Patent ID: 6584351
Filing Date: 2003-06-24
Classification: A61N,Y10S

Abstract:
A medical device for implantation in a human body for stimulating heart tissue comprising a housing containing a noise cancellation circuit and an indifferent electrode at said housing connected to said noise cancellation circuit, an electrode lead mechanically connected to said housing and electrically connected to said noise cancellation circuit and comprising a tip electrode for sensing electrical signals, relative to said indifferent electrode, originating within said heart tissue, and said housing comprising a noise sensing electrode connected to said noise cancellation circuit for sensing electrical noise signals, relative to said indifferent electrode from the human body originating outside said heart tissue, said noise sensing electrode being electrically insulated from said indifferent electrode said noise cancellation circuit being supplied with the respective signals from said tip electrode and said noise sensing electrode, and cancelling said noise signals sensed by said noise sensing electrode from said electrical signals originating within the heart tissue sensed by said tip electrode, and said noise cancellation circuit comprising a proportional signal generator supplied with said signal from said noise sensing electrode for generating a signal proportional to the noise signal and a difference former which forms a difference signal as a difference between the electrical signal originating within the heart tissue and said proportional signal.