Respiratory Frequency Research Articles

Spectral Analysis of Heart Rate Variability in Time-Varying Conditions and in the Presence of Confounding Factors.

The tools for spectrally analyzing heart rate variability (HRV) has in recent years grown considerably, with emphasis on the handling of time-varying conditions and confounding factors. Time-frequency analysis holds since long an important position in HRV analysis, however, this technique cannot alone handle a mean heart rate or a respiratory frequency which vary over time. Overlapping frequency bands represents another critical condition which needs to be dealt with to produce accurate spectral measurements. The present survey offers a comprehensive account of techniques designed to handle such conditions and factors by providing a brief description of the main principles of the different methods. Several methods derive from a mathematical/statistical model, suggesting that the model can be used to simulate data used for performance evaluation. The inclusion of a respiratory signal, whether measured or derived, is another feature of many recent methods, e.g., used to guide the decomposition of the HRV signal so that signals related as well as unrelated to respiration can be analyzed. It is concluded that the development of new approaches to handling time-varying scenarios are warranted, as is benchmarking of performance evaluated in technical as well as in physiological/clinical terms.

Physiological effects of filtering facepiece respirators based on age and exercise intensity.

During the coronavirus disease 2019 pandemic, Filtering Facepiece Respirators (FFRs) were highly effective, but concerns arose regarding their physiological effects across different age groups. This study evaluated these effects based on age and exercise intensity in 28 participants (children, young adults, and older individuals). Physiological parameters such as respiratory frequency (Rf), minute ventilation (VE), carbon dioxide production (VCO2), oxygen consumption (VO2), heart rate (HR), metabolic equivalents (METs), percutaneous oxygen saturation (SpO2) and the concentration of O2 and CO2 in the FFRs were measured during treadmill tests with and without FFRs (cup-shaped, flat-folded, and with an exhalation valve). There was no significant difference in physiological effects between the control and FFR types, although Rf, VE, VCO2, VO2, METs, and HR increased with increasing exercise intensity. Depending on the exercise intensity, the O2 level in the FFR dead space decreased, and the CO2 level increased but this was independent of the dead space volume or FFR type. The study concluded that FFRs did not substantially impact daily life or short-term exercise, supporting their safe and effective use as a public health measure during pandemics and informing inclusive guidelines and policies.

An accurate respiratory rate estimation algorithm for a rubber fiber respiratory sensor

Respiratory measurement is a crucial indicator for assessing health status; however, current methods for measuring respiratory rate and frequency are passive and not intuitive. This study investigates peak detection algorithms using a resistive strain sensor integrated into a garment for respiratory rate monitoring. The sensor, constructed with CNT material and a flexible rubber substrate, exhibits high conformity to the body’s contours. Designed for respiration measurement, the sensor maintains a low 6% strain for optimal sensitivity, demonstrating a 4% decrease after 800 repetitions of 10% elongation. Garment design emphasizes cohesion between the sensor and fabric, achieved through a piping technique. Respiratory measurement relies on a resistive sensor principle, where abdominal volume changes induce tension, altering resistance. Three peak detection algorithms are evaluated: the window size algorithm, low-pass filter, and FIR filter. The window size algorithm shows a 93% matching rate for normal breathing but requires manual adjustments based on breathing speed. The low-pass filter reduces noise but introduces lag, challenging peak matching. The FIR filter effectively detects peaks at increased speeds, achieving a matching rate exceeding 98%. The study concludes that the choice of algorithm depends on respiratory scenarios, with the window size algorithm suitable for regular cycles, the low-pass filter for real-time monitoring, and the FIR filter for accelerated respiratory rates. The study primarily explores static situations, indicating the need for future research on dynamic respiratory movements to enhance algorithm versatility.

