magnetically-assisted-remote-controlled-microcatheter-tip-deflection

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging

X-ray fluoroscopy-guided  endovascular procedures have several significant limitations, including  difficult catheter navigation and use of ionizing ...

University of California, San Francisco 

Current applied to wire coils wound at the tip of an endovascular catheter can be used to remotely steer a catheter under magnetic resonance imaging guidance. In this study, we derive and validate an equation that characterizes the relationship between deflection and a number of physical factors: theta/sin(gamma-theta) = nIABL/EI(A) where theta is the deflection angle, n is the number of solenoidal turns, I is the current, A is the cross-sectional area of the catheter tip, B is the magnetic resonance (MR) scanner main magnetic field, L is the unconstrained catheter length, E is Young's Modulus for the catheter material, and I(A) is the area moment of inertia, and y is the initial angle between the catheter tip and B. Solenoids of 50, 100, or 150 turns were wound on 1.8 F and 5 F catheters. Varying currents were applied remotely using a DC power supply in the MRI control room. The distal catheter tip was suspended within a phantom at varying lengths. Images were obtained with a 1.5 T or a 3 T MR scanner using "real-time" MR pulse sequences. Deflection angles were measured on acquired images. Catheter bending stiffess was determined using a tensile testing apparatus and a stereomicroscope. Predicted relationships between deflection and various physical factors were observed (R2 = 0.98-0.99). The derived equation provides a framework for modeling of the behavior of the specialized catheter tip. Each physical factor studied has implications for catheter design and device implementation.

Magnetically-assisted remote control (MARC) steering of endovascular catheters for interventional MRI: a model for deflection and design implications.

Courant appliqu&eacute; aux bobines de fil enroul&eacute; &agrave; l&#39;extr&eacute;mit&eacute; d&#39;un cath&eacute;ter endovasculaires peut &ecirc;tre utilis&eacute; pour piloter &agrave; distance un cath&eacute;ter sous direction de l&#39;imagerie par r&eacute;sonance magn&eacute;tique. Dans cette &eacute;tude, nous tirent et valider une &eacute;quation qui caract&eacute;rise les relations entre d&eacute;formation et un certain nombre de facteurs physiques : theta/sin(gamma-theta) = nIABL/EI(A) o&ugrave; theta est l&#39;angle de d&eacute;flexion, n est le nombre de spires sol&eacute;no&iuml;dale, I est le courant, A est la section transversale de l&#39;extr&eacute;mit&eacute; du cath&eacute;ter, B est le champ magn&eacute;tique principal &agrave; scanner par r&eacute;sonance magn&eacute;tique (RM)L est la longueur du cath&eacute;ter sans contrainte, E est le module de Young pour le mat&eacute;riel de cath&eacute;ter, point a i est le moment d&#39;inertie de la r&eacute;gion et y est l&#39;angle initial entre l&#39;extr&eacute;mit&eacute; du cath&eacute;ter et les sol&eacute;no&iuml;des de B. de 50, 100 ou 150 tours &eacute;taient enroul&eacute;es sur des cath&eacute;ters F 1,8 F et 5. Diff&eacute;rents courants ont &eacute;t&eacute; appliqu&eacute;s &agrave; distance en utilisant une alimentation CC dans la salle de contr&ocirc;le de MRI. L&#39;extr&eacute;mit&eacute; du cath&eacute;ter distal &eacute;tait suspendue dans un fant&ocirc;me &agrave; diff&eacute;rentes longueurs. Images ont &eacute;t&eacute; obtenues avec un 1,5 T ou 3 T M. scanner &agrave; l&#39;aide de s&eacute;quences d&#39;impulsions Monsieur &laquo; temps r&eacute;el &raquo;. Angles de d&eacute;flexion ont &eacute;t&eacute; mesur&eacute;s sur les images acquises. Cath&eacute;ter stiffess de flexion a &eacute;t&eacute; d&eacute;termin&eacute;e &agrave; l&#39;aide d&#39;un appareil d&#39;essai traction et un st&eacute;r&eacute;omicroscope. Pr&eacute;dit des relations entre d&eacute;formation et diff&eacute;rents facteurs physiques ont &eacute;t&eacute; observ&eacute;es (R2 = 0,98-0,99). L&#39;&eacute;quation d&eacute;riv&eacute;e fournit un cadre pour la mod&eacute;lisation du comportement de l&#39;extr&eacute;mit&eacute; du cath&eacute;ter sp&eacute;cialis&eacute;s. Chaque facteur physique &eacute;tudi&eacute; a des implications pour l&#39;application de conception et dispositif de cath&eacute;ter.

