Magnetic Capsule Research Articles

Dynamic modeling and simulation of a new conceptual design of a magnetic capsule robot by application of endoscopic capsule

This paper investigates design, modeling, simulation, and dynamic issues related to self-propelled endoscopic capsule navigated inside the human body through external magnetic fields. A novel magnetic propulsion system is proposed and fabricated, which has great potential of being used in the field of noninvasive gastrointestinal endoscopy. The endoscopic capsule dynamic is studied on a medical silicone plate as the closest available material for the stomach tissue. First, the mechanical characteristics of the medical silicone plate is measured. Next, the forces acted on the endoscopic capsule which are friction, hydrodynamic and magnetic forces are determined by means of test and numerical techniques such as finite element method. Having known the magnitude of forces and torques on the endoscopic capsule, the dynamics of capsule are calculated under different initial conditions and external magnetic fields.

A novel method of cardia visualization and comfort level enhancement during magnetic capsule gastroscopy via sugar-glued tether-assisted technique: a randomized pilot study inspired by a Chinese snack-making process (with video).

Magnetic capsule gastroscopy (MCG) is a non-invasive diagnostic method for the digestive tract. However, its efficiency in visualizing the gastric cardia is often compromised due to the capsule's rapid passage. This study introduces a novel sugar-glued tether-assisted technique inspired by a traditional Chinese snack-making process to enhance cardia visualization and patient comfort during MCG. This pilot, open-label, single-center, randomized controlled, non-inferiority study was conducted at Binzhou Medical University Hospital. Seventy-eight patients were enrolled and divided into three groups: conventional MCG, suction cup tether-assisted MCG, and sugar-glued tether-assisted MCG. The primary outcomes included safety, comfort level, and gastric cardia visualization quality. Secondary outcomes assessed technique-associated performance and clinical factors. The sugar-glued tether-assisted MCG demonstrated comparable cardia visualization quality to the suction cup method, with significantly better results than conventional MCG. Comfort levels were significantly higher in the sugar-glued group compared to the suction cup group. The number of swallow attempts was significantly lower in the sugar-glued group, with no adverse events reported. Secondary outcomes showed no significant differences in MCG assembly time and ingestion-to-detachment period between the suction cup and sugar-glued groups. The sugar-glued tether-assisted MCG is a feasible and safe modification that enhances gastric cardia visualization while improving patient comfort. This technique provides a cost-effective alternative to the suction cup method, warranting further investigation in larger, multi-center studies.

External Steering of Vine Robots via Magnetic Actuation.

This article explores the concept of external magnetic control for vine robots to enable their high curvature steering and navigation for use in endoluminal applications. Vine robots, inspired by natural growth and locomotion strategies, present unique shape adaptation capabilities that allow passive deformation around obstacles. However, without additional steering mechanisms, they lack the ability to actively select the desired direction of growth. The principles of magnetically steered growing robots are discussed, and experimental results showcase the effectiveness of the proposed magnetic actuation approach. We present a 25-mm-diameter vine robot with an integrated magnetic tip capsule, including 6 degrees of freedom (DOF) localization system and camera, and demonstrate a minimum bending radius of 3.85 cm with an internal pressure of 30 kPa. Furthermore, we evaluate the robot's ability to form tight curvature through complex navigation tasks, with magnetic actuation allowing for extended free-space navigation without buckling. The suspension of the magnetic tip was also validated using the 6 DOF localization system to ensure that the shear-free nature of vine robots was preserved. Additionally, by exploiting the magnetic wrench at the tip, we showcase preliminary results of vine retraction. The findings contribute to the development of controllable vine robots for endoluminal applications, providing high tip force and shear-free navigation.

Painless colonoscopy: fact or fiction?

Although colonoscopy is a routinely performed procedure, it is not devoid of challenges, such as the potential for perforation and considerable patient discomfort, leading to patients postponing the procedure with several healthcare risks. This review delves into preprocedural and procedural solutions, and emerging technologies aimed at addressing the drawbacks of colonoscopies. Insufflation and sedation techniques, together with various other methods, have been explored to increase patient satisfaction, and thereby, the quality of endoscopy. Recent advances in this field include the prevention of loop formation, encompassing the use of variable-stiffness endoscopes, computer-guided scopes, magnetic endoscopic imaging, robotics, and capsule endoscopy. An autonomous endoscope that relies on self-propulsion to completely avoid looping is a potentially groundbreaking technology for the next generation of endoscopes. Nevertheless, critical techniques need to be refined to ensure the development of effective and efficient endoscopes.

