A review of contemporary techniques for measuring ergonomic wear comfort of protective and sport clothing

Protective and sport clothing is governed by protection requirements, performance, and comfort of the user. The comfort and impact performance of protective and sport clothing are typically subjectively measured, and this is a multifactorial and dynamic process. The aim of this review paper is to review the contemporary methodologies and approaches for measuring ergonomic wear comfort, including objective and subjective techniques. Special emphasis is given to the discussion of different methods, such as objective techniques, subjective techniques, and a combination of techniques, as well as a new biomechanical approach called modeling of skin. Literature indicates that there are four main techniques to measure wear comfort: subjective evaluation, objective measurements, a combination of subjective and objective techniques, and computer modeling of human–textile interaction. In objective measurement methods, the repeatability of results is excellent, and quantified results are obtained, but in some cases, such quantified results are quite different from the real perception of human comfort. Studies indicate that subjective analysis of comfort is less reliable than objective analysis because human subjects vary among themselves. Therefore, it can be concluded that a combination of objective and subjective measuring techniques could be the valid approach to model the comfort of textile materials

Oral application of L-menthol in the heat: From pleasure to performance

When menthol is applied to the oral cavity it presents with a familiar refreshing sensation and cooling mint flavour. This may be deemed hedonic in some individuals, but may cause irritation in others. This variation in response is likely dependent upon trigeminal sensitivity toward cold stimuli, suggesting a need for a menthol solution that can be easily personalised. Menthol’s characteristics can also be enhanced by matching colour to qualitative outcomes; a factor which can easily be manipulated by practitioners working in athletic or occupational settings to potentially enhance intervention efficacy. This presentation will outline the efficacy of oral menthol application for improving time trial performance to date, either via swilling or via co-ingestion with other cooling strategies, with an emphasis upon how menthol can be applied in ecologically valid scenarios. Situations in which performance is not expected to be enhanced will also be discussed. An updated model by which menthol may prove hedonic, satiate thirst and affect ventilation will also be presented, with the potential performance implications of these findings discussed and modelled. Qualitative reflections from athletes that have implemented menthol mouth swilling in competition, training and maximal exercise will also be included

