Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2512.18048

Design of a Polymer-based Steerable Cannula for Neurosurgical Applications

Nidhi Malhotra·Amber K. Rothe·Revanth Konda·Jaydev P. Desai
View original source ↗Read source document ↗Export metadata ↓

Abstract

Robotically steerable compliant surgical tools offer several advantages over rigid tools, including enhanced dexterity, reduced tissue damage, and the ability to generate non-linear trajectories in minimally invasive neurosurgical procedures. Many existing robotic neurosurgical tools are designed using stainless steel or nitinol materials. Using polymer-based materials instead can offer advantages such as reduced interference in magnetic resonance imaging, enhanced safety for guiding electrically powered instruments, and reduced tissue damage due to inherent compliance. Several polymer materials have been used in robotic surgical applications, such as polyimide, polycarbonate, and elastic resin. Various fabrication strategies have also been proposed, including standard microfabrication techniques, thermal drawing, and 3-D printing. In our previous work, a tendon-driven, notched-tube was designed for several neurosurgical robotic tools, utilizing laser micromachining to reduce the stiffness of the tube in certain directions. This fabrication method is desirable because it has a single-step process, has high precision, and does not require a cleanroom or harsh chemicals. Past studies have explored laser-micromachining of polymer material for surgical applications such as stent fabrication. In this work, we explore extending the use of the laser micromachining approach to the fabrication of polyimide (PI) robotically steerable cannulas for neurosurgical applications. Utilizing the method presented in this work, we fabricated joints as small as 1.5 mm outer diameter (OD). Multiple joints were fabricated using PI tubes of different ODs, and the loading behavior of the fabricated joints was experimentally characterized.

Explore related subjects

cs.RO

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Nidhi Malhotra, Amber K. Rothe, Revanth Konda, Jaydev P. Desai. 2025-12-19. Design of a Polymer-based Steerable Cannula for Neurosurgical Applications. https://arxiv.org/abs/2512.18048

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

IMLE-VLA: Fast Single-Step Action Generation for Vision-Language-Action Policies

Vision-language-action (VLA) policies leverage pretrained vision-language backbones to achieve strong cross-task generalization. A leading design couples this backbone with a dedicated continuous action head trained via diffusion or flow matching. However, such heads rely on iterative multi-step sampling, for example 10 Euler steps in $\pi_{0.5}$. This creates an inference bottleneck that produces stop-and-go movement in the robot and slower task completion. We introduce IMLE-VLA, which replaces the iterative action head with a single-step conditional generator trained via conditional Implicit Maximum Likelihood Estimation (cIMLE). The cIMLE objective promotes multimodal action coverage, avoiding the mode collapse of naive regression heads while eliminating multi-step sampling entirely. When IMLE-VLA is applied to $\pi_{0.5}$, it increases inference frequency 3.67x (55 Hz vs. 15 Hz), enabling up to 11x higher action throughput. On the 40-task LIBERO benchmark, IMLE-VLA achieves the highest average success rate (98.0%) among all baselines while leading in inference frequency. Under the test-time perturbations of LIBERO-plus, IMLE-VLA retains $\pi_{0.5}$'s robustness while other baselines degrade sharply, confirming that the cIMLE head preserves generalization. Real-world experiments on a Franka Emika Panda across four tasks demonstrate smoother motion (2.2x to 3.0x lower jerk) and faster task completion, with IMLE-VLA outperforming $\pi_{0.5}$ on every task and reducing average VLA inference time per episode by 3.9x to 6.6x. Videos and code are available at https://kianhk6.github.io/IMLE-VLA/

cs.RO↗
arXiv2026

ObstaDiff: Generalizable Diffusion Policy Learning via Obstacle-aware Representations

Imitation learning has achieved impressive results in robotic manipulation, yet most existing approaches assume clean backgrounds and lack explicit mechanisms for obstacle-aware motion generation. Extending such policies to cluttered, real-world scenes with unstructured obstacles remains a key generalization challenge. We present ObstaDiff, a decomposed diffusion-policy framework with a lightweight obstacle-aware visual encoder. ObstaDiff extracts a structured target-obstacle-background representation, enabling the downstream alignment policy to generate end-effector trajectories toward a target-centered bottleneck pose while reasoning about surrounding obstacles. We evaluate ObstaDiff on 61 real-robot greenhouse trials per method (366 executions in total). ObstaDiff achieves 75.41% average task success and 8.20% average obstacle collision rate, outperforming representative imitation-learning baselines and improving generalization in cluttered agricultural scenes.

cs.RO↗
arXiv2026

Testing Between the Test Cases: Proving End-to-End Steering in Conditions You Never Drove

AI-based automated vehicle testing is challenging because a model that passes every test condition can still fail in the real world. Formal verification offers a way to directly address this gap. On a simulated highway and an arterial road we trained two small end-to-end steering networks each in CARLA, one on clear conditions alone and one on clear, fog, night and low sun. All four models were driven against a 2.19 ft lane-departure budget. Without driving again, we used bound propagation, a formal method that reads the trained weights, to compute how far steering can drift at every disturbance strength between two captured images. One calculation covers more than a campaign could drive: on the arterial it spans 133 poses, where ten intensities each would be 10^133 combinations, in minutes on one GPU. Not only did formal verification find conditions that broke the clear-trained policy without simulation testing, it provided some preliminary evidence for potential failures between the test cases. Our overall conclusion is that formal verification is a viable complement to simulation, and could be adopted as a part of verification and validation for automated driving.

cs.RO↗