Computational model of predicting thermal performance of a clothed human by considering the clothing pumping effect

Author(s):  
Yi Teng ◽  
Ruomei Wang ◽  
Jiao Jiao ◽  
Yi Li

Abstract In order to predict the functional performance of a thermal-functional-designed clothing, computer simulation method is adopted to investigate on the thermoregulation of a clothed human. The primary aim of this study is to develop a computational model which can simulate the thermal physiological indicators and pumping effect simultaneously, while the previous models can only simulate the human thermal physiological performance or clothing pumping effect particularly. The second aim is to compare the simulation results predicted by the optimized model, either considering the pumping-effect or not, with the results in a physiological experiment conducted by human participants in terms of different thermal responses including core temperatures and mean skin temperature. A computational model was established to predict thermal performance of a clothed human by considering clothing pumping effect in the Human-Clothing-Environment (HCE) system. In addition, the validation of the developed computational model has been investigated by compared the predicted results of simulation (with or without pumping effect) with the experimental results on human participants, which demonstrates that the clothing pumping effect must be considered during simulation process due to its vital influence on thermoregulation of a live clothed human. The results from the simulation and the human experiment showed that the pumping effect could dissipate the heat from the body to outside environment, affected the skin temperature and consequently delayed the increasing of core temperature, especially during the running process.

2001 ◽  
Vol 95 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Han-Jung Chen ◽  
Cheng-Loong Liang ◽  
Kang Lu

Object. Transthoracic endoscopic T2–3 sympathectomy is currently the treatment of choice for palmar hyperhidrosis. Compensatory sweating of the face, trunk, thigh, and sole of the foot was found in more than 50% of patients who underwent this procedure. The authors conducted this study to investigate the associated intraoperative changes in plantar skin temperature and postoperative plantar sweating. Methods. One hundred patients with palmar hyperhidrosis underwent bilateral transthoracic endoscopic T2–3 sympathectomy. There were 60 female and 40 male patients who ranged in age from 13 to 40 years (mean age 21.6 years). Characteristics studied included changes in palmar and plantar skin temperature measured intraoperatively, as well as pre- and postoperative changes in plantar sweating and sympathetic skin responses (SSRs). In 59 patients (59%) elevation of plantar temperature was demonstrated at the end of the surgical procedure. In this group, plantar sweating was found to be exacerbated in three patients (5%); plantar sweating was improved in 52 patients (88.1%); and no change was demonstrated in four patients (6.8%). In the other group of patients in whom no temperature change occurred, increased plantar sweating was demonstrated in three patients (7.3%); plantar sweating was improved in 20 patients (48.8%); and no change was shown in 18 patients (43.9%). The difference between temperature and sweating change was significant (p = 0.001). Compared with the presympathectomy rate, the rate of absent SSR also significantly increased after sympathectomy: from 20 to 76% after electrical stimulation and 36 to 64% after deep inspiration stimulation, respectively (p < 0.05). Conclusions. In contrast to compensatory sweating in other parts of the body after T2–3 sympathetomy, improvement in plantar sweating was shown in 72% and worsened symptoms in 6% of patients. The intraoperative plantar skin temperature change and perioperative SSR demonstrated a correlation between these changes.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Shanta Pandian ◽  
Kamal Narayan Arya ◽  
Dharmendra Kumar

Background. Balance and functional abilities are controlled by both sides of the body. The role of nonparetic side has never been explored for such skills.Objective. The objective of the present study was to examine the effect of a motor therapy program primarily involving the nonparetic side on balance and function in chronic stroke.Method. A randomized controlled, double blinded trial was conducted on 39 poststroke hemiparetic subjects (21, men; mean age, 42 years; mean poststroke duration, 13 months). They were randomly divided into the experimental group(n=20)and control group(n=19). The participants received either motor therapy focusing on the nonparetic side along with the conventional program or conventional program alone for 8 weeks (3 session/week, 60 minutes each). The balance ability was assessed using Berg Balance Scale (BBS) and Functional Reach Test (FRT) while the functional performance was measured by Barthel Index (BI).Result. After intervention, the experimental group exhibited significant(P<0.05)change on BBS (5.65 versus 2.52) and BI (12.75 versus 2.16) scores in comparison to the control group.Conclusion. The motor therapy program incorporating the nonparetic side along with the affected side was found to be effective in enhancing balance and function in stroke.


