Outdoor breathing trials with simulated avalanche snow are fundamental for the research of the gas exchange under avalanche snow, which supports the development of the international resuscitation guidelines. However, these studies have to face numerous problems, including unstable weather and variable snow properties. This pilot study examines a mineral material perlite as a potential snow model for studies of ventilation and gas exchange parameters. Thirteen male subjects underwent three breathing phases-into snow, wet perlite and dry perlite. The resulting trends of gas exchange parameters in all tested materials were similar and when there was a significant difference observed, the trends in the parameters for high density snow used in the study lay in between the trends in dry and wet perlite. These findings, together with its stability and accessibility year-round, make perlite a potential avalanche snow model material. Perlite seems suitable especially for simulation and preparation of breathing trials assessing gas exchange under avalanche snow, and potentially for testing of new avalanche safety equipment before their validation in real snow.The study was registered in ClinicalTrials.gov on January 22, 2018; the registration number is NCT03413878.
- MeSH
- dospělí MeSH
- dvojitá slepá metoda MeSH
- dýchání * MeSH
- kardiopulmonální resuscitace metody MeSH
- klinické křížové studie MeSH
- laviny * MeSH
- lidé MeSH
- mladý dospělý MeSH
- oxid hlinitý * MeSH
- oxid křemičitý * MeSH
- pilotní projekty MeSH
- prospektivní studie MeSH
- sníh * MeSH
- teoretické modely MeSH
- tréninková simulace MeSH
- výměna plynů v plicích fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
- Geografické názvy
- Česká republika MeSH
Terrain experiments for avalanche survival research require appropriate snow conditions, which may not be available year round. To prepare these experiments and test the protocol, it might be advantageous to test them in a laboratory with a snow model. The aim of the study was to find a material that can be used to simulate snow for studying gas exchange of a person covered with avalanche snow. Three loose porous materials (perlite, wood shavings and polystyrene) were tested in two forms—dry and moisturized. Each volunteer underwent six phases of the experiment in random order (three materials, each dry and moisturized) during experimental breathing into the tested materials. Physiological parameters and fractions of oxygen and carbon dioxide in the airways were recorded continuously. All the materials selected as possible models of the avalanche snow negatively affected gas exchange during the breathing of the volunteers in a very similar extent. The time courses of the recorded parameters were very similar and were bordered from one side by the wet perlite and from the other side by the dry perlite. Therefore, other tested materials may be substituted with perlite with an appropriate water content. From all the tested materials, perlite is the best to simulate avalanche snow because of its homogeneity, reproducibility and easy manipulation.
- MeSH
- dýchání MeSH
- hyperkapnie * MeSH
- laviny * MeSH
- lidé MeSH
- respirační insuficience MeSH
- testování materiálů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Presence of an air pocket and its size play an important role in survival of victims buried in the avalanche snow. Even small air pockets facilitate breathing. We hypothesize that the size of the air pocket significantly affects the airflow resistance and work of breathing. The aims of the study are (1) to investigate the effect of the presence of an air pocket on gas exchange and work of breathing in subjects breathing into the simulated avalanche snow and (2) to test whether it is possible to breathe with no air pocket. The prospective interventional double-blinded study involved 12 male volunteers, from which 10 completed the whole protocol. Each volunteer underwent two phases of the experiment in a random order: phase "AP"--breathing into the snow with a one-liter air pocket, and phase "NP"--breathing into the snow with no air pocket. Physiological parameters, fractions of oxygen and carbon dioxide in the airways and work of breathing expressed as pressure-time product were recorded continuously. The main finding of the study is that it is possible to breath in the avalanche snow even with no air pocket (0 L volume), but breathing under this condition is associated with significantly increased work of breathing. The significant differences were initially observed for end-tidal values of the respiratory gases (EtO2 and EtCO2) and peripheral oxygen saturation (SpO2) between AP and NP phases, whereas significant differences in inspiratory fractions occurred much later (for FIO2) or never (for FICO2). The limiting factor in no air pocket conditions is excessive increase in work of breathing that induces increase in metabolism accompanied by higher oxygen consumption and carbon dioxide production. The presence of even a small air pocket reduces significantly the work of breathing.
- MeSH
- asfyxie patofyziologie prevence a kontrola MeSH
- dechová práce fyziologie MeSH
- dechový objem fyziologie MeSH
- dospělí MeSH
- dvojitá slepá metoda MeSH
- hyperkapnie patofyziologie MeSH
- hypoxie patofyziologie MeSH
- inspirační rezervní objem fyziologie MeSH
- katastrofy * MeSH
- klinické křížové studie MeSH
- kyslík fyziologie MeSH
- laviny * MeSH
- lidé MeSH
- monitorování fyziologických funkcí MeSH
- oxid uhličitý fyziologie MeSH
- sníh MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
BACKGROUND: Cortisol, along with other hormones of hypothalamo-pituitary-adrenal axis, belongs to one of the main factors influencing psychological and pathognomic factors, intelligence, and memory. METHODS: The aim of our study was to review a large battery of psychological, performance, IQ and memory tests as to their relation with cortisol, testosterone and estrogen levels in groups of 100 men and 93 women who attended the Central Military Hospital in Prague for regular entrance psychological examinations for military personnel. RESULTS: In men, we detected positive correlations between cortisol and emotional lability, and negative correlations with impulsivity, while in women hypochondria and psychopathology were negatively correlated, and aggression measured with the Meili selective memory test had a positive relation to cortisol level. Testosterone correlated positively with emotional liability and negatively with impulsivity in men, and negatively with hypochondria and psychasteny, indirect aggression, irritability and paranoia in women. Estradiol correlated positively with psychopathology in men, and negatively with phobia. It was positively correlated with negativism in women. No clear correlation was observed between the concentration of steroid hormones and psychomotor performance or intelligence. CONCLUSIONS: Concentrations of steroid hormones correlate with results of several psychological tests, the sign and magnitude of these correlations, however, very often differ in military men and women.
