• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.429-439
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• 2013

Purpose: This study was assessed to investigate the change of subjective and/or objective symptoms and the light transmissibility of lens caused by over-usage of daily disposable circle contact lenses (circle lens). Methods: Three daily disposable circle lenses made of etafilcon A, hilafilcon B, and nelfilcon A were applied on 20 normal eyes free from any eye diseases by when subjects complained any kind of discomfort. On the first and the last days of lens wearing, subjective discomfort, blinking rate, non-invasive break-up time, lens centration on corneal surface and visible light transmissibility of lens were recorded at every case and compared. Results: The circle lens wearers complained discomfort when they wore the circle lens more than 15 hours, in excess of 8 hours being the recommended wearing time and the most circle lens wearers quit the lens wearing when they wore more than 30 hours. On the last day of lens wearing, the representative subjective discomforts were stiffness, dryness and tiredness. When the subjects wore circle lens more than the recommended time, a tendency of increased blinking rate and decreased NIBUT was observed when it compared with the values right after lens wearing. On the last day of lens wearing, the lens centration was shown to be decentrated from the pupil center compared with the centration right after the wearing. These changes in lens centration and blinking rate were consistently shown in all cases of lens wearing however, the difference in the degree of subjective and/or objective change was present depending on lens materials and subjects. The visible light transmissibility of circle lens has largely been changed. Conclusions: From these results, it was thought that the decreased NIBUT induced dryness and stiffness and decreased visible light transmissibility caused more blinking when daily disposable circle lens was exceedingly used, which provoked lens decentration and subjective discomfort. However, the difference of subjective and/or objective change was largely varied in accordance with the lens material types and individuality and thus it may occur some unexpected problems by the individual base. Therefore, the education about the necessity to comply with the recommended wearing time and the problem will be essential.

• Physical Therapy Rehabilitation Science
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• v.10 no.4
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• pp.438-443
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• 2021

Objective: The purpose of this study was to determine the effect of the difference in mask filters on the respiration rate of healthy people. Design: A randomized cross-over design. Methods: A total of 15 subjects were selected for this study (n=15). After filling out the Physical Activity Readiness Questionnaire, the selected participants abstained from caffeinated beverages and meals 30 minutes before and sat in a chair 10 minutes before stabilizing their breathing. Afterwards, the lung function test was performed 3 times for each mask, and the maximum value was used. The provided masks were Mask Free, Dental Mask, KF80, and KF94. Exhalation was measured for 6 seconds for each mask, and breathing was stabilized by repeating inhalation and exhalation until the next time. Results: In this study, the difference in respiratory function according to the mask type was statistically significant except for FEV1 and FVC (p<0.05). As a result of post-hoc analysis, FVC, FEV1, PEF, and FEF values were significantly lower than those of the control group not wearing a mask (p<0.05). When wearing KF94, FVC, FEV1, PEF25-25%, and FEF were significantly lower than when wearing a dental mask (p<0.05). When wearing a KF80 mask, it was significantly lower in FVC and FEV1 than when wearing a dental mask (p<0.05). In FEV1/FVC, the difference by mask type was not statistically significant (p<0.05), but it was lower than the spirometry standard of COPD patients (FEV1/FVC<0.7). Conclusions: As Now that wearing a mask is essential, it has been confirmed that the mask affects the respiratory rate.Therefore, in the case of healthy adults, it is recommended to rest after wearing a mask if attention deficit or headache occurs. People with low breathing capacity are recommended to have low-intensity activities and frequent rest periods after wearing a mask.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.1
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• pp.43-49
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• 2015

