Objective: Wireless capsule endoscopy has been well used for gastrointestinal (GI) tract diagnosis. However, it can only obtain images and cannot take samples of GI tract tissues. In this study, we designed a magnetically-actuated biopsy capsule (MABC) robot for GI tract diagnosis. Methods: The proposed robot can achieve locomotion and biopsy functions under the control of external electromagnetic actuation (EMA) system. Two types of active locomotion can be achieved, plane motion refers to the robot rolling on the surface of the GI tract with a rotating uniform magnetic field. 3D motion refers to the robot moving in 3D space under the control of the EMA system. After reaching the target position, the biopsy needle can be sprung out for sampling and then retracted under a gradient magnetic field. Results: A pill-shaped robot prototype ( $\phi$ 15 mm×32 mm) has been fabricated and tested with phantom experiments. The average motion control error is 0.32 mm in vertical direction, 3.3 mm in horizontal direction, and the maximum sampling error is about 5.0 mm. The average volume of the sampled tissue is about 0.35 mm $^{3}$ . Conclusion: We designed a MABC robot and proposed a control framework which enables planar and 3D spatial locomotion and biopsy sampling. Significance: The untethered MABC robot can be remotely controlled to achieve accurate sampling in multiple directions without internal power sources, paving the way towards precision sampling techniques for GI diseases in clinical procedures.

Magnetic localization methods have been widely studied to provide accurate position and orientation information of intra-body objects, such as wireless capsule endoscopes. However, these methods cannot work well in dynamic scenarios when using a wearable sensor array due to the geomagnetic field. In this article, we propose a novel approach for tracking wireless capsules in a mobile setup based on differential signals from adjacent magnetic sensors. Compared to the previous passive magnetic localization framework, the proposed algorithm can eliminate the interference of the geomagnetic field without introducing other compensation sensors or signals. As a result, the proposed method can be used for wearable sensor arrays without knowing the distribution of the geomagnetic field and the movement of the sensor array in advance. Moreover, the relationship between position error and distance of adjacent sensors has been studied to improve tracking accuracy. Finally, a sensor array with 16 three-axis magnetic sensors is developed. Both static and dynamic experiments have been carried out, whose results verified the effectiveness of the proposed method.

This article proposes a novel targeted-location drug delivery system for lower gastrointestinal (GI) tract (such as the small intestine) capsule robots. The proposed system takes a “2-in-1” approach that enables both the magnetically actuated anchoring and drug release by using only one internal magnet. The integrated design consists of a magnetically actuated decoupling module, an anchoring module, and a drug release module. The magnetically actuated decoupling module is equipped with two decoupling mechanisms at both ends, which can, respectively, provide one-way rotation for anchoring and drug release functions. The two functions can be decoupled controlled. The anchoring module can simultaneously extend two C-shaped anchoring legs, which can help the capsule anchor at a given position inside the GI tract without damaging it. The drug release module can load 1.6-mL liquid drug and quickly release all the drugs under the control of an external magnet. A capsule robot prototype of the proposed design has been built with 16-mm diameter and 50-mm length. Phantom and in vitro experiments on anchoring and drug release modules have been conducted and have validated the effectiveness of the proposed design and control method.

Intraluminal epithelial abnormalities, potential precursors to significant conditions like cancer, necessitate early detection for improved prognosis. We present a motor-free telerobotic optical coherence tomography (OCT) endoscope that offers high-resolution intraluminal imaging and overcomes the limitations of traditional systems in navigating curved lumens. This system incorporates a compact magnetic rotor with a rotatable diametrically magnetized cylinder permanent magnet (RDPM) and a reflector, effectively mitigating thermal and electrical risks by utilizing an external magnetic field to maintain temperature increases below 0.5 °C and generated voltage under 0.02 mV. Additionally, a learning-based method corrects imaging distortions resulting from nonuniform rotational speeds. Demonstrating superior maneuverability, the device achieves steerable angles up to 110° and operates effectively in vivo, providing distortion-free 3D programmable imaging in mouse colons. This advancement represents a significant step towards guidewire-independent endomicroscopy, enhancing both safety and potential patient outcomes.

The complex anatomy of internal luminal organs, like bronchioles, poses challenges for endoscopic optical coherence tomography (OCT). These challenges include limited steerability for targeted imaging and nonuniform rotation distortion (NURD) with proximal scanning. Using rotary micromotors for distal scanning could address NURD but raises concerns about electrical safety and costs. We present pneumaOCT, the first pneumatic OCT endoscope, comprising a steerable catheter with a soft pneumatic actuator and an imaging probe with a miniature pneumatic turbine. With a diameter of 2.8 mm, pneumaOCT allows for a bending angle of up to 237°, facilitating navigation through narrow turns. The pneumatic turbine enables adjustable imaging speeds from 51 to 446 revolutions per second. We demonstrate the pneumaOCT in vivo imaging of mouse esophagus and colon, as well as targeted and distortion-free imaging of peripheral bronchioles in a bronchial phantom and a porcine lung. This advancement substantially improves endoscopic OCT for navigational imaging in curved and narrow lumens.

Magnetic soft robots have attracted widespread attention for their untethered, remotely operated, and compliant deformation characteristics. Earlier work has demonstrated magnetic origami robots' diverse locomotion capabilities. This letter will focus on the motion generation and open-loop control of an untethered magnetic flexible robot with a stretch-twist coupling origami spring (OS) skeleton only using uniform magnetic field control. We investigate the associated motion generation mechanism and the corresponding control signals for the magnetic spring robot (MSR). The MSR can perform in-plane crawling ( Worm Crawling ) and perpendicular in-plane crawling ( Crab Crawling ) under two-dimensional magnetic signal inputs. Moreover, the OS's stretch-twist coupling characteristic is utilized to achieve axial Rolling Motion with axial magnetization configuration. We further experimentally tested the performance of three motions with average normalized velocities of 0.34 $\pm$ 0.039(body length/s), 0.054 $\pm$ 0.0066(body length/s), and 1.46 $\pm$ 0.069(body length/s), respectively.