A simple and reproducible capacitive electrode

Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling fo...

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Detalles Bibliográficos
Autores: Spinelli, Enrique Mario, Guerrero, Federico Nicolás, García, Pablo Andrés, Haberman, Marcelo Alejandro
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/105075
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/105075
Access Level:acceso abierto
Palabra clave:Ingeniería
Electrotecnia
insulating electrodes
active electrodes
non-contact measurements
Descripción
Sumario:Capacitive Electrodes (CE) allow the acquisition of biopotentials through a dielectric layer, without the use of electrolytes, just by placing them on skin or clothing, but demands front-ends with ultra-high input impedances. This must be achieved while providing a path for bias currents, calling for ultra-high value resistors and special components and construction techniques. A simple CE that uses bootstrap techniques to avoid ultra-high value components and special materials is proposed. When electrodes are placed on the skin; that is, with coupling capacitances C<sub>S</sub> of around 100 pF, they present a noise level of 3.3 μV<sub>RMS</sub> in a 0.5-100 Hz bandwidth, which is appropriate for electrocardiography (ECG) measurements. Construction details of the CE and the complete circuit, including a fast recovery feature, are presented.