Purpose: This study was to compare the habitual soft contact lens wear to recommended wearing schedule for subjects and suggest a clinical guideline for prescribing contact lens. Methods: 611 adults (39 men and 572 women) with contact lens experience took part in this study. The survey collected information about current wearing schedule (hours/day and days/week), types of lenses worn and awareness of recommended wear schedule. Results: The subjects wore the daily contact lens for $7.97{\pm}3.60$ hours/day in average. Of these, 247 subjects (40.4%) exceeded the recommended wear schedule and 36 (5.9%) wore for over 15 hours. It turned out that subjects with 3-month extended contact lenses and the ones with the conventional daily wear wore for $9.79{\pm}2.68$ hours and $8.98{\pm}3.30$ hours/day, respectively. For subjects wearing contact lenses longer than five days/week it tended to wear for over 9 hours. Those who were aware of the wear schedule were 293 (48.0%), and those not were 318 (52.0%). 56.7% of subjects who were aware of the wear schedule respected the recommendation whereas only 22.3% of those unaware of it were found to respect it. The possibility to respect the wear schedule was 4.55 times higher when wearers were aware of it. Conclusions: Korean office workers wearing contact lenses wore for $7.97{\pm}3.60$ hours/day. 247 (40.4%) of subjects wore contact lens longer than recommended wear schedule. This implies that it will need to educate contact lens wearer about recommended wear schedule and advice for the long time wearer.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.151-156
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• 2015

Purpose: This study has been compared the degree of corneal edema arising from the material of the lens after wearing the recommended wearing time for the contact lens. Methods: For the study, 43 adults of 77 eyes who did not use drugs and have not any disease participated. Three types of lenses including narafilcon A, HEMA, and silicone hydrogel material regular replaceable lenses were used. Central corneal thickness was measured before and after 8 hours from wearing lenses using Pentacam. The degree of corneal edema was determined by the difference before and after wearing. Results: The average corneal edema of narafilcon A, HEMA material lens, and silicone hydrogel material regular replaceable lens were $2.36{\pm}6.15{\mu}m(Mean{\pm}SD)$, $23.61{\pm}10.71{\mu}m$, $18.25{\pm}8.64{\mu}m$, respectively. The central corneal thickness after wearing narafilcon A was not statistically significant with the central corneal thickness before wearing the lens. Central corneal thickness before and after wearing HEMA material lens and silicone hydrogel material regular replaceable lens were statistically significant. Conclusions: The amount of corneal edema induced by silicone hydrogel material regular replaceable lens was no statistically significant difference to the amount of corneal edema induced by HEMA material lens, but there was significant difference to narafilcon A. Therefore, it is judged to be careful not to exceed the recommended wearing time depending on the composition of the contact lens material.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.2
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• pp.153-162
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• 2014

Purpose: This study was assessed to investigate the change of subjective and/or objective symptoms and the light transmittance of lens caused by the use longer than recommended wearing time of daily disposable circle contact lenses (circle lens) in dry eyes. Methods: Three daily disposable circle lenses made of etafilcon A, hilafilcon B, and nelfilcon A were applied on 30 dry eyes with smaller tear volume than normal eyes in their twenties free from any eye diseases by when subjects complained any kind of discomfort. On the first and the last days of lens wearing, subjective discomfort, blinking rate, lens centration on corneal surface and visible light transmittance of lens were recorded at every case and compared. Results: The circle lens wearers complained subjective discomfort and quit the lens wearing when they wore the circle lens longer than 10 hours even though there were some difference according to the lens materials of daily disposable circle lens. However, around 20% of dry eyes could wear the circle lens made of non-ionic materials longer than 40 hours. Dry eyes showed most sensitive feeling of subjective discomfort against the circle lens made of etafilcon A among three different lens materials. On the last day of lens wearing, the representative subjective discomforts were irritation, stiffness, dryness and tiredness. When the subjects wore circle lens more than the recommended time, blinking rate was significantly increased about 20~30% regardless of lens materials when it compared with the values right after lens wearing. On the last day of lens wearing, the vertical direction of lens centration was shifted to pupil center however, its distribution in horizontal direction was wide compared with the distribution right after lens wearing. Especially, the centration of etafilcon A lens was unstable. Furthermore, the visible light transmittance of 3 different circle lenses in dry eyes has significantly been reduced around 15% averaged. Conclusions: From these results, it was known that the increase of dryness and stiffness caused by overusage of daily disposable circle lens induced excess irritation and decreased visible light transmittance and caused significant more blinking, which provoked lens decentration. It was also revealed that dry eyes showed sensitive reaction subjectively and objectively against the overusage of circle lens made of high water content/ionic lens material even there were some difference of the degree depending on the individual and the lens material. Thus, this research can be suggested as the basic reference for the education about some unexpected problems and the side effect caused by the wearing of circle lens in dry eyes.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.1
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• pp.1-12
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• 2011

