Letter to the Editor Regarding "Instrumental Assessment of Aero-Resistive Expiratory Muscle Strength Rehabilitation Devices".

This Letter to the Editor was created in response to the article titled, "Instrumental Assessment of Aero-Resistive Expiratory Muscle Strength Rehabilitation Devices" by Dietsch et al. (2024). The article aims to compare six expiratory muscle strength training (EMST) devices and investigates their minimum trigger pressure, variability across the settings, and stability. The models tested include five positive expiratory pressure (PEP) devices, Acapella, TheraPEP, Threshold PEP, EMST75, and EMST150. It also includes a combined inspiratory and expiratory muscle training device, the Breather. We have several concerns about the integrity of results presented regarding the Breather as presented in the article. These include the heterogeneity of device sample used, as well as inadequate methodology and the experimental setup.

The Training to Improve Dyspnoea Study- Patient Experiences of Using a High Frequency Airway Oscillating Device.

Introduction: The High Frequency Airway Oscillating device (HFAO) was developed to help patients with COPD feel less breathless through flow resistive respiratory muscle training and fixed rate oscillations. Previous work has demonstrated that this device can improve inspiratory muscle strength over and above a sham device. Both groups improved their breathlessness and preserved clinical benefits though there were no statistically significant differences seen over and above the sham device. It is important to understand patient perceptions of using a device and how this may influence their treatment and therefore a qualitative analysis was conducted to understand participant experiences of a HFAO device. Methods: This was an exploratory qualitative analysis involving participants recruited to the Training to Improve Dyspnoea (TIDe) study. Participants completed a satisfaction survey and were invited to take part in a focus group. Focus groups were conducted by a researcher independent to the randomised controlled trial. Data was analysed independently by two researchers using inductive thematic analysis, and themes/sub-themes were agreed jointly. Data is presented in themes and sub themes and triangulated with survey response data. Results: Fourteen participants were recruited to two focus groups (71% male, mean [SD] age 64[9] years). The key themes were patient selection, device use, and investment. Patient selection explores the disease characteristics, emotional impact and management of care. Device use explores the device prescription and usage, routine and lifestyle and effectiveness. Investment covers accessibility, understanding, benefits vs participation and overall perceptions of the device. Conclusion: This research demonstrates the complexity of device interventions and that key considerations should be given to patient selection, the device use itself and, the time and cost investment required for participants to successfully implement the device into daily life.

Evaluation of Autonomic Nervous System Function During Sleep by Mindful Breathing Using a Tablet Device: Randomized Controlled Trial.

BACKGROUND: One issue to be considered in universities is the need for interventions to improve sleep quality and educational systems for university students. However, sleep problems remain unresolved. As a clinical practice technique, a mindfulness-based stress reduction method can help students develop mindfulness skills to cope with stress, self-healing skills, and sleep. OBJECTIVE: We aim to verify the effectiveness of mindful breathing exercises using a tablet device. METHODS: In total, 18 nursing students, aged 18-22 years, were randomly assigned and divided equally into mindfulness (Mi) and nonmindfulness (nMi) implementation groups using tablet devices. During the 9-day experimental period, cardiac potentials were measured on days 1, 5, and 9. In each sleep stage (sleep with sympathetic nerve dominance, shallow sleep with parasympathetic nerve dominance, and deep sleep with parasympathetic nerve dominance), low frequency (LF) value, high frequency (HF) value, and LF/HF ratios obtained from the cardiac potentials were evaluated. RESULTS: On day 5, a significant correlation was observed between sleep duration and each sleep stage in both groups. In comparison to each experimental day, the LF and LF/HF ratios of the Mi group were significantly higher on day 1 than on days 5 and 10. LF and HF values in the nMi group were significantly higher on day 1 than on day 5. CONCLUSIONS: The correlation between sleep duration and each sleep stage on day 5 suggested that sleep homeostasis in both groups was activated on day 5, resulting in similar changes in sleep stages. During the experimental period, the cardiac potentials in the nMi group showed a wide range of fluctuations, whereas the LF values and LF/HF ratio in the Mi group showed a decreasing trend over time. This finding suggests that implementing mindful breathing exercises using a tablet device may suppress sympathetic activity during sleep. TRIAL REGISTRATION: UMIN-CTR Clinical Trials Registry UMIN000054639; https://tinyurl.com/mu2vdrks.

