• The Korean Journal of Physiology
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• 제6권2호
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• pp.31-37
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• 1972

The right cervical vagus nerve was electrically stimulated for 30 sec, and 30 minutes recording cardiac rate responses and electrocardiogram. The main purposes of the present experiment are to determine effect of stimulation frequency on the maintenance of cardiac rate responses and to determine recovery time of sinus rhythm after asystole period followed by idioventricular rhythm during prolonged electrical stimulation of the vagus, and the optimal stimulation parameters for vagal stimulation were studied as well. The results obtained are summarized as follows: 1. The maximum negative chrontropic responses were obtained with the following ranges of electrical parameters. Intensity: 3V-7V, Frequency: 20/sec-60/sec, and pulse duration: 5 msec-20 msec. 2. Compared with the responses from sympathetic effectors, cardiac rate responses to electrical stimulation of vagus nerve were well maintained with all stimulation frequencies. 3. At all stimulation frequencies except 20/sec, sinus node started to take over primary pacemaker activity when cardiac rates were restored to about 38-40/min. 4. It was indicated that upper limit of idioventricular rhythm does not exceed 38-40/min. 5. With the stimulation parameter set of 20/sec-5 msec-3 V, sinus rhythm did not appear during 30 minutes of stimulation period. Therefore, this electrical parameter set appears to be optimal for elicitation of prolonged and maximum cardiac rate responses by vagal stimulation.

• Journal of the Korean Home Economics Association
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• 제40권11호
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• pp.193-205
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• 2002

To evaluate farmers' workload during harvesting grapes in summer, this study investigated farmers' physiological, psychological responses, work postures and thermal environment around in the field. This field study was conducted in the Anseong County of Kyonggi Province at the end of August. Five career farmers (1 male, 4 females) volunteered as subjects. Three of them were over their sixties. During harvesting grapes in the field, physiological responses were monitored continuously. 1. Air temperature (T/sub a/), air humidity(H/sub a/), black globe temperature(T/sub g/), air velocity and WBGT around the grape field were 26.9℃, 77.7%RH, 32.8℃, 0.08㎧ and 26.3℃, respectively. Because farmers started the harvesting task in early morning, thermal environments weren't conditions to give farmers severe heat strain. 2. The percentage of the work postures was larger in order of standing, walking, and bending one's back posture. Particularly, the percentage of standing posture with raising both arms above shoulder of two farmers was up to 29% and 61% of the total work duration. 3. Rectal temperature (T/sub re/), mean skin temperature (T/sub sk/), clothing microclimate temperature (T/sub cl/) on the chest and the back, heart rate (HR) and energy expenditure (EE) were 37.2℃, 33.1℃, 32.0℃, 32.4℃, 88bpm and 1.3 Kca1/㎡/min respectively. In the point of these physiological results, we evaluated that the harvesting task was a moderate work. 4. All farmers expressed‘hard, hot, humid and slightly uncomfortable’ at the end of works for each subjective questionnaire. The grape harvesting tasks were not evaluated as a very hard work in the point of physiological work standards. But we considered 1) inappropriate work posture (standing posture with raising both arms above shoulder) and 2) farmers' age as burden factors. These findings suggest that adding adequate protective clothing/equipments for farmers may contribute to maintain their body temperature within the normal range, stabilize HR and decrease psychological strain.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제50권2호
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• pp.153-159
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• 2017

We examined changes in the physiological responses of gray mullet Mugil cephalus exposed to acidic seawater (pH 6.0, 6.5, 7.0) and normal seawater (pH 8.0, control) for 15 days. As pH decreased, survival rate and body weight also decreased. Levels of aminotransferase, total protein and triglycerides also differed significantly with changes in pH, presumably due to stress caused by exposure to acidic water. The level of osmotic pressure was significantly higher in the pH 6.0 group than in other groups. Superoxide dismutase was significantly higher in the pH 6.5 and 7.0 groups than in the pH 8.0 group, and glutathione level was lowest in the pH 6.0 group. We conclude that decreasing the pH level of seawater induces a stress response in fish, damaging their ability to control their hematological and osmotic pressure. Antioxidant enzymes are generally sensitive to osmotic stress; in this study, antioxidant activity significantly changed with pH level. These results indicate that physiological stress induced by exposure to acidification reduces survival rates and inhibits growth in M. cephalus.

