MR conditional prostate intervention systems and actuations review

Magnetic resonance imaging (MRI) has the ability to provide high-resolution images of soft tissues without the use of radiation. So much research has been focused on the development of actuators and robotic devices that can be used in the MRI environment so “real-time” images can be obtained during surgeries. With real-time guidance from MRI, robots can perform surgical procedures with high accuracy and through less invasive routes. This technique can also significantly reduce the operation time and simplify pre-surgical procedures. Therefore, research on robot-assisted MRI-guided prostate intervention has attracted a great deal of interest, and several successful clinical trials have been published in recent years, pointing to the great potential of this technology. However, the development of MRI-guided robots is still in the primary stage, and collaboration between researchers and commercial suppliers is still needed to improve such robot systems. This review presents an overview of MRI-guided prostate intervention devices and actuators. Additionally, the expected technical challenges and future advances in this field are discussed

The Integration of Robotic Arm and Vision System With Magnetic Tractor Beam Control for Precision Catheter Manipulation in Medical Procedures

This study addresses the challenges of traditional catheterization techniques by integrating UFACTORY's uArm Swift Pro robotic arm with the OpenMV camera module, enhanced by the magnetic tractor beam (MTB) method. The goal is to improve precision, stability, and minimally invasive operation in catheter-based medical procedures. The uArm Swift Pro offers a robust and adaptable platform, while the OpenMV camera provides accurate real-time tracking of catheter tips. To evaluate the system's effectiveness, experimental models replicating realistic anatomical scenarios were created using advanced three-dimensional (3D) printing techniques. Preliminary results demonstrate that this integrated system enhances the accuracy and safety of catheterization, suggesting its potential to advance medical robotics and contribute to more patient-friendly interventions. This work underscores the potential for robotics to revolutionize medical procedures, ensuring better outcomes and reduced patient discomfort

Cycloidal Stepper Motor: A Systematic Approach for Designing a Nonmagnetic Rotary Actuator

Magnetic resonance imaging (MRI) has the ability to provide high-quality images of soft tissues and obtain the positions of surgical tools and target tissues, which is extremely useful in minimally invasive surgery. Hence, there is a significant need for surgical robots capable of working in the MRI environment, but designing MR-conditional actuators is one of the biggest obstacles to developing such robots. This article provides a novel approach to building pneumatic motors. A gear set design inspired by the curtate hypocycloid is applied for the motion of the rotor. The motor's operating principle and mechanical design, including rotor and housing, are presented. The relationship between different transmission ratios and motors is explored, showing that motors with more chambers and higher resolution can be obtained based on this hypocycloid. A physical prototype is made by three-dimensional printing and laser cutting, and the experimental data show that the presented motor can achieve a maximum speed of 2000 r/min and a torque of 11 mN·m

Design of a Square Rotor Driven Pneumatic Stepper Actuator for MR-Guided Therapy

Magnetic resonance (MR) imaging has been widely used in the diagnostics and treatment of soft tissues due to its ability to acquire high-resolution images with outstanding contrast. Therefore, MR-guided therapy and its supporting equipment, including MR-conditional sensors and actuators, have been developed rapidly. In this article, a nonmagnetic pneumatic stepper motor was developed. The working principle was analyzed, and the theoretical static output torque was expressed mathematically. The driven part of the proposed design is a polygon rotor derived from the Wankel engine. Besides, the outline of the inner wall of the housing was investigated. Experiments were conducted with the motor functioning at different speeds under different air pressures; by controlling the air in each chamber sequentially, the rotor can rotate continuously in dual directions with a torque of up to 38 mN·m and a maximum speed of 400 r/min. The MR test showed that no image artifact was found

