Magnetic continuum robots offer flexibility and controllability, making them promising for minimally invasive surgery (MIS). However, the clinical application of these robots is relatively limited due to the difficulty of integrating miniaturized triaxial force sensors and their single functionality. This paper proposes a multifunctional magnetic catheter robot with magnetic actuation steering and triaxial force-sensing capabilities. The robot features 3 channels at its tip that integrate multi-segmented magnets, a novel triaxial force sensor, and various functional instruments. The sensor is calibrated, demonstrating high sensitivity and accuracy. The steering characterization of the robot confirms that the catheter tip exhibits effective flexibility and force sensing. Palpation experiments involving various hard lumps are performed on porcine kidney, with results verifying that the robot can reliably detect abnormal hard lumps within tissues. Additionally, palpation experiments in bronchial phantom demonstrate the robot’s imaging and palpation capabilities for lung nodules with an integrated endoscope. Further, the robot, equipped with biopsy forceps, successfully performs palpation and biopsy functions on simulated stomach polyps, demonstrating its capability for effective tissue manipulation. By leveraging force-sensing capabilities and integrating multifunctional instruments, the robot shows potential for expanded applications in MIS, paving the way for important advancements in clinical procedures.

This paper develops a high-precision miniature three-dimensional Fiber Bragg Grating (FBG) force sensor designed for detecting and locating hard masses within tissues during Minimally Invasive Surgery (MIS) and robotic-assisted MIS palpation processes. The prototype consists of three FBG-etched optical fibers and an integrated elastomer. The fibers are suspended and parallel to each other within the elastomer, allowing each FBG to be directly compressed or stretched under stress. A novel model, combining segment-by-segment sensitivity and differential decoupling, is adopted for decoupling three-dimensional forces. This approach significantly reduces the crosstalk error caused by spatial forces, avoids the complexity of assembling multiple fibers in previous designs, and reduces the sensor's size, facilitating its integration into MIS procedures. Calibration experiments are conducted to determine the sensor's force sensitivity coefficients, achieving resolutions of 4.35 mN, 3.99 mN, and 3.30 mN in the X, Y, and Z directions, respectively. Through discrete and drag palpation tests on silicone with different types of hard inclusions, the results demonstrate that the proposed prototype has the ability to effectively identify the size, hardness, and depth of hard objects from the contact force information. Additionally, ex vivo porcine kidney palpation experiments are conducted to further verify the feasibility of locating hard masses during MIS palpation.

This paper establishes a widely applicable method for designing hollow-core anti-resonant fiber (HC-ARF) model based on geometric principles, which is feasible under practical manufacturing conditions and is defined by concise equations. We define this problem as a combinatorial optimization issue under the constraints of mixed integer nonlinearity. We iteratively refine the solution space through multiple steps, culminating in an integrated algorithm for automated modeling computation and data extraction. Through exhaustive calculation of models under limited conditions, we obtained multiple rigid HC-ARFs with low confinement loss (CL), low bend loss, and relatively high birefringence. The minimum CL is $\text{8.8}\times \text{10}^{-3}$ dB/m. At bending radius of 5 cm, the lowest bend loss is $\text{2.7}\times \text{10}^{-2}$ dB/m, and the highest birefringence is $\text{2.2}\times \text{10}^{-6}$ . After statistical analysis, two key factors influencing single anti-resonance layer HC-ARF have been determined: the number and radius of the rings hold the primary importance, followed by the rings arrangement. Further study demonstrates that the proposed model design method can be applied to various optical fiber designs.

This work introduces a novel fiber Bragg grating (FBG)-based tactile sensor specifically developed for real-time force monitoring at the tips of flexible ureteroscopes. With a diameter of only 1.5 mm, the sensor features a dual-FBG configuration that effectively separates temperature effects from force signals, integrated with an innovative elastomer structure based on staggered parallelogram elements. Finite element analyses comparing traditional spiral and parallel groove designs indicate that the new configuration not only enhances axial sensitivity through optimized deformation characteristics but also significantly improves resistance to transverse forces via superior stress distribution and structural stability. In the sensor, a suspended lateral FBG is employed for thermal compensation, while an axially constrained FBG is dedicated to force detection. Calibration using a segmented approach yielded dual-range sensitivities of approximately 283.85 pm/N for the 0–0.5 N range and 258.57 pm/N for the 0.5–1 N range, with a maximum error of 0.07 N. Ex vivo ureteroscopy simulations further demonstrated the sensor’s capability to detect tissue–instrument interactions and to discriminate contact events effectively. This miniaturized solution offers a promising approach to achieving precise force feedback in endoscopic procedures while conforming to the dimensional constraints of standard ureteroscopes.

Bronchoscopy robots are pivotal for improving the accuracy and efficiency of early lung cancer diagnosis. However, the stiffness of existing systems is fixed, which limits the robot from accurately navigating and performing stable operations on distant peripheral nodules. This paper introduces a novel bronchoscopy robot equipped with a magnetic multi‐segment variable stiffness catheter, whose stiffness can be precisely adjusted in real time. The soft state of the catheter can enhance the flexibility of movement, while the rigid state can provide stable support. The catheter's slender profile and wirelessly magnetic steerability facilitate access to the distal terminal bronchi for examination. The catheter achieved a maximum bending angle of 49.07° in soft state and 1.11° in rigid state. By independently controlling the stiffness of each segment, the catheter could conform to various complex shapes. In vitro experiments showed that the bronchoscopy robot could reach deep branches of the lung and operate in conjunction with tools such as lasers. The results of the live pig experiment confirmed that the bronchoscopy robot could navigate to the bronchial target location for detection. By accessing distal bronchi unreachable by commercial systems, our robot offers a superior solution for early‐stage lung cancer bronchoscopy.