• Asian-Australasian Journal of Animal Sciences
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• 제13권4호
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• pp.528-534
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• 2000

Sixteen specific pathogen free 4-wk-old crossbred weanling pigs were allotted into a $2{\times}2$ factorial design to evaluate chromium picolinate (CrPic) on growth and physiological responses. Two factors included (1) no Cr or 400 ppb Cr supplementation from chromium picolinate and (2) lipopolysaccharide (LPS) injection on day 21 (d 21) and 35 (d 35) compared to saline application. Plasma samples and rectal temperature were obtained from all piglets before (h 0) and at 2 h (h 2), 4 h (h 4), 8 h (h 8), and 24 h (h 24) after LPS injection ($200{\mu}g/kg$ BW, intraperitoneally). The rectal temperature on d 21 was significantly decreased (p<0.05) of about $0.36^{\circ}C$ with Cr supplementation before LPS injection. After LPS injection, the daily gain of piglets was decreased during d 35-38. Supplementation of Cr had no effect in general on growth performance particularly after LPS injection. The plasma glucose, triglycerides and urea nitrogen concentrations were changed in different ways after LPS injection. Plasma cortisol level was significantly elevated at h 2 after LPS injection on d 21 and d 35. The supplementation of Cr in the diet can delayed plasma cortisol release on d 35. The results suggest that 400 ppb Cr supplementation from CrPic may modulate the physiological response during immune stress in weanling pigs.

• Journal of Biosystems Engineering
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• 제36권3호
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• pp.223-230
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• 2011

Physiological signals such as body temperature, heart rate, blood pressure and heart rate variability and biomechanical workload for stress analysis were investigated during the cherry tomato harvesting work in a greenhouse. The skin temperatures raised $0.05^{\circ}C$/min, $0.03^{\circ}C$/ min, and $0.08^{\circ}C$/min in standing, stooping and squatting postures, respectively. Breath rate significantly increased from 18 to 28 breaths/min during the cherry tomato harvesting work. As the heart rate during the work ranged from about 72 to 110 beats/min (bpm), the cherry tomato harvesting work appeared to be a light intensity task of less than 110 bpm. The worker's average energy consumption rate in three positions during 43 min working time was 65.74 kcal (91 kcal/h in 70 kg). This was a light intensity of work, compared to 75 kcal/h in 70 kg of basic metabolic energy consumption rate of a worker with 70 kg weight; The maximum shear force on the disk (L5/ S1) due to static workload in the cherry tomato harvesting work was 446 N in the stooping posture, 321 N in the squatting posture and 287 N in the standing posture. Acute stress index expressed with the heart rate variability, increased parasympathetic activation up to about 70 while workers were doing most agricultural work in this study. This study provided a system to measure quantitatively workers' physiological change, kinematics and kinetic factors without any restrictions of space in the greenhouse works.

• Journal of Aquaculture
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• 제16권1호
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• pp.31-36
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• 2003

Two experiments were conducted for the physiological and growth responses of yearling sea bass, Lateolabrax japonicus (total length 24.4$\pm$1.5 cm, body weight 125.4$\pm$25.4 g) by the manipulation of salinity. To study the physiological responses of the sea bass by acute salinity change, we changed water salinity from 30 ppt into 2 ppt in rearing tank through 1 hour or 6 hour. To access the effect of salinity in the growth of sea bass, we also examined the growth of the sea bass in 2, 10, 20 and 30 ppt for 180 days. After salinity change, all yearlings appeared some stress response and ions changes in blood. The yearlings showed a slow recovery by an acute salinity exchange, but a fast recovery by slow salinity exchange. In the study about the influence of salinity in growth, although the food intake of yearlings in 20 ppt was significantly higher than the yearling in the other salinities, feed efficiency was higher in 10 ppt than the other salinities. However, the food intake and the feed efficiency in 2 ppt were significantly lower than in other groups. The growth of yearlings was significantly faster in 20 ppt than in the other salinities, but the growth showed significantly slower in 2 ppt than in the other salinities.

