Search results

1 – 10 of 78
Article
Publication date: 7 March 2016

Joanna E. Laszczyk and Andrzej J Nowak

The purpose of this paper is to present the computational model of the neonate’s brain cooling process. The main aim of the analysis is to tune the developed computational model…

Abstract

Purpose

The purpose of this paper is to present the computational model of the neonate’s brain cooling process. The main aim of the analysis is to tune the developed computational model, make it convergent and representing the hypothermia therapy reasonably. To find the appropriate model parameters the trial of an inverse analysis, based on the standard least-square method, is performed. Having partially validated model the number of numerical simulations are carried out to compare their results with measurements made during real therapy.

Design Methodology Approach

The geometrical model of the newborn’s body is built using MRI and CT scans utilizing Mimics software and the Design Modeler while Ansys Fluent with its User Defined Function capability was used to implement the whole model and to carry out simulations. To model the bioheat transfer the Pennes bioheat equation is applied. In the mathematical model blood perfusion rate, metabolic heat generation rate as well as the arterial blood temperature are dependent on the tissue temperature. In order to determine the proper values of model parameters of bioheat transport in neonate’s body the attempt to inverse analysis is also performed.

Findings

The performed inverse analysis resulted in the values of model parameters (metabolic heat sources, blood perfusions etc.). Tuned model was then applied to simulate brain cooling process with reasonable accuracy. Obtained model parameters were also compared to the data obtained from neonatologists.

Research limitations implications

The presented numerical model still requires tests and simulations. The results from the inverse analysis based on the real measurements can be very valuable.

Practical implications

The determination of the proper parameters of the bioheat transfer in the neonatal body can finally be used to control the numerical simulations of the brain cooling process. The simulation of the re-warming process after hypothermic therapy can be improved considerably.

Social implications

The performance of the numerical simulations of the brain cooling process in the proper way can finally helps protect newborns’ health and life.

Originality Value

In the paper 3-D real geometrical model of the newborn’s body includes head, torso and limbs and different types of tissues are distinguished in the model. The considered bioheat transfer problem is also fully 3-D. This model is then utilised together with inverse analysis in order to determine the model parameters for the newborn’s body.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 26 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 29 April 2014

Joanna Łaszczyk, Anna Maczko, Wojciech Walas and Andrzej J. Nowak

This paper aims to test the inverse analysis, based on the standard least-square method, which will finally lead to find the appropriate parameters of modelling of the brain…

Abstract

Purpose

This paper aims to test the inverse analysis, based on the standard least-square method, which will finally lead to find the appropriate parameters of modelling of the brain cooling process.

Design/methodology/approach

To test the presented in this paper method of inverse analysis the numerical simulations of the bioheat transfer process in the neonatal body were performed. To model the bioheat transfer the Pennes bioheat equation and the modified Fiala model were applied.

Findings

The performed tests of the inverse analysis proved that it is possible to estimate the proper parameters of the process using this tool, but always with the small mistake.

Research limitations/implications

The presented method still requires a lot of tests. The test with the data from real measurements can be very valuable.

Practical implications

The determination of the proper parameters of the bioheat transfer in the neonatal body can finally be used to perform the numerical simulations of the brain cooling process.

Social implications

The performance of the numerical simulations of the brain cooling process in the proper way can finally helps protect newborns’ health and life.

Originality/value

In the paper the attempt of the inverse analysis in order to determine the parameters of bioheat transfer in the newborn's body is made.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 24 no. 4
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 December 1995

Lisa A. Shanley, David D. Pascoe, Layne Anderson and Teresa Bellingar

Endeavours to determine the physiological and perceptual responses to forearm cold water immersion as influenced by the use of an experimental fireproof carbonaceous insulation…

268

Abstract

Endeavours to determine the physiological and perceptual responses to forearm cold water immersion as influenced by the use of an experimental fireproof carbonaceous insulation (ECI), Thinsulate (a commercial insulation), and Nomex flight gloves. The primary objective was to determine if ECI could provide adequate protection from cold water immersion while providing superior protection from fire. Physiological responses including rectal and skin temperatures to –1 degree C water were recorded. Perceptions of thermal discomfort and grip strength were also measured. The experimental carbonaceous insulation was able to provide better thermal protection as evidenced by significantly higher skin temperatures than the Thinsulate. Subjects perceived the Thinsulate gloves to be only slightly more comfortable than the ECI gloves. Both ECI and Thinsulate provided negligible loss of grip strength. The Nomex gloves provided virtually no thermal protection and substantial loss of grip strength post‐immersion.

