Respiratory Biofeedback Research Articles

A Comparative Study between Conventional Diaphragmatic Breathing Exercise and Virtual Reality-based Diaphragmatic Breathing Exercise on Quality of Life in Chronic Obstructive Pulmonary Disease Patients: A Randomized Control Trial

Background and Aim: Breathing exercise is an exercise intended to promote effective and healthy breathing and breathing control. Virtual reality (VR) is defined as a computer-generated simulation, such as a set of images and sounds that represent a real place or situation that can be interacted within a seemingly real or physical way by a person using special electronic equipment. Breathing exercises with VR have shown benefits over conventional diaphragmatic breathing exercises in normal individuals in many new studies. We propose the use of a novel VR-based approach as a respiratory biofeedback to improve breathing patterns in chronic obstructive pulmonary disease (COPD) patients, decrease their work of breathing, and improve breathing control. Materials and Methods: In a randomized controlled study involving 72 COPD patients divided into two groups of 36 in each, the control and experimental groups performed a short 5 min breathing exercise for 6 consecutive days. In experimental group patients performed breathing exercise with VR goggles while in controls they performed without VR goggles. Results: Both the control and experimental groups showed improved changes in vitals and better quality of life, but not statistically as significant when compared to each other. Conclusion: Future studies need to address the long-term effects and stability of the results with a larger sample size, compare the approach with the existing treatments, and make the required smaller changes to the program for better outcomes.

Visual respiratory biofeedback to improve visuospatial cognition and cardiac interoception in migraineurs: a study protocol for a randomized controlled trial.

Migraine is a complex neurological disorder that typically presents with unilateral cephalgia associated with cognitive impairment and reduced interoception. These symptoms result in socio-economic repercussions due to reduced productivity, efficiency, and work performance. Therefore, along with headache management, improving cognition and interoception should also be significant therapeutic targets to effectively manage migraine. To achieve this, we propose to explore the role of a yoga-based visual respiratory biofeedback (VRB) as a possible therapeutic strategy. At least 64 participants will be recruited for the trial after screening for eligibility criteria, using the migraine screening questionnaire and Montreal cognitive assessment test. They will be randomly allocated (1:1) to either the experimental group receiving a 20-min session of yoga-based VRB or the control group who will be asked to watch a documentary film for the same duration. Visuospatial cognition will be assessed by the Corsi block-tapping task, and cardiac interoceptive accuracy will be assessed by the heartbeat counting task at baseline and immediately after the intervention. Based on the distribution and variance of the data obtained, analysis will be conducted based on linear mixed models using SPSS version 28.0.1.0, with a two-sided p-value of < 0.05 considered to be statistically significant. To the best of our knowledge, this is the first study to design and assess the effects of yoga-based biofeedback therapy on cognition and cardiac interoception in migraineurs. Furthermore, we postulated that pranayama's therapeutic effects might be enhanced by using visual yogic respiratory biofeedback. Considering the socio-economic burden of migraine, if found effective, VRB investigated in the trial could be considered as a therapeutic strategy. ClinicalTrials.gov CTRI, CTRI/2023/03/050430.

Dynamics of Physiological, Biochemical and Psychological Markers during Single Session of Virtual Reality-Based Respiratory Biofeedback Relaxation.

Psychological stress exposure is associated with long-lasting health effects including memory problems, depression, aches and pains, eating disorders, and alcohol or drug use. Thus, there is a need to develop effective stress management strategies that are easy to learn and practice. Respiratory biofeedback is an evidence-based stress management technique presenting breathing-related information to help subjects learn specific breathing skills for relaxation. It is suggested that the use of biofeedback techniques in conjunction with virtual reality makes biofeedback training an even more effective tool for stress management. The current study aimed to investigate dynamics of distinct stress indicators before, after, as well as during one brief virtual reality-based respiratory biofeedback session. Thirty-nine healthy volunteers participated in the study. Individuals provided their saliva samples and evaluated their mood status, fatigue, and strain level before and after the session. The subjects' heart and respiratory rate, heart rate variability, and galvanic skin response measures were recorded during the session. The results showed that after single 12 min relaxation session, there was a significant decrease in salivary cortisol concentration, heart and respiratory rate, as well as decrease in skin conductance values. Self-reported strain, fatigue level, and mood status also significantly improved. VR-based respiratory-biofeedback-assisted relaxation sessions might serve as an effective stress management strategy, as even single session had positive effects on subjects' autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis activity, as well as self-reported fatigue, strain level, and mood status.

