Systems and methods using flexible capacitive electrodes for measuring biosignals

A system is provided for measuring biometric signals, including at least two electrodes, wherein at least one is a capacitive electrode with a flexible structure, the system having a circuit for measuring the voltage between the two electrodes, where in some embodiments both electrodes are capacitive electrodes, and can be arranged as flexible belts, the system being suitable for measuring ECG signals and can be configured to measure also respiratory effort with Respiratory Inductive Plethysmography (RIP) technology, using the same electrodes which are used for measuring capacitively the ECG signals, a method being further provided for measuring biosignals with the system of the invention, the method further including generating an added current signal with a signal generator connected to the circuit, where the added signal has a frequency substantially removed from the frequency of the biosignal of interest, and by measuring the voltage signal of the frequency component corresponding to the added current signal one can determine fluctuations in the overall impedance and fluctuations in the capacitance of the circuit, and correct for fluctuations in the capacitance to obtain a corrected voltage signal representing the measured biosignal.