This study tests the performance of the recommended winter dress OnMapsi for an office worker through the analysis of skin temperature changes according to the heating environment. We tested and compared the effects of with/without undergarments for 4 male subjects in an artificial-climate chamber with two air temperatures of $19^{\circ}C$ and $22^{\circ}C$, $50{\pm}10%$ R.H. During the 60 minute experiment that simulated office work, the subjective feelings (that included thermal, humidity and comfort sensation, and skin temperature) were measured at equal intervals. The results show that the forehead and chest skin temperatures were not affected by air temperature or clothing type, while the hand and foot skin temperatures were affected at $0.3-0.9^{\circ}C$ depending on clothing type and $1.9-2.2^{\circ}C$ depending on air temperature. The mean skin temperature was decreased by the experimental time pass more with regular formal wear than with OnMapsi. The second experiment located the ambient temperature in which subjects wearing OnMapsi show equal skin temperaturesto those without undergarments at $22^{\circ}C$. Therefore it is possible to decrease heating temperatures to $18-21^{\circ}C$ in the office for winter OnMapsi wear that produces a skin temperature and thermal sensation that is the same as those at $22^{\circ}C$.

• The Journal of Korea Robotics Society
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• v.18 no.2
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• pp.189-196
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• 2023

An abdominal brace is a recommended treatment for patients with lumbar spinal disorders. However, due to the nature of the static brace, it uniformly compresses the lumbar region, which can weaken the lumbar muscles or create a psychological dependence that worsens the condition of the spine when worn for an extended period of time. Due to these issues, doctors limit the wearing time when prescribing it to patients. In this paper, we propose a device that can dynamically provide abdominal pressure and support according to the lumbar motion. The proposed device is a wearable robot in the form of a brace, with actuators and a driving unit mounted on the brace. To enhance wearability and reduce the weight of the device, worm gears actuator and a multi-pulley mechanism were adopted. Based on the spinal motion of the wearer measured by the Inertia measurement unit sensors, the drives wire by driving pulley, which provide tension to the multi-pulley mechanism on both sides, dynamically tightening or loosening the device. Finally, the device can dynamically provide abdominal pressure and support. We describe the hardware and system configuration of the device and demonstrate its potential through basic control experiments.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.187-198
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• 2002

