The study assess the effect of the VR technology (Pure Purr technology) on the recovery of the autonomic nervous system in healthy volunteers affected by moderate stress. Study subject randomized into two groups: in Group 1 volunteers first be tested with the VR headset A, and during the next visit- headset B. Group 2 volunteers first be tested with the VR headset B, and during the next visit- headset A. Before, after and during VR session was conducted stress modulation and ECG recording.

The Pure Purr technology combines several audio and visual stimuli aimed at activation of the parasympathetic nervous system. Therefore, this study will investigate the effect of this technology on the recovery of autonomic nervous system performance after moderate stress.

Pure Purr technology is based on discoveries in neurophysiology, medicine, acoustics, and computer engineering, which are used to initiate the physiological process of recreation, i.e. allostasis. Literally this term means "achieving stability through change". This is an active mechanism playing a part in normalization of the tone of the autonomic nervous system and maintaining stability of the body internal environment. The condition in which all our functions are implemented fully and sparingly in response to the load, and the level of adaptation remains high for a long time. Pure Purr is a software and hardware complex for relaxation and recreation based on a virtual reality headset with a display with sufficient resolution, built-in processor, memory, and extended-range stereo speakers. Positive effect on the cognitive function of the brain and the system of neurohumoral regulation is achieved due to the synchronous actuation of a number of stimuli, such as: visual sequence enhanced by the effect of virtual reality, harmonious music with the binaural rhythm technology, and modified cat purrs. Currently, the use of each technology is a scientifically proven trigger for the activation of individual parts of the human nervous system. And combining them in one software complex enhances the overall effect.

Inclusion Criteria:

1. Females and males 20-60 years old;
2. Volunteers have no history of cardiovascular diseases;
3. Volunteers have no essential abnormalities on the ECG;
4. Normal or moderate level of situational anxiety based on the Spielberger State-Trait Anxiety Inventory (STAI);
5. Signed Informed Consent Form for participation in the study.

Exclusion Criteria:

1. Intolerance to the VR technology;
2. HR 110 bpm or below 50 bpm;
3. RR above 23 breaths per minute;
4. Abuse of alcohol, psychotropic substances and narcotic agents;
5. Smoking more than 100 cigarettes a week;
6. Administration of medicinal products for the treatment of cardiovascular and nervous system diseases 3 days prior to participation in the study;
7. Drinking tonics and energy drinks for at least 2 hours prior to participation in the study;
8. Severe or acute forms of respiratory, urogenital, gastrointestinal, haematological, metabolic, endocrine, or neurological diseases;
9. Mental disorders, which, in the opinion of the investigator, may distort the results of the study;
10. Participation in any clinical study over the last 3 months prior to enrolment to the study;
11. Parkinson's disease, Parkinson's symptoms, tremor, restless leg syndrome, and other motility disorders;
12. Pregnancy;
13. Any disease of the thyroid gland.