An optically coupled sensor for the measurement of currents induced by MRI gradient fields into endocardial leads.
MAGMA
; 28(3): 291-303, 2015 Jun.
Article
em En
| MEDLINE
| ID: mdl-25304063
ABSTRACT
OBJECT The gradient fields generated during magnetic resonance imaging (MRI) procedures have the potential to induce electrical current on implanted endocardial leads. Whether this current can result in undesired cardiac stimulation is unknown. MATERIALS AND METHODS:
This paper provides a detailed description of how to construct an optically coupled sensor for the measurement of gradient-field-induced currents into endocardial leads. The system is based on a microcontroller that works as analog-to-digital converter and sends the current signal acquired from the lead to an optical high-speed, light-emitting diode transmitter. A plastic fiber guides the light outside the MRI chamber to a photodiode receiver and then to an acquisition board connected to a PC laptop.RESULTS:
The performance of the system has been characterized in terms of power consumption (8 mA on average), sampling frequency (20.5 kHz), measurement range (-12.8 to 10.3 mA) and resolution (22.6 µA). Results inside a 3 T MRI scanner are also presented.CONCLUSIONS:
The detailed description of the current sensor could permit more standardized study of MRI gradient current induction in pacemaker systems. Results show the potential of gradient currents to affect the pacemaker capability of triggering a heartbeat, by modifying the overall energy delivered by the stimulator.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transdutores
/
Imageamento por Ressonância Magnética
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Eletrodos Implantados
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Campos Eletromagnéticos
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Endocárdio
/
Dispositivos Ópticos
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article