this study wants to analyse the effect of trigeminal stimulation on Heart rate Variability. There are going to be two groups, in the test group it will be administered stimulation of the tongue with TENS, while in the control goup TENS will be administered at tragus level.

This study analyses the effect of trigeminal stimulation with TENS on Heart rate variability (HRV). A new intraoral device will be administered on the dorsal surface of the tongue for TENS stimulation in the test group. The RMSSD, LF, HF and LF/HF will be monitered by photoplethysmographic wave. the results obtained with tongue stimulation will be compared with the results obtained in the control group, where it will be administered TENS stimulation at the tragus level. This work sought to assess whether there is a difference in HRV in relation to the site of application of dental ULFTENS (tragus vs tongue).

If effective in reducing the activity of arousal circuits, this tongue-level stimulation technique could have new clinical applications.

Inclusion Criteria:

• Healthy Women
• Age 18-30 years

Exclusion Criteria:

• presence of acute and/or chronic cardio-circulatory and respiratory disorders
• metabolic and autonomic system disorders
• intake of excitatory or inhibiting substances of the peripheral and central nervous system
• presence of generalised anxiety and/or panic attacks or mood disorders.