Feasibility of a portable respiratory training system with a gyroscope sensor.

OBJECTIVES: A portable respiratory training system with a gyroscope sensor (gyroscope respiratory training system [GRTS]) was developed and the feasibility of respiratory training was evaluated. METHODS: Simulated respiratory waveforms from a respiratory motion phantom and actual respirator waveforms from volunteers were acquired using the GRTS and Respiratory Gating for Scanners system (RGSC). Respiratory training was evaluated by comparing the stability and reproducibility of respiratory waveforms from patients undergoing expiratory breath-hold radiation therapy, with and without the GRTS. The stability and reproducibility of respiratory waveforms were assessed by root mean square error and gold marker placement-based success rate of expiratory breath-hold, respectively. RESULTS: The absolute mean difference for sinusoidal waveforms between the GRTS and RGSC was 2.0%. Among volunteers, the mean percentages of errors within ±15% of the respiratory waveforms acquired by the GRTS and RGSC were 96.1% for free breathing and 88.2% for expiratory breath-hold. The mean root mean square error and success rate of expiratory breath-hold (standard deviation) with and without the GRTS were 0.65 (0.24) and 0.88 (0.89) cm and 91.0% (6.9) and 89.1% (11.6), respectively. CONCLUSIONS: Respiratory waveforms acquired by the GRTS exhibit good agreement with waveforms acquired by the RGSC. Respiratory training with the GRTS reduces inter-patient variability in respiratory waveforms, thereby improving the success of expiratory breath-hold radiation therapy. ADVANCES IN KNOWLEDGE: A respiratory training system with a gyroscope sensor is inexpensive and portable, making it ideal for respiratory training. This is the first report concerning clinical implementation of a respiratory training system.

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.

Effectiveness of expiratory flow acceleration in patients with Parkinson's disease and swallowing deficiency: A preliminary study.

OBJECTIVES: Parkinson's disease (PD) causes dysfunction both to swallowing and to the cough mechanism. Oropharyngeal dysphagia is the main cause of pneumonia, due to silent aspiration of food and saliva. Pneumonia is the leading cause of death in PD. Different strategies exist to reduce the risk of inhalation and associated lung infections, but evidence of their efficacy is still unclear. The aim of this preliminary study was to investigate if adding an expiratory flow acceleration (EFA®) technique to standard therapy (ST) for dysphagia can reduce the incidence of bronchopulmonary infections and improve quality of life, respiratory function parameters, cough, and airways encumbrance perception. MATERIALS AND METHODS: Twenty-five patients with PD were randomized to two groups: ST vs. ST + EFA. Patients were re-assessed at 30, 180 and 360 days from start of treatment. The primary outcome was the incidence of respiratory exacerbations together with quality of life score (PDQ-39). Secondary outcomes were changes in respiratory function tests, cough capacity (CPEF), perceived health status (Euro-QOL-VAS), cough, and upper airways encumbrance perception evaluated by visual numeric scale (VNS). RESULTS: Twenty patients concluded the study (10 each group). Albeit the difference was not significant, less respiratory infections, symptoms, hospital admissions and medical visits were found in the study group. Furthermore, there was a significant difference in cough effectiveness measured with the peak cough expiratory flow (PCEF) and other spirometry parameters (FEV1, FVC), and also in specific and generic health-related quality of life measures (PDQ-39, Euro-QoL-VAS). CONCLUSION: The results of this preliminary study support the use of EFA® technology in Parkinson's patients with dysphagia to reduce the risk of respiratory complications. Nevertheless, further studies are needed in a larger, more representative sample to definitively confirm the usefulness of this technique in PD patients.

Effects of a Rehabilitation Programme with a Nasal Inspiratory Restriction Device on Exercise Capacity and Quality of Life in COPD.