Multi-sector thermophysiological head simulator for headgear research

[EN] Predicting thermal comfort perceived during wearing protective clothing is important especially for the head as it is one of the most sensitive body parts to heat. Since helmets typically induce an additional thermal insulation that impairs the heat dissipation from the head, a special attention should be drawn to a heat strain leading to a decrease of the cognitive performance and to adverse health effects. Thermal manikins allow systematic analysis of the heat and mass transfer properties of protective clothing. However, this methodology does not provide sufficient information about the local and the whole body human physiological response in different cases of use. The prediction of the physiological state of the body is provided by a thermophysiological model. However, they are not capable of accounting for complex heat and mass exchange processes at the skin surface when the clothing is worn. Thermal devices could measure the overall effect of these processes when wearing the given actual gear and being exposed to the surrounding environment. Several attempts to couple thermal manikins with physiological models have been undertaken, however, the partial coupling of a body part manikin with a physiological model has not been addressed so far. Hence, the aim of this work was to develop a novel thermophysiological human head simulator for headgear evaluation based on the coupling of a thermal head manikin with a thermophysiological model. This method would be able to realistically reproduce the effect of clothing on the heat and mass transfer from the head's skin to the environment. A thermal head manikin with a dedicated segmentation for headgear testing was evaluated for the thermophysiological human head simulator. This head manikin showed consistent when compared to previously published data of a less segmented head manikin and the more detailed investigation of the local heat transfer at head brought additional information regarding the contribution of the local design characteristics of the headgear to the overall heat exchange. The thermal head manikin was evaluated in the most demanding scenarios according to the human physiology. It was possible to consistently define four head parts, namely, forehead, cranial, face and neck parts. When heterogeneous surface temperature distribution was applied on the head manikin, the gradients between head parts could compromise the precision of skin temperature prediction at forehead and face. The passive heating and cooling responsiveness of the head manikin did not present any limitation for simulating sudden temperature step changes. However, when the manikin heating and cooling processes were modulated by the PI control with default settings, the time needed to reach the temperature set point was larger than the time required by the human physiology. The thermophysiological model was validated for prediction of global and local skin temperatures by comparing simulations against human experimental data in a wide range of conditions. The physiological model showed a good precision in general when predicting core and mean skin temperature. A reduced precision was observed for some local skin temperatures. Finally, the thermal head manikin and the physiological model were coupled to build up the thermophysiological head simulator. The comparison of the prediction of the coupled system with human experimental data in several scenarios showed a good agreement for rectal and mean skin temperatures. However, some greater discrepancy was observed for forehead temperature in exposures in which participants were exercising in warm environments. The representation of the human sweat evaporation could be affected by a reduced evaporation efficiency and manikin sweat dynamics. The industry will benefit from this thermophysiological human head simulator, which will lead to the development of helmet designs with enhanced thermal comfort, and therefore, with higher acceptance by users[ES] Poder predecir el confort térmico durante el uso de indumentaria de protección es muy relevante especialmente en el caso de la cabeza, ya que es una de las partes más sensibles del cuerpo al calor. Los cascos y otros elementos de protección frente a impactos incorporan un aislamiento adicional que di-ficulta la disipación de calor en la cabeza. Los maniquís térmicos permiten analizar de manera sistemática las propiedades de transferencia de calor y humedad de la indumentaria de protección. Sin embargo, esta metodología no permite inferir la respuesta fisiológica del usuario cuando utiliza la prenda. Existen modelos termofisiológicos que permiten predecir la respuesta térmica humana pero presentan algunas limitaciones cuando se representan los procesos de transferencia de calor y humedad a través de la ropa. En este caso, un maniquí térmico podría cuantificar el intercambio real de calor que se pro-duce con el ambiente térmico cuando se viste una determinada prenda. Existen experiencias en las que un maniquí de cuerpo completo ha sido acoplado con un modelo termofisiológico. Sin embargo, el acoplamiento de un maniquí que representa únicamente una parte del cuerpo con un modelo de la fisiología humana no ha sido llevado a cabo hasta ahora. Por lo tanto, el objetivo de este trabajo ha sido desarrollar una nueva metodología para evaluar cascos y equipos de protección para la cabeza basándose en el acoplamiento de un maniquí térmico de cabeza con un modelo fisiológico. Un maniquí térmico de cabeza ha sido evaluado para ser acoplado con un modelo termofisiológico. Sus medidas fueron consistentes con resultados anteriormente publicados realizados con un maniquí en menos seccionado. Este nuevo maniquí introdujo información adicional sobre la contribución en particular de las distintas características de diseño del casco al intercambio de calor global. El maniquí térmico de cabeza fue evaluado en los escenarios más extremos identificados para la fisiología humana. Se pudo identificar cuatro partes en el sistema acoplado, frente, cráneo, cara y cuello. En el caso de simular una distribución heterogénea de temperatura, los gradientes generados entre las diferentes partes podrían comprometer la precisión en la predicción de la temperatura de la piel en la frente y la cara. La capacidad pasiva de calentamiento y enfriamiento del maniquí de cabeza no supuso ninguna limitación para simular los cambios súbitos de temperatura de la piel pero cuando el control PI del maniquí moduló los procesos de calentamiento y enfriamiento, el tiempo necesario para alcanzar la temperatura de consigna fue mayor que el tiempo de reacción observado en la fisiología humana. Las predicciones de temperatura obtenidas con el modelo de la fisiología humana fueron validadas mediante la comparación con datos humanos experimentales. En general, el modelo mostró buena precisión para la predicción de la temperatura interna y la temperatura media de la piel. Sin embargo, la precisión observada fue menor para la predicción de algunas temperaturas locales. El maniquí térmico de cabeza y el modelo termofisiológico fueron acoplados. La comparación de las predicciones del sistema acoplado con datos humanos experimentales en diferentes escenarios mostró concordancia para la temperatura rectal y media de la piel. No obstante, se observó una mayor discrepancia en la predicción de la temperatura de la frente si se comparaba las simulaciones obtenidas con el modelo por sí solo y con el sistema acoplado en escenarios en los que los participantes realizaban actividad física ambientes cálidos. La representación de la evaporación del sudor humano en el sistema acoplado podría estar condicionada por una menor eficiencia en la evaporación y la respuesta dinámica de la sudoración del maniquí. La industria se podrá beneficiar de este sistema para avanzar en el desarrollo de nuevos productos que proporcionen[CA] Poder predir el confort tèrmic durant l'ús d'indumentària de protecció es especialment rellevant en el cas del cap, ja que és una de les parts més sensibles del cos a la calor. Els cascs incorporen un aïllament adicional que dificulta la dissipació de la calor al cap. Aquest fet és particularment dramàtic quan l'estrès tèrmic afecta negativament a la funció cognitiva i té efectes negatius sobre la salut. Els maniquins tèrmics permeten analitzar de manera sistemàtica les propietats tèrmiques de la indumentària de protecció. No obstant, aquesta metodologia no permet inferir la resposta fisiològica de l'usuari quan utilitza la indumentària. En l'actualitat existixen models matemàtics que permeten predir l'estat fisiològic del cos humà però presenten algunes limitacions quan es tracta de simular els complexos processos de transferència de calor i humitat que ocorren amb roba. En aquest cas, un maniquí tèrmic podria quantificar l'intercanvi real de calor que es produïx en l'ambient tèrmic quan es porta una determinada roba. Existixen experiències prèvies en les que un maniquí de cos complet ha sigut acoblat en un model de la fisiologia humana. No obstant, l'acoblament d'un maniquí que representa únicament una part del cos en un model de la fisiologia humana no ha sigut dut a terme fins ara. Per tant, l'objectiu d'aquest treball es desenvolupar una nova metodologia per a evaluar cascs i indumentària de protecció per al cap basada en l'acoblament d'un maniquí tèrmic de cap amb un model fisiològic. Un maniquí tèrmic de cap ha sigut valorat per a ser acoplat en un model de la fisiologia humana. Les mesures del maniquí van ser consistents amb els resultats publicats en maniquís menys seccionats. Aquest maniquí tèrmic de cap introduix informació adicional sobre la contribució particular de les dife-rents característiques del disseny dels cascs a l'intercanvi de calor global. El maniquí tèrmic de cap ha sigut valorat en els escenaris més extrems identificats per la fisiologia hu-mana. Es van poder identificar quatre parts al sistema acoblat, front, crani, cara i coll. En el cas de simular una distribució heterogènia de temperatura en la superfície del maniquí de cap, els gradients generats entre les diferents parts podria comprometre la precisió en la predicció de la temperatura de la pell en el front i la cara. La capacitat passiva de calfament i refredament del maniquí de cap no va suposar ninguna limitació per simular els canvis sobtats de temperatura de la pell observats en la fisiologia humana. No obstant, quant el control PI del maniquí modulà els processos de calfament i refredament, el temps necessari per alcançar la temperatura de consigna va ser major que el temps de reacció observat en la fisiologia humana. Les prediccions de temperatura obtingudes en el model de la fisiologia humana previst per formar part del sistema acoblat van ser validades amb dades humanes experimentals. En general, el model va mostrar una bona precisió en la predicció de la temperatura interna i la temperatura mitjana de la pell. No obstant, la precisió va ser menor en la predicció de las temperaturas locals. El maniquí tèrmic de cap i el model de la fisiologia humana van ser acoblats. La comparació de les prediccions del sistema acoblat amb dades humanes experimentals mostraren concordança en el cas de la temperatura rectal i mitjana de la pell. No obstant, s'observà una major discrepància en la predicció de la temperatura del front quant es comparaven les simulacions obtingudes en el model per sí mateix i el sistema acoblat en escenaris en els quals els participants realitzaven activitat física en am-bients càlids. La representació de l'evaporament del suor humà en el sistema acoblat podria estar con-dicionada per una menor eficiència en l'evaporament. La indústria es podra beneficiar d'aquest sistema per a avançar en el desenvolupament de nous productes que proporcioneMartínez Guillamón, N. (2016). Multi-sector thermophysiological head simulator for headgear research [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61487TESI

