Abstract
The electrode-lead system for an ambulatory electrocardiographic system should be less sensitive to the noise interference than those of a standard ecg system because the patient under observation lives his normal daily life in his home and office where lots of inducing noise sources such as television sets and personal computers are in use.In an ambulatory ecg recorder the shielding effect of the conventional shield cables is not always sufficient to suppress the noise interference, because the lowest impedance of the electrodelead assembly is limited by the contact resistance between the electrode and the human skin. In this paper we report the immunity for noise interference of the electrode-lead system, in which a preamplifier is incorporated at the back of each electrode attached to the patient's body. With this configuration the level of the induced noise was reduced by 30db.