• International Journal of Highway Engineering
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• 제20권1호
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• pp.107-115
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• 2018

PURPOSES : As the population of the mobility handicapped, who are classified as the disabled, the elderly, pregnant women, children, etc., has increased, the voices for guaranteeing their rights have been increasing as well. Thus, the design manuals for roads and sidewalks for the mobility handicapped were developed by the local government, such as the Ministry of Land, Transport, and Tourism, in Seoul City. However, according to the 2013 survey results of the Seoul Metropolitan City, the mobility handicapped still feel uncomfortable with the sidewalks, and particularly request for the improvement of the step and slope of the sidewalk curb. Therefore, in this study, we conducted an empirical experimental study to determine the slope of the sidewalk curb and height of the steps considering the mobility handicapped and analyzed whether there is a statistically significant difference. METHODS : The methodology of this study is an empirical experimental one. In the study, five non-disabled people, 10 wheelchair users, and 10 eye patch and stick users walked about 2-3 min on the sidewalk plates of the sloped type (0%, 5%, 6.3%, 8.3%) and stepped type (0 cm, 1 cm, 3 cm, 6 cm), and their human physiological responses, such as the skin temperature, volume of perspiration on forehead and chest, and heart rate, were measured and recorded. After combining the data, we conducted a nonparametric test, ANOVA, or t-test to determine whether there was a statistically significant difference according to each slope and step type. RESULTS : It was found that for the non-disabled, there was no significant difference in human physiological responses according to the slope and steps of the sidewalk. It can be said that the non-disabled do not feel much physiological discomfort while walking. In the case of the sloped sidewalk plate, the heart rate of the wheel chair users increased when the slope was 6.3%. In the case of the eye patch and stick users, the volume of perspiration on the chest increased at a slope of 5.0%. In general, it is judged that a sidewalk with a slope that is less than 5% does not cause a change in the physiological response. In the case of a stepped sidewalk plate, when 0 cm, 1 cm, and 3 cm were compared for wheelchair users, the amount of forehead perspiration increased from 1 cm. Meanwhile, in the case of the eye patch and stick users, when 0 cm and 6 cm were compared, the amount of perspiration on the forehead and chest as well as the heart rate all increased at 6 cm. Taken together, in the case of wheelchair users, a difference was shown when the height of the step of the sidewalk plate was 1 cm, suggesting that installing it at 0 cm does not cause any physiological discomfort. Moreover, in the case of the eye patch and stick users, when comparing only 0 cm and 6 cm, 0 cm was considered to be suitable, as there was a difference in physiological response at 6 cm. CONCLUSIONS : In this study, we set the human physiological responses such as chest skin temperature, amount of perspiration, and heart rate as evaluation items, and our study was considered to be a meaningful experiment that targeted wheelchair users as well as eye patch and stick users. The validity of the evaluation items was confirmed, as the results of human physiological responses were significant. As for the sidewalk design, according to the experiment result, it is considered that differential application should be implemented according to the type of mobility handicap, rather than uniformly applying a sidewalk step of 2 cm and sidewalk slope of 1/25, which are the current legal standards.

• Child Health Nursing Research
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• 제7권1호
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• pp.35-50
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• 2001

