35 accepted papers
Electromagnetic Navigation Systems can be used to remotely guide medical devices such as magnetic catheters or guidewires, holding potential in a variety of minimally invasive surgical applications. This paper introduces a method to simultaneously actuate and localize a tethered magnetic device with…
Electromagnetic navigation systems (eMNS) are increasingly used in minimally invasive procedures such as endovascular interventions and targeted drug delivery due to their ability to generate fast and precise magnetic fields. In this paper, we utilize the OctoMag and a custom 13-coil eMNS to achieve
Precise magnetic field modeling is fundamental to the closed-loop control of electromagnetic navigation systems (eMNS) and the analytical Multipole Expansion Model (MPEM) is the current standard. However, the MPEM relies on strict physical assumptions regarding source symmetry and isolation, and req…
Electromagnetic Navigation Systems enable remote actuation of untethered micro and nanorobots, as well as the precise control of magnetic surgical tools for minimally invasive medical procedures. Accurate modeling of the magnetic fields generated by the electromagnets composing these systems is esse
Magnetic navigation offers wireless control over magnetic objects, which has important medical applications, such as targeted drug delivery and minimally invasive surgery. Magnetic navigation systems are categorized into systems using permanent magnets and systems based on electromagnets. Electromag
Electromagnetic Navigation Systems can be used to remotely guide medical devices such as magnetic catheters or guidewires, holding potential in a variety of minimally invasive surgical applications. This paper introduces a method to simultaneously actuate and localize a tethered magnetic device with
Selective control mechanisms of microrobots have attracted significant attention from researchers. So far, selective control within multiple/swarm magnetic microrobots has been achieved with many strategies, such as utilizing locally specified magnetic fields, applying electrostatic anchoring, takin
Resonant electromagnetic navigation systems generate controllable oscillating and rotating magnetic fields using resonant electronic networks. This modality holds great potential to control untethered magnetic robots remotely for medical applications using fast rotating magnetic fields. However, the
Remote magnetic navigation is a technology used to robotically steer magnetic medical instruments, such as magnetic catheters and guidewires, for minimally invasive surgery. The ability to model and simulate the behavior of these magnetic instruments in complex anatomies is important for their clini
Magnetic helical microrobots driven by low-strength rotating magnetic fields have found wide applications, particularly in biomedical research. The motion dynamics of magnetic helical microrobots is critical for their intelligent control and for performing tasks in complex environments. These micror
Variable stiffness catheters typically rely on thermally induced stiffness transitions with a transition temperature above body temperature. This imposes considerable safety limitations for medical applications. In this work, we present a variable stiffness catheter using a hybrid control strategy c…
Remote magnetic navigation offers an ideal platform for automated catheter navigation. Magnetically guided catheters show great dexterity and can reach locations that are otherwise challenging to access. By automating aspects of catheterization procedures, we can simplify and expedite the procedure
Topology applied to real world data using persistent homology has started to find applications within machine learning, including deep learning. We present a differentiable topology layer that computes persistent homology based on level set filtrations and edge-based filtrations. We present three n…
Electromagnetic Navigation Systems (eMNS) can be used to control a variety of multiscale devices within the human body for remote surgery. Accurate modeling of the magnetic fields generated by the electromagnets of an eMNS is crucial for the precise control of these devices. Existing methods assume…
We propose thrombolysis using a magnetic nanoparticle microswarm with tissue plasminogen activator (tPA) under ultrasound imaging. The microswarm is generated in blood using an oscillating magnetic field and can be navigated with locomotion along both the long and short axis. By modulating the input…
The advanced state of diabetic retinopathy, a leading cause of blindness, is treated by panretinal photocoagulation (PRP), a repetitive procedure performed by a surgeon using a handheld laser probe. In its place we propose a soft-robotic flexible probe precisely steered using magnetic fields generat
Plant growth and morphogenesis is directed by cell division and the expansion of individual cells. How the tightly controlled process of cell expansion is regulated is poorly understood. We introduce a microrobotic platform able to separately measure the turgor pressure and cell wall elasticity of i
