Spinelli Enrique, Guerrero Federico, García Pablo, Haberman Marcelo
LEICI - Departamento de Electrotecnia, Universidad Nacional de La Plata, CC 91 (1900) La Plata, Argentina; Consejo de Investigaciones Científicas y Técnicas (CONICET), Argentina .
LEICI - Departamento de Electrotecnia, Universidad Nacional de La Plata, CC 91 (1900) La Plata, Argentina; Consejo de Investigaciones Científicas y Técnicas (CONICET), Argentina.
Med Eng Phys. 2016 Mar;38(3):286-9. doi: 10.1016/j.medengphy.2015.12.006. Epub 2016 Jan 11.
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(S) of around 100 pF, they present a noise level of 3.3 µV(RMS) 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.
电容式电极（CE）允许通过介电层采集生物电位，无需使用电解质，只需将其放置在皮肤或衣物上即可，但需要具有超高输入阻抗的前端。这必须在为偏置电流提供路径的同时实现，这就需要超高阻值的电阻以及特殊的元件和构造技术。本文提出了一种使用自举技术来避免使用超高阻值元件和特殊材料的简单电容式电极。当电极放置在皮肤上时，即耦合电容C(S)约为100 pF时，在0.5 - 100 Hz带宽内呈现出3.3 µV（均方根值）的噪声水平，这适用于心电图（ECG）测量。文中给出了电容式电极的结构细节以及完整电路，包括快速恢复功能。
