Flicker Values Research Articles

On the Balance of Skill and Operation : 2 nd Report, The Relation between the Flicker Value and the Operational Ability of Workers during the Operation of the Simulator

This paper deals with the relation between the operational ability of workers and the work load shown by the flicker value measurement. The subjects are assigned to operate a simulator of the motor-man's platform of the automobile under working conditions, in which subjects are obliged to watch one, two or three vigilance objects. The flicker value and the frequency of missing objects are measured in working hours and analysed by the statistical multivariate method. It is made clear that the work load of a subject increases as the number of objects increases. And the subject who directs his attention to a certain vigilance object can direct also his attention to other objects and his operational ability is very high but his work load is very heavy. Further the work load on the subject, whose operational ability to all vigilance objects is medium, is lightest. Therefore, it is possible to select workers who are fit for work by these results.

Urinary excretion of hippuric acid and m- or p-methylhippuric acid in the urine of persons exposed to vapours of toluene and m- or p-xylene as a test of exposure.

<b>Ogata, M., Tomokuni, K., and Takatsuka, Y. (1970).</b><i>Brit. J. industr. Med.,</i><b>27,</b> 43-50. <b>Urinary excretion of hippuric acid and <i>m</i>- or <i>p</i>-methylhippuric acid in the urine of persons exposed to vapours of toluene and <i>m</i>- or <i>p</i>-xylene as a test of exposure.</b> Twenty-three male volunteers were exposed in groups of four or five to toluene and <i>m</i>- and <i>p</i>-xylene vapour for periods of 3 hours or of 7 hours with one break of an hour. Urine was collected at hourly intervals for several hours, and thereafter all urine was collected until 18 hours after the end of the exposure period, and was analysed for hippuric and methylhippuric acids. It was shown that hippuric acid was excreted equivalent to 68% of the toluene absorbed, and <i>m</i>-methylhippuric acid equivalent to 72% of the <i>m</i>-xylene absorbed. Up to hydrocarbon concentrations of 200 ppm the total quantity of hippuric acids excerted was proportional to the total exposure (ppm × hours). In descending order of precision the following were also related to exposure: rate of excretion during the exposure period; concentrations of hippuric acid in urine corrected to constant urine density; and concentrations in urine uncorrected for density. The last could not be used to calculate exposure, but the others could be to give screening tests to show whether workmen could have been exposed to concentrations greater than the maximum allowable. The effects of exposure on blood pressure, pulse rate, flicker value, and reaction time were measured. There were some variations which suggested that the MAC of toluene should be set higher than 200 ppm.

On the Balance of Skill and Operation : 1st Repot, On the Business Management Using the Modified Control Chart of the Flicker Value

This paper deals with the problem of the business management of workers using the control chart of flicker value. We define the range of flicker value for a day or two consecutive days. This measure is to reduce the personal difference of flicker value. The control chart of the quality control is modified to be suitable for the business management. This method is applied to the control of bus drivers in working hours. Then it is made clear that the range of flicker value of worker decreases as worker's years of experience increase and factors which disturb the controlled condition can be found from this chart. It is possible to carry out the business management numerically by this method.

電信電話作業者の疲労に関する調査研究

Telegraph and telephone services compel the operators to work by imposing on them visual and auditory senses, manual cooperative actions, and nervous tension for quick and accurate reply. Accordingly, the fatigue of the operators caused by mental and sensory tension is likely to be angmented with the mechanization of equipment, the increase of the intensity of operation, and the midnight shift. Researches were carried out to make these points clear with the following approaches: (A)comparison of fatigue complaints among operators on various jobs and shifts in different offices of different scales; (B) measurement of flicker values related with working conditions of the operators; (C) recording physiological responses while working, such as heart rate, respiration, and galvanic skin resistance (GSR). Results are as follows: 1) a) Fatigue complaints of punchers and deliverers were most frequent as characteristic symptoms compared with those of other workers. In such jobs a tendency of accumulation and fixation of fatigue was seen. Communication and telephone operators came to the next. Those fatigue symptoms were mainly of neurosensory origin, such as strain of the eye and heavy-feeling of the head. Complaints of punchers were focussed on shoulder and waist due presumably to constrained working posture. b) Fatigue complaints were most frequently expressed by night-shift workers and less frequent in different kinds of workers in the order: evening shift workers, daytime workers for 8 hours, those of 6 hours, and half-day workers. At larger offices in the municipal area fatigue complaints of the operators were more pronounced than those at the smaller offices in the rural area. 2) Results of the flicker test on the operators also revealed some differences among jobs and shifts. A remarkable decrease of the flicker value was found in the night-shift workers, especially in female operators after a nap. 3) Physiological responses of the operators during the working time were manifold according to the job. a) Physical movements and acts necessary for operating work, such as reply to telephone calls and arrangement of slips in the telephone operators, stamping and typewriting in the printed form of communication operators, precision work and going up and down the stairs in the machinists, could easily provoke excited reactions in the heart rate, in the respiratory pattern, and in the galvanic skin resistance, as sensory and emotional stimuli. b) Generally speaking, a prompt elevation of nervous tension was observed from the beginning of work with a stationary condition after 20-40 minutes. After the pause of work, a temporary 'rest effect' was noted. However, after 5-6 hours from the beginning of the work or 1 hour after one set of continued operation, a definite increase of the heart rate (10-20% on an average) with greater fluctuations was noted. This was particularly remarkable at night work. c) In unskilled operators the 'rest effect' was scarcely noted, and the auto-correlation coefficient of heart rate revealed a marked difference compared with that in the skilled. This may be due to the greater nervous tension in the unskilled operators. It is concluded that the feature of fatigue caused by telegraph and telephone operations accompanied with neuro-sensory tension is influenced by various working conditions, especially hours of work, arrangement of pause, night-shift, frequencey of operations, constrained posture, and skillfulness of workers. Therefore, the necessity of improvement of these working conditions should be stressed.