OBJECTIVE: The objective was to assess the effects of a nasal restriction device for inspiratory muscle training, called Feelbreathe®, added to a rehabilitation program (RP) on exercise capacity, quality of life, dyspnea and inspiratory muscle strength in patients with stable COPD. METHODS: Patients were randomized into three groups, one performed a supervised RP using the Feelbreathe® device (FB group), the second group developed the same RP with oronasal breathing without FB (ONB group) and the third was the control group (CG). We evaluated inspiratory muscle strength (PImax), dyspnea (mMRC), quality of life (CAT) and exercise capacity (6MWT) before and after 8-week of RP. RESULTS: A total of 16 patients completed the study, seven in FB group, five in ONB group and four in the CG. After the RP, the FB group showed a significant increase in PImax (93.3 ± 19.1 vs. 123.0 ± 15.8 mmHg) and in the 6MWT distance (462.9 ± 71.8m vs. 529.1 ± 50.1 m) and a decrease in the CAT score (9.7 ± 6.5 vs. 5.9 ± 6.0) and in the mMRC dyspnea score. FB provides greater improvement in PImax, dyspnea, quality of life and 6MWT than ONB. CONCLUSIONS: The Feelbreathe® device provides greater improvements in quality of life, dyspnea, exercise capacity and inspiratory muscle strength compared to patients that did not use it.

Respiratory Muscle Training Improves Functional Outcomes and Reduces Fatigue in Patients with Myasthenia Gravis: A Single-Center Hospital-Based Prospective Study.

BACKGROUND: Myasthenia gravis (MG) is an immune-mediated disorder characterized by muscle fatigue and fluctuating weakness. Impairment in respiratory strength and endurance has been described in patients with generalized MG. We tested the hypothesis that respiratory muscle training (RMT) can improve functional outcomes and reduce fatigue in patients with MG. METHODS: Eighteen patients with mild to moderate MG participated in this study. The training group underwent home-based RMT three times a week for 12 weeks. Sixteen patients with MG without RMT were enrolled as a disease control group. Lung function, autonomic testing, Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), and functional outcome measurement by using quantitative myasthenia gravis (QMG) score and myasthenia gravis composite (MGC) scale were measured before and after the 12-week RMT. RESULTS: The 12-week RMT significantly increased forced vital capacity (FVC) from 77.9 ± 12.6% to 83.8 ± 17.7% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (p = 0.03), forced expiratory volume in one second (FEV1) from 75.2 ± 18.3% to 83.3 ± 19.0% (. CONCLUSION: The home-based RMT is an effective pulmonary function training for MG patients. The RMT can not only improve short-term outcomes but also reduce fatigue in patients with mild to moderate generalized MG.

A Randomized Controlled Trial of Device Guided, Slow-Paced Respiration in Women with Overactive Bladder Syndrome.

PURPOSE: We evaluated the effects of device guided, slow-paced respiration on urgency associated urinary symptoms, perceived stress and anxiety, and autonomic function in women with overactive bladder syndrome. MATERIALS AND METHODS: We performed a randomized, parallel group trial of slow-paced respiration to improve perceived stress and autonomic dysfunction as potential contributors to overactive bladder. Ambulatory women who reported at least 3 voiding or incontinence episodes per day associated with moderate to severe urgency were randomized to use a portable biofeedback device to practice daily, slow, guided breathing exercises or a control device which appeared identical and was reprogrammed to play music without guiding breathing. During 12 weeks we evaluated changes in urinary symptoms by voiding diaries, perceived stress and anxiety by validated questionnaires, and autonomic function by heart rate variability and impedance cardiography. RESULTS: In the 161 randomized participants, including 79 randomized to paced respiration and 82 randomized to the control group, the average ± SD baseline frequency of voiding or incontinence associated with moderate to severe urgency was 6.9 ± 3.4 episodes per day. Compared to controls the participants randomized to paced respiration demonstrated greater improvement in perceived stress (average Perceived Stress Scale score decrease 2.8 vs 1.1, p=0.03) but not in autonomic function markers. During 12 weeks the average frequency of voiding or incontinence associated with moderate to severe urgency, which was the study primary outcome, decreased by a mean of 0.9 ± 3.2 episodes per day but no significant between group difference was detected. CONCLUSIONS: Among women with overactive bladder slow-paced respiration was associated with a modest improvement in perceived stress during 12 weeks. However, it was not superior to a music listening control for reducing urinary symptoms or changing autonomic function.

