Vagal Approaches on Long COVID-19

The PHQ-8 is a gold-standard screening tool for major depressive disorder, endorsed by the CDC and WHO, with strong criterion validity and sensitivity to clinical change.

The GAD-7 captures both somatic and cognitive components of generalized anxiety. Extensively used in both clinical and epidemiological contexts, the GAD-7 shows excellent internal consistency (α > 0.90) and convergent validity with clinician-administered diagnostic tools.

The Abbreviated PCL-5 captures re-experiencing, avoidance, hyperarousal, and mood alterations. The Abbreviated PCL-5 is validated across diverse populations and is widely used in both military and civilian trauma research. It is recommended by the National Center for PTSD.

The SBQ-LC measures the intensity and impact of Long COVID symptoms, offering key insight into the ongoing symptom burden experienced. The SBQ-LC demonstrates strong psychometric properties with high internal consistency across subscales and good convergent validity with established measures of symptom severity and functional impairment. It has been validated across diverse Long COVID populations in multiple clinical settings.

The BPQ assesses self-reported autonomic reactivity and has been used in a range of international neural, behavioral, and clinical studies and translated into several languages. It has been corroborated with sensor-based measures of autonomic function.

The Benefits Scale assesses biobehavioral state, including the ability to quiet thoughts, awareness of bodily rhythms, breathing, muscular relaxation, physical pain levels, and emotional states such as peacefulness, relaxation, anxiety, irritability, feeling overwhelmed, worry about the future, and vulnerability.

The investigators will use the sleep categories of accumulated minutes of deep sleep, REM sleep, light sleep, and wakefulness during the night to provide us with sleep architecture.

Monitoring resting heart rate will allow us to assess whether SAT and Truvaga Electrical Vagus Nerve Stimulator are effective in lowering the elevated resting heart rate often observed in Long COVID patients via parasympathetic stimulation.

Monitoring steps will allow us to assess whether SAT and Truvaga Electrical Vagus Nerve Stimulator are associated with an increase in average daily steps, which may indicate enhanced functional capacity or reduced fatigue.

This measurement captures a user's average breaths per minute during sleep.

Heart rate variability (HRV) is a widely recognized biomarker for autonomic nervous system regulation. Long COVID is commonly associated with reduced HRV, reflecting autonomic nervous system dysregulation. Lower HRV in these patients has been linked to greater symptom burden.

Tracking changes in estimated aerobic capacity can help evaluate whether approaches are improving cardiovascular function and exercise tolerance over time.

SpO2 measures blood oxygen saturation levels, indicating how well oxygen is being transported throughout the body.

Active Zone Minutes are a measure of time spent in elevated heart rate zones, including Fat Burn, Cardio, and Peak zones.

ATES captures developmental and lifetime adversity that may impact vagal tone and neuroception. The ATES will allow us to examine the effectiveness of SAT and the Electrical Vagus Nerve Stimulator in individuals who report being impacted by their adversity histories.

The BBCSS assesses sensory processing difficulties that may reflect underlying autonomic dysfunction.

The PIL-SF measures existential meaning, motivational vitality, and psychological presence.

The NPSS evaluates subjective experiences of social safety/co-regulation and physiological regulation.

This tool enables tailored interpretation of individual differences in responsivity to Sonic Augmentation Technology and vagus nerve stimulation, particularly in populations with heightened neurophysiological sensitivity or neurodivergent traits.