Respiratory sinus arrhythmia during biofeedback is linked to persistent improvements in attention, short-term memory, and positive self-referential episodic memory.

BackgroundHeart rate variability (HRV) biofeedback, an intervention based on the voluntary self-regulation of autonomic parameters, has been shown to affect prefrontal brain functioning and improve executive functions. The interest in using HRV biofeedback as cognitive training is typically ascribed to parasympathetic activation and optimized physiological functioning deriving from increased cardiac vagal control. However, the persistence of cognitive effects is poorly studied and their association with biofeedback-evoked autonomic changes has not yet been explored. In addition, no study has so far investigated the influence of HRV biofeedback in adults on long-term episodic memory, which is particularly concerned with self-referential encoding processing.MethodsIn the present study, a novel training system was developed integrating HRV and respiratory biofeedback into an immersive virtual reality environment to enhance training efficacy. Twenty-two young healthy adults were subjected to a blinded randomized placebo-controlled experiment, including six self-regulation training sessions, to evaluate the effect of biofeedback on autonomic and cognitive changes. Cardiac vagal control was assessed before, during, and 5 min after each training session. Executive functions, episodic memory, and the self-referential encoding effect were evaluated 1 week before and after the training program using a set of validated tasks.ResultsLinear mixed-effects models showed that HRV biofeedback greatly stimulated respiratory sinus arrhythmia during and after training. Moreover, it improved the attentional capabilities required for the identification and discrimination of stimuli ( = 0.17), auditory short-term memory ( = 0.23), and self-referential episodic memory recollection of positive stimuli ( = 0.23). Episodic memory outcomes indicated that HRV biofeedback reinforced positive self-reference encoding processing. Cognitive changes were strongly dependent on the level of respiratory sinus arrhythmia evoked during self-regulation training.ConclusionThe present study provides evidence that biofeedback moderates respiration-related cardiac vagal control, which in turn mediates improvements in several cognitive processes crucial for everyday functioning including episodic memory, that are maintained beyond the training period. The results highlight the interest in HRV biofeedback as an innovative research tool and medication-free therapeutic approach to affect autonomic and neurocognitive functioning. Finally, a neurocognitive model of biofeedback-supported autonomic self-regulation as a scaffolding for episodic memory is proposed.

Effects of Virtual Reality-Based Relaxation Techniques on Psychological, Physiological, and Biochemical Stress Indicators.

Various relaxation techniques could benefit from merging with virtual reality (VR) technologies, as these technologies are easily applicable, involving, and user-friendly. To date, it is unclear which relaxation technique using biofeedback combined with VR technology is the most effective. The study aimed to compare the effectiveness of brief VR-based biofeedback-assisted relaxation techniques including electroencephalographic biofeedback, mindfulness-based biofeedback, galvanic skin response biofeedback, and respiratory biofeedback. Forty-three healthy volunteers (age 34.7 ± 7.2 years), comprising 28 (65%) women and 15 (35%) men, were enrolled in the study. All the participants were exposed to four distinct relaxation sessions according to a computer-generated random sequence. The efficacy of relaxation methods was evaluated by examining psychological, physiological, and biochemical stress indicators. All VR-based relaxation techniques reduced salivary steroid hormone (i.e., cortisol, cortisone, and total glucocorticoid) levels and increased galvanic skin response values. Similarly, all interventions led to a significantly reduced subjectively perceived psychological strain level. Three out of the four interventions (i.e., electroencephalographic, respiratory, and galvanic skin response-based biofeedback relaxation sessions) resulted in a decreased self-reported fatigue level. We suggest that newly developed VR-based relaxations techniques are potential tools for stress reduction and might be particularly suitable for individuals who are not capable of adhering to a strict and time-consuming stress management intervention schedule.

Exploring the Embodiment of a Virtual Hand in a Spatially Augmented Respiratory Biofeedback Setting.

