electrocardiogram, ecg grid graph, ruler grid on white background. set of rulers

drawing line diagram font sketch text document cartoon map brand plan artwork circle presentation pattern handwriting grid graph frame beat cardio pulse ekg electrocardiogram heartbeat medicine ecg chart heart hospital doctor square paper health cardiogram business medical test care cardiology analysis vector design background wallpaper element white texture abstract black graphic vintage backdrop template decorative print tile light paint modern rough ruler isolated background set rulers vectortor