The ornamental design for a blower casing for respiratoryassistance device, as shown and described.
FIG. 1.1 is a top perspective view of a blower casing for respiratory assistance device showing my new design;
FIG. 1.2 is a bottom perspective view thereof;
FIG. 1.3 is a front view thereof;
FIG. 1.4 is a back view thereof;
FIG. 1.5 is a right side view thereof;
FIG. 1.6 is a left side view thereof;
FIG. 1.7 is a top view thereof; and
FIG. 1.8 is a bottom view thereof.
The parts shown in broken lines do not form part of the claimed design. The dashed-dotted lines shown in the reproductions are provided only to indicate the boundary between the claimed part and the unclaimed part.