Apparatus and method for measuring a plurality of electrical signals from the body of a patient

An apparatus for measuring electrical signals emanating from a body of a patient, said apparatus comprising:

• a catheter comprising an electrode array;
• a first amplifier for measuring a voltage from a first electrode of said array;
• and
• a cascade of differential amplifiers, each of said differential amplifiers of said cascade measuring a voltage difference between two successive electrodes in said array;
• wherein the voltage, Vn, at electrode n is given by the expression
• 7 V n = a 1 + ∑ i = 2 n ⁢ ⁢ a i ,
• wherein a1 is the voltage at said first electrode as measured by said first amplifier and each of said ai is a differential voltage between electrode i and electrode (i−1) of said array as measured by said differential amplifiers.

A method for measuring a plurality of electrical signals from an electrode array, said method comprising:

• providing:
• a first amplifier for measuring a voltage at a first electrode of said array;
• and
• a cascade of differential amplifiers, each of said differential amplifiers of said cascade measuring a voltage difference between two successive electrodes in said array;
• and
• computing a voltage at each of said electrodes, wherein the voltage, Vn, at electrode n is given by the expression
• 8 V n = a 1 + ∑ i = 2 n ⁢ ⁢ a i ;
• wherein a1 is the voltage at said first electrode as measured by said first amplifier and each of said a1 is a differential voltage between electrode i and electrode (i−1) of said array as measured by said differential amplifiers.