Capacitively coupled electrode system with variable capacitance for sensing potentials at the surface of tissue

摘要

An electrical activity sensor for sensing and reproducing electrical potentials at the surface of a test item such as a human being has an electrode configured to be capacitively coupled to the test item and a variable capacitance coupled to the electrode. The capacitively coupled electrode and the variable capacitance cooperate to mitigate a need for conductively coupling the electrode to the test subject.