Enhancing the embodiment of artificial limbs—the individuals' feeling that a virtual or robotic limb is integrated in their own body scheme—is an impactful strategy for improving prosthetic technology acceptance and human-machine interaction. Most studies so far focused on visuo-tactile strategies to empower the embodiment processes. However, novel approaches could emerge from self-regulation techniques able to change the psychophysiological conditions of an individual. Accordingly, this pilot study investigates the effects of a self-regulated breathing exercise on the processes of body ownership underlying the embodiment of a virtual right hand within a Spatially Augmented Respiratory Biofeedback (SARB) setting. This investigation also aims at evaluating the feasibility of the breathing exercise enabled by a low-cost SARB implementation designed for upcoming remote studies (a need emerged during the COVID-19 pandemic). Twenty-two subjects without impairments, and two transradial prosthesis users for a preparatory test, were asked (in each condition of a within-group design) to maintain a normal (about 14 breaths/min) or slow (about 6 breaths/min) respiratory rate to keep a static virtual right hand “visible” on a screen. Meanwhile, a computer-generated sphere moved from left to right toward the virtual hand during each trial (1 min) of 16. If the participant's breathing rate was within the target (slow or normal) range, a visuo-tactile event was triggered by the sphere passing under the virtual hand (the subjects observed it shaking while they perceived a vibratory feedback generated by a smartphone). Our results—mainly based on questionnaire scores and proprioceptive drift—highlight that the slow breathing condition induced higher embodiment than the normal one. This preliminary study reveals the feasibility and potential of a novel psychophysiological training strategy to enhance the embodiment of artificial limbs. Future studies are needed to further investigate mechanisms, efficacy and generalizability of the SARB techniques in training a bionic limb embodiment.

Development of a modular stress management platform (Performance Edge VR) and a pilot efficacy trial of a bio-feedback enhanced training module for controlled breathing.

This paper describes the conceptual design of a virtual reality-based stress management training tool and evaluation of the initial prototype in a pilot efficacy study. Performance Edge virtual-reality (VR) was co-developed with the Australian Defence Force (ADF) to address the need for practical stress management training for ADF personnel. The VR application is biofeedback-enabled and contains key stress management techniques derived from acceptance and commitment and cognitive behavioural therapy in a modular framework. End-user-provided feedback on usability, design, and user experience was positive, and particularly complimentary of the respiratory biofeedback functionality. Training of controlled breathing delivered across 3 sessions increased participants' self-reported use of breath control in everyday life and progressively improved controlled breathing skills (objectively assessed as a reduction in breathing rate and variability). Thus the data show that a biofeedback-enabled controlled breathing protocol delivered through Performance Edge VR can produce both behaviour change and objective improvement in breathing metrics. These results confirm the validity of Performance Edge VR platform, and its Controlled Breathing module, as a novel approach to tailoring VR-based applications to train stress management skills in a workplace setting.

The Use of a Respiratory Biofeedback Device to Reduce Dental Anxiety in Children: A Randomized Controlled Clinical Trial

Introduction: Dental anxiety occurs when the patient presents to the dentist with the anticipation of dental treatment. Many children react to dental stressful situations through uncooperative behaviors. Objectives: Investigate the effect of a respiratory biofeedback device (RESPeRATETM) in reduction of preoperative anxiety in children undergoing dental procedures under local anesthesia. Materials and methods: A randomized controlled clinical trial comprising 110 healthy children, of age range 7-12 years, were selected. Their scores were 19 or more according to the Faces version of Modified Child Dental Anxiety Scale. Participants were randomly allocated into two groups: Study and Control group. For both groups, heart rate was recorded prior to local anesthesia administration and a salivary sample was collected to measure the salivary amylase. The study group was submitted to a session of respiratory biofeedback “RESPeRATETM”. The control group was managed by a routine behavioral management technique “Tell, Show and Do”. Infiltration or block local anesthesia injections were administered, after which heart rate measurement and salivary sample was repeated. T and paired T tests were used for statistical analysis. Results: Heart rate decreased significantly in the study group (P=0.001), and increased significantly in the control group (P=0.002). There were non-significant changes among both groups regarding salivary amylase. A weak correlation was found between heart rate and salivary amylase. Conclusions: “RESPeRATETM” group showed a decrease in dental anxiety, as evidenced by decreased heart rate. “RESPeRATETM” can be used effectively before dental procedures for anxious children. Salivary alpha amylase was a poor stress biomarker.