Chlorpyrifos is an organophosphate insecticide and one of the most commonly and widely used insecticide. However, a little known about the dermal risk of chlorpyrifos on human being. Therefore, this study was conducted for the dermal risk assessment after exposure to chlorpyrifos in Korean farmers. First, skin irritation by chlorpyrifos (10 mg/$\textrm{cm}^2$, 50 mg/$\textrm{cm}^2$, 100 mg/$\textrm{cm}^2$, 250 mg/$\textrm{cm}^2$ in acetone) was determined in rabbits for 5 days considering the usage of chlorpyrifos short term highly exposure. The index of skin irritation by chlorpyrifos was increased in each dose and length of exposure dependent manners. Next, using benchmark dose (BMD$_{5}$) approach, the dose-response relationship was assessed to calculate the reference dose (RfD). The value of RfD was 2.84 $\mu\textrm{g}$/kg/day from 142.16 $\mu\textrm{g}$/kg/day BMD5 value divided uncertainty factor 50. Finally, we assessed human dermal risk of chlorpyrifos with exposure level and RfD. Skin absorbed levels were assumed with several exposure scenarios encounting the circumstances of exposure that application method, protection equipment and cloth, exposure time and exposure frequency during chlorpyrifos spraying. By the comparison of skin absorbed dose with the reference dose, it was identified that risk values (risk index) to skin chlorpyrifos exposure were 0.958 from the point of above results and it was recommended that the occurrence of hazard effect (skin irritation toxicity) of chlorpyrifos would not be expected. Risk index was smaller than 1 in the case of spraying vehicle mounted application, 1hour exposure time and wearing protective cloth exposure. Whereas, risk index was above 1 in the case of hand-held application, 2hour exposure time and wearing common cloth. Comparing two kinds of application method, total risk index of the hand held application (1.67) was higher than vehicle mounted (0.27). Therefore, chlorpyrifos skin exposure was mainly affected by application equipment and applied form. The results of risk assessment on the human dermal toxicity of chlorpyrifos should be required to control in keeping safety rules, skin surface area available for contact, spraying time ,and spraying frequency.y.

• Journal of Society of Preventive Korean Medicine
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• v.27 no.1
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• pp.89-98
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• 2023

Objectives : This study collected sleep information by wearable device in the Korean medicine Daejeon citizen cohort (KDCC). It was measured based on the sleep record information measured by wearing a Fitbit, and the possibility of clinical use was examined for compliance with objective sleep collection. Based on compliance, the possibility of clinical use was examined. Methods : After surveying personal information and PSQI(Pittsburgh Sleep Quality Index), sleep information was collected by Fitbit for 14 days. Compliance was measured based on sleep record information by Fitbit. Compliance was analyzed by sex, age, BMI(Body Mass Index), and sleep group(deep/poor). Results : The number of participants was 730, and the compliance was 94.3%, and the compliance group was 675(92.5%). The age of the participants varied from 30 to 60 years old, and the average age was 46±6.7 years. There were 218 males and 512 females. Young people have high compliance. Males are more compliance than females. As the BMI score decreased in the 30s, the compliance was higher. The underweight group in all age groups had 100 compliance. The underweight group was all female. The low compliance groups were that 30 years males (obesity level2), 50 years females (overweight group), and 50 years females (obesity level2). There was no significant difference in compliance between deep sleep group and poor sleep group. In deep sleep group, females showed higher compliance. In poor sleep group, males showed higher compliance. The average duration of Fitbit usage among participants was 20.1 days. The compliant group wore the device for an average of 21.3 days, while the non-compliant group wore it for only 5.2 days. Of the compliant group, 86.9% (73.8% of all participants) continued to wear the Fitbit after the recommended 14-day period, and 50.8% wore it for more than 20 days. Conclusions : This study showed the possibility of adaptation for wearing a Fitbit for collecting objective sleep information. It is judged that the compliance is high because it was worn for more than 13.2 days out of the 14 days required. It is considered meaningful because the compliance was measured based on the sleep information by Fitbit, not the questionnaire. As the data on objective sleep time is collected automatically, we believe that the burden on participants after the study period is not significant for a certain period. Compliance may be even higher for cohorts related to illnesses and with doctor's orders, rather than for the general population.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2624-2628
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• 2011

Exposed dose of a patient was measured by Radiophotoluminescent Glass Rod Detector with a use of a panorama graphic device in dental examination. The effect of exposed dose in optic lens was measured by comparing the different materials of the glasses. Depending on the dental location, the exposed dose distribution was 82.4~2,340uSv. It showed that the maximum difference in dose distribution was over 300%. Thus, when manufacturing the devices, it seemed to require shortening the pre-heat time and additional shielding in order to control the diagnosis and exposed dose. The measurement data of the exposed dose in optic lens was increased 20~75uSv per each test when compared putting on glasses with not wearing. As a result, taking off the glasses is recommended to improve efficiency of the test and minimize the exposed dose during dental panorama graphic examinations.