Bioimpedance Sensing and Ablation Needles for Image-Guided Therapy

Sensing and ablation needles and catheter instruments combined with multimodal imaging, navigation and AI-assisted diagnosis have been increasingly utilised by interventional radiologists for image-guided therapy, emerging as an innovative tool for both diagnosis and treatment. This paper reviews the significant advancements in the field over the past decade, focusing on the development and refinement of both bioimpedance sensing needles and thermal ablation needles. Bioimpedance sensing needles differentiate pathological tissues by measuring impedance variations in biological tissues, offering a less invasive diagnostic approach. Thermal ablation needles, on the other hand, employ Radio Frequency (RF) techniques or Electrolytic Ablation (EA) to effectively target and treat lesions. This review covers the evolution of these needles, including advancements in materials, novel sensor technologies, impedance analysis methods, ablation catheter powering techniques, and needle design. It also provides insights into the needle structure, fabrication methods, and testing outcomes of these advanced sensing and ablation needles. Additionally, the paper presents an analysis of bioimpedance data across various pathological tissues and discusses innovative impedance analysis methodologies. The review concludes by presenting the current challenges in the field and discussing directions for future research, thereby providing an overview of the state-of-the-art in electronic technology for medical diagnosis and treatment needles

A Narrative Review of In-Textile Sensors in Human Health Applications

Sensors have become more versatile and sophisticated in recent years to fulfill the increasing demands for human health applications. Physiological information such as electrocardiogram, pulse rate, and respiration are essential indications of personal health, often collected as vitals, which are typically collected from medical-grade electrocardiogram (ECG) machines. In-textile sensors are a fast-growing sub-category of wearable sensors embedded in smart textiles to acquire physiological information and movement index and provide harmful chemical warnings without compromising the comfortable nature of clothing. Recent literature has shown that integrating new materials has greatly improved the stability, specificity, and selectivity of in-textile sensors. For example, polyvinylidene fluoride nanofiber produced a highly stretchable sensor to measure ECG readings during movement without losing data quality. This review discusses a group of nanomaterial-based in-textile sensors for consumer use in the home, workplace, and healthcare environments. This review will focus on exploring and analyzing the latest developments in these nanomaterial-based e-textiles due to their ability to be more easily integrated for daily use and their great potential for medical applications. Future work will be necessary to incorporate recycled materials, improve the method of powering these sensors, and ultimately refine the designs to be appropriate for more sustainable use

A Pneumatic Driven MRI-Guided Robot System for Prostate Interventions

Under the guidance of high-resolution Magnetic Resonance Imaging (MRI), robotic devices offer a great advantage for prostate intervention. This paper presents an MR-safe robot, where a needle is attached to the needle guide to obtain prostate biopsies during surgeries. The robot is powered by three actuators, two of them are customized to function as a work plane that allows the needle to move horizontally and vertically, and the third actuator controls the rotation of the work plane, allowing the needle to be inserted into the prostate from different directions. All the actuators are pneumatically actuated to allow them to work in a Magnetic Resonance (MR) environment. The kinematics and mechanism of the robot are analyzed. A user interface developed using LabView is created to calculate the target position and generate a control signal for the valves. In the open-air test, the needle can reach the target with an accuracy of 1.3 mm. The signal-to-noise ratio (SNR) variation was measured below 5% under a 3T MR scanner

Angular needle tracker and stabilizer for image-guided interventions

Introduction Minimally invasive image-guided interventions have changed the face of procedural medicine. For these procedures, safety and efficacy depend on precise needle placement. Needle targeting devices help improve the accuracy of needle placement, but their use has not seen broad penetration. Some of these devices are costly and require major modifications to the clinical workflow. In this article, we developed a low-cost, disposable, and easy-to-use angulation tracking device, which was based on a redesigned commercial passive needle holder. Material and methods The new design provided real-time angulation information for needle tracking. In this design, two potentiometers were used as angulation sensors, and they were connected to two axes of the passive needle holder’s arch structure through a 3 D-printed bridge structure. A control unit included an Arduino Pro Mini, a Bluetooth module, and two rechargeable batteries. The angulation was calculated and communicated in real time to a novel developed smartphone app, where real-time angulation information was displayed for guiding the operator to position the needle to the planned angles. Results The open-air test results showed that the average errors are 1.03° and 1.08° for left–right angulation and head–foot angulation, respectively. The animal cadaver tests revealed that the novel system had an average angular error of 3.2° and a radial distance error of 3.1 mm. Conclusions The accuracy was comparable with some commercially available solutions. The novel and low-cost needle tracking device may find a role as part of a real-time precision approach to both planning and implementation of image-guided therapies