A substantial body of preclinical literature documents autonomic nervous system (ANS) dysregulation in patients with PTSD. Preliminary results suggest that portable heart rate variability (HRV)/respiratory sinus arrhythmia (RSA) biofeedback is a promising adjunct treatment for autonomic arousal disorders. The StressEraser, a HRV/RSA biofeedback device, is indicated for relaxation, relaxation training, and stress reduction. This small handheld device measures and displays real-time RSA via an infrared finger sensor.