Observation of the curative effect of device-guided rehabilitation on respiratory function in stable patients with chronic obstructive pulmonary disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a serious lung disease for individuals in middle age and especially in old people. The study was aimed to observe the curative effect of device-guided rehabilitation on respiratory functions in stable COPD patients. METHODS: Sixty-seven stable COPD patients were enrolled and assigned to the experiment group (n = 36) and the control group (n = 31). The conventional pulmonary rehabilitation treatments, including pursed lips breathing (PLB) and abdominal breathing training, were applied in the control group. Respiratory muscle training of the experiment group was performed using the respiratory endurance training device combined with traditional techniques. Both groups were assessed by 6-minute walk test (6MWT), COPD assessment test (CAT), body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index. Besides, the pulmonary function (FVC%, FEVl%) were measured at 6 months before and after treatment. RESULTS: After treatment, the 6MWT, CAT, BODE index were significantly increased compared with pre-treatment in both groups (P < .01), but not FVC% and FEVl%. Compared with the control group, the combination therapy in the experiment group could significantly improve the 6MWT (P = .0094), CAT (P = .0071) and BODE index (P = .0064) as well as the changes of 6MWT (P < .01), CAT (P < .01), and BODE index (P < .01) before and after treatment. CONCLUSIONS: The traditional respiratory training combined with device-guided pulmonary rehabilitation can improve the respiratory muscle function and athletic ability in stable COPD patients.

Self-Care System for Family Caregivers of Cancer Patients Using Resonant Breathing with a Portable Home Device: A Randomized Open-Label Study.

BACKGROUND: Self-care systems for early-stage specialist palliative care for cancer patients and their family caregivers have received much attention recently. Resonant breathing is an established method for maximizing heart rate variability (HRV), but it has not been implemented for home self-care. OBJECTIVE: We aimed to examine the usefulness and ease of implementation for family caregivers to administer resonant breathing using a portable device at home. DESIGN: We divided caregivers into two groups-a home self-care group and a control group-and we conducted a randomized open-label study, with rate of change in HRV being the primary outcome. SETTING/SUBJECTS: We administered HRV biofeedback (HRV-BF) using resonant breathing to 54 family caregivers who felt burdened by their nursing care responsibilities. RESULTS: Among the self-care group, 92.6% of participants completed the study in their homes; 28 days after intervention initiation, the resonant breathing implementation rate at home was 86.1%. There was an interaction between time course and grouping in our HRV comparisons: the change rate in the home self-care group was higher during HRV-BF than before HRV-BF. CONCLUSIONS: Because family caregivers in our study learned to quickly administer resonant breathing using a portable device at home, resonant breathing improved rapidly, along with autonomic nerve function and quality of life.

Preliminary study: comparative effects of lung volume therapy between slow and fast deep-breathing techniques on pulmonary function, respiratory muscle strength, oxidative stress, cytokines, 6-minute walking distance, and quality of life in persons with COPD.

BACKGROUND: Lung volume therapy with the Voldyne® device can improve lung volume and has a nonsignificant benefit on respiratory muscle strength via the slow deep-breathing technique (SDBT); whereas respiratory muscle training with a respiratory muscle trainer via the fast deep-breathing technique (FDBT) has produced a significant improvement in people with COPD. Thus, the aim of this study was to compare the efficiency of lung volume therapy with the Voldyne® device with the SDBT and FDBT on pulmonary function, respiratory muscle strength, oxidative stress, cytokines, walking capacity, and quality of life (QoL) in people with COPD. METHODS: A total of 30 COPD patient volunteers with mild (stage I) to moderate (stage II) severity were randomized into two groups: SDBT (n=15) and FDBT (n=15). Pulmonary function (FVC, FEV1, and FEV1/FVC), maximal inspiratory mouth pressure (PImax), oxidative stress status (total antioxidant capacity [TAC], glutathione [GSH], malondialdehyde [MDA], and nitric oxide [NO]), inflammatory cytokines (tumor necrosis factor-alpha [TNF-α] and IL-6), 6-minute walking distance (6MWD), and total clinical COPD questionnaire (CCQ) score were evaluated before and after 4 weeks of training. RESULTS: All the parameters had no statistical difference between the groups before training. The PImax, TAC, IL-6, total QoL score, and 6MWD changed significantly in the SDBT group after the 4-week experiment as compared to those in the pre-experimental period, whereas FVC, FEV1, FEV1%, FEV1/FVC%, PImax, TAC, MDA, NO, TNF-α, IL-6, 6MWD, and total CCQ score changed significantly in the FDBT group as compared to those in the pre-experimental period. The FEV1%, PImax, TNF-α, IL-6, and total CCQ score differed significantly in the FDBT group in the post-experimental period as compared to those in the SDBT group. CONCLUSION: This preliminary study concluded that the application of incentive spirometry with the Voldyne® device via fast deep breathing possibly improved respiratory muscle strength and QoL and reduced inflammatory cytokines, MDA, and NO better than that via slow deep breathing among people with COPD.