APPLICATION OF SIMPLE INHALATION THERAPY IN PULMONARY TB PATIENTS TO OVERCOME THE INEFECTIVENESS OF BREATH WAY CLEANING

Background: Inadequate airway clearance is one of the nursing issues that arises during the pulmonary tuberculosis disease process. If untreated, ineffective airway clearance can result in hypoxemia, decreased consciousness, and even cell death. Objective: The purpose of this study is to see that simple inhalation therapy can help pulmonary tuberculosis patients at the Banyu Urip Community Health Center to overcome ineffective airway clearance. Methods: The research methodology combines a case study approach with a family nursing process approach, with one case as the unit of analysis, Mrs. K, a pulmonary tuberculosis patient who get treatment at the Banyu Urip Community Health Center working area. Data was gathered through interviews, physical examinations, supporting examinations, and a literature review. In the study, 350 ml of hot water steam and 5 drops of eucalyptus oil were applied twice a day for three days, for 10-15 minutes. Result: The research results of simple inhalation therapy proved to have a positive effect on Mrs. K, as evidenced by a reduction in verbal complaints, including ease in driving out secretions, respiratory frequency was within normal limits, and breathing became easier, because the cineol content of eucalyptus oil has mucolytic, bronchodilator, and anti-inflammatory functions. Conclusion: To overcome airway ineffectiveness and improve health status, simple inhalation therapy combined with eucalyptus oil can be used as an alternative. Non-pharmacological techniques that are simple, easy to use but provide numerous benefits in health care facilities, such as simple inhalation therapy, are expected of health care workers.

Respiratory sinus arrhythmia in spontaneously breathing, unanesthetized newborn and adult Wistar rats

We examined respiratory sinus arrhythmia (RSA) and possible interaction with respiratory frequency (fR) and heart rate (HR) in spontaneously breathing, unanesthetized newborn Wistar rats (2- to 5-day-old; n = 54) and the adult rats (8-week-old; n = 34). Instantaneous heart rate (inst-HR) was calculated as the reciprocal of the inter-beat-interval. For each breath, RSA was determined as the difference between the maximum and minimum inst-HR value. The absolute RSA or RSA% (RSA per HR) were calculated as the average RSA of 10 consecutive breaths. RSA (or RSA%) in the newborn rats was significantly lower than that in the adult rats. Correlation coefficient between RSA (or RSA%) and 1/fR or HR/fR, but not HR, was significant in newborn rats, whereas only that between RSA (or RSA%) and HR was significant in adult rats. The power spectrum density of heartbeat fluctuation was detectable in both age groups. The present findings suggest that RSA exists and could be influenced by fR, rather than HR, in newborn rats.

Analysis of Nursing Clinical Practice with Chest Physiotherapy Innovation Intervention and Pronation Position on Airway Clearance in Pediatric Patients with Pneumonia in The Keruing Room

Introduction: Pneumonia is also known as "the forgotten killer of children". Based on the 2018 Riskesdas report, the age prevalence of pneumonia among children aged 1-5 years was 2.1%. The prevalence of pneumonia in toddlers and children based on gender characteristics was (2.1%) in males and (2.0%) in females. After observations and interviews in the Keruing room of Harapan Insan Sendawar Hospital, it was found that the innovative intervention of chest physiotherapy and pronation position to improve airway clearance in pediatric patients with pneumonia had never been carried out. Objective: The purpose of KIAN is to analyze the intervention of providing chest physiotherapy actions and pronation positions on improving airway clearance in pneumonia patients in the Keruing room. Methods: Sampling in this KIAN was selected according to the inclusion criteria desired by the researcher with a total sample size of five pneumonia clients. Results and Discussion: From the results of the study, it was found that the provision of chest physiotherapy and a pronated position had changes in secretion production, breath sounds, oxygen saturation (SPO2), pulse and respiratory frequency (RR) in the five patients. So that the intervention of chest physiotherapy innovation and a pronated position is very effective in dealing with airway cleansing in pediatric pneumonia patients. Conclusion: Chest physiotherapy intervention and pronation position can reduce secretion production and increase SPO2 in paediatric pneumonia patients

Impact of heat stress on blood physiological parameters, body temperature, respiratory frequency, antioxidant status, carcass quality, production performance, and egg quality of Japanese quails