Auditory Flutter Fusion Method(フラッター法)の意義とその応用 : 聴覚系を利用する新しい中枢神経機能測定法 (第1報)

The author investigated the significance and the practical usage of the auditory flutter fusion (AFF) method which might indicate some aspects of the function of the central nervous system by way of the auditory nervous system. The flutter values by the AFF method were taken under several conditions. It was revealed that flutter values obtained during a week on persons loaded with mentally and physically light work distribute almost normally and that the values obtained on some air traffic control specialists correlate inversely and closely with the degree of mental fatigue evaluated by other methods. Comparing the flutter values and the flicker values on the same subjects kept awake for 24 hours, the author found that the decrease in the former was less than that in the latter. And the author discussed the likeness and the difference of the meaning between both values. The AFF was thought by the author to indicate some aspects of homeostatic of the human nervous center.

東北積雪地帯農民の労働と保健に関する研究 : 第3報 農繁期の疲労について

A long-term investigation was made on the physical load and fatigue of the farmers lasting three months in the spring and autumn of 1962. The farmers tested were divided into two groups, namely, one consisting of six families which cultivate mainly apples and the other of nine families which cultivate mainly rice (Tab.1). The flicker fusion frequency and the threshold of patellar reflex were examined on the farm once a week. The Donaggio reaction and the amount of creatinine and of uropepsin in the second urine in the morning were examined once a week as well. The results were as follows: (1) Daily calory consumption is less in the apple farmers than in the rice farmers, though daily working hours are longer in the former than in the latter, averaging ten hours and a half in the busiest week in June in the former (Tabs. 2, 3 and Fig.1). (2) The acute fatigue in the rice farmers at the rice-planting season is greater than in the apple farmers (from unpublished data), but the chronic fatigue throughout the spring is greater in the apple farmers than in the rice farmers (Figs. 3, 4, 5, 7, 8). That may be due to the fact that the apple cultivation requires longer daily hours and longer term of working, continuing to the begining of summer. (3) The fatigue in the spring is greater than in the autumn, and the fatigue in females is greater than that in males. (4) The flicker value in the apple farmers declines sharply as the daily working hours exceed nine hours (Fig.6). This fact shows that the optimum working hours in the apple farming is almost the same as that in many industrial works. (5) According to the results of tests on the urine and the blood (Figs.9, 10, 11 and Tab.4), it is concluded that physically stressed conditions continue more constantly in the apple farmers than in the rice farmers. These facts may be due to the difference of the nature of work in the both farmings. In the apple cultivation the sustained work is comparatively light and constant. (6) After all, the physiological loads in the apple farmers are heavier than in the rice farmers throughout the busy seasons.

東北積雪地帯農民の労働と保健に関する研究 : 第4報 農繁期疲労に及ぼすアスパラギン酸塩およびビタミンB&lt;SUB&gt;1&lt;/SUB&gt;の影響について