Single-domain structure of Fe3O4 nanoparticles encapsulation by magnetic surfactant M(AOT)2 (M=Co, Ni)

Investigating the magnetic nanoparticle size and the effective magnetic interactions that form the magnetic domain can lead us to nanoparticles with targeted applications, such as targeted drug delivery and higher resolution MRI imaging. In this study magnetic susceptibility and coercive field properties, and the structure size range of single-domain magnetic capsules with high magnetization were obtained by structural analysis of volumetric DLS properties. In this regard, the role of exchange, anisotropy, and magnetostatic interaction was investigated in the structure of a magnetic capsule containing Fe3O4 nanoparticles (MCap-NPs). The stable capsules were synthesized in an emulsion solution with magnetic surfactants M(AOT)2 (M = Co, Ni). Vibrating Sample Magnetometer (VSM) and capsule relative volume (CRV) of Dynamic Light Scattering (DLS) were used to determine the magnetic properties of the single-domain (SD) structure. The produced emulsion samples were found to have superparamagnetic properties property with saturation magnetization in the range of 2–6 × 10−3emu/g for NiCap-NPs, and 5-13 × 10−3emu/g for CoCap-NPs. The results show that nanoparticles have the most significant effect on magnetization. The coercive field, the anisotropy energy values, and the SD of M(AOT)2 were determined using magnetic susceptibility distribution. The outcome results show that the surface of the magnetic capsule plays an essential role in forming a single-domain structure. It was also found that the saturation magnetization of the samples in the emulsion solution is proportional to the nanoparticle density and not to the mass of nanoparticles. All produced samples have distinct peaks in CRV versus capsule size, and each peak follows a log-normal distribution. For both samples, except for the samples with molar ratios ω of 23 (Co3 and Ni4 samples), the positions of the second and third relative volume peaks were constant at 269 ± 3 nm and 424±6 nm, respectively. The behavior of the CRV function normalized to the peak size showed a proportionality between the coercive field and the CRV.

Mitigating Singularities in Control of Magnetic Capsule Endoscopes Using a Novel Nested Electromagnetic Coil System

Magnetic actuation systems that utilize external electromagnetic coils present a promising approach for controlling untethered small-scale robots, notably in medical applications. However, these systems frequently experience actuation singularities at which robotic control over the agent is lost or severely diminished. Such singularities may lead to excessively large current or rapid current changes that significantly affect the robots’ stability in specific areas of the workspace. In order to effectively mitigate these actuation singularities, this paper introduces a closed-loop control method using a novel nested electromagnetic coil system, leveraging finite element analysis-based magnetic field data and a novel controller combining a singularity solver and optimal current control method. The electromagnetic system has 12 coils nested in four coil units, each having three concentric coils with different outer radius, surrounding a central workspace. We call the 12-coil system Variable Outer Radius Individually Addressable Coil Stacks (VORIACS). Here, we experimentally evaluate the method for closed-loop trajectory tracking of a soft magnetic capsule endoscope (PillCam™) and a permanent magnet robot inside the VORIACS system at different magnetic field orientations. The results demonstrate that the VORIACS system with a singularity solver reduces root mean square (RMS) position tracking errors of the PillCam™by 46% to 50% and orientation tracking errors by 41% to 42% compared to a standard 4-coil system. Moreover, the system can achieve a notable 60.73% reduction in RMS position error, with sub-millimeter precision control when controlling the permanent magnet robot. We further manipulate the PillCam™for tracking a medical application-inspired complex trajectory, showcasing the system’s potential in precise control of magnetic devices for medical use.

