| 摘要 |
An apparatus for measuring electrical signals emanating from a body of a patient, and, in particular, from the patient's heart, comprises a catheter having an electrode array, preferably on its distal end. The apparatus of the invention further comprises a first amplifier for measuring a voltage from a first electrode of the array, and a cascade of differential amplifiers, each of which measures a voltage difference between two successive electrodes in the array. The voltage, Vn, at electrode n is given by the expression: <CHEM> wherein a1 is the voltage at the first electrode as measured by the first amplifier and each ai is a differential voltage between electrode i and electrode (i-1) of the array as measured by the differential amplifiers. The catheter electrode array preferably comprises at least one contact electrode and a plurality of non-contact electrodes, the first amplifier is preferably used to measure the signal at the contact electrode and the amplifier cascade is preferably used to measure the signals from the non-contact electrodes. The catheter further preferably comprises at least one position sensor, preferably, an electromagnetic position sensor. <IMAGE> |