An investigation was made on the effects of aspartate and vitamin B1 upon the fatigue in 75 apple cultivating farmers. These farmers were divided into three groups, to each member of which a tablet including 150 mg of K- and Mg-aspartate, a tablet including 5 mg of VB1, and a tablet of placebo was respectively given every day. In some of them, the fatigue, subjective and objective, was estimated weekly; namely, the former was estimated by the questionnaire method and the latter by measuring body weight, physiological functions (flicker fusion frequency, threshold of patellar reflex, and blood pressure), Donaggio reaction and uropepsin during the farming season, May, June and July. In the other farmers, the subjective fatigue, body weight and blood pressure were measured once a month in the same season. The results were as follows: (1) The subjective fatigue in the group given aspartate and VB1 tends to decline in the later period of the season (Figs.1 & 2). (2) The body weight decreases gradually through the farming period. However, the decrease in the aspartate group is lower than in the other groups (Fig.3, Tab.1). This fact suggests an anabolic effect of aspartate through activation of the adrenal gland. (3) The flicker fusion frequency increases and the threshold of patellar reflex decreases in the middle period, and these changes are more remarkable in the group of aspartate and VB1 than in the placebo group. In the last period the flicker value decreases and the threshold value increases, and these changes are less in the former two groups than in the latter (Fig.5 and Tabs.2, 3). (4) Examinations of Donaggio reaction and uropepsin in the urine after the farming work revealed that the former tended to be lower in the VB1 group and the latter lower in the aspartate group (Fig.6). (5) The blood pressure tends to decline monthly in the aspartate and the control group, but not in the VB1 group (Fig.4). This tendency suggests that the seasonal variation of the physiological functions, including the blood pressure, is related not only to the variation of climate but of nutrition and other factors. These results show first that the aspartate and VB1 lighten the chronic fatigue in the farming seasons. However, it is a question whether the subjects were deficient in VB1 and the above effect of VB1 on the VB1 group was not pharmacological and positive but nutritional just supplying the deficiency. From this point of view, the effect of aspartate also should be further reexamined in the experimental conditions in which the nutritional requirements of VB1 in the subjects have certainly been fulfiled.

岸壁クレーン操縦者の疲労に関する研究

Eight healthy male operators of wharf cranes were chosen for fatigue condition investigation. The investigations were done once in summer and once in winter of which a report is presented herewith. The period of the investigation in winter was consecutive five days from February 9 and that in Summer was five days as well from July 19 on. Their working time was extended from 8 a.m. to 4 p.m. with one hour's rest period coming after every hour of actual labor. 1. The environmental conditions of the operating seat were examined at 10 a.m. and 2 p.m. every day and were found to be almost equal to outdoor conditions, The temperature in winter was 7.2°C at 10 a.m. and 10.2°C at 2 p.m., and in summer it was 24°C at 10 a.m. and 28°C at 2 p.m. The humidity was 48.5% at 10 a.m. and 45.7% at 2 p.m., in winter, and in summer 58.2% at 10 a.m. and 60.4% at 2 p.m.. 2. The investigation of their living schedules revealed that they actually worked daily 200 minutes in summer and 250 minutes in winter and that they slept daily 521 minutes in winter and 424 minutes in summer, that is, they were sleeping longer time in winter than in summer while working about equal length of time in both seasons. Besides, hours of excercise, recreational activities and miscellaneous work were longer in summer than in winter Their caloric consumptions, were about that of the medium labor. Their nutritional intakes were just about covering their needs but for calcium, vitamins A and C, which were all a little short. 3. Their blinker values and grip strength values were lower in summer than in winter, indicating that those physiological functions were decreased in summer. 4. In summer, blinker and flicker values as well as grip strength values tended to lower during the lapse of days, suggesting that their fatigue was accumulative. 5. All the three values occasionally became a littel higher immediately after the beginning of work in the moring, but lapse of working hours they Iowered gradually, and at the time the work was over they were so low indicating an onset of established fatigue. The fact that the decrease of flicker values more than that of grip strength or blinker values suggested that the mental fatigue was more marked than the muscular fatigue. This decrease of flicker values were more in summer than in winter, suggesting that fatigue was more masked in summer than in winter. 6. In the thourly alternate repetition of work and rest, it was observed that blinker and flicker values lowered by work and recovered to some extent by rest, but in the afternoon, the decline of these values increased while the recovery became less and less, flicker values recoveringnil by rest in some occasions. The same tendency was observed in grip strength values though not as distinct as in the cases of the other two.

電気閃光値よりみたアルコール飲用に対するチオクト酸アミド製剤の効果

By means of Motokawa's Method of electric flicker the authors examined the change in electric flicker values (EFV) of 6 healthy males due to alcohol drinking with and without oral administration of TAS (10mg) one hour in advance. As drinking alcohol, whisky and Japanese wine were chosen. EFV obtained after drinking whisky (40s60cc) increased remarkably, but EFV obtained after whisky drinking combined with TAS administration did not show any marked increase and EFV showing increase, if any, soon returned to the initial value. As to EFV obtained after drinking Japanese wine (120cc, 150cc, 200cc and 300cc), of the 6 subjects, in 2 it increased remarkably, and their EFV after Japanese wine drinking combined with TAS administration showed decrease and returned rapidly to the initial value. In another 2 subjects EFV showed, after increase, only rapid return to the intial value by TAS administration. In the remaining 2 subjects EFV did not show any remarkable effects due to TAS administration, while in the same subjects, administration of