Design, Development, and Characterization of BreathForce: A Respiratory Training System for Patients with Spinal Cord Injuries.

In this effort, we report the development of a portable inspiratory-expiratory training device for use in rehabilitation of participants with cardiovascular and respiratory motor deficits. The device uses existing airway restriction components to establish a manually adjustable respiratory training apparatus and includes an integrated pressure sensor with custom software to direct and track therapy sessions. The battery-powered system promotes proven rehabilitation methodologies performed at the clinic in a platform to be translated to the home for participants with spinal cord injuries.

A Pilot Study of Inspiratory Muscle Training to Improve Exercise Capacity in Patients with Fontan Physiology.

While the Fontan procedure has improved life expectancy, patients with single ventricle physiology have impaired exercise capacity due to limited increase in pulmonary blood flow during activity. Enhancing the "thoracic pump" using inspiratory muscle training (IMT) may ameliorate this impairment. Adult nonsmokers with Fontan physiology were recruited through Boston Children's Hospital's outpatient clinic. Participants underwent cardiopulmonary exercise testing and pulmonary function testing, followed by 12 weeks of IMT and then repeat testing. The primary endpoint was change in % predicted peak oxygen consumption (VO2). Secondary endpoints were changes in other exercise metrics. Eleven patients (6 male) were enrolled. Median ages at time of enrollment and Fontan completion were 28.8 years (25.7, 45.5) and 7.8 years (3.9, 16.5), respectively. Average baseline maximal inspiratory pressure (MIP) was normal; only 2 patients had MIP <70% predicted. Peak work rate improved significantly from baseline after 12 weeks of IMT (116.5 ± 45.0 to 126.8 ± 47.0 W, P = 0.019). Peak VO2 tended to improve (baseline 68.1 ± 14.3, change + 5.3 ± 9.6% predicted, P = 0.12), as did VE/VCO2 slope (34.1 ± 6.7 to 31.4 ± 3.6, P = 0.12). There was no change in peak tidal volume or MIP. In a small cohort of Fontan patients with mostly normal MIP, IMT was associated with significant improvement in peak work rate and a trend toward higher peak VO2 and improved ventilatory efficiency. Larger studies are needed to determine if this reflects true lack of effect or whether this pilot study was underpowered for effect size, and whether IMT is more narrowly useful for patients with impaired MIP.

Effect of a Respiratory Training Program Using Wind Instruments on Cardiopulmonary Function, Endurance, and Quality of Life of Elderly Women.

BACKGROUND Physical changes due to aging lead to weakening of respiratory muscles and decreased lung functions that result in increasing risk of chronic respiratory disease. A complex respiratory rehabilitation program is needed to prevent respiratory diseases and improve lung functions and quality of life. The purpose of the present study was to examine the effects of respiratory training programs on pulmonary functions, cardiovascular endurance, and quality of life in elderly women. MATERIAL AND METHODS The program was structured with respiration exercise and playing wind musical instruments for 10 weeks (n=13) and 5 weeks (n=16), respectively, for elderly women in 2 different community welfare centers. The program consisted of breathing exercises twice a week, 20 min per session, and 40 min of wind instrumentation. Effects were assessed using forced vital capacity (FVC), forced expiratory volume-one second (FEV1), FEV1/FVC ratio (FEV1%), maximum voluntary ventilation (MVV), 6-minute walk test (6MWT), modified Borg scale (MBS), and life satisfaction scale (LSS). RESULTS The 10-week program group (10WPG) showed significant differences in FVC, MVV, 6MWT, MBS, and LSS before and after interventions (p<.05), and the 5-week program group (5WPG) showed significant differences in FVC and 6MWT. MVV, MBS, and LSS were not significantly different between the 2 groups (p<.05). CONCLUSIONS This study confirms that the long-term respiration training program has positive effects on pulmonary functions, cardiopulmonary endurance, and quality of life. Various respiratory training programs and long-term implementations are needed to prevent respiratory illness and to improve lung functions and quality of life of respiratory patients.

Effects of inspiratory muscle training in COPD patients: A systematic review and meta-analysis.