The study was performed with three experiments. The first experiment studied respiratory rate (RR), body temperature (BT), blood physiological parameters (BPP), serum antioxidant enzyme activities (SAEA), and meat quality of 240 quails under three temperatures (38 °C, 25 °C, and environmental temperature 30 °C) and two bodyweights (heavy and lighter). Heat stress (HS) increased RR and BT of quails but had no effect on BPP; superoxide dismutase (SOD) activity was decreased in group 38 °C (P<0.05), and a trend of increasing glutathione peroxidase (GSH-Px) was also observed in group 38 °C (P=0.06); meat quality was not affected by HS except yellow index of meat color was increased (P<0.05). The second experiment was conducted with 168 quails (experiment 1) to record reproductive performance and egg quality. HS negatively affected feed intake, egg weight, egg height, albumen height, yolk weight, yolk color, and Haugh unit (P<0.05). The third experiment was performed to evaluate the effect of HS on growth and reproductive performance, and SAEA of the first generation (G1) from 84 quails (experiment 2). Feed intake, weight gain, and feed conversion ratio in the 38 °C H – G1 quail line were not significantly different from other groups. The higher egg weight and egg production were discovered in heat-stressed G1 groups. The lowest value of SOD and GSH-Px was reported in the 38 °C H – G1 quail line but no different in catalase (P>0.05). The 38 °C – G1 quail groups adapted to HS from G0 by expanding feed intake at the growing phase, improving egg weight and egg production, and maintaining the low SAEA.

Method of Extracting the Instantaneous Phases and Frequencies of Respiration from the Signal of a Photoplethysmogram

We propose for the first time a method for extracting the instantaneous phases of respiration from the signal of a photoplethysmogram (PPG). In addition to the instantaneous phases of respiration, this method allows for more accurately extracting the instantaneous frequencies of respiration from a PPG than other methods. The proposed method is based on a calculation of the element-wise product of the wavelet spectrum of a PPG and the sequence of intervals between the heartbeats extracted from a PPG, and a calculation of the skeleton of the resulting spectrum in the respiratory frequency range. It is shown that such an element-wise product makes it possible to extract the instantaneous phases and instantaneous frequencies of respiration more accurately than using the wavelet transform of a PPG signal or the sequence of the heartbeat intervals. The proposed method was verified by analyzing the signals from healthy subjects recorded during stress-inducing cognitive tasks. This method can be used in wearable devices for signal processing.

Influence of Respiratory Frequency of Slow-Paced Breathing on Vagally-Mediated Heart Rate Variability.

Breathing techniques, particularly slow-paced breathing (SPB), have gained popularity among athletes due to their potential to enhance performance by increasing cardiac vagal activity (CVA), which in turn can help manage stress and regulate emotions. However, it is still unclear whether the frequency of SPB affects its effectiveness in increasing CVA. Therefore, this study aimed to investigate the effects of a brief SPB intervention (i.e., 5min) on CVA using heart rate variability (HRV) measurement as an index. A total of 75 athletes (22 female; Mage = 22.32; age range = 19-31) participated in the study, attending one lab session where they performed six breathing exercises, including SPB at different frequencies (5 cycles per minute (cpm), 5.5cpm, 6cpm, 6.5cpm, 7cpm), and a control condition of spontaneous breathing. The study found that CVA was significantly higher in all SPB conditions compared to the control condition, as indexed by both root mean square of the successive differences (RMSSD) and low-frequency HRV (LF-HRVms2). Interestingly, LF-HRVms2 was more sensitive in differentiating the respiratory frequencies than RMSSD. These results suggest that SPB at a range of 5cpm to 7cpm can be an effective method to increase CVA and potentially improve stress management and emotion regulation in athletes. This short SPB exercise can be a simple yet useful tool for athletes to use during competitive scenarios and short breaks in competitions. Overall, these findings highlight the potential benefits of incorporating SPB into athletes' training and competition routines.