The ability of neonates to perceive and react to pain, has been acknowledged recently. Recent researches have been shown that even short term pain can have lasting negative effects. We know that most of the anatomical pathway and neurotrans-mitter function necessary for pain perception are fully or nearly fully developed in the neonatal period. Many people are still reluctant to believe that pain felt by neonates may be as severe as that felt by older children or adults yet. The objective of the study is to assess and compare the analgesic effects of orally administered sucrose and pacifiers. And to determine the synergistic analgesic effects of sucrose and pacifiers. The tools for this study is Lawrence's NIPS (neonatal infant pain scale) with behavioural pain responses and index for pain physiological reponses as heart rate, respiratory rate and degree of SaO₂. The participants are 96 healthy infants of neonatal age 1-7days and randomised to receive heel prick before 2minutes to blood sampling and physiological test in Nursery of K Medical University Hospital on May-July, 2000. The experimental group assigned to one of three treatment groups : no treatment; a pacifier; placebo(2ml 25％ sucrose). Collected data were analyzed with the SAS program using X²-test, ANOVA and Duncan's multiple range test as post hoc. The results were as follows. 1) Pain behaviour responses: The pain score of placebo group(2ml 25％ sucrose) is lower than no treatment group and pacifier group significantly(P=.000). Placebo group is different from no treatment and pacifier group with Duncan's multiple range test. 2) Pain physiologic responses (1) heart rate: The heart rate of placebo group(2ml 25％ sucrose) is different from that of no treatment group and pacifier group significantly(P=.000). The heart rate change of placebo group is less than the other groups. (2) respiratory rate: The respiratory rate of placebo group(2ml 25％ sucrose) is different from that of no treatment group and pacifier group insignificantly (P=.2340). But, the respiratory rate of placebo group is lower than the other groups. (3) SaO₂: The SaO₂ score of placebo group(2ml 25％ sucrose) is different from that of no treatment group and pacifier group insignificantly (P=.3265). But, the change of SaO₂ score of placebo group is less than the other groups. In conclusion, the sucrose placebo showed pain relief effect in behavior responses and less physiological responses. Accordingly, the sucrose placebo should be applied nursing intervention for simple pain management as heel prick.

• ETRI Journal
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• 제45권1호
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• pp.105-118
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• 2023

We tested the feasibility of automated discrimination of patients with panic disorder (PD) from healthy controls (HCs) based on multimodal physiological responses using machine learning. Electrocardiogram (ECG), electrodermal activity (EDA), respiration (RESP), and peripheral temperature (PT) of the participants were measured during three experimental phases: rest, stress, and recovery. Eleven physiological features were extracted from each phase and used as input data. Logistic regression (LoR), k-nearest neighbor (KNN), support vector machine (SVM), random forest (RF), and multilayer perceptron (MLP) algorithms were implemented with nested cross-validation. Linear regression analysis showed that ECG and PT features obtained in the stress and recovery phases were significant predictors of PD. We achieved the highest accuracy (75.61%) with MLP using all 33 features. With the exception of MLP, applying the significant predictors led to a higher accuracy than using 24 ECG features. These results suggest that combining multimodal physiological signals measured during various states of autonomic arousal has the potential to differentiate patients with PD from HCs.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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• pp.370-379
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• 2000

Autonomic responses were analyzed in 323 college students exposed to visual stimulation with Korean Affective Picture System (KAPS). Cardiac, vascular and electrodermal variables were recorded during 30 sec of viewing affective pictures. The same slides intended to elicit basic emotions (fear, anger, surprise, disgust, sadness, happiness) were presented to subjects in 2 trials with different experimental context. The first time slides were shown without any instructions (passive viewing), while during the second with instruction to exert efforts to magnify experienced emotion induced by pictures (active viewing). The aim of the study was to differentiate autonomic manifestations of emotions elicited by KAPS stimulation and to identify the role of instructed emotional engagement on physiological response profiles. The obtained results demonstrated reproducibility of responses in both trials with different contexts. Pairwise comparison of physiological responses in emotion conditions revealed the most pronounced differentiation for "ear-anger" and "fear-sadness" pairs (in electrodermal and HR variability parameters). "Fear-surprise" pair was also well differentiable. The typical response profile for all emotions included HR acceleration (except happiness and surprise), an increase of electrodermal activity, and a decrease of pulse volume. Higher cardiovascular and electrodermal reactivity to fear observed in this study, e.g., as compared to data with IAPS as stimuli, can be explained by cultural relevance and higher effectiveness of KAPS as stimuli, can be explained by cultural relevance and higher effectiveness of KAPS in producing certain emotions such as fear in Koreans.