Details

International Journal of Clothing Science and Technology, vol. 7 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 20 July 2021

Yoon Jeong Baek, Seung-Hyun Kim, Sayup Kim, Eui-Sang Yoo and Joo-Young Lee

The purpose of the present study was to evaluate the effect of air mattress pressure on sleep quality.

Abstract

Purpose

The purpose of the present study was to evaluate the effect of air mattress pressure on sleep quality.

Design/methodology/approach

Ten young healthy males participated in all hard surface [AH], shoulder soft [SS] and shoulder and hip soft mattress [SHS] conditions. The surface pressure for SS and SHS were set at their preferred levels.

Findings

The results showed that sleep efficiencies were over 95% for all the three conditions; there were no significant differences in individual sleep variables among the three conditions, but overall sleep quality was better for SS than AH (p = 0.065); heart rates during sleep was greater for AH than the other two conditions (p < 0.1); and a stronger relationship between clothing and bed microclimate humidity were found for SS and SHS than that for AH.

Research limitations/implications

These results indicated that the both pressure relief air mattresses that were set at their own preferred levels provided high quality sleep with no marked differences.

Practical implications

Air pressure relief mattresses can improve sleep quality of healthy individuals during sleep at night. The results can be used to understand appropriate pressure distribution on surface mattress according to body region, and also to develop algorithms to provide optimum sleep using mattresses with surface pressure control by body region.

Originality/value

The present study found that the shoulder and/or hip pressure relief air mattresses that were set at their own preferred levels provided high quality sleep with no marked differences.

Details

International Journal of Clothing Science and Technology, vol. 34 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 June 2002

Toshinari Nakajima, Yuki Hachino and Haruko Yamano

The effectiveness of the far infrared radiation processing cloth as clothing material is discussed. Temperature rise of the irradiation plane is more rapid than the heating by…

Abstract

The effectiveness of the far infrared radiation processing cloth as clothing material is discussed. Temperature rise of the irradiation plane is more rapid than the heating by heat conduction and convection for the radiant heating. Skin temperature change and thermal sensation of the examinee wearing the sweater with a plastic heater at back were examined. “The relation of the inverse proportion of heat intensity to the time needed until the extent of thermal stimulation perceived was examined. Individual examinees tested, by oral contact, the extent of the pleasant sensation produced by the warming condition. They judged the extent of the warming according to whether it felt comfortable. Individually, they differed a great extent in their opinion of what was comfortable. However, for all examinees, the relationship of warming and feeling comfortable was confined within narrow parameters. In this experiment, a unit of the radiant heat stimulation was determined by dividing mW/cm2 by the warming period, since intermittent warming was carried out.” The degree of the skin temperature perceived by the sensation was almost fixed at 33–35, even if the radiant heat strength differed. The rapid thermal stimulation by radiant heating can be perceived even for a slight temperature rise of the skin. It is also necessary to consider the temperature rise speed, except for the temperature rise of the cloth surface, when the effectiveness of the far infrared radiation processing cloth was discussed.

Details

International Journal of Clothing Science and Technology, vol. 14 no. 3/4
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 10 April 2019

Yan Hong, Xuechun Cao, Yan Chen, Zhijuan Pan, Yu Chen and Xianyi Zeng

The purpose of this paper is to investigate physiological indices related to comfort and health condition, based on which corresponding electronic equipment are selected and…

Abstract

Purpose

The purpose of this paper is to investigate physiological indices related to comfort and health condition, based on which corresponding electronic equipment are selected and applied. A wearable monitoring system using sensor and liquid crystal display (LCD) techniques are then designed. Sensors are used to collect and transmit recording required signals from the wearer. A microcomputer with the type of AT89C52 is used to record and analyze the collected data. LCD is applied to display the health and comfort condition of the wearer.

Design/methodology/approach

A novel wearable monitoring system for the measurement of physiological indices and clothing microclimate is proposed in this study in order to monitoring both health and comfort condition of the wearer.

Findings

The proposed system provides reference for the application of sensor and display technologies in the field of smart clothing, which can be further applied to infant and child care, health care, home entertainment, military and industry.

Originality/value

This paper, first, investigated a framework of a wearable monitoring system considering both comfort and health condition and summarized the related physiological indices. The requirements of both comfort and health condition monitoring are analyzed to select appropriate electronic elements.