Magn&eacute;tiquement assist&eacute; par t&eacute;l&eacute;commande (MARC), directeur de cath&eacute;ters endovasculaire pour IRM interventionnelle : un mod&egrave;le pour les implications d&eacute;flexion et de conception.

Corrente applicata a bobine di filo avvolto sulla punta di un catetere endovascolare pu&ograve; essere utilizzato per guidare in remoto un catetere sotto guida di risonanza magnetica. In questo studio, abbiamo derivano e convalidare un&#39;equazione che caratterizza il rapporto tra la deformazione e un certo numero di fattori fisici: theta/sin(gamma-theta) = nIABL/EI(A) dove teta &egrave; l&#39;angolo di deflessione, dove n &egrave; il numero di spire solenoidale, I &egrave; la corrente, dove A &egrave; l&#39;area della sezione trasversale della punta del catetere, B &egrave; il campo magnetico principale di risonanza magnetica (MR) scannerL &egrave; la lunghezza del catetere senza vincoli, E &egrave; il modulo di Young per il materiale del catetere, constatata &egrave; il momento d&#39;inerzia di area e y &egrave; l&#39;angolo iniziale tra la punta del catetere e B. elettromagneti di 50, 100 o 150 giri erano avvolti su cateteri F F 1,8 e 5. Diverse correnti sono state applicate in remoto utilizzando un alimentatore DC nella sala di controllo MRI. La punta distale del catetere &egrave; stato sospeso all&#39;interno di un fantasma a diverse lunghezze. Immagini sono state ottenute con un 1,5 T o uno scanner T Signor 3 utilizzando sequenze di impulsi signor &quot;tempo reale&quot;. Angoli di deviazione sono stati misurati su immagini acquisite. Catetere stiffess di flessione &egrave; stata determinata utilizzando apparecchi per test a trazione e uno stereomicroscopio. Predetto rapporto tra deformazione e vari fattori fisici sono stati osservati (R2 = 0,98-0,99). L&#39;equazione derivata fornisce un framework per la modellazione del comportamento della punta del catetere specializzati. Ogni fattore fisico studiato ha implicazioni per l&#39;implementazione di design e dispositivo di catetere.

Magneticamente assistita telecomando (MARC) sterzo di cateteri endovascolari per interventional MRI: un modello per le implicazioni di deflessione e design.

Corriente aplicada a las bobinas de alambre de la herida en la punta de un cat&eacute;ter endovascular puede utilizarse para dirigir de forma remota un cat&eacute;ter bajo direcci&oacute;n de la proyecci&oacute;n de imagen de resonancia magn&eacute;tica. En este estudio derivan y validar una ecuaci&oacute;n que caracteriza la relaci&oacute;n entre la desviaci&oacute;n y una serie de factores f&iacute;sicos: theta/sin(gamma-theta) = nIABL/EI(A) donde theta es el &aacute;ngulo de desviaci&oacute;n, n es el n&uacute;mero de vueltas solenoidales, I es la corriente, A es el &aacute;rea transversal de la punta del cat&eacute;ter, B es el campo de magn&eacute;tico principal esc&aacute;ner de resonancia magn&eacute;tica (RM)L es la longitud del cat&eacute;ter sin restricciones, E es el m&oacute;dulo de Young para el material del cat&eacute;ter y a i es el momento de inercia de &aacute;rea y y es el &aacute;ngulo inicial entre la punta del cat&eacute;ter y B. solenoides de 50, 100 o 150 vueltas fueron heridas en cat&eacute;teres de 1,8 F 5 F. Se aplicaron diferentes corrientes remotamente usando una fuente de corriente continua en la sala de control de MRI. La punta del cat&eacute;ter distal fue suspendida dentro de un fantasma en diferentes longitudes. Se obtuvieron im&aacute;genes con un 1.5 T o un esc&aacute;ner de Sr. T 3 utilizando secuencias de pulso de Se&ntilde;or &quot;tiempo real&quot;. Se midieron los &aacute;ngulos de desviaci&oacute;n en im&aacute;genes adquiridas. Cat&eacute;ter stiffess de flexi&oacute;n se determin&oacute; usando un aparato de prueba de tracci&oacute;n y un Estereomicroscopio. Predijo que las relaciones entre la desviaci&oacute;n y varios factores f&iacute;sicos fueron observadas (R2 = 0.98 0.99). La ecuaci&oacute;n derivada proporciona un marco para el modelado del comportamiento de la punta del cat&eacute;ter especializado. Cada factor f&iacute;sico estudiado tiene implicaciones para la implementaci&oacute;n de dise&ntilde;o y dispositivo de cat&eacute;ter.

