... International Symposium on Medical Robotics. International Symposium on Medical Robotics最新文献

In this paper, we present a robotically steerable laser ablation probe with application to interstitial thermal therapy. Existing laser interstitial thermal therapy (LITT) methods utilize a straight probe to deliver laser energy around the tip or to the side of the tip. These methods are inadequate to provide effective treatment for large, irregularly shaped tumors. Our robotic probe can be manipulated inside soft tissue to perform ablation at multiple locations, thus enabling conformable ablation for large and complicated tumors. Instead of directly firing laser into soft tissue, a Polydimethylsiloxane (PDMS)/Carbon nanoparticles (CNPs) mixture hosts a multi-mode optical fiber at the probe tip to work as a heater when laser is activated to improve the procedural safety. This paper presents the design and fabrication of the robotic ablation probe, simulation of laser thermal transformation using finite element analysis, and experimental studies that characterize the robot motion and heating effects and demonstrate in vitro ablation.

Retinal microsurgery is a high-precision surgery performed on a delicate tissue requiring the skill of highly trained surgeons. Given the restricted range of instrument motion in the confined intraocular space, snake-like robots may prove to be a promising technology to provide surgeons with greater flexibility, dexterity, and positioning accuracy during retinal procedures such as retinal vein cannulation and epiretinal membrane peeling. Kinematics modeling of these robots is an essential step toward accurate position control. Unlike conventional manipulators, modeling these robots does not follow a straightforward method due to their complex mechanical structure and actuation mechanisms. The hysteresis problem can especially impact the positioning accuracy significantly in wire-driven snake-like robots. In this paper, we propose a data-driven kinematics model using a probabilistic Gaussian mixture model (GMM) and Gaussian mixture regression (GMR) approach with a hysteresis compensation algorithm. Experimental results on the two-degree-of-freedom (DOF) integrated robotic intraocular snake (I²RIS) show that the proposed model with the hysteresis compensation can predict the snake tip bending angle for pitch and yaw with 0.45° and 0.39° root mean square error (RMSE), respectively. This results in overall 60% and 70% improvements of accuracy for yaw and pitch over the same model without the hysteresis compensation.

While the use of tissue-mimicking (TM) phantoms has been ubiquitous in surgical robotics, the translation of technology from laboratory experiments to equivalent intraoperative tissue conditions has been a challenge. The increasing use of lasers for surgical tumor resection has introduced the need to develop a modular, low-cost, functionally relevant TM phantom to model the complex laser-tissue interaction. In this paper, a TM phantom with mechanically and thermally similar properties as human brain tissue suited for photoablation studies and subsequent visualization is developed. The proposed study demonstrates the tuned phantom response to laser ablation for fixed laser power, time, and angle. Additionally, the ablated crater profile is visualized using optical coherence tomography (OCT), enabling high-resolution surface profile generation.

Bevel-tip needles are commonly utilized in percutaneous medical interventions where a curved insertion trajectory is required. To avoid deviation from the intended trajectory, needle shape sensing and tip localization is crucial in providing the operator with feedback. There is an abundance of previous work that investigate the medical application of fiber Bragg grating (FBG) sensors, but most works select only one specific type of fiber among the many available sensor options to integrate into their hardware designs. In this work, we compare two different types of FBG sensors under identical conditions and application, namely, acting as the sensor for needle insertion shape reconstruction. We built a three-channel single core needle and a seven-channel multicore fiber (MCF) needle and discuss the pros and cons of both constructions for shape sensing experiments into constant curvature jigs. The overall needle tip error is 1.23 mm for the single core needle and 2.08 mm for the multicore needle.

High precision is required for ophthalmic robotic systems. This paper presents the kinematic calibration for the delta robot which is part of the next generation of Steady-Hand Eye Robot (SHER). A linear error model is derived based on geometric error parameters. Two experiments with different ranges of workspace are conducted with laser sensors measuring displacement. The error parameters are identified and applied in the kinematics to compensate for modeling error. To achieve better accuracy, Bernstein polynomials are adopted to fit the error residuals after compensation. After the kinematic calibration process, the error residuals of the delta robot are reduced to satisfy the clinical requirements.

Vitreoretinal surgery requires dexterity and force sensitivity from the clinician. A system to cooperatively control an integrated surgical robot for high dexterity manipulation within the eye's vitreous space was developed and validated in simulation. The system is composed of a 2 degrees of freedom (DoF) snake-like continuum manipulator that is attached to the end-effector of a 5-DoF rigid robot arm. It is capable of receiving position and orientation commands from a 5-DoF input device in real-time, as well as following pre-planned trajectories. The manipulator is moved to each target pose in real-time, using an optimization method to calculate the inverse kinematics solution. Constraints on the position and orientation ensure the target pose does not harm the patient within the vitreous space, enabling the robot to safely assist the clinician with vitreoretinal surgery when operating in real-time. The simulation demonstrates the system's feasibility and benefits over the existing non-dexterous system.

This work introduces design, manipulation, and operator control of a bidirectional robotic tool for minimally invasive targeted prostate biopsy. The robotic tool is purposed to be used as a compliant flexure section of active biopsy needles. The design of the robotic tool comprises of a flexure section fabricated on a nitinol tube that enables bidirectional bending via actuation of two internal tendons. The statics of the flexure section is presented and validated with experimental data. Finally, the capability of the robotic tool to reach targeted positions inside prostate gland is evaluated.

High-dose-rate brachytherapy (HDR BT) is a radiation therapy that places radioactive sources at cancerous tissue using needles. HDR BT offers better dose conformality and sparing of clinical structures, lower operator dependency, and fewer acute irritative symptoms compared to the other form of BT (low-dose-rate (LDR)). However, use of HDR BT is limited for patients with pubic arch interference, where the transperineal path to the prostate is blocked. This study aims to introduce a tendon-driven needle that can bend inside tissue to reach desired positions inside prostate. Initial experiments in a phantom tissue showed the feasibility of the needle to get around the pubic arch for placement at hard-to-reach target positions.

The adoption of robotic image-guided surgeries has enabled physicians to perform therapeutic and diagnostic procedures with less invasiveness and higher accuracy. One example is the MRI-guided stereotactic robotic-assisted surgery for conformal brain tumor ablation, where the robot is used to position and orient a thin probe to target a desired region within the brain. Requirements such as the remote center of motion and precise manipulation, impose the use of complex kinematic structures, which result in non-trivial workspaces in these robots. The lack of workspace visualization poses a challenge in selecting valid entry and target points during the surgical planning and navigation stage. In this paper, we present a surgical planning toolkit called the "NeuroPlan" for our MRI-compatible stereotactic neurosurgery robot developed as a module for 3D Slicer software. This toolkit streamlines the current surgical workflow by rendering and overlaying the robot's reachable workspace on the MRI image. It also assists with identifying the optimal entry point by segmenting the cranial burr hole volume and locating its center. We demonstrate the accuracy of the workspace rendering and burr hole parameter detection through both phantom and MR-images acquired from previously conducted animal studies.