A new industrially magnetic capsule MedRobot integrated with smart motion controller

Capsule medical robots with unique application advantages have broad prospects for gastrointestinal detection, targeted drug delivery, medical assistance, and other fields. However, due to the complexity of the gastrointestinal environment and the limitations of the space magnetic field, robust motion control of capsule robots is still a challenge. Using a permanent magnet (NdFeB) as a space magnetic source, a capsule robot manipulation instrument with an integrated motion intelligent control approach is proposed in this work. First of all, a steering fixture controlling a permanent magnet is designed, and a manipulation instrument capable of five degrees of motion freedom is built with low cost and high accuracy. Furthermore, an integrated motion control approach, consisting of a primary motion subsystem and an auxiliary motion subsystem, is presented, where the motion route of the capsule robot is planned. A parallel optimization strategy is adopted to improve the traditional Gray Wolf Optimization Algorithm, the improved version of which is utilized to tune the parameters of controllers. Finally, some experiments of the designed capsule robot are carried out in different planes and slopes, as well as simulated stomach and real pig stomach, respectively. The results show that the motion characteristics are continuous and stable, and the average position error is 4.2 mm, which meets the application requirements.

Review of Capsule Endoscope Technology

This essay explores the dynamic landscape of gastrointestinal health, highlighting the increasing incidence of conditions such as infections, ulcers, bleeding, and cancers. The crucial imperative of timely detection and diagnosis is emphasized, leading to examining capsule endoscopy and the transformative impact of magnetic sensor-based positioning techniques. From the initial development of capsule endoscopy in 2001 to the evolution of Simultaneous Magnetic Actuation and Localization (SMAL), the essay delves into advancements that enhance precision and control within the intricate gastrointestinal tract. Notwithstanding notable progress, challenges such as the necessity for miniaturization, reliance on external magnetic fields, and safety considerations are acknowledged. Future developments in navigation algorithms, wireless communication, and power management are anticipated and discussed as potential solutions. Envisioning a future where magnetic sensor-based capsule endoscopy integrates with artificial intelligence, the essay foresees personalized medicine, home-based monitoring, and global healthcare accessibility. Ultimately, the collaborative efforts needed to overcome challenges and unleash the full potential of this technology are emphasized, shaping the trajectory of gastrointestinal healthcare.

A Novel Magnetic Spiral Capsule Endoscope Localization Method Based on an Improved Artificial Bee Colony Algorithm

A Novel Magnetic Spiral Capsule Endoscope Localization Method Based on an Improved Artificial Bee Colony Algorithm

A Magnetic Capsule Robot with an Exoskeleton to Withstand Esophageal Pressure and Delivery Drug in Stomach

A Magnetic Capsule Robot with an Exoskeleton to Withstand Esophageal Pressure and Delivery Drug in Stomach

Enhanced Localization Strategy for Magnetic Capsule Robot Using On-Board Nine-Axis IMU Through Incorporation of Alternating Magnetic Field

Enhanced Localization Strategy for Magnetic Capsule Robot Using On-Board Nine-Axis IMU Through Incorporation of Alternating Magnetic Field

The Future of Minimally Invasive Capsule Panendoscopy: Robotic Precision, Wireless Imaging and AI-Driven Insights.

In the early 2000s, the introduction of single-camera wireless capsule endoscopy (CE) redefined small bowel study. Progress continued with the development of double-camera devices, first for the colon and rectum, and then, for panenteric assessment. Advancements continued with magnetic capsule endoscopy (MCE), particularly when assisted by a robotic arm, designed to enhance gastric evaluation. Indeed, as CE provides full visualization of the entire gastrointestinal (GI) tract, a minimally invasive capsule panendoscopy (CPE) could be a feasible alternative, despite its time-consuming nature and learning curve, assuming appropriate bowel cleansing has been carried out. Recent progress in artificial intelligence (AI), particularly in the development of convolutional neural networks (CNN) for CE auxiliary reading (detecting and diagnosing), may provide the missing link in fulfilling the goal of establishing the use of panendoscopy, although prospective studies are still needed to validate these models in actual clinical scenarios. Recent CE advancements will be discussed, focusing on the current evidence on CNN developments, and their real-life implementation potential and associated ethical challenges.