Hydrogen sulfide production in the medullary respiratory center modulates the neural circuit for respiratory pattern and rhythm generations

Hydrogen sulfide (H2S), which is synthesized in the brain, modulates the neural network. Recently, the importance of H2S in respiratory central pattern generation has been recognized, yet the function of H2S in the medullary respiratory network remains poorly understood. Here, to evaluate the functional roles of H2S in the medullary respiratory network, the Bötzinger complex (BötC), the pre-Bötzinger complex (preBötC), and the rostral ventral respiratory group (rVRG), we observed the effects of inhibition of H2S synthesis at each region on the respiratory pattern by using an in situ arterially perfused preparation of decerebrated male rats. After microinjection of an H2S synthase inhibitor, cystathionine β-synthase, into the BötC or preBötC, the amplitude of the inspiratory burst decreased and the respiratory frequency increased according to shorter expiration and inspiration, respectively. These alterations were abolished or attenuated in the presence of a blocker of excitatory synaptic transmission. On the other hand, after microinjection of the H2S synthase inhibitor into the rVRG, the amplitude of the inspiratory burst was attenuated, and the respiratory frequency decreased, which was the opposite effect to those obtained by blockade of inhibitory synaptic transmission at the rVRG. These results suggest that H2S synthesized in the BötC and preBötC functions to limit respiratory frequency by sustaining the respiratory phase and to maintain the power of inspiration. In contrast, H2S synthesized in the rVRG functions to promote respiratory frequency by modulating the interval of inspiration and to maintain the power of inspiration. The underlying mechanism might facilitate excitatory synaptic transmission and/or attenuate inhibitory synaptic transmission.

Effect of Acute and Cumulative Stress on Gene Expression in Mammary Tissue and Their Interactions with Physiological Responses and Milk Yield in Saanen Goats

This study addresses the hypothesis that different acute stressors can cumulatively decrease milk yield. In fact, in a time of global warming, the impact of environmental stress and farm management practices on milk production remains unclear. In this context, our objective was to investigate the effect of acute and cumulative stress on gene expression in mammary tissue and their interactions with physiological responses and milk yield in Saanen goats. Thirty lactating goats were subjected to two treatments: (1) control (CT), in which goats were maintained following a habitual routine under comfort conditions; (2) stress (ST), in which the goats were subjected to different types of environmental stress: heat stress, adrenocorticotropic hormone administration, hoof care management, and exposure to rain. These stressors were performed sequentially, with one stress per day on four consecutive lactation days, to evaluate their effect on milk quality and milk yield. Our results showed that compared to CT goats, cumulative stress increased the gene expression of glucocorticoid receptor (GR), interferon-gamma (IFN-γ), superoxide dismutase (SOD), and catalase (CAT) in mammary tissue, which are indicators of cortisol action, inflammatory response, and antioxidant enzymes. Furthermore, the acute challenges imposed on ST goats changed their rectal temperature and respiratory frequency and increased cortisol, glucose, cholesterol, triglycerides, and high-density lipoprotein release in plasma when compared to CT goats. Although these physiological and metabolic responses restore homeostasis, ST goats showed lower milk yield and higher somatic cell count in milk than CT goats. In conclusion, the results confirmed our initial hypothesis that different acute stressors cumulatively decrease the milk yield in Saanen goats.

Evaluation of Work Efficiency in Structural Firefighters.