A mobile VR-based respiratory biofeedback game to foster diaphragmatic breathing

Virtual reality (VR) has become popular in mental health research. Several studies have explored the use of VR in the context of biofeedback protocols. In the present paper, we report on the development and evaluation of a VR-based respiratory biofeedback game to foster diaphragmatic breathing. The game integrates respiratory biofeedback, restorative VR and gamification. The game is designed to run on a mobile, all-in-one VR headset. Notably, an integrated VR hand controller is utilized as a sensor to detect respiration-induced movements of the diaphragm. In a longitudinal within-subjects study, we explored the feasibility of the game and tested the effectiveness of six training sessions. Participants reported a pleasant user experience. Moreover, the results show that the brief VR-based breathing training increased perceived breath awareness, improved diaphragmatic breathing, increased relaxation, decreased perceived stress, reduced symptoms of burnout and boosted relaxation-related self-efficacy. Future studies need to address the generalizability and long-term stability of the results, compare the approach with existing treatments and fine-tune the training components.

Gaming Away Stress: Using Biofeedback Games to Learn Paced Breathing

Biofeedback games are an attractive alternative to standard techniques for learning short-term relaxation skills. In this paper, we present the design, implementation, and evaluation of three respiratory biofeedback games. To validate these games, we compared breathing rate across 100 male participants (23 years ± 3.2 years) playing biofeedback and audio pacing versions of these games as well as a paced breathing app. The games were placed between repeat runs of a cognitively stressful Stroop-based task and the impact of the games on breathing and cognitive performance in the task also assessed. Our results showed that 1) differences in gameplay did not impact player performance; 2) biofeedback not only led to better breath control during play but also during the subsequent cognitively stressful task; and 3) biofeedback led to better attentional-cognitive performance in the subsequent task. Our multi-game experiments show that using respiratory biofeedback in video games is an effective strategy to learn paced breathing—on par with the standalone technique of paced breathing—and to self-regulate stress levels in later stressful scenarios. Furthermore, owing to its entertainment value, our relaxation solution has the potential to be more engaging and accessible than standalone paced breathing, for use over longer durations.

Breathing Biofeedback Relaxation Intervention for Wheelchair Users in City Navigation.

Manual wheelchair users experience numerous invisible barriers while navigating cities, often reporting how stressful journeys are. This stress affects a wheelchair user's quality of life. To alleviate such psychological burden, we propose a novel intervention strategy with a respiratory biofeedback interface which is designed to help users feel relaxed in urban navigation. We conducted a study in a real-world setting to explore its potential to provide real-time psychological support. From qualitative and quantitative analysis, we report on the strengths and weaknesses of the approach.

WiRelax: Towards real-time respiratory biofeedback during meditation using WiFi

Respiratory pattern tracking proved to be critical for many applications ranging from well-being monitoring and stress management to dealing with chronic breathing abnormalities. Specific breathing and meditation exercises have been designed to improve well-being of users based on monitoring the complete breathing waveform. While wearable systems had leveraged a wealth of information available from respiration stream in a variety of applications, contact-less sensing systems are lagging behind when it comes to capturing detailed breathing metrics. In this work we propose WiRelax; the first non-contact respiratory biofeedback system that relies solely on WiFi availability. We propose algorithms that map the changes in the Channel State Information (CSI) to the instantaneous breathing state. The key contribution is a model that relates relative phase of the received signal and the micro-motion of the chest during breathing. A novel processing pipeline is developed to extract a single breathing waveform from CSI data captured across noisy multiple sub-carriers in real-time. Our evaluation in a real-world setup shows that WiRelax can estimate real-time breath-by-breath cycle time with median error less than 0.25 s ( < 13% relative to the cycle length) thus enabling accurate device-free respiratory biofeedback.