- MeSH
- dospělí MeSH
- duševní poruchy krev patofyziologie MeSH
- estrogeny krev fyziologie MeSH
- hydrokortison krev fyziologie MeSH
- inteligence fyziologie MeSH
- inteligenční testy statistika a číselné údaje MeSH
- lidé MeSH
- ozbrojené síly psychologie statistika a číselné údaje MeSH
- paměť fyziologie MeSH
- psychiatrické posuzovací škály statistika a číselné údaje MeSH
- psychomotorický výkon fyziologie MeSH
- testosteron krev fyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The aim of our work is to assess the influence of tiredness on changes in respiratory parameters during monotonous hypokinetic loading. In the current phase of the work, we are looking for the answer to the question whether these changes can predict upcoming tiredness or indicate only. On the pilot measurement, three males and two females aged 25-35 were participated. To capture the transition states of consciousness, a measurement was proposed in two modes: active vs. tired individual. For recording of breathing, two chest straps and a spiroergometer were used. Symptoms of tiredness were monitored by ECG and EEG. The course of the experiment was recorded by a video camera. Currently, we process the obtained data and from actual results, we can confirm that the upcomming tiredness can be with certainty found in the respiratory curves. The upcoming tiredness assessed merely by subjective analysis of videos was apparently associated with changes in breathing pattern. Quite a clear answer, if changes of the breathing pattern has predictive or indicative character, we will obtain from further comparison the respiratory curves with results of analyses of EEG and ECG signals, which are currently under processing.
- Klíčová slova
- monotomie, hypokinetická zátěž,
- MeSH
- audiovizuální záznam využití MeSH
- dospělí MeSH
- dýchací soustava MeSH
- dýchání MeSH
- elektroencefalografie metody využití MeSH
- elektrokardiografie metody využití MeSH
- experimenty na lidech MeSH
- financování organizované MeSH
- hypokineze etiologie MeSH
- lidé MeSH
- mechanika dýchání fyziologie MeSH
- pilotní projekty MeSH
- pohybová aktivita fyziologie MeSH
- spirometrie metody využití MeSH
- statistika jako téma MeSH
- únava etiologie komplikace MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- MeSH
- hypotermie terapie MeSH
- lidé MeSH
- první pomoc MeSH
- terapeutické zahřívání metody MeSH
- Check Tag
- lidé MeSH
Medicína používá pro diagnostikování stavu pacienta řadu zobrazovacích metod jako je RTG (roentgen), CT (výpočetní tomografii), MRI (magnetic resonance imaging – magnetickou rezonanci) a další. Infračervený obor elektromagnetického spektra zůstával dlouhou dobu nevyužit pro obtížnou realizaci prakticky použitelných obrazových senzorů. Se zlevněním vhodných zobrazovacích prvků se začíná objevovat možnost praktického využití IR zobrazovacích metod v praxi. Zatím je to stále spíše doménou výzkumných pracovišť, i když od prvního použití v medicíně uplynulo více než 50 let. Na základě současných poznatků si článek všímá možných směrů vývoje ve využití IR zobrazení v medicínské praxi.
In contemporary medicine, many systems used for diagnostics, such as X-ray (roentgenography), computed tomography (CT), magnetic resonance imaging (MRI) and other imaging systems, utilise different frequency bands of electromagnetic spectrum. Nevertheless, infrared electromagnetic band has not been used recently due to the lack of suitable and accessible infrared image sensors. The IR imaging technique still remains a research method rather than a common investigation technique, even though it was introduced into medicine more than 50 years ago. Since novel technologies offer high-performance image infrared sensors for a reasonable price, the possibility of frequent infrared imaging in medicine becomes possible and accessible. The study summarises recent development in IR imaging sensors and describes the current possible applications of infrared imaging in the clinical practice.
- MeSH
- diagnostické zobrazování metody přístrojové vybavení trendy MeSH
- infračervené záření dějiny diagnostické užití MeSH
- kardiologie metody přístrojové vybavení trendy MeSH
- lidé MeSH
- nádory prsu diagnóza krevní zásobení MeSH
- neurologie metody přístrojové vybavení trendy MeSH
- ortopedie metody trendy MeSH
- revmatologie metody přístrojové vybavení trendy MeSH
- technologie lékařská metody přístrojové vybavení trendy MeSH
- tělesná teplota fyziologie účinky záření MeSH
- termografie metody přístrojové vybavení trendy MeSH
- Check Tag
- lidé MeSH
