Stress is an unavoidable and persistent component of life and holistic approaches for its management are being considered. A standardized methodology was created to demonstrate the feasibility of a breath-based stress management protocol that can be used with commercially available portable technology.
A pragmatic breath-based intervention to benefit human performance and stress management is timely and valuable to individuals seeking holistic approaches for emotional regulation and optimizing compensatory reserve mechanisms. This protocol is designed to not only teach mind-body awareness but also to provide feedback utilizing physiological data and survey results. The primary findings of this study showed that heart coherence and alpha variables were significantly correlated after four weeks of the breath-based meditation stress protocol. Meditation and rhythmic breathing produced significant increases in alpha brain activity. These brain physiological responses conformed to the Pleth Variability Index (PVI) changes, suggesting the ability of the human body to enter into a meditative state and effectively manage stress. When assessed after four weeks of daily practicing the techniques employed in the stress management protocol, based on the Five Facet Mindfulness Questionnaire, subjects improved in applying mindfulness skills. The overall mindfulness score, Pleth variability index (PVI), and perfusion index (PI) increased after the 4-week intervention period. Results from electroencephalography (brain waves) were consistent with a meditative state during the post-study follow-up session. This provides evidence that wearable devices are feasible for data collection during a breath-based stress management intervention. This protocol can be easily and efficiently implemented into any study design in which physiological data are desired in a non-laboratory-based setting.
Although stress is an unavoidable and persistent component of life, alternative approaches for the management of physical and emotional stimuli are being considered1,2,3,4. Uninterrupted stress is associated with the early onset and development of chronic conditions such as diabetes, obesity, cardiac, and cerebrovascular disease4,5. In recent years, an increasing percentage of Americans have reported stress has a negative impact on their mental and physical health6, and a sizable proportion did not feel they were doing enough to manage their stress7. Furthermore, a recent study showed that when individuals perceived that stress is negatively impacting their physical health, there was an elevated risk of premature death8.
Traditionally, public health and medical professionals have focused on physical activity as a means to manage stress. However, a significant portion of the United States population develops unhealthy lifestyle habits (i.e., smoking or excessive alcohol consumption) or unhealthy behaviors (i.e., poor diet patterns) as a result of stressful lifestyles. Currently, more Americans are becoming aware of the potential use of various forms of yoga and breathing exercises for stress management4,6,9. However, due to a lack of scientific validation, cultural appropriation, and the requisite physical environments (i.e., yoga studios), a significant portion of the United States population are not considering these alternative approaches for stress management6.
In an attempt to deliver holistic stress management techniques such as yogic breathing and guided relaxation to a broader audience, a protocol was developed and delivered to a small group of individuals in a non-laboratory setting. Previous studies have shown that techniques such as alternate nostril breathing are effective in delivering a more relaxed state of mind and body4.
Until recently, scientific studies of complex physiological measurements such as brain activity, respiration, and tissue perfusion were limited to laboratory settings, and thus studies relied on less complex measures such as ambulatory arterial blood pressure (ABP), respiratory rate (RR), and heart rate (HR). However, with the development of more scientifically accurate, wearable devices, the physiological responses to stress management interventions can be studied in non-laboratory settings.
The goal of this project is to create an accessible, inexpensive management program for stress that is generalizable to both laboratory and non-laboratory settings. Additionally, this article provides the methodology for an evidence-based approach to investigating physiological responses during a stress management protocol in a non-laboratory setting while utilizing commercially available wearable devices.
Recommendations are made to allow investigators to study better stress management interventions, as well as the setup and utilization of the portable electroencephalogram (EEG) system in a systematic way that is easily adaptable to various settings. The details needed to replicate the program are specified.
The protocol was approved by the Institutional Review Board (IRB) and all participants signed an informed consent form. Briefly, twelve healthy, normotensive, nonsmoking subjects (five men, seven women) aged between 31 and 65 years (mean age = 44 ± 12 years) volunteered to participate in this study. Brown and Gerbarg3 studied meditation and similar breathing techniques in individuals across a broad age range (14 – 85 years of age) for the management of anxiety, post-traumatic stress disorder, and overall wellness and lifestyle management.
1. Participant Selection
2. Setup for Research Grade Wireless Electroencephalography (EEG) System
3. Setup of the Bluetooth-Enabled Pulse Oximeter
4. Overview Five Facet Mindfulness Questionnaire
Note: This questionnaire is available in both paper and electronic format for administration10. The paper form is provided in Appendix A. Each of the five facets are based on a scale of mindfulness from 1 to 5. There is no cutoff score for being mindful or not mindful; rather it is a continuum from low to high. Each of the subscales related to the five facets of mindfulness is below.
5. Alternate Nostril Breath Protocol (5 min)
6. Victorious Breath Protocol (5 min)
7. Bellows Breath Protocol (5 min)
8. Guided Relaxation Body Scan (8 – 10 min)
NOTE: Read these instructions to the participants: "The purpose of this guided relaxation is to bring the attention to different areas of the body and may assist with better awareness of physical sensations in various areas of the body. Drawing attention to various regions of the body trains the mind to be more attentive to these feelings."
