Smart VR Mindfulness for Breast Cancer: Integrating Biofeedback and Evaluating Chemotherapy Effectiveness

Inclusion Criteria: * Age above 18 years. * Diagnosed with breast cancer stages I to III, with diagnostic codes C50, C79.81, C84.7A, D03.52, D05, D24, D48, or D49; there are no restrictions on tumor type, receptor subtype, or whether breast tumor removal surgery has been performed. * Undergoing the first inpatient preoperative or postoperative chemotherapy, without restrictions on the type of medication or treatment cycles. * Able to communicate in Mandarin and literate; without cognitive impairments, psychiatric disorders, motion sickness, epilepsy, or a history of drug or alcohol addiction. * No prior experience with mindfulness-based interventions. Understanding of the research procedures, agreement to participate, and signing of the informed consent form; owning a smartphone capable of installing the required research applications and able to operate independently. Exclusion Criteria: * individuals with blindness or visual impairments that preclude the identification of on-screen visuals * individuals with auditory impairments preventing the recognition of sounds through headphones.