2018 ◽  
Vol 6 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Guillaume Lamé ◽  
Rebecca K Simmons

Simulation is a technique that evokes or replicates substantial aspects of the real world, in order to experiment with a simplified imitation of an operations system, for the purpose of better understanding and/or improving that system. Simulation provides a safe environment for investigating individual and organisational behaviour and a risk-free testbed for new policies and procedures. Therefore, it can complement or replace direct field observations and trial-and-error approaches, which can be time consuming, costly and difficult to carry out. However, simulation has low adoption as a research and improvement tool in healthcare management and policy-making. The literature on simulation in these fields is dispersed across different disciplinary traditions and typically focuses on a single simulation method. In this article, we examine how simulation can be used to investigate, understand and improve management and policy-making in healthcare organisations. We develop the rationale for using simulation and provide an integrative overview of existing approaches, using examples of in vivo behavioural simulations involving live participants, pure in silico computer simulations and intermediate approaches (virtual simulation) where human participants interact with computer simulations of health organisations. We also discuss the combination of these approaches to organisational simulation and the evaluation of simulation-based interventions.


2020 ◽  
Vol 16 (12) ◽  
pp. e1008484
Author(s):  
Ryan Smith ◽  
Rayus Kuplicki ◽  
Justin Feinstein ◽  
Katherine L. Forthman ◽  
Jennifer L. Stewart ◽  
...  

Recent neurocomputational theories have hypothesized that abnormalities in prior beliefs and/or the precision-weighting of afferent interoceptive signals may facilitate the transdiagnostic emergence of psychopathology. Specifically, it has been suggested that, in certain psychiatric disorders, interoceptive processing mechanisms either over-weight prior beliefs or under-weight signals from the viscera (or both), leading to a failure to accurately update beliefs about the body. However, this has not been directly tested empirically. To evaluate the potential roles of prior beliefs and interoceptive precision in this context, we fit a Bayesian computational model to behavior in a transdiagnostic patient sample during an interoceptive awareness (heartbeat tapping) task. Modelling revealed that, during an interoceptive perturbation condition (inspiratory breath-holding during heartbeat tapping), healthy individuals (N = 52) assigned greater precision to ascending cardiac signals than individuals with symptoms of anxiety (N = 15), depression (N = 69), co-morbid depression/anxiety (N = 153), substance use disorders (N = 131), and eating disorders (N = 14)–who failed to increase their precision estimates from resting levels. In contrast, we did not find strong evidence for differences in prior beliefs. These results provide the first empirical computational modeling evidence of a selective dysfunction in adaptive interoceptive processing in psychiatric conditions, and lay the groundwork for future studies examining how reduced interoceptive precision influences visceral regulation and interoceptively-guided decision-making.


2020 ◽  
Vol 24 (3) ◽  
pp. 253-261
Author(s):  
M. A Merkulova ◽  
M. M Lapkin

Physiological value is one of the factors affecting the effectiveness of human activities. Currently, there is no single approach to assess the physiological value of human behavior. The article presents data on the role of the physiological cost of human activity, estimated by the indicators of mathematical analysis of heart rate, in the reproduction of matrix visual images. The article puts forward the position that the physiological cost of activity is an important factor in the formation of unequal performance. At the same time, the physiological cost is reflected not only in shifts in a number of physiological indicators when the subjects perform a particular activity, but in the nature and levels of expression of correlation relationships between indicators of this activity and indicators that reflect physiological changes in the body at the same time.


Author(s):  
Benjamin W. Scandling ◽  
Jia Gou ◽  
Jessica Thomas ◽  
Jacqueline Xuan ◽  
Chuan Xue ◽  
...  

Many cells in the body experience cyclic mechanical loading, which can impact cellular processes and morphology. In vitro studies often report that cells reorient in response to cyclic stretch of their substrate. To explore cellular mechanisms involved in this reorientation, a computational model was developed by utilizing the previous computational models of the actin-myosin-integrin motor-clutch system developed by others. The computational model predicts that under most conditions, actin bundles align perpendicular to the direction of applied cyclic stretch, but under specific conditions, such as low substrate stiffness, actin bundles align parallel to the direction of stretch. The model also predicts that stretch frequency impacts the rate of reorientation, and that proper myosin function is critical in the reorientation response. These computational predictions are consistent with reports from the literature and new experimental results presented here. The model suggests that the impact of different stretching conditions (stretch type, amplitude, frequency, substrate stiffness, etc.) on the direction of cell alignment can largely be understood by considering their impact on cell-substrate detachment events, specifically whether detachment occurs during stretching or relaxing of the substrate.


