CoBreath: Designing a VR-Based Dyadic Biofeedback System to Support Breathing Exercise for Breast Cancer Survivors

Paper Title

CoBreath: Designing a VR-Based Dyadic Biofeedback System to Support Breathing Exercise for Breast Cancer Survivors

Publication Info

• Topic area: VR-based biofeedback for stress management in breast cancer survivors
• Keywords: VR biofeedback, dyadic interaction, breast cancer survivors, relaxation training, paced breathing, HRV, stress management, peer support, usability, physiological relaxation

Background and Problem

• Problem / challenge: Breast cancer survivors (BCSs) face persistent psychosomatic symptoms like anxiety, fatigue, and pain, exacerbated by chronic stress. Existing biofeedback (BF) systems often lack engagement and are designed for single users, while VR-based BF systems rarely address the specific needs of BCSs or integrate peer support.
• Significance: Addressing stress and anxiety in BCSs can improve their quality of life and long-term recovery. Combining VR and biofeedback with peer support could enhance engagement and relaxation outcomes.
• Motivation and related work: Prior research highlights the effectiveness of paced breathing and biofeedback for stress reduction, as well as the benefits of peer-supported interventions. However, few studies explore integrating these elements into a VR-based system tailored for BCSs.

Solution

• Proposed approach: CoBreath, a VR-based dyadic biofeedback system that integrates breathing and heart rate variability (HRV) feedback into a calming virtual environment, enabling two users to practice paced breathing together.
• Novelty:
  1. Introduction of a dyadic biofeedback mode for peer-supported breathing exercises.
  2. Development of an intuitive VR interface with natural biofeedback mapping.
  3. Integration of respiration and HRV data into a shared, non-competitive relaxation experience.
  4. Empirical evaluation of the system’s usability, user experience, and physiological effects.
• Procedure and key techniques:
  • Wearable biosensors (breathing belt and HRV wrist sensor) capture physiological data.
  • VR environment visualizes biofeedback through light fields and halo rings, synchronized with users’ breathing and HRV.
  • Dyadic mode allows two users to see each other’s biofeedback and practice synchronized breathing.
  • Studies with clinicians and BCSs evaluated usability, user experience, and relaxation outcomes.

Results

• Concrete findings:
  • Dyadic mode led to a larger increase in HRV (RMSSD) (+18.6%) compared to individual mode (+14.8%).
  • Dyadic mode scored higher on usability (SUS: 92.34 vs. 85.78) and user experience dimensions like attractiveness, efficiency, and stimulation.
  • Both modes were rated as “excellent” in usability and effectively supported relaxation.
• Advantage over baselines:
  • Dyadic mode enhanced engagement, emotional support, and physiological relaxation compared to individual mode.
  • Peer-supported interactions reduced feelings of isolation and increased motivation.
• Experiments / evaluation:
  • Study One: Ten clinicians evaluated system usability (SUS: 88.5) and credibility (CEQ: Credibility = 22.8, Expectancy = 23.3).
  • Study Two: 32 BCSs participated in a between-group study comparing individual and dyadic modes. Metrics included HRV (RMSSD), SUS, and UEQ.
• Limitations and future work:
  • Limited personalization of HRV biofeedback mapping; future iterations should include individualized calibration.
  • Participants were recruited from a single urban hospital; broader demographic studies are needed.
  • Short-term effects were measured; future research should explore long-term clinical impact through longitudinal studies.

Summary

CoBreath is a VR-based dyadic biofeedback system designed to support paced breathing and relaxation training for breast cancer survivors. By integrating respiration and HRV biofeedback into a shared VR environment, the system enables peer-supported co-practice, fostering emotional connection and enhanced relaxation. Clinical and patient studies demonstrated its high usability, credibility, and effectiveness, with the dyadic mode showing superior outcomes in user experience and physiological relaxation compared to the individual mode. Future work will focus on personalization, long-term evaluation, and expanding application scenarios to hospital and home settings.