The ornamental design for an electrocardiograph, as shown and described.
FIG. 1 is a front perspective view of a design for an electrocardiograph according to the present invention.
FIG. 2 is a back perspective view of the electrocardiograph of FIG. 1.
FIG. 3 is a front view of the electrocardiograph of FIG. 1.
FIG. 4 is back view of the electrocardiograph of FIG. 1.
FIG. 5 is a left side view of the electrocardiograph of FIG. 1.
FIG. 6 is a right side view of the electrocardiograph of FIG. 1.
FIG. 7 is a top view of the electrocardiograph of FIG. 1.
FIG. 8 is a bottom view of the electrocardiograph of FIG. 1; and,
FIG. 9 is a front perspective view of the electrocardiograph in an open configuration of FIG. 1.
The broken lines in the drawings are included for the purposes of illustrating portions of the electrocardiograph that form no part of the claimed design.