OBJECTIVES: In chronic obstructive pulmonary disease (COPD), quality of life and exercise capacity are altered in relationship to dyspnea. Benefits of inspiratory muscle training (IMT) on quality of life, dyspnea, and exercise capacity were demonstrated, but when it is associated to pulmonary rehabilitation (PR), its efficacy on dyspnea is not demonstrated. The aim of this systematic review with meta-analysis was to verify the effect of IMT using threshold devices in COPD patients on dyspnea, quality of life, exercise capacity, and inspiratory muscles strength, and the added effect on dyspnea of IMT associated with PR (vs. PR alone). STUDY SELECTION: This systematic review and meta-analysis was conducted on the databases from PubMed, Science direct, Cochrane library, Web of science, and Pascal. Following key words were used: inspiratory, respiratory, ventilatory, muscle, and training. The searching period extended to December 2017. Two reviewers independently assessed studies quality. RESULTS: Forty-three studies were included in the systematic review and thirty-seven studies in the meta-analysis. Overall treatment group consisted of six hundred forty two patients. Dyspnea (Baseline Dyspnea Index) is decreased after IMT. Quality of life (Saint George's Respiratory Questionnaire), exercise capacity (6 min walk test) and Maximal inspiratory pressure were increased after IMT. During PR, no added effect of IMT on dyspnea was found. CONCLUSION: IMT using threshold devices improves inspiratory muscle strength, exercise capacity and quality of life, decreases dyspnea. However, there is no added effect of IMT on dyspnea during PR (compared with PR alone).

Acute effects of device-guided slow breathing on sympathetic nerve activity and baroreflex sensitivity in posttraumatic stress disorder.

Patients with posttraumatic stress disorder (PTSD) have elevated sympathetic nervous system reactivity and impaired sympathetic and cardiovagal baroreflex sensitivity (BRS). Device-guided slow breathing (DGB) has been shown to lower blood pressure (BP) and sympathetic activity in other patient populations. We hypothesized that DGB acutely lowers BP, heart rate (HR), and improves BRS in PTSD. In 23 prehypertensive veterans with PTSD, we measured continuous BP, ECG, and muscle sympathetic nerve activity (MSNA) at rest and during 15 min of DGB at 5 breaths/min ( n = 13) or identical sham device breathing at normal rates of 14 breaths/min (sham; n = 10). Sympathetic and cardiovagal BRS was quantified using pharmacological manipulation of BP via the modified Oxford technique at baseline and during the last 5 min of DGB or sham. There was a significant reduction in systolic BP (by -9 ± 2 mmHg, P < 0.001), diastolic BP (by -3 ± 1 mmHg, P = 0.019), mean arterial pressure (by -4 ± 1 mmHg, P = 0.002), and MSNA burst frequency (by -7.8 ± 2.1 bursts/min, P = 0.004) with DGB but no significant change in HR ( P > 0.05). Within the sham group, there was no significant change in diastolic BP, mean arterial pressure, HR, or MSNA burst frequency, but there was a small but significant decrease in systolic BP ( P = 0.034) and MSNA burst incidence ( P = 0.033). Sympathetic BRS increased significantly in the DGB group (-1.08 ± 0.25 to -2.29 ± 0.24 bursts·100 heart beats-1·mmHg-1, P = 0.014) but decreased in the sham group (-1.58 ± 0.34 to -0.82 ± 0.28 bursts·100 heart beats-1·mmHg-1, P = 0.025) (time × device, P = 0.001). There was no significant difference in the change in cardiovagal BRS between the groups (time × device, P = 0.496). DGB acutely lowers BP and MSNA and improves sympathetic but not cardiovagal BRS in prehypertensive veterans with PTSD. NEW & NOTEWORTHY Posttraumatic stress disorder is characterized by augmented sympathetic reactivity, impaired baroreflex sensitivity, and an increased risk for developing hypertension and cardiovascular disease. This is the first study to examine the potential beneficial effects of device-guided slow breathing on hemodynamics, sympathetic activity, and arterial baroreflex sensitivity in prehypertensive veterans with posttraumatic stress disorder.

Earable ZEN: Development of an Earphone-Type Zazen Support Wearable System.