Biofeedback-Assisted Relaxation Training: A Clinically Effective Treatment Protocol

Purchasing biofeedback instruments and learning the technical process of operating each biofeedback instrument with a human subject are not enough. These steps are necessary, but they do not clearly guide one as to how the instruments should be used. A treatment protocol is required that provides an explanation of the patient's current suffering or problem, as well as a rationale for using biofeedback training in a fashion that can reasonably be expected to relieve that suffering. Such models or protocols are necessary to organize the process of the biofeedback training and provide a reasonable explanation to motivate the trainee/client. Experience shows that clients who understand how the intervention is relevant for their complaint apply themselves more fully and follow through with any homework more reliably. There are a number of such protocols, including biofeedback-assisted relaxation training, the breath training and respiratory biofeedback model, resonance frequency heart rate variability training, the neuromuscular rehabilitation model, various neurofeedback training models, and psychophysiological psychotherapy. This article will introduce biofeedback-assisted relaxation training (BART). BART is a widely applied biofeedback protocol in clinical practice and has been documented as effective in clinical studies from 1969 to the present, for anxiety disorders, diabetes, headaches, and a variety of other common medical and psychological conditions.

Development and Pilot Test of a Virtual Reality Respiratory Biofeedback Approach

Breathing exercises with biofeedback have benefits over breathing exercises without biofeedback. However, the traditional measurement of respiratory signals that is required as part of feeding back the breath incurs high cost and effort. We propose a novel virtual reality (VR) based approach to respiratory biofeedback that utilizes the positionally tracked hand controllers integrated into modern VR systems to capture and feedback the respiration-induced abdominal movements. In a randomized controlled laboratory study, we investigated the feasibility and efficacy of the developed biofeedback algorithm. In total, 72 participants performed a short breathing exercise in VR with or without respiratory biofeedback. The feedback integration resulted in a satisfactory user experience, a heightened breath awareness, a greater focus on slow diaphragmatic breathing and an increased respiratory sinus arrhythmia. This evidences that the novel biofeedback approach is low-cost, unobtrusive, usable and effective in increasing breath awareness and promoting slow diaphragmatic breathing in the context of VR-based breathing exercises. Future studies need to investigate the broader applicability and long-term effects.

Respiratory Biofeedback Device and Reduction of Dental Anxiety Associated With Local Anesthesia in Children

Respiratory Biofeedback Device and Reduction of Dental Anxiety Associated With Local Anesthesia in Children

Biofeedback and Neurofeedback for Anxiety Disorders: A Quantitative and Qualitative Systematic Review.

Biofeedback refers to the operant training of physiological responding. Variants include electromyography (EMG), electrodermal activity (EDA), skin temperature, heart rate (HR) and heart rate variability (HRV), respiratory biofeedback of end-tidal CO2 (ETCO2), electroencephalography (EEG) signal, and blood oxygen-level dependent signal using functional magnetic resonance imaging (fMRI). This chapter presents a qualitative and quantitative systematic review of randomized controlled trials of biofeedback for anxiety disorders as defined by the 3rd through 5th editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). Meta-analytic results indicated that biofeedback (broadly defined) is superior to wait list, but has not been shown to be superior to active treatment conditions or to conditions in which patients are trained to change their physiological responding in a countertherapeutic direction. Thus, although biofeedback appears generally efficacious for anxiety disorders, the specific effects of biofeedback cannot be distinguished from nonspecific effects of treatment. Further, significant limitations were identified in the existing literature, with the majority receiving a "weak" rating according to Effective Public Health Practice Project (EPHPP) rating system guidelines. Future directions for research are discussed.

Virtual Reality-Based Biofeedback and Guided Meditation in Rheumatology: A Pilot Study.

