieving targeting errors less than the radius of clinically relevant lung nodules. We also demonstrated that our approach offers greater accuracy compared with a standard manual bronchoscopy technique. Our results show the feasibility and advantage of deploying autonomous steerable needle robots in living tissue and how these systems can extend the current capabilities of physicians to further improve patient care.

An Improved High-Gain Observer Design for Flexible Needle Steering

In the robot-assisted puncture surgery, the posture of the needle tip may not be available directly owing to the small dimension of the needle tip and the existence of measurement noise. On the other hand, the existing high-gain observers are robust against model uncertainty but sensitive to measurement noise. The peaking phenomenon is also a typical problem when applying those high-gain observers. Aiming at these issues, an improved high-gain observer is devised to observe the pose of the needle tip in this paper. To reduce the effect of the measurement noise and the peaking phenomenon, the power of observer gain is designed as 2 by extending the observer degree and a correction term of measurement estimation is added to improve the property of the observer against the measurement noise. Finally, the performance of the proposed observer is verified via a simulation example.

Design and Evaluation of a Puncture Control Method for the Deflection of Ultrafine Needles due to Interfacial Passage-Proposal of Puncture Control Strategy for Increasing.

With the demand for sophisticated techniques to easily prevent the deflection of needles, robotic CT (computed tomography)-guided puncture with an ultrafine needle is being investigated. Quantification of deflection is essential for accurate puncture with ultrafine needles. Research on the quantification of deflection caused by tissue reaction forces to which the beveled surface of the needle tip is in progress, and this method has been applied for deflection reduction and needle steering within the tissue. However, when the needle tip passes through a tissue boundary, the needle deflects regardless of the direction of the beveled surface. Although several methods have been proposed to reduce the deflection caused by the boundary surface, no curve puncture method has been constructed using the deflection. This work aimed to construct a refraction model that can back-calculate the curved path from the body surface to the target. Assumptions of the refraction model were made based on the results of ex vivo examination, and the model was validated through in vivo examination. A refraction model in which the refraction angle is linearly proportional to the needle penetration angle relative to the boundary was hypothesized. Validation test revealed that the correlation coefficient exceeded 0.9, which was similar to that of the model and suggested the biological adaptability of the proposed model. A curve puncture method using this refraction model will be developed in the future.

MR-guided HDR prostate brachytherapy with teleoperated steerable needles

Conformity of tumour volumes and dose plans in prostate brachytherapy (BT) can be constrained by unwanted needle deflections, needle access restrictions and visualisation limitations. This work validates the feasibility of teleoperated robotic control of an active steerable needle using magnetic resonance (MR) for guidance. With this system, perturbations can be counteracted and critical structures can be circumvented to access currently inaccessible areas. The system comprises of (1) a novel steerable needle, (2) the minimally invasive robotics in an MR environment (MIRIAM) system, and (3) the daVinci Research Kit (dVRK). MR scans provide visual feedback to the operator controlling the dVRK. Needle steering is performed along curved trajectories to avoid the urethra towards targets (representing tumour tissue) in a prostate phantom with a targeting error of 1.2 ± 1.0 mm. This work shows the potential clinical applicability of active needle steering for prostate BT with a teleoperated robotic system in an MR environment.

Towards a Procedure-Optimised Steerable Catheter for Deep-Seated Neurosurgery.

In recent years, steerable needles have attracted significant interest in relation to minimally invasive surgery (MIS). Specifically, the flexible, programmable bevel-tip needle (PBN) concept was successfully demonstrated in vivo in an evaluation of the feasibility of convection-enhanced delivery (CED) for chemotherapeutics within the ovine model with a 2.5 mm PBN prototype. However, further size reductions are necessary for other diagnostic and therapeutic procedures and drug delivery operations involving deep-seated tissue structures. Since PBNs have a complex cross-section geometry, standard production methods, such as extrusion, fail, as the outer diameter is reduced further. This paper presents our first attempt to demonstrate a new manufacturing method for PBNs that employs thermal drawing technology. Experimental characterisation tests were performed for the 2.5 mm PBN and the new 1.3 mm thermally drawn (TD) PBN prototype described here. The results show that thermal drawing presents a significant advantage in miniaturising complex needle structures. However, the steering behaviour was affected due to the choice of material in this first attempt, a limitation which will be addressed in future work.