Langford, EL, Bergstrom, HC, Lanham, S, Eastman, AQ, Best, S, Ma, X, Mason, MR, and Abel, MG. Evaluation of work efficiency in structural firefighters. J Strength Cond Res 37(12): 2457-2466, 2023-To perform occupational tasks safely and effectively, firefighters (FF) must work quickly and consume air provided by the self-contained breathing apparatus (SCBA) efficiently. However, most literature only factors work rate into performance, neglecting the inherent time limitation imposed by the SCBA. The purpose of this article was to (a) evaluate the reliability and variability in a "work efficiency" (WE) performance metric reflective of both work rate and air consumption; (b) explore the relationship between WE and established measures of metabolic strain; and (c) identify fitness, anthropometric, and demographic correlates of WE. About 79 structural FF completed an air consumption drill while breathing through an SCBA. Self-paced work duration and air consumption were entered into the WE equation. A subsample of FF (n = 44) completed another randomized trial while breathing through a portable gas analyzer. Anthropometric and fitness data were collected separately. Correlations were performed between WE vs. fitness, anthropometric, demographic, and metabolic outcomes. Multiple linear regression was used to identify the strongest predictors of WE. WE was reliable (intraclass correlation coefficient = 0.71) and yielded inter-FF variability {0.79 ± 0.25 ([lb·in-2·min]-1) × 104; coefficient of variation = 31.6%}. WE was positively correlated to oxygen consumption (V̇O2) (L·minute-1, mL·kg-1·minute-1) and tidal volume and negatively correlated to V̇E/V̇O2 and respiratory frequency. Height, upper-body endurance, and aerobic endurance were identified as the strongest predictors of WE (adjusted R2 = 0.59, RMSE = 0.16). WE is a reliable and occupationally relevant method to assess FF performance because it accounts for work rate and air consumption. Firefighters may enhance WE through a training intervention focused on improving metabolic tolerance, upper-body endurance, and aerobic endurance.

Physiological Response of Broiler Chicken To Cage Temperature

This study aims to study the physiological response shown by broiler chickens to cage temperatures at different times. A completely randomised design was used in this research, with three treatments and five replications of each. The treatments were the average temperature of the cage in the afternoon (30.15oC) , afternoon (27.04oC), and morning (26.01 °C). Each treatment was repeated six times, and each replication consisted of 5 chickens. The variables measured in this study are respiratory rate, heart rate, and rectal temperature in broiler chickens. If the results of the analysis of variance show that there is a significant difference between treatments, it is continued with the Duncan Multiple Range test. The results showed that the temperature of the cage during the day significantly increased the frequency of breathing of broiler chickens (74.90 times/minute), heart rate (279.50 times/minute), and rectal temperature (41.53 oC) compared to the frequency of breathing (57 times). ,27 times/minute and 55.77 times/minute), heart rate (274.07 times/minute and 272.47 times/minute), and rectal temperature (40.74oC and 40.61oC) In the afternoon and the morning, it can be concluded that the temperature of the cage during the day resulted in the frequency of breathing, heart rate and rectal temperature in broilers which were significantly higher than the temperature of the cell in the afternoon and morning, while the temperature of the cell in In the afternoon, the respiratory frequency, heart rate, and rectal temperature were not significantly higher than the cage temperature in the morning.

ANALYSIS OF STUDENTS’ MISCONCEPTION PROFILE ON HUMAN RESPIRATORY SYSTEM MATERIAL USING FOUR-TIER DIAGNOSTIC TEST

In science subjects, the material of the human respiratory system is widely misconceived by students. These students' misconceptions need to be identified because it may cause students to have difficulty connecting old concepts with new concepts. Based on this, a study was conducted to determine the students' misconception profile on the material of the respiratory system. This research method uses descriptive methods with a quantitative approach. This study involved 90 students of class VIII in Driyorejo District. The instrument used in this study was a four-tier diagnostic test with total 20 questions related to human respiratory system.. The results show that students in junior high schools in Driyorejo District experience 52% misconceptions which is categorized as moderate. Misconceptions occur in all concepts of respiratory system material with the highest percentage of misconceptions in the concept of respiratory frequency which is misconceived by 62% of SMP 5 YPM students.

Highly sensitive Ti3C2Tx MXenes-RGO humidity sensor for human non-contact respiratory monitoring