The primary findings of this study showed that heart coherence and alpha variables were significantly correlated after the primary endpoint, the baseline after four weeks, and the endpoint after four weeks of the breath-based meditation stress protocol, but not during the baseline measurement (Figure 1). Based on these findings, it was concluded that this protocol produced significant increases in alpha brain activity consistent with meditative states. These brain physiological changes were in line with the PVI changes (Figure 2), suggesting the ability of the human body to enter into a meditative state and effectively manage stress. When assessed after four weeks of daily practice of the techniques employed in the stress management protocol, based on the Five Facet Mindfulness Questionnaire, improvements in using mindfulness skills were achieved. All of the five facets—observing, describing, acting with awareness, non-judging of inner experience, and nonreactivity to inner experience—increased on average by 0.9 to 1.3 points on a scale of 1 (never) to 5 (often).
From a methodological perspective, the study confirmed that this home-based stress management program could be conducted and could capture useable data with wearable devices. The measurements of these whole-body physiological changes are practical in a non-clinical or laboratory setting. Evidence-based stress management programs are needed, and the participants' ability to observe their own physiological data after the study can be valuable.
Figure 1. Alpha activity data captured with the EEG headset during four time periods over the course of the 4-week stress management protocol.
Significant changes in alpha activity were observed by the end of the 4-week period, suggesting a meditative state was achieved. Please click here to view a larger version of this figure.
Figure 2. Pleth variability index (PVI) data captured with a pulse oximeter during four time periods over the course of the 4-week stress management protocol.
Significant changes in PVI were observed by the end of the 4-week period, which may be consistent with more responsive physiologic factors in vascular tone and circulating blood volume. Please click here to view a larger version of this figure.
The evolution of wearable technology and its ability to accurately track physiological responses can revolutionize the daily management of stress and monitor physical and cognitive performance across a range of interventions18. There has already been a host of clinical applications involving stress interventions that have been analyzed, including but not limited to blood pressure, heart rate, and motion or activity prediction. These technologies are continuously being improved upon by machine learning algorithms such as the Pleth variability index (PVI) and the compensatory reserve index (CRI) and can extend into any academic research field of study or community-based intervention19. However, wireless sensing technologies must demonstrate reliability, validity, and physiological responsiveness to a range of clinical and human performance–related activities.
One constraint of delivering a protocol in a non-laboratory setting is the need to ensure that environmental factors such as noise, ambient temperature, lighting, and unexpected visitors are minimized. This research successfully illustrates the feasibility and effectiveness of the implementation of breathing exercises with wearable technology within the confines of the unique constraints and characteristics of a non-laboratory environment.
Teaching the specifics of how to cultivate more adaptive ways of responding to life stressors is a critical piece of any instructor–student relationship. The opportunity to review their physiological data gives participants a way to quantify the effectiveness of stress management and progression in an unconventional approach to managing stress as they become increasingly aware of the attentiveness, alertness, and respiratory rates that are all reflective of stress levels. A key feature of this breathing protocol is the flexibility to deploy it in various populations and meet the needs of chronically stressed individuals and communities and improve their human performance.
There are important technical considerations to consider for users of the portal EEG system and PVI pulse oximetry. The EEG electrodes may shift along the scalp due to the spring-loaded system affixed to the plastic headset. Furthermore, the impedance of electrodes is based on maintaining appropriate saline, so investigators must ensure the electrodes have the appropriate amount of saline to reduce the likelihood of drying during the investigation. It may be necessary to replace the loss of the saline solution to some of the electrodes over the course of longer recording sessions.
It is essential for the investigators to minimize any external distractions during the EEG and PVI pulse oximeter recording as the devices may produce unwanted results and excessive noise to the EEG and PVI recordings.
Some individuals have reported moderate discomfort from wearing the EEG headset during extended periods of time (more than 2 hours). During this investigation, the recording sessions were limited to less than 2 hours to reduce the likelihood of any extreme discomfort associated with pressure from the electrodes and the headset.
Previous studies have reported volunteers getting bored during meditation and breathing protocols, while others have reported utilizing several biofeedback techniques to make the breathing tasks more enjoyable. The protocol described in this paper is associated with high compliance. It is essential that the participants are very comfortable with the guided meditation and breathing tasks. Most individuals reported that the CD with the guided audio of the breathing functions and meditation were of significant value.
Investigators interested in employing this technology and stress management protocol will need to identify an appropriate control group for the population being studied. Although this paper focused on the physiological monitoring and the stress management protocol, it is recognized that a control group is needed to validate any potential benefits of this protocol. Rather, the scope of this paper was to report the stress management protocol, associated wireless physiological monitoring devices, and stress reaction questionnaire.
The authors have nothing to disclose.
The authors would like to thank Dr. Harpreet Dhanoa for her generous insights toward the design of the breathing and meditation program so that it was safe, therapeutic, and impactful for individuals with stress management issues.
KC, RC, and JH conceived the project. RC and KC performed a literature search, study selection, and data extraction. All authors participated in the development of the manuscript and provided input into the final version.
Epoc+ 14 channel wireless EEG | Emotiv Systems | Assemble the headset. Fully saturate the felt pads using 0.5% saline solution. When the headset is placed on the scalp, the pads should feel wet. Measurements: Brain Waves, Facial Expression, Mental Command | |
Fingertip Pulse Oximeter with Bluetooth and Pleth Variability Index | Masimo Mighty Sat with PVI | Measurements: Pulse Rate, Oxygen Saturation, Perfusion Index, Pleth Variability Index (PVI) | |
The 39-item Five Facet Mindfulness Questionnaire | A psychometric instrument used to assess five facets of mindfulness | Questionnaire available in electronic and pencil and paper versions. Measurements: Mood, cognition function |