Meditation has been included in mental health care and the treatment of hypertension and pain. Zazen is a method of entering the meditative state. We have carried out R&D on a wearable system (earable ZEN) that casually and simply allows the subject to perform zazen without going to a temple or even having a zazen monitor present. In zazen, it is important to prepare one's breathing and posture. The earable ZEN is comprised of an earphone-type sensor (ear sensor) for measuring the breathing and posture of the user, a miniature actuator (neck belt) for communicating disturbances in the breathing and posture of the user, and a microcomputer. In an evaluation experiment, disturbance in breathing was simulated as "deep mouth breathing" and disturbance in posture was simulated as "nodding". The average accuracy value for seven healthy subjects wearing the earable ZEN was 99.9% for mouth breathing and 100% for nodding. In the same way, the average precision value was 98.7% for mouth breathing and 100% for nodding, with an average recall value of 97.1% for mouth breathing and 100% for nodding. None of the subjects considered the ear sensor and neck belt to be an obstacle to zazen.

Simple artificial training device for respiratory muscle strength and lung volumes in healthy young male and female subjects: A pilot study.

OBJECTIVE: The aim of this study was to evaluate the efficiency of a simple artificial device for respiratory muscle strength training and lung volumes using either combined or non-combined exercise with elastic bands in healthy young participants. METHODS: Forty healthy young participants (20 male and 20 female) aged 19-24 years old were randomized into two main experiments with four sub-groups; (1) artificial device (n = 10) & standard device (n = 10) training, and (2) artificial device training combined with elastic band (EB) exercise (n = 10) & standard device training combined with EB (n = 10) exercise. Respiratory muscle strength with maximal peak inspiratory pressure (PImax), and lung volumes; tidal volume (TV), inspiratory reserve volume (IRV), expiratory reserve volume (ERV) and vital capacity (VC) were evaluated before and after training once daily for 3 weeks. Moreover, the peak dyspnea score and vital sign parameters were compared between the experimental groups after final training. RESULTS: All parameters had no statistical differences (p > 0.5) between the training devices alone and those combined with EB exercise prior to any experiments. Results from the first experiment showed that training with an artificial device increased all parameters (PImax, VC, IRV, ERV) significantly (p < 0.05), except for TV, when compared to pre training results, which were the same as those in the standard device training group. No statistical difference was shown between these groups after the training period had been performed. Furthermore, results of applying artificial device training combined with EB exercise showed a significant increase in all parameters, except for TV, and they were the same as the increased results in training with the standard device combined with EB exercise. There was no significant difference of data between these groups after the training period. Finally, the results of peak dyspnea score and all vital sign parameters from using the artificial device, with or without EB exercise, showed no statistical difference when compared to use of the standard device. CONCLUSION: This study proposed that a simple artificial device can be used to train the respiratory muscle with or without elastic band exercise in healthy young subjects.

Effects of a simple prototype respiratory muscle trainer on respiratory muscle strength, quality of life and dyspnea, and oxidative stress in COPD patients: a preliminary study.

BACKGROUND: The aim of this study was to evaluate the efficiency of a simple prototype device for training respiratory muscles in lung function, respiratory muscle strength, walking capacity, quality of life (QOL), dyspnea, and oxidative stress in patients with COPD. METHODS: Thirty COPD patients with moderate severity of the disease were randomized into three groups: control (n=10, 6 males and 4 females), standard training (n=10, 4 males and 6 females), and prototype device (n=10, 5 males and 5 females). Respiratory muscle strength (maximal inspiratory pressure [PImax] and maximal expiratory pressure [PEmax]), lung function (forced vital capacity [FVC], percentage of FVC, forced expiratory volume in 1 second [FEV1], percentage of FEV1 [FEV1%], and FEV1/FVC), 6-minute walking distance (6MWD), QOL, and oxidative stress markers (total antioxidant capacity [TAC]), glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) were evaluated before and after 6 weeks of training. Moreover, dyspnea scores were assessed before; during week 2, 4, and 6 of training; and at rest after training. RESULTS: All parameters between the groups had no statistical difference before training, and no statistical change in the control group after week 6. FVC, FEV1/FVC, PImax, PEmax, QOL, MDA, and NO showed significant changes after 6 weeks of training with either the standard or prototype device, compared to pre-training. FEV1, FEV1%, 6MWD, TAC, and GSH data did not change statistically. Furthermore, the results of significant changes in all parameters were not statistically different between training groups using the standard and prototype device. The peak dyspnea scores increased significantly in week 4 and 6 when applying the standard or prototype device, and then lowered significantly at rest after 6 weeks of training, compared to pre-training. CONCLUSION: This study proposes that a simple prototype device can be used clinically in COPD patients as a standard device to train respiratory muscles, improving lung function and QOL, as well as involving MDA and NO levels.