In this study, a highly sensitive and stable Ti3C2Tx MXenes-RGO humidity sensor was developed for real-time respiratory monitoring. Ti3C2Tx-RGO composite material increases the interlayer spacing of RGO, further expanding the channels for water molecule transport. Introduction of Ti3C2Tx promotes the generation of more -O, -OH, -F groups on the composite material surface, which can serve as adsorption sites for water molecules to improve response, and they form weak physical adsorption with water molecules, shortening the response and recovery time of the sensor. Ti3C2Tx-RGO composite material increases the interlayer spacing of RGO, further expanding the channels for water molecule transport. Density functional theory (DFT) calculation results indicate that Ti3C2Tx surface -F has higher adsorption energy for water molecules, which is beneficial for enhancing the sensitivity of the humidity sensor. Ti3C2Tx-RGO humidity sensor exhibits high sensitivity (22,117), low humidity hysteresis (1%), relatively short response/recovery time (7/16 s), and good stability and repeatability in the range of 11%− 95% RH. The sensor can also monitor changes in respiratory intensity and frequency, achieving real-time analysis of respiratory patterns, making it demonstrate strong application potential in non-contact human respiratory detection. This study provides new research ideas and methods for preparing high-performance humidity sensors.

Predicting Abnormal Respiratory Patterns in Older Adults Using Supervised Machine Learning on Internet of Medical Things Respiratory Frequency Data

Wearable Internet of Medical Things (IoMT) technology, designed for non-invasive respiratory monitoring, has demonstrated considerable promise in the early detection of severe diseases. This paper introduces the application of supervised machine learning techniques to predict respiratory abnormalities through frequency data analysis. The principal aim is to identify respiratory-related health risks in older adults using data collected from non-invasive wearable devices. This article presents the development, assessment, and comparison of three machine learning models, underscoring their potential for accurately predicting respiratory-related health issues in older adults. The convergence of wearable IoMT technology and machine learning holds immense potential for proactive and personalized healthcare among older adults, ultimately enhancing their quality of life.

Implementation of Deep Breath Relaxation Techniques As An Effort to Overcome Shortness Of Breath in Congestive Heart Failure Patients

Introduction: Congestive heart failure (CHF) is a cardiovascular disease that is defined as a deadly disease in the world. CHF is a condition in which the heart is unable to pump blood to meet the needs of oxygen and nutrients in the body's tissues. Objective: To present care with deep breathing relaxation interventions as an effort to overcome shortness of breath in congestive heart failure patients with ineffective breathing patterns. Method: The research design used is descriptive analysis with a case study approach. Subjects in this case study were adult patients with congestive heart failure (CHF) and ineffective breathing patterns. Data collection techniques include interviews, observation, physical examination, and documentation studies. Result: The case study at the assessment stage found that the client complained of shortness of breath. The intervention and implementation used to reduce shortness of breath is by providing breathing relaxation exercises for 10 minutes when complaints of shortness of breath are felt. After the intervention, the client's breathing frequency decreased from 28 x/minute to 22 x/minute, while the subjective data from the anamnesis showed that the client's shortness of breath was reduced. Conclusion: Nursing care for patients with congestive heart failure (CHF) and shortness of breath is well managed. Providing deep breathing relaxation interventions is effective in reducing respiratory frequency.

Effects of acute hypoxic post-feeding condition on respiratory metabolism and digestion in yellow catfish (Pelteobagrus fulvidraco)

In this study, acute hypoxia was applied to two states of yellow catfish (Pelteobagrus fulvidraco) (non-feeding and feeding) for 48 h. We investigated the effects of acute hypoxia on the respiratory metabolism and digestive ability of yellow catfish (mean body length: 7.61 ± 0.52 cm). The results indicated that the respiratory frequency of yellow catfish under acute hypoxic post-feeding condition was rapidly accelerated and the oxygen consumption rate was reduced. The level of succinate dehydrogenase in the gills first increased and then significantly decreased (p < 0.05) and the level of lactate dehydrogenase significantly increased (p < 0.05). When the expression level of hypoxia-inducing factor was significantly increased (p < 0.05), the downstream coding genes (hexokinase 1 (hk1), phosphofructokinase (pfkla), and pyruvate kinase M1/2a (pkma)), key molecules of glycolysis, and the activity of crucial enzymes (hexokinase, phosphofructokinase, and pyruvate kinase) increased. At the same time, the glucose level dropped and the lactic acid level increased, indicating that the metabolic mode in the gills of yellow catfish under acute hypoxic post-feeding condition gradually changed to anaerobic, and the anaerobic glycolysis process was activated to provide the required energy for the body. In addition, we found that the activity of digestive enzymes (trypsin, lipase, and amylase) and expression levels of digestive genes (trypsin, lipase, and amylase) were inhibited in the liver and intestine of yellow catfish under the acute hypoxic post-feeding condition, indicating that their digestive ability was reduced. This may adversely affect growth and development. This study analyzed the effects of acute hypoxic post-feeding exposure on the respiratory metabolism and digestive capacity of yellow catfish, providing new insights into fish physiology and sustainable fish culture.

