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Exposure therapy is a widely used treatment for patients with post-traumatic stress dis -order. It involves reduction of fear through progressive exposure to frightening stimuli in a therapeutic environment. Here we propose a new method designed to improve the effectiveness of exposure therapy. We hypothesized that device-guided breathing during exposure therapy can increase the capability of the patient to undergo effective exposure. The successful application of the method is described for a single patient. Using a device to slow and regularize breathing, the patient was calmed and experienced a greater sense of control and a profound effect of the exposure. The use of the breathing-guiding device is believed to reduce arousal level and excitability of sympathetic “fight-flight” behaviors. The present study suggests that device-guided breathing integrated with exposure therapy may provide a practically feasible and potentially promising non-pharmacological treatment after trauma.

This study was performed to confirm that autonomic nervous activity is affected by breathing speed. I hypothesized that prolonged expiratory breathing would promote parasympathetic dominance, whereas rapid breathing would promote sympathetic dominance. Ten healthy men, ages 21-28 years old, were instructed to perform prolonged expiratory breathing (6 seconds expiration, 4 seconds inspiration) after spontaneous breathing and rapid breathing (1 second expiration, 1 second inspiration) after spontaneous breathing; changes in high frequency (HF) and low frequency (LF)/HF of heart rate variability (HRV) were measured during each type of breathing. During prolonged expiratory breathing, parasympathetic nervous function was significantly activated. Conversely, during rapid breathing, parasympathetic nervous function was significantly suppressed. The HRV method assessing sympathetic and parasympathetic modulation in this study is an indirect, noninvasive method with clear limitations. The use of additional techniques should be considered to clarify the relationships between the breathing speed and the mind.

This chapter starts from the assertion that leading is a physically demanding activity. The challenges associated with it arise from at least three sources: as a response to ambiguous ‘wicked’ problems taking the lead necessitates moving into unknown situations; followers’ projections and the leader’s conscious or unconscious desire to fulfil them create psychological and emotional pressure and leaders often work in isolation. These realities of leading create physical stress that can result in disrupted sleep, digestive ailments and over-reliance on food and alcohol for short-term relief. Conscious breathing is introduced as a way of mitigating these physical effects. Such breathing can halt the vicious cycle of feeling stressed because one is breathing shallowly and breathing shallowly because of feeling stressed. Additionally, it can reduce the sense of time pressure by introducing an experience of greater spaciousness and provide a means whereby the leader can access her or his ‘best self’ in meeting the demands of the role. The ideas are illustrated through a case study of a senior executive who successfully used conscious breathing practices to transform the way in which he led his team.

Breathing resistance is the main factor that influences the wearing comfort of respirators. This paper aims to demonstrate the feasibility of using the gene expression programming (GEP) for the purpose of predicting subjective perceptions of breathing resistances of wearing respirators via surface electromyography (sEMG) and respiratory signals (RSP) sensors.

The authors developed a physiological signal monitoring system with a specific garment. The inputs included seven physical measures extracted from (RSP) and (sEMG) signals. The output was the subjective index of breathing resistances of wearing respirators derived from the category partitioning-100 scale with proven levels of reliability and validity. The prediction model was developed and validated using data collected from 30 subjects and 24 test combinations (12 respirator conditions × 2 motion conditions). The subjects evaluated 24 conditions of breathing resistances in repeated measures fashion.

The results show that the GEP model can provide good prediction performance (R² = 0.71, RMSE = 0.11). This study demonstrates that subjective perceptions of breathing resistance of wearing respirators on the human body can be predicted using the GEP via sEMG and RSP in real-time, at little cost, non-invasively and automatically.

This is the first paper suggesting that subjective perceptions of subjective breathing resistances can be predicted from sEMG and RSP sensors using a GEP model, which will remain helpful to the scientific community to start further human-centered research work and product development using wearable biosensors and evolutionary algorithms.

Stress damages us and our performance. It is a real part of most manager's experience and can be said to occur when significant demands exceed perceived management responsibilities and routines. Stress can be the essence of working life, and certainly need not always be damaging to us. But when it becomes excessive, it is something unwanted.

Investigating the subjective breathing resistance of wearing respirators requires a valid and reliable technique to measure breathing resistance. The purpose of this study is to test the validity and reliability of several rating scales and select the best for investigation of breathing resistance.

The authors designed three scales, that is, BRX scale, CP-100 scale and RVAS scale, and 30 subjects were separated into three groups, each group with a different scale. They sat for 5 min and walked for 5 min while wearing three models of respirators. After each trial, subjects were asked to complete subjective ratings of breathing resistance. Reliability was examined by the coefficient of Cronbach’s α, and validity was examined through content validity, discriminant validity and criterion validity. Generally, subjects were capable of reporting their sensation of breathing resistance by using the rating scale technique. However, the accuracy of rating strongly depended upon the properties of the scale.

The CP-100 scale was found to be highly reliable and most valid for rating subjective breath resistance. The validated CP-100 scale is very sensitive and accurate.

This is the first paper to select the best subjective scale for investigation of breathing resistance of respirators. The CP-100 scale will find wide applications in subjective breathing resistance evaluation for the use of respirators in industrial benchmarking activities. It will introduce the human factor engineering into the respirator manufacturing to improve the comfort of respirators.

The purpose of this paper is to investigate the effects of hydrogen humidity on the performance of air-breathing proton exchange membrane (PEM) fuel cells.

An efficient mathematical model for air-breathing PEM fuel cells has been built in MATLAB. The sensitivity of the fuel cell performance to the heat transfer coefficient is investigated first. The effect of hydrogen humidity is also studied. In addition, under different hydrogen humidities, the most appropriate thickness of the gas diffusion layer (GDL) is investigated.

The heat transfer coefficient dictates the performance limiting mode of the air-breathing PEM fuel cell, the modelled air-breathing fuel cell is limited by the dry-out of the membrane at high current densities. The performance of the fuel cell is mainly influenced by the hydrogen humidity. Besides, an optimal cathode GDL and relatively thinner anode GDL are favoured to achieve a good performance of the fuel cell.

The current study improves the understanding of the effect of the hydrogen humidity in air-breathing fuel cells and this new model can be used to investigate different component properties in real designs.

The hydrogen relative humidity and the GDL thickness can be controlled to improve the performance of air-breathing fuel cells.

To clarify the physiological and psychological effects of deep breathing, the effects of extreme prolongation of expiration breathing (Okinaga) were investigated using electroencephalogram (EEG) and electrocardiogram (ECG). Participants were five male Okinaga practitioners in their 50s and 60s. Participants performed Okinaga for 31 minutes while continuous EEG and ECG measurements were taken. After 16 minutes of Okinaga, and until the end of the session, the percentages of theta and alpha 2 waves were significantly higher than at baseline. After 20 minutes, and until the end of the session, the percentage of beta waves was significantly lower than at baseline. The high frequency component of heart rate variability was significantly lower after 12 minutes of Okinaga and lasted until 23 minutes. The low frequency/high frequency ratio was significantly lower after 18 minutes of Okinaga and until the end of the session. Okinaga produced relaxation, suggesting that deep breathing may relieve anxiety. However, study limitations include potential ambiguity in the interpretation of the low frequency/high frequency ratio, the small sample, and the fact that EEG was measured only on the forehead.

THE partial pressure of the oxygen content in the atmosphere decreases directly with the atmospheric pressure, i.e., with the altitude, the proportion of oxygen in the atmosphere (about 20·9 per cent) remaining practically constant in the substratosphere.