Effects of Nature-Based Virtual Reality and Binaural Beats on Heart Rate Variability and Relaxation (VRELAX)

Effects of Nature-Based Virtual Reality and Binaural Beats on Heart Rate Variability and Relaxation: A Controlled Within-Subject Study

The VRELAX study is a non-clinical sub-study within the "Decreasing Preoperative Stress to Prevent Postoperative Delirium and Postoperative Cognitive Decline in Cardiac Surgical Patients"- research program (DESTRESS; NCT05036538), which investigates non-pharmacological relaxation interventions using virtual reality and binaural auditory stimulation. In a randomized counterbalanced within-subject design, non-clinical adult participants complete two sessions separated by a 1 day intervention-free interval. A 30-minute immersive nature-based virtual reality exposure combined with gradually decreasing binaural beats (10-1 Hertz (Hz)), and a control condition without relaxation. Heart rate variability (HRV) is recorded continuously, and subjective stress is assessed before and after each condition. The primary outcome is parasympathetic activation operationalized as high-frequency (HF) power of heart rate variability. Secondary outcomes include additional HRV parameters and self-reported stress ratings. The study aims to characterize short-term relaxation effects and evaluate the feasibility of independent use in everyday settings, supporting interpretation of clinical findings of the DESTRESS trial.

Study Overview

• Status: Not yet recruiting
• Conditions: Stress; Virtual Reality; Relaxation; Binaural Beats
• Intervention / Treatment: Behavioral: Nature-Based Virtual Reality With Binaural Beats

Detailed Description

Psychological stress contributes to cardiovascular risk through dysregulation of the autonomic nervous system. Immersive virtual reality environments and binaural auditory stimulation have each shown stress-reducing effects, but their combined physiological impact remains insufficiently investigated. The DESTRESS research program (NCT05036538) evaluates these interventions in cardiac surgical patients. To isolate intervention-specific mechanisms independent of medical conditions, the VRELAX study was designed as a non-clinical sub-study with a randomized cross-over design in adult participants. Each participant undergoes two experimental conditions in counterbalanced order. A 30-minute immersive nature-based virtual reality exposure combined with binaural beats decreasing from alpha to delta frequency range (10-1 Hz). And a everyday cognitive activities without relaxation intervention. Sessions are separated by a 1 day intervention-free interval to reduce carryover effects. Heart rate variability is continuously measured using a validated chest-strap sensor. Subjective stress is assessed pre- and post-condition visual analogue scales. The primary outcome is HF-power of heart rate variability as an indicator of parasympathetic activation and physiological relaxation. Secondary outcomes are additional HRV parameters (root mean square of successive differences (RMSSD), number of successive normal-to-normal intervals differing by more than 50 milliseconds (NN50), percentage of successive normal-to-normal intervals differing by more than 50 milliseconds (pNN50), normalized high-frequency power of heart rate variability (HF%)), subjective stress ratings, and feasibility of independent intervention use based on participant instruction. By investigating physiological relaxation mechanisms in a non-clinical population, the study allows interpretation of intervention-specific effects independent of disease, medication, or perioperative factors. The findings will provide mechanistic context for the clinical DESTRESS trial and evaluate whether an easily implementable immersive relaxation procedure may serve as a preventive approach for reducing everyday and work-related stress.

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Marius Butz, PhD, M.Sc.; Phone Number: Tel.: +49(0)6032/996 5812; Email: m.butz@kerckhoff-klinik.de
• Study Contact Backup: Name: Nicole Schmidt-Bodensohn, PhD, M.Sc.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 18 years or older
• Ability to understand study procedures and provide written informed consent
• Sufficient proficiency in the German language to complete questionnaires and follow study instructions
• Willingness to participate in a single approximately 60-minute study session

Exclusion Criteria:

• Current or history of neurological or psychiatric disorders that may interfere with data collection (e.g., dementia, major depressive disorder, stroke, epilepsy)
• Severe visual or hearing impairments that would limit the use of virtual reality equipment or headphones
• History of adverse reactions to virtual reality