Precise catheter control is crucial to the success of radiofrequency cardiac arrhythmia ablations. Remote control using external magnetic fields to directly steer the catheter tip is a promising strategy to accurately and easily perform cardiac catheter steering. Magnetic catheters must be flexible
Small-scale robots with soft joints and hinges have recently attracted interest because these components allow for more sophisticated locomotion mechanisms. Here, we investigate two different types of nanoscale swimmers as depicted in Figure 1. One consists of a rigid magnetic head linked to a semi-…
Magnetic continuum robots (m-CR) have grown interest in several applicative contexts that take benefits from their high flexibility and remote control. When submitted to external magnetic fields, m-CR exhibit large elastic deformations, which may lead to a highly nonlinear and complex behavior that
Three-dimensional (3-D) tracking of microrobots is demonstrated using stereo holographic projections. The method detects the lateral position of a microrobot in two orthogonal in-line holography images and triangulates to obtain the 3-D position in an observable volume of 1 cm <inline-formula xmlns:
Remote magnetic navigation of catheters is a technique used to perform radiofrequency ablation of heart tissue in order to treat cardiac arrhythmias. The flexible magnetic catheters used in this context are in some cases not sufficiently dexterous to navigate the complex and patient-specific anatomy…
A robust automated system to collect protein crystals for X-ray crystallography is presented. This system uses an ultraviolet imaging system based on commercial off-the-shelf components, a magnetically manipulated tool, and a resilient behavior-based controller. The system is validated by collecting
Particle tracking has emerged as a powerful tool for investigating the swarm control of microrobots and the dynamic biological processes in the life sciences. In seed plants, pollen tubes, a part of the male gametophyte, are excellent models for understanding plant growth and cellular behavior, beca…
Recent advances in smart materials and microfabrication techniques lead to the development of microrobots for on-demand and targeted therapy. Self-folded hydrogel tubes are particularly promising vehicles as they provide relatively large surface area-to-volume ratio and cargo space for therapeutic a
Digital holography is used to track the three-dimensional position of a magnetic microrobot maneuvered in real time by means of an electromagnetic manipulation system. The method presented is able to process holograms at 40 Hz with a position accuracy in the imaging plane and in depth of <inline-for
Retinal diseases including age-related macular degeneration and diabetic retinopathy are leading causes of visual impairment and a growing medical crisis worldwide. As a result, new therapies and methods of safely delivering these new therapies can be of significant benefit to society. In this paper…
Cardiac arrhythmias are commonly treated by minimally invasive catheter ablation. Because of challenges in precisely manipulating the distal end of the catheter, several magnetic manipulation systems (MMS) have been developed to aid in steering the tip inside the heart. Due to the relative stiffness…
Shape shifting soft microrobots are generated from self-folding hydrogel bilayer structures. The folding conditions are analyzed to develop an optimal strategy for producing desired three-dimensional shapes. We present two different methods for programming magnetization in these microrobots that are
A magnetic-tip steerable needle is presented with application to aiding deep brain stimulation electrode placement. The magnetic needle is 1.3mm in diameter at the tip with a 0.7mm diameter shaft, which is selected to match the size of a deep brain stimulation electrode. The tip orientation is contr
In this work, we present a model predictive control (MPC) approach to the motion control of a nonholonomic rolling microrobot. The mobile microrobot is designed to follow a rotating magnetic field such that it rolls on a supporting surface in a low Reynold's number liquid environment. The MPC framew
This paper presents the design, kinematics, fabrication, and magnetic manipulation of a milli-gripper for medical applications. The design employs a permanent magnet for two purposes. It actuates the compliant gripper and allows for maneuverability of the milli-gripper in an externally applied magne…
In this paper, we present a holistic system for automating the motion of a rolling microrobot for protein crystal harvesting. The RodBot, which was introduced in previous work, is able to perform noncontact manipulation of microscopic objects such as fragile crystals by trapping them in an induced v…
We introduce the modelling and control of a rolling microrobot. The microrobot is capable of manipulating micro-objects through the use of a magnetic visual control system. This system consists of a rod-shaped microrobot, a magnetic actuation system and a visual control system. Motion of the rolling…
This paper presents a method to localize a magnetically guided catheter using a single rotating C-Arm. Because the three dimensional position of the catheter tip, when extracted from a single view, contains large uncertainties, we propose to combine multiple views by rotating the C-Arm and using a K…