1965 ◽  
Vol 13 (3) ◽  
pp. 437 ◽  
Author(s):  
MD Murray ◽  
DG Nicholls

Although the southern elephant seals, Mirounga leonina, that breed on Macquarie I., come ashore for only 3-5 weeks twice a year, the hind flippers of most of them are infested with the blood-sucking louse Lepidophthirus macrorhini. L. macrorhini does not oviposit, and eggs do not hatch, in water. Reproduction occurs when the elephant seal is ashore on the beach or in the adjacent tussock. The life cycle can be completed in c. 3 weeks and, because 6-9 eggs are laid daily, multiplication can be rapid. Temperatures greater than 25�C are required for rapid multiplication, and these temperatures occur more frequently on the hind flippers than elsewhere on the body. The number of L. macrorhini on a hind flipper however rarely exceeds 100. The principal causes of mortality of the lice are failure to survive the seal's prolonged stay at sea, the moult of the seal, and transmission to unfavourable sites on the seal. When an elephant seal goes to sea its skin temperature falls to nearly that of the sea. The reduction in the metabolic rate of the louse at low temperatures results in the amount of oxygen obtained from the sea by cutaneous respiration being sufficient for survival. The lice do not enter into a state of complete suspended animation, and a blood meal is required at least once a week to enable sufficient to survive to repopulate the seal. The skin temperature of a seal at sea rises more frequently on the flippers than elsewhere on the body because of the increased rate of blood flow to the flippers after diving and whenever it is necessary to dissipate heat. Consequently, there are more opportunities for the lice on the hind flippers to feed. L. macrorhini burrows into the stratum corneum, thus reducing losses to the population when the elephant seal annually sheds the outer layers of the stratum corneum attached to the hair, because only the roof of the burrow is lost. Lice do not reproduce on the older seals that moult in muddy wallows, and consequently fewer lice are found on these animals. Pups are infested within a few days of birth, and the gregarious habits of the elephant seal spread infestations through the seal population. Lice transfer to all parts of the bodies of seals but it is the multiplication of those on the flippers that maintains the louse population. The abundance of L. macrorhini is determined largely by the frequency and duration of opportunities to reproduce when the elephant seal is ashore, and to feed when the elephant seal is at sea.


2020 ◽  
Vol 18 (6) ◽  
pp. 1711-1730 ◽  
Author(s):  
Dubem Ikediashi ◽  
Godfrey Udo ◽  
Maureen Ofoegbu

Purpose This study aims to evaluate the performance of buildings in the University of Uyo using the post-occupancy evaluation (POE) technique. Design/methodology/approach A quantitative questionnaire survey is adopted in which 333 copies of a validated questionnaire are administered to academic, administrative and maintenance staff and some students who occupy four buildings used for the survey. However, 124 valid responses are received giving a response rate of 37per cent. Data collected are analysed using descriptive and inferential statistical tools while the Kruskal Wallis chi-square (χ2) test is used to analyse hypotheses postulated for the study. Findings Findings reveal that the General Administration (GA) building has high ratings in five technical performance criteria of ambient level of sound in offices, the integrity of materials used for walls, and correctness of stair risers, threads in the building quality of lighting and quantity of lighting. Findings on the functional performance of GA building show that cleaning, friendliness, parking space, landscaping and indoor climate are the top five rated. Findings also reveal that lack of awareness about POE is a top-rated barrier, followed by a lack of orientation of stakeholders and a lack of adequately trained staff. Originality/value The study contributes to the body of knowledge on POE, particularly in universities by conducting an empirical evaluation of both technical and functional performance of the University of Uyo buildings. Besides, it establishes a set of factors that significantly hinder the implementation of POEs in universities. From a practice perspective, it provides valid feedback on which universities can build upon to improve conditions of their facilities and ultimately bolster the conducive environment for teaching and learning.


2001 ◽  
Vol 90 (6) ◽  
pp. 2445-2452 ◽  
Author(s):  
Dragan Brajkovic ◽  
Michel B. Ducharme ◽  
John Frim

The purpose of the present experiment was to examine the relationship between rate of body heat storage (S˙), change in body heat content (ΔHb), extremity temperatures, and finger dexterity. S˙, ΔHb , finger skin temperature (Tfing), toe skin temperature, finger dexterity, and rectal temperature were measured during active torso heating while the subjects sat in a chair and were exposed to −25°C air. S˙ and ΔHb were measured using partitional calorimetry, rather than thermometry, which was used in the majority of previous studies. Eight men were exposed to four conditions in which the clothing covering the body or the level of torso heating was modified. After 3 h, Tfing was 34.9 ± 0.4, 31.2 ± 1.2, 18.3 ± 3.1, and 12.1 ± 0.5°C for the four conditions, whereas finger dexterity decreased by 0, 0, 26, and 39%, respectively. In contrast to some past studies, extremity comfort can be maintained, despite S˙ that is slightly negative. This study also found a direct linear relationship between ΔHb and Tfing and toe skin temperature at a negative ΔHb. In addition, ΔHb was a better indicator of the relative changes in extremity temperatures and finger dexterity over time than S˙.


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