An imaging device includes a read circuit having a bias circuit for biasing the signal currents output from a sensor array to correct variations of the sensor array. The transmitter includes a DC balance skew generator. In this connection state, flying capacitor Ca is charged by the current supplied from DC power supply 10, while flying capacitor Cb discharges to the load side. Delayed conduction left ventricular beats are not erroneously recognized as a subsequent right ventricular beat, preventing such short intervals from inappropriately triggering a defibrillation countershock. The lifter contacts the common camshaft lobe and a corresponding pushrod that engages a reciprocating bucket follower with a compliant coupling to corresponding rocker arms.