Mando asistido magn&eacute;ticamente (MARC) manejo de cat&eacute;teres endovasculares para MRI intervencionista: un modelo para las implicaciones de la desviaci&oacute;n y el dise&ntilde;o.

The aims of this study were to assess resistive heating of microwires used for remote catheter steering in interventional magnetic resonance imaging and to investigate the use of alumina to facilitate heat transfer to saline flowing in the catheter lumen.

Steerable catheter microcoils for interventional MRI reducing resistive heating.

Les objectifs de cette &eacute;tude &eacute;taient d&#39;&eacute;valuer un chauffage r&eacute;sistif de microfils utilis&eacute; pour cath&eacute;ter distant de direction dans l&#39;imagerie par r&eacute;sonance magn&eacute;tique interventionnelle et d&#39;enqu&ecirc;ter sur l&#39;utilisation de l&#39;alumine pour faciliter le transfert de chaleur &agrave; saline qui coule dans la lumi&egrave;re du cath&eacute;ter.

Cath&eacute;ter orientable microressorts pour IRM interventionnelle r&eacute;duisant le chauffage r&eacute;sistif.

Gli obiettivi di questo studio erano di valutare riscaldamento resistivo di microwires utilizzato per catetere remoto dello sterzo in interventistica imaging a risonanza magnetica e di investigare l&#39;uso dell&#39;allumina per facilitare il trasferimento di calore alla soluzione salina che scorre nel lume del catetere.

Catetere orientabile microcoils per interventional MRI riduzione riscaldamento resistivo.

Los objetivos de este estudio fueron evaluar calefacci&oacute;n resistente de microhilos utilizado para el manejo de cat&eacute;ter remoto en la proyecci&oacute;n de imagen de resonancia magn&eacute;tica intervencionista e investigar el uso de al&uacute;mina para facilitar la transferencia de calor a salina que fluye en el lumen del cat&eacute;ter.

Cat&eacute;ter orientable microcoils para MRI intervencionista, reduciendo el calentamiento resistivo.

The aim of this study was too assess magnetic resonance imaging (MRI) radiofrequency (RF)-related heating of conductive wire coils used in magnetically steerable endovascular catheters.

RF Heating of MRI-Assisted Catheter Steering Coils for Interventional MRI.

Le but de cette &eacute;tude &eacute;tait trop &eacute;valuer l&#39;imagerie par r&eacute;sonance magn&eacute;tique (IRM) de radiofr&eacute;quence (RF)-li&eacute;s &agrave; l&#39;&eacute;chauffement des bobines de fil conducteur utilis&eacute;s dans les cath&eacute;ters endovasculaire magn&eacute;tique orientable.

Chauffage RF du cath&eacute;ter assist&eacute;e par IRM bobines au volant pour l&#39;IRM interventionnelle.

Lo scopo di questo studio era di valutare anche la risonanza magnetica (MRI) radiofrequenza (RF)-correlati a riscaldamento di bobine di filo conduttore utilizzati in cateteri endovascolari magneticamente orientabile.

Riscaldamento RF del catetere MRI-assistita sterzo bobine per Interventional MRI.

El objetivo de este estudio fue evaluar tambi&eacute;n la proyecci&oacute;n de imagen de resonancia magn&eacute;tica (MRI) de radiofrecuencia (RF)-relacionadas con calefacci&oacute;n de bobinas de hilo conductor para cat&eacute;teres endovasculares magn&eacute;ticamente orientable.

Article	Year
Magnetically-assisted remote control (MARC) steering of endovascular catheters for interventional MRI: a model for deflection and design implications. Medical physics\| PubMed ID: 17879774	2007
Steerable catheter microcoils for interventional MRI reducing resistive heating. Academic radiology\| PubMed ID: 21075017	2011
RF Heating of MRI-Assisted Catheter Steering Coils for Interventional MRI. Academic radiology\| PubMed ID: 21075019	2011

Vincent Malba

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