DEMA: Robotic dual-electromagnet actuation system integrated with localization for a magnetic capsule endoscope

DEMA: Robotic dual-electromagnet actuation system integrated with localization for a magnetic capsule endoscope

Magnetic-controlled capsule endoscopy performance in aging patients

BackgroundThe increasing elderly population and wide use of magnetic capsule endoscopy (MCE) have led to more attention to elderly patients.AimThe aim of this study was to assess the performance (including transit time, cleanliness score, positive findings and safety) of MCE in aging patients (≥ 60 years), especially patients over 80 years old.MethodsConsecutive patients of ≥ 60 years undergoing MCE at our center from August 2017 to August 2022 were classified into the oldest (≥ 80 years) and the older (60–79 years) groups. Esophageal transit time (ETT), gastric examination time (GET), small bowel transit time (SITT), and the quality of gastric preparation were compared. Information on examination indications, subjective discomforts, adverse events, and MCE outcomes were compared.ResultsOf 293 enrolled patients, 128 patients were in the oldest group and 165 patients were in the older group. ETT and GET were longer in the oldest group, whereas SITT was slightly longer in the oldest patients. Visualization scores were significantly lower in the body and antrum in the oldest patients. The total visualization score was lower in the older group compared with the oldest group; however, the difference was not significant. Cleanliness scores at the fundus and antrum and total cleanliness scores were lower in the oldest patients compared with the older patients. Positive findings and ulcers and erosions in the small intestine were more common in the oldest group. One patient had nausea during the gastric examination. Capsule retention in the cecum occurred in one case.ConclusionMCE was feasible and safe for aging patients. ETT and GET were markedly longer and gastric cleanliness and visualization were worse, while overall small intestine-positive findings were higher in the oldest patients compared with the older patients.

Versatile magnetic hydrogel soft capsule microrobots for targeted delivery

Maintaining the completeness of cargo and achieving on-demand cargo release during long navigations in complex environments of the internal human body is crucial. Herein, we report a novel design of magnetic hydrogel soft capsule microrobots, which can be physically disintegrated to release microrobot swarms and diverse cargoes with almost no loss. CaCl2 solution and magnetic powders are utilized to produce suspension droplets, which are put into sodium alginate solution to generate magnetic hydrogel membranes for enclosing microrobot swarms and cargos. Low-density rotating magnetic fields drive the microrobots. Strong gradient magnetic fields break the mechanical structure of the hydrogel shell to implement on-demand release. Under the guidance of ultrasound imaging, the microrobot is remotely controlled in acidic or alkaline environments, similar to those in the human digestion system. The proposed capsule microrobots provide a promising solution for targeted cargo delivery in the internal human body.

Construction of Multifunctional Composites for Electromagnetic Shielding and Infrared Stealth Based on Magnetic Phase Change Capsules and Silicone Rubber Foam

AbstractFunctionalization of phase change capsules is recognized as one of the promising technologies to improve energy efficiency and promote their versatile application. Herein, a new magnetic phase change capsule (NiFe2O4‐encapsulated phase change material (EPCM)) composed of paraffin wax core and SiO2‐NiFe2O4 double‐layer shell is designed. The prepared NiFe2O4‐EPCMs possess sensitive magnetic response, excellent thermal management performance, and enhanced thermal stability. In particular, the representative NiFe2O4‐EPCM‐4 has the highest saturation magnetization (8.41 emu · g−1) and high enthalpy of 131.2 J · g−1. Subsequently, NiFe2O4‐EPCM‐4 is introduced into silicone rubber foam (SRF) matrix and magnetic composite SRFs (MSRFs) are prepared. The latent heat of MSRF‐3 containing 30% NiFe2O4‐EPCM‐4 can reach 28.9 J g−1 and there is almost no change even after 200 cycles. In comparison with pure SRF, the tensile strength and compressive strength of MSRF‐3 are increased by 167.7% and 941.8%, respectively. Importantly, the electromagnetic interference shielding effectiveness of MSRF‐3 is significantly improved from 15.9 to 30.6 dB. Besides, the MSR‐3 can achieve an intriguing infrared stealth function for targets both in human body temperature and high temperature environment. Therefore, this work might stimulate people's interest and inspiration in the design and preparation of multifunctional phase change capsules.