Details

International Journal of Clothing Science and Technology, vol. 31 no. 3
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 October 2002

P. Zhang, R.H. Gong, Y. Yanai and H. Tokura

One of the main purposes of clothing is to provide the wearer protection against undesirable environments. The properties of clothing materials have critical influences on the…

1061

Abstract

One of the main purposes of clothing is to provide the wearer protection against undesirable environments. The properties of clothing materials have critical influences on the comfort of the wearer. Also, clothing is not just a passive cover for the skin, it interacts with and modifies the heat regulating function of the skin and has effects that are modified by the environment condition. Up to the present, most physiological studies have been on the thermal regulation of the human body without clothing. Although it is a necessary first step, more realistic and valuable information can only be obtained through studies of the interaction between clothing and the physiological aspects of the human wearer. This study reports an investigation into the combined effects of the properties of the clothing material and environment conditions on the rectal temperature of human wearers. The rectal temperature was the highest for the clothing with the lower air permeability and moisture regain during both the cooling and heating periods. In the hot environment after heating, the rectal temperature was the lowest for the clothing with the higher air permeability and moisture regain in environments of both with and without wind.

Details

International Journal of Clothing Science and Technology, vol. 14 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 30 November 2017

Sora Shin, Hae-Hyun Choi, Yung Bin Kim, Byung-Hee Hong and Joo-Young Lee

The purpose of this paper is to evaluate the effects of intermittent and continuous heating protocols using graphene-heated clothing and identify more effective body region for…

Abstract

Purpose

The purpose of this paper is to evaluate the effects of intermittent and continuous heating protocols using graphene-heated clothing and identify more effective body region for heating in a cold environment.

Design/methodology/approach

Eight males participated in five experimental conditions at an air temperature of 0.6°C with 40 percent relative humidity: no heating, continuous heating the chest, continuous heating the back, intermittent heating the chest, and intermittent heating the back.

Findings

The results showed that the electric power consumption of the intermittent heating protocol (2.49 W) was conserved by 71 percent compared to the continuous protocol (8.58 W). Rectal temperature, cardiovascular and respiratory responses showed no significant differences among the four heating conditions, while heating the back showed more beneficial effects on skin temperatures than heating the chest.

Originality/value

First of all, this study was the first report to evaluate cold protective clothing with graphene heaters. Second, the authors provided effective intermittent heating protocols in terms of reducing power consumption, which was able to be evaluated with the characteristics of fast-responsive graphene heaters. Third, an intermittent heating protocol on the back was recommended to keep a balance between saving electric power and minimizing thermal discomfort in cold environments.

Details

International Journal of Clothing Science and Technology, vol. 29 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 July 2006

Hiroyuki Ueda, Yoshimitsu Inoue, Mitsuo Matsudaira, Tsutomu Araki and George Havenith

The aim of this study is to explore the influence of the clothing ventilation in three body regions on the humidity of the local clothing microclimates under five work‐shirts…

1030

Abstract

Purpose

The aim of this study is to explore the influence of the clothing ventilation in three body regions on the humidity of the local clothing microclimates under five work‐shirts immediately after the onset of sweating in light exercise.

Design/methodology/approach

The clothing microclimate ventilations were measured at chest, back and upper arm using a manikin. Separate wear trials were performed to determine the sweat production and the humidity of the clothing microclimate at the same locations as where the ventilation was measured during light exercise.

Findings

Every shirt shows the greatest value of ventilation index (VI) for the chest and the smallest one for the upper arm. The values of VI differ remarkably at the chest among the five shirts. Comfort sensation became gradually worse as the time passed after starting exercise. There was no significant difference among the clothing conditions in mean values of rectal temperature, local skin temperatures, microclimate temperatures, microclimate relative humidities and local sweat rates at three regions over 10 min after the onset of sweating. A relationship was observed between the ratio of the mean moisture concentration in the clothing microclimate to the mean sweat rate at the chest and the back and the VI.

Originality/value

The results suggest that clothing ventilation should be measured in different body regions in response to sweat rates in corresponding regions.

Details

International Journal of Clothing Science and Technology, vol. 18 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 31 July 2019

Pengpeng Cheng and Daoling Chen

The purpose of this paper is to analyze the influence of underwear on the microenvironment of human clothing.

Abstract

Purpose

The purpose of this paper is to analyze the influence of underwear on the microenvironment of human clothing.

Design/methodology/approach

Based on the basic laws of energy and mass conservation, the paper combined the theory of heat and mass transfer to establish the simulation of the influence of underwear on human thermal reaction in microclimate and prediction model of human thermal reaction law.

Findings

The impact on the microenvironment affected by tighter underwear is less than the effect of loose underwear and computational flow dynamics (CFD) can accurately predict the thermal reaction parameters’ values of the human body.

Originality/value

It can be effectively used for the prediction of heat exchange between human body and environment in high-temperature environment and human thermophysiological parameters, and overcomes the individual differences of human experiments and the danger and repeatability of high-temperature environmental experiments.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 12
Type: Research Article
ISSN: 0961-5539

Keywords

1 – 10 of 78