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 361)

This bibliography lists 141 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during Mar. 1992. Subject coverage includes: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance

EFFECT OF RELATIVE HUMIDITY AND TEMPERATURE CONTROL ON IN-CABIN THERMAL COMFORT STATE

This dissertation discusses the effect of manipulating the relative humidity RH levels inside vehicular cabins on the thermal comfort and human occupants\u27 thermal sensation. Three different techniques are used to investigate this effect. Firstly, thermodynamic and psychometric analyses are used to incorporate the effect of changing RH along with the dry bulb temperature on the human comfort window. Specifically, the study computes the effect of changing the relative humidity on the amount of heat rejected from the passenger compartment and the effect on occupants comfort zone. A practical system implementation is also discussed in terms of an evaporative cooler design. Secondly, a 3-D finite difference simulation is used to predict the RH effects on the thermal sensation metrics. The study uses the Berkeley and the Fanger models to investigate the human comfort using four specific perspectives; (i) the effect on other environmental conditions, (ii) the effect on the body segments temperature variation within the cabin, (iii) the cabin local sensation (LS) and comfort (LC) for the different body segments; in addition to the overall sensation (OS) and overall comfort (OC), (iv) the human sensation is also measured by the Predicted Mean Value (PMV) and the Predicted Percentage Dissatisfied (PPD) indices during the summer and the winter periods following the Fanger model calculations. Thirdly, the analysis and modeling of the vehicular thermal comfort parameters is conducted using a set of designed experiments aided by thermography measurements. The experiments employed a full size climatic chamber to host the test vehicle, to accurately assess the transient and steady state temperature distributions of the test vehicle cabins. The experimental and simulation work show that controlling the RH levels along with the Dry Bulb Temperature helps the A/C system achieve the human comfort zone faster than the case if the RH value is not controlled. Also, the results show that changing the RH along with Dry Bulb Temperature inside vehicular cabins can improve the air conditioning efficiency by reducing the amount of heat removed. Finally, this work has developed the passenger thermal-comfort psychometric zones during summer and winter periods using Berkeley and Fanger models

Virtual Reality Games for Motor Rehabilitation

This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion

Thermal comfort models for indoor spaces and vehicles—Current capabilities and future perspectives

International audienceThroughout this paper, we reviewed the most popular thermal comfort models and methods of assessing thermal comfort in buildings and vehicular spaces. Most of them are limited to specific steady state, thermally homogenous environments and only a few of them address human responses to both non-uniform and transient conditions with a detailed thermo-regulation model. Some of them are defined by a series of international standards which stayed unchanged for more than a decade. The article proposes a global approach, starting from the physiological reaction of the body in thermal stress conditions and ending with the model implementation. The physiological bases of thermal comfort are presented, followed by the main thermal comfort models and standards and finishing with the current methods of assessing thermal comfort in practice. Within the last part we will focus mainly on thermal manikin experimental studies, and on CFD (computational fluid dynamics) numerical approach, as in our opinion these methods will be mostly considered for future development in this field of researc