Safer Motion Planning of Steerable Needles via a Shaft-to-Tissue Force Model

Steerable needles are capable of accurately targeting difficult-to-reach clinical sites in the body. By bending around sensitive anatomical structures, steerable needles have the potential to reduce the invasiveness of many medical procedures. However, inserting these needles with curved trajectories increases the risk of tissue damage due to perpendicular forces exerted on the surrounding tissue by the needle’s shaft, potentially resulting in lateral shearing through tissue. Such forces can cause significant tissue damage, negatively affecting patient outcomes. In this work, we derive a tissue and needle force model based on a Cosserat string formulation, which describes the normal forces and frictional forces along the shaft as a function of the planned needle path, friction model and parameters, and tip piercing force. We propose this new force model and associated cost function as a safer and more clinically relevant metric than those currently used in motion planning for steerable needles. We fit and validate our model through physical needle robot experiments in a gel phantom. We use this force model to define a bottleneck cost function for motion planning and evaluate it against the commonly used path-length cost function in hundreds of randomly generated three-dimensional (3D) environments. Plans generated with our force-based cost show a 62% reduction in the peak modeled tissue force with only a 0.07% increase in length on average compared to using the path-length cost in planning. Additionally, we demonstrate planning with our force-based cost function in a lung tumor biopsy scenario from a segmented computed tomography (CT) scan. By directly minimizing the modeled needle-to-tissue force, our method may reduce patient risk and improve medical outcomes from steerable needle interventions.

Toward certifiable optimal motion planning for medical steerable needles

Medical steerable needles can follow 3D curvilinear trajectories to avoid anatomical obstacles and reach clinically significant targets inside the human body. Automating steerable needle procedures can enable physicians and patients to harness the full potential of steerable needles by maximally leveraging their steerability to safely and accurately reach targets for medical procedures such as biopsies. For the automation of medical procedures to be clinically accepted, it is critical from a patient care, safety, and regulatory perspective to certify the correctness and effectiveness of the planning algorithms involved in procedure automation. In this paper, we take an important step toward creating a certifiable optimal planner for steerable needles. We present an efficient, resolution-complete motion planner for steerable needles based on a novel adaptation of multi-resolution planning. This is the first motion planner for steerable needles that guarantees to compute in finite time an obstacle-avoiding plan (or notify the user that no such plan exists), under clinically appropriate assumptions. Based on this planner, we then develop the first resolution-optimal motion planner for steerable needles that further provides theoretical guarantees on the quality of the computed motion plan, that is, global optimality, in finite time. Compared to state-of-the-art steerable needle motion planners, we demonstrate with clinically realistic simulations that our planners not only provide theoretical guarantees but also have higher success rates, have lower computation times, and result in higher quality plans.

PD-0415 Steerable needles enable HDR prostate BT for patients with pubic arch interference

PD-0415 Steerable needles enable HDR prostate BT for patients with pubic arch interference

On using steerable needles for the 3D printing of biomaterials

Steerable needles are often used in surgical operations (such as percutaneous intervention) as a relatively non-invasive approach in the treatment of certain diseases (e.g., cancer, etc.). The key advantage of this being that the needle tip can work its way through a body, avoiding all sensitive areas and / or obstacles, and ultimately reach an otherwise unreachable area (causing minimal damage). This work describes an approach to 3D printing utilizing steerable needles and defines a methodology through which biomaterial can be deposited and polymerized in place within a penetrable body to create a fibre of certain characteristics and / or behaviour. Using gelatine as the phantom body in which we 3D print with steerable needles, it is possible using a novel steerable needle experimental machine to deposit sodium alginate of a certain length in a particular orientation at certain points within the phantom and subsequently add calcium chloride to initiate polymerization into a calcium alginate fibre of certain properties. This article presents the engineering and software requirements to control a steerable needle with specific definition for 3D printing, the phantom within which we 3D print is defined, and finally calcium alginate fibers are offered, that are polymerized within the gelatine phantom. This work attempts to take a step towards the development of electro-mechanical devices which could in future allow for the 3D printing of fibers or other specific structures within the human body as part of the biomedical field.