Multi-device Testing for Autonomic Nervous System Stimulation

Multi-device Testing for Autonomic Nervous System Stimulation

The Vagus nerve (VN) serve as an "unconscious inner brain" that integrates messages from the body and provides metabolic homeostatic regulation to various organs.In this study the investigators want to compare different ways to stimulate the vagus nerve to assess their respective effects compared to a sham stimulation.

Each participant will be exposed in a random way to 7 different ways to stimulate the VN:

• Manual Head Massage
• Mechanical Head Massager (BREO Inc. Helmet)
• Low laser Therapy (LLT)
• Sham LLT
• Transcutaneous Electrical Nervous Stimulation (TENS) ear stimulation (as testing phase prototype device)
• Deep and slow breathing (as testing intervention based on video app)
• Relaxed reading time (as control situation)

Therefore, within the same design the investigators want to conduct two separate studies that should lead to two separate publications:

• Study 1: comparison of manual head massage to mechanical Helmet massager and relaxed reading
• Study 2: comparison of LLT with sham LLT and relaxed reading

The two other interventions: TENS ear stimulation and Deep and Slow breathing are purely observational to gain knowledge in context of a convenient design.

OBJECTIVES Overall objective is to assess the respective effects of the different ways to stimulate the Vagus Nerve on the Heart Rate Variability (HRV) parameters: High Frequency (HF), Low Frequency (LF), Total Power (TP), Heart rate (HR), and blood pressure (BP).

Specific objectives:

• Comparison of Manual Head Massage to Mechanical Head Massager to Control situation
• Comparison of Low Laser Therapy (LLT) to sham LLT to control situation
• Effects of TENS ear stimulation (descriptive)
• Effects of Deep and Slow breathing (descriptive)

Inclusion Criteria:

• Healthy volunteers aged 20 to 40 in normal context

Exclusion Criteria:

• To have work night shift the night before
• To use certain drugs that affect the ANS (beta blockers, beta stimulant, hypnotic, for instance)
• To be in situation of unusual life stress
• To have a chronic disease that require some daily treatment
• Not to stay in Beijing for the duration of the investigation