Five-degree-of-freedom robust control of a magnetic endoscopic capsule using an electromagnetic system

Capsule endoscopy is a minimally invasive gastrointestinal diagnostic procedure. The active endoscopic capsule enables the physician to steer the device to any desired position and direction, resulting in a better diagnosis of the disease. Due to the model uncertainties and the existence of disturbances in the gastrointestinal system, traditional control methods cannot achieve robust performance and stability. To overcome this issue, in this paper, a robust sliding mode controller is proposed for 5 Degrees Of Freedom (DOF) control (3-DOF closed-loop control for position and 2-DOF open-loop control for orientation) of the capsule endoscope using an electromagnetic actuation system. The efficiency of the proposed control method is compared with a Proportional–Integral–Derivative (PID) controller considering the model uncertainties and external disturbances. The results of simulations considering 5% of uncertainty in the model parameters show that the suggested approach can precisely and efficiently actuate the capsule to follow the desired trajectory, with position and orientation accuracy of 0.53 mm and 0.69 degree, respectively. Experiments demonstrate the efficiency of the proposed controller, revealing a tracking error of about 0.73 mm in the capsule position. Furthermore, it has been proven by experiments that even in the presence of external disturbances, the proposed control system performs very well and keeps the capsule on the desired trajectory.

Robot-Aided Magnetic Navigation System for Wireless Capsule Manipulation

Magnetic navigation systems (MNSs) have been developed to use in the diagnosis of gastrointestinal problems. However, most conventional magnetic navigation systems are expensive and have structural problems because of their large weights and volumes. Therefore, this paper proposes C-Mag, a novel compact MNS composed of two electromagnets and a robotic arm. The two electromagnets generate a planar magnetic field, and the robotic arm rotates and translates the electromagnets to manipulate the magnetic capsule in a large 3-dimensional (3-D) space. The C-Mag design considers the payload of the robotic arm and the capacity of the power supply unit. Under these limited conditions, the C-Mag was optimized to generate the maximum magnetic field considering several major factors. Finally, the C-Mag was constructed, and the maximum magnetic field that could be generated in one direction was 18.65 mT in the downward direction. Additionally, the maximum rotating magnetic field was 13.21 mT, which was used to manipulate the capsule. The performance was verified by measuring the generated magnetic field, and it matched well with the simulated result. Additionally, the path-following experiment of the magnetic capsule showed that the proposed C-Mag can effectively manipulate the magnetic capsule in 3-D space using the robotic arm. This study is expected to contribute to the further development of magnetic navigation systems to treat gastrointestinal problems.

Treatment With Adalimumab 80 mg Every Other Week in Inflammatory Bowel Disease: Results of Treatment Intensification in Clinical Practice.

Loss of response to anti-tumor necrosis factor drugs in patients with inflammatory bowel disease (IBD) is frequent and, in case of low drug levels, treatment intensification is recommended. In addition, in cases in which clinical response without attainment of remission (clinical, endoscopic, or radiological), intensification could be justified since higher drug levels are associated with better outcomes. For adalimumab (ADA), the standard intensification regimen is 40 mg every week (ew). Availability of ADA 80 mg prefilled pens has enabled every other week (eow) intensification. We assessed the clinical efficacy of intensification with ADA 80 mg eow. This retrospective study was conducted at a tertiary hospital in Spain. Patients with IBD receiving maintenance ADA 80 mg eow with clinical, biomarker, and drug-level assessments were included. Demographics and clinical, biological, and endoscopic evaluation of the disease before and after ADA intensification, and pharmacokinetic assessments, were collected. Eighty-seven patients (72 Crohn's disease, 15 ulcerative colitis; average age 50 years) were included. Reasons for ADA intensification were: low ADA levels-<5 µg mL-1-(17%), low ADA levels-<5 µg mL-1-without clinical response (63%), clinical response without clinical remission (15%) and active disease on objective evaluation (including colonoscopy, magnetic resonance imaging, capsule endoscopy, and/or intestinal ultrasound; 5%). Following treatment intensification to ADA 80 mg eow, 75 patients (86%) were in clinical remission and 69 (79.3%) were in biologic remission (clinical remission and normalization of biomarkers). After a median follow-up of 19 months (interquartile range 13-25), 63 patients (72%) remained on treatment and in clinical remission. There were no serious infections, hospitalizations, or deaths. Drug costs did not increase with the 80 mg eow regimen versus a standard intensification regimen. ADA intensification to 80 mg eow was safe, effective, and did not increase drug costs versus standard intensification to 40 mg ew in our experience.

Author commentary on Xi Jiang et al.

Xi Jiang et al. Small-sized versus standard magnetic capsule endoscopy in adults: a two-center, double-blinded randomized controlled trial