Inclusion criteria: (1) Premature infants over 32 weeks old, (2) Stable physiological conditions.  Exclusion criteria: (1) taking drugs that may interfere with sleep, (2) suffering from retinopathy (ROP) stage 3 or higher, (3) suffering from intracranial hemorrhage, grade 3 or higher, (4) suffering from upper limb injury or movement disorders, (5) The family has alcohol and drug abuse problems, (6) currently using respirators.