ObjectiveAs technology continues to improve, it plays an increasingly vital role in the practice of medicine. This study aimed to assess the feasibility of the implementation of virtual reality (VR) in a rheumatology clinic as a platform to administer guided meditation and biofeedback as a means of reducing chronic pain.MethodsTwenty participants were recruited from a rheumatology clinic. These participants included adults with physician‐diagnosed autoimmune disorders who were on a stable regimen of medication and had a score of at least 5 on the pain Visual Analog Scale (VAS) for a minimum of 4 days during the prior 30 days. VAS, part of most composite outcome measurements in rheumatology, is an instrument used to assess pain that consists of a straight line with the endpoints ranging from “no pain at all” and “pain as bad as it could be.” Patients were randomized into two groups that differed in the order in which they experienced the two VR modules. One module consisted of a guided meditation (GM) environment, whereas the other module consisted of a respiratory biofeedback (BFD) environment. Data on pain and anxiety levels were gathered before, during, and after the two modules.ResultsThe three most common diagnoses among participants were rheumatoid arthiritis (RA), lupus, and fibromyalgia. There was a significant reduction in VAS scores after BFD and GM (P values = 0.01 and 0.04, respectively). There was a significant reduction in Facial Anxiety Scale after the GM compared with the BFD (P values = 0.02 and 0.08, respectively).ConclusionThis novel study demonstrated that VR could be a feasible solution for the management of pain and anxiety in rheumatology patients. Further trials with varying treatment exposures and durations are required to solidify the viability of VR as a treatment option in rheumatology clinics.

Feasibility Study of a novel MRI-safe and interactive respiratory biofeedback system.

This paper presents a feasibility study of a novel MRI-safe and interactive respiratory biofeedback system. Breathing-induced organ motion is a huge problem in medical imaging as well as in radiation therapy. Controlled breathing is an essential requirement for the efficiency of a successful diagnosis and therapy. To address this problem, a new interactive feedback system was developed. A commando unit provides instructions regarding the desired respiration pattern for the proband and a feedback unit gives a response about the deviation between the actual and the desired respiratory motion. A first feasibility study confirmed the viability of the new system. By means of the interactive biofeedback system, the test persons were able to adjust their respiration according to a prescribed breathing pattern. Our results showed that an interactive respiratory biofeedback system is able to reduce breathing motion and with that could be very beneficial for MR-imaging and also for radiation therapy procedures.

Reducing bedtime physiological arousal levels using immersive audio-visual respiratory bio-feedback: a pilot study in women with insomnia symptoms.

Hyperarousal is a critical component of insomnia, particularly at bedtime when individuals are trying to fall asleep. The current study evaluated the effect of a novel, acute behavioral experimental manipulation (combined immersive audio-visual relaxation and biofeedback) in reducing bedtime physiological hyperarousal in women with insomnia symptoms. After a clinical/adaptation polysomnographic (PSG) night, sixteen women with insomnia symptoms had two random-order PSG nights: immersive audio-visual respiratory bio-feedback across the falling asleep period (manipulation night), and no pre-sleep arousal manipulation (control night). While using immersive audio-visual respiratory bio-feedback, overall heart rate variability was increased and heart rate (HR) was reduced (by ~ 5bpm; p < 0.01), reflecting downregulation of autonomic pre-sleep arousal, relative to no-manipulation. HR continued to be lower during sleep, and participants had fewer awakenings and sleep stage transitions on the manipulation night relative to the control night (p < 0.05). The manipulation did not affect sleep onset latency or other PSG parameters. Overall, this novel behavioral approach targeting the falling asleep process emphasizes the importance of pre-sleep hyperarousal as a potential target for improving sleep and nocturnal autonomic function during sleep in insomnia.

Respiratory Biofeedback Does Not Facilitate Lowering Arousal in Meditation Through Virtual Reality

The current study examined the effectiveness of respiratory biofeedback in lowering subjective and objective arousal after stress. Participants were presented with a meditation session in virtual reality while subjective and objective arousal were measured, the latter measured through ECG and EEG. Three conditions were used: (a) a respiratory biofeedback condition, in which visual feedback was paired to breathing; (b) a control feedback placebo condition, in which visual feedback was not paired to breathing; and (c) a control no-feedback condition, in which no visual feedback was used. Subjective and objective arousal decreased during meditation after stress in all conditions, demonstrating recovery after stress during meditation in virtual reality. However, the reduction in arousal (on all outcome measures combined and heart rate specifically) was largest in the control feedback placebo condition, in which no biofeedback was used, indicating that respiratory biofeedback had no additional value in reducing arousal. The findings of the current study highlight the importance of including a control feedback placebo condition in order to establish the exact additional value of biofeedback and offer insights in applying cost-effective virtual reality meditation training.