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: VR + Binaural Beats; Participants receive a 30-minute immersive nature-based virtual reality relaxation intervention combined with binaural beats.	Behavioral: Nature-Based Virtual Reality With Binaural Beats; A 30-minute immersive virtual reality exposure to natural environments combined with binaural auditory stimulation gradually decreasing from alpha to delta frequency range (10-1 Hz).
No Intervention: Control Condition; Participants undergo a control condition involving everyday cognitive activities without relaxation intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in High-Frequency Power of Heart Rate Variability (HF Power)	Spectral power in the high-frequency band (0.15-0.40 Hz) of heart rate variability measured in ms². Higher values reflect greater parasympathetic activity. The primary outcome is defined as the pre- to post-intervention change in HF-HRV measured continuously during the intervention or control condition.	Pre- and post-intervention within a single 30-minute study session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Root Mean Square of Successive Differences (RMSSD)	RMSSD of normal-to-normal heart beat intervals, measured in milliseconds (ms). Higher values indicate greater parasympathetic (vagal) activity and lower physiological stress. Changes in RMSSD will be assessed during the intervention or control condition.	Pre- and post-intervention within a single 30-minute study session
Change in Number of Successive NN Interval Differences Greater Than 50 ms (NN50)	Number of pairs of successive normal-to-normal (NN) intervals differing by more than 50 milliseconds. Higher values indicate increased parasympathetic activity. Changes in NN50 will be assessed during the intervention or control condition.	Pre- and post-intervention within a single 30-minute study session
Change in Proportion of NN50 (pNN50)	Percentage of successive normal-to-normal intervals differing by more than 50 ms (%). Higher values indicate increased parasympathetic activity and reduced physiological stress. Changes in pNN50 will be assessed during the intervention or control condition.	Pre- and post-intervention within a single 30-minute study session
Change in Relative High-Frequency Power (HF%)	Relative proportion of high-frequency power as percentage of total spectral power (%). Higher values indicate parasympathetic dominance. Changes in HF% will be assessed during the intervention or control condition.	Pre- and post-intervention within a single 30-minute study session
Change in Self-Reported Stress (Visual Analog Scale)	Participants rate their perceived stress on a visual analog scale ranging from 0 (no stress) to 10 (maximum stress). The outcome is defined as the change from pre- to post-intervention, with lower scores indicating lower perceived stress.	Pre- and post-intervention within a single 30-minute study session

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Successful independent completion of the intervention based on pictorial instructions	Binary outcome (Yes/No) indicating whether participants are able to independently set up, start, and correctly terminate the virtual reality intervention without assistance using only pictorial instructions.	Postprocedural / Postintervention. Immediately at the end of the 30-minute intervention session
Usability rating of the pictorial instruction	Participants rate the usability and comprehensibility of the pictorial instruction after completing the intervention on a 5-point Likert scale ranging from 1 (very difficult to understand/use) to 5 (very easy to understand/use).	Postprocedual / Postintervention. Within 5 minutes after the end of the 30-minute intervention session.

Collaborators and Investigators

• Sponsor: Heart and Brain Research Group, Germany

Study record dates

Study Major Dates

• Study Start (Estimated): February 25, 2026
• Primary Completion (Estimated): December 20, 2026
• Study Completion (Estimated): December 20, 2026

Study Registration Dates

• First Submitted: February 5, 2026
• First Submitted That Met QC Criteria: February 18, 2026
• First Posted (Actual): February 25, 2026

Study Record Updates

• Last Update Posted (Actual): February 25, 2026
• Last Update Submitted That Met QC Criteria: February 18, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Heart Rate Variability; Virtual Reality; Stress Reduction; Binaural Beats; Relaxation Intervention; Non-Clinical Population
• Other Study ID Numbers: 110/21-VRELAX; DESTRESS (NCT05036538) (Other Identifier: Heart and Brain Research Group, Germany)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No