  We performed a search for 4He-eta bound state with high statistics and high
acceptance with the WASA-at-COSY facility using a ramped beam technique. The
signature of eta-mesic nuclei is searched for in dd -> 3Henpi0 and dd ->
3Heppi- reactions by the measurement of the excitation functions in the
vicinity of the {\eta} production threshold. This paper presents the
experimental method and the preliminary results of the data analysis for dd ->
3Henpi0 process.