The impact of diaphragmatic breathing on the endurance of contemporary dancers at the Institut Seni Budaya Indonesia Aceh: model-based experimental design

Managing dance movement elements is crucial for maintaining endurance and movement quality. The purpose of this study was to investigate the effects of applying diaphragmatic breathing on dancer endurance. The study employed a mixed-methods approach with an exploratory sequential design. The first phase, qualitative in nature, aimed to formulate hypotheses concerning the endurance issues faced by dancers in choreography courses. The second phase tested these hypotheses through experiments, incorporating control variables between two groups: Group 1, trained in dance movements using diaphragmatic breathing, and Group 2, solely trained in movements. The experiment took place at the Indonesian Institute of Cultural Arts in Aceh, with six female dancers enrolled in choreography classes randomly divided into two groups. None of the participants had prior experience with diaphragmatic breathing techniques while dancing. The study utilized a sphygmomanometer and oximetry for measurement. The endurance test involved dancing to a metronome for 5 minutes at tempos of 100, 110, and 120 without interruption. The results indicated that the respiratory frequency of dancers using diaphragmatic breathing was more stable compared to the group that did not employ this technique. These findings suggest that incorporating diaphragmatic breathing alternately while dancing can serve as a recommendation for maintaining dancers' endurance, particularly for students at the Indonesian Institute of Cultural Arts in Aceh.

Virtual reality hypnosis diminishes experimental cold pain and alters autonomic responses.

Immersive virtual reality (VR) is a promising tool to reduce pain in clinical setting. Digital scripts displayed by VR disposals can be enriched by several analgesic interventions, which are widely used to reduce pain. One of these techniques is hypnosis induced through the VR script (VRH) which is facilitated by immersive environment and particularly efficient even for low hypnotizable patients. The aim of this study is to assess the efficacy of a VRH script on experimentally induced cold pain perception (intensity and unpleasantness) and physiological expression. 41 healthy volunteers had been recruited in this within-subjects study. They received 9 stimulations of 20 s (3 non-nociceptive cold; 3 low nociceptive cold and 3 highly nociceptive cold) during a VRH session of 20 min (VRH condition) or without VRH (noVRH condition). Physiological monitoring during the cold pain stimulation protocol consisted of recording heart rate, heart rate variability and respiratory frequency. Maximum cold pain intensity perception, measured through the visual analog scale (VAS) on 10, was of 3.66 ± 1.84 (VAS score/10) in noVRH condition and 2.46 ± 1.54 in VRH (Wilcoxon, p < 0.0001). Considering pain unpleasantness perception, 3.68 ± 2.06 in noVRH and 2.21 ± 1.63 in VRH (Wilcoxon, p < 0.0001). Hypnotizability negatively correlated with the decrease in VAS intensity from noVRH to VRH (Spearman r = -0.45; p = 0.0038). In our sample, we found that 31/41 volunteers (75.6%) displayed a reduction of more than 10% of their VAS pain intensity and unpleasantness scores. Trait anxiety was the best predictor of the VRH responders, as well as heart rate variability. In addition, respiratory rate was diminished under VRH in every subgroup. VRH is an effective tool to reduced pain intensity and unpleasantness in a vast majority of healthy subjects. We further indicate in this study that heart rate variability parameter RMSSD (root mean square of successive differences) is a good predictor of this effect, as well as anxiety as a personality trait (but not state anxiety). Further studies are expected to determine more precisely to whom it will be the most useful to offer tailored, non-pharmacological pain management solutions to patients.