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1.
Int J Rob Res ; 28(9): 1169-1182, 2009 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-19890446

RESUMO

Medical nanorobotics exploits nanometer-scale components and phenomena with robotics to provide new medical diagnostic and interventional tools. Here, the architecture and main specifications of a novel medical interventional platform based on nanorobotics and nanomedicine, and suited to target regions inaccessible to catheterization are described. The robotic platform uses magnetic resonance imaging (MRI) for feeding back information to a controller responsible for the real-time control and navigation along pre-planned paths in the blood vessels of untethered magnetic carriers, nanorobots, and/or magnetotactic bacteria (MTB) loaded with sensory or therapeutic agents acting like a wireless robotic arm, manipulator, or other extensions necessary to perform specific remote tasks. Unlike known magnetic targeting methods, the present platform allows us to reach locations deep in the human body while enhancing targeting efficacy using real-time navigational or trajectory control. The paper describes several versions of the platform upgraded through additional software and hardware modules allowing enhanced targeting efficacy and operations in very difficult locations such as tumoral lesions only accessible through complex microvasculature networks.

2.
Comput Aided Surg ; 13(6): 340-52, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19031286

RESUMO

The possibility of automatically navigating untethered microdevices or future nanorobots to conduct target endovascular interventions has been demonstrated by our group with the computer-controlled displacement of a magnetic sphere along a pre-planned path inside the carotid artery of a living swine. However, although the feasibility of propelling, tracking and performing real-time closed-loop control of an untethered ferromagnetic object inside a living animal model with a relatively close similarity to human anatomical conditions has been validated using a standard clinical Magnetic Resonance Imaging (MRI) system, little information has been published so far concerning the medical and technical protocol used. In fact, such a protocol developed within technological and physiological constraints was a key element in the success of the experiment. More precisely, special software modules were developed within the MRI software environment to offer an effective tool for experimenters interested in conducting such novel interventions. These additional software modules were also designed to assist an interventional radiologist in all critical real-time aspects that are executed at a speed beyond human capability, and include tracking, propulsion, event timing and closed-loop position control. These real-time tasks were necessary to avoid a loss of navigation control that could result in serious injury to the patient. Here, additional simulation and experimental results for microdevices designed to be targeted more towards the microvasculature have also been considered in the identification, validation and description of a specific sequence of events defining a new computer-assisted interventional protocol that provides the framework for future target interventions conducted in humans.


Assuntos
Implante de Prótese Vascular , Imagem por Ressonância Magnética Intervencionista , Magnetismo , Micromanipulação/instrumentação , Nanomedicina/instrumentação , Robótica , Animais , Artérias Carótidas/cirurgia , Simulação por Computador , Humanos , Modelos Animais , Cirurgia Assistida por Computador , Suínos
3.
IEEE Trans Biomed Eng ; 55(7): 1854-63, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18595804

RESUMO

This paper shows that even a simple proportional-integral-derivative (PID) controller can be used in a clinical MRI system for real-time navigation of a ferromagnetic bead along a predefined trajectory. Although the PID controller has been validated in vivo in the artery of a living animal using a conventional clinical MRI platform, here the rectilinear navigation of a ferromagnetic bead is assessed experimentally along a two-dimensional (2D) path as well as the control of the bead in a pulsatile flow. The experimental results suggest the likelihood of controlling untethered microdevices or robots equipped with a ferromagnetic core inside complex pathways in the human body.


Assuntos
Algoritmos , Vasos Sanguíneos/anatomia & histologia , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/métodos , Magnetismo/instrumentação , Transdutores , Sistemas Computacionais , Desenho de Equipamento , Análise de Falha de Equipamento
4.
Magn Reson Med ; 59(6): 1287-97, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18506794

RESUMO

A dedicated software architecture for a novel interventional method allowing the navigation of ferromagnetic endovascular devices using a standard real-time clinical MRI system is shown. Through a specially developed software environment integrating a tracking method and a real-time controller algorithm, a clinical 1.5T Siemens Avanto MRI system is adapted to provide new functionality for potential automated interventional applications. The proposed software architecture was successfully validated through in vivo controlled navigation inside the carotid artery of a swine. Here we present how this MRI-upgraded software environment could also be used in more complex vasculature models through the real-time navigation of a 1.5 mm diameter chrome steel bead in two different MR-compatible phantoms with flowless and quiescent flow conditions. The developed platform and software modules needed for such navigation are also presented. Real-time tracking achieved through a dedicated positioning method based on an off-resonance excitation technique has also been successfully integrated in the software platform while maintaining adequate real-time performance. These preliminary feasibility experiments suggest that navigation of such devices can be achieved using a similar software architecture on other conventional clinical MRI systems at an operational closed-loop control frequency of 32 Hz.


Assuntos
Compostos Férricos , Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética Intervencionista/instrumentação , Design de Software , Animais , Desenho de Equipamento , Humanos , Imagem por Ressonância Magnética Intervencionista/métodos , Imagens de Fantasmas , Suínos
5.
Med Image Comput Comput Assist Interv ; 10(Pt 1): 144-52, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18051242

RESUMO

A 1.5 mm magnetic sphere was navigated automatically inside the carotid artery of a living swine. The propulsion force, tracking and real-time capabilities of a Magnetic Resonance Imaging (MRI) system were integrated into a closed loop control platform. The sphere was released using an endovascular catheter approach. Specially developed software is responsible for the tracking, propulsion, event timing and closed loop position control in order to follow a 10 roundtrips preplanned trajectory on a distance of 5 cm inside the right carotid artery of the animal. Experimental protocol linking the technical aspects of this in vivo assay is presented. In the context of this demonstration, many challenges which provide insights about concrete issues of future nanomedical interventions and interventional platforms have been identified and addressed.


Assuntos
Artérias Carótidas/anatomia & histologia , Interpretação de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética Intervencionista/métodos , Micromanipulação/métodos , Robótica/instrumentação , Robótica/métodos , Telemetria/instrumentação , Animais , Biotecnologia/métodos , Imagem por Ressonância Magnética Intervencionista/instrumentação , Micromanipulação/instrumentação , Suínos , Telemetria/métodos
6.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 3916-20, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-17281088

RESUMO

Potential field algorithms often used in path finding applications on a 2D plane are expanded onto a 3D map trajectories for navigation planning of a microdevice designed to be propelled through the cardiovascular system using magnetic gradients generated by a clinical MRI system. This system assembles a 3D reconstruction of a cardiovascular system through magnetic resonance angiography images. The method also allows the extraction of the physiological properties of the given network.

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