a bed support having a hollow portion;

a cushion container including a main body having a top portion, a bottom portion, and a lateral wall between the top portion and the bottom portion, wherein the top portion is received in the hollow portion, a chamber provided inside the main body, and at least one first heat dissipating hole extending through the lateral wall of the cushion container from an interior surface of the lateral wall to an exterior surface of the lateral wall and communicated with the chamber to an ambient environment;

a vibrating motor disposed in the chamber of the cushion container; and

a retaining belt disposed with the bed support and attached on the bottom edge of the cushion container to fix the cushion container to the bed support,

wherein the retaining belt comprises a first end forming a first opening and a second end forming a second opening, wherein the first and second openings are spaced apart to receive the cushion container and at least one second heat dissipating hole is formed on the retaining belt between the first and second ends, wherein the at least one second heat dissipating hole is aimed at the at least one first heat dissipating hole of the lateral wall, such that the chamber is communicated with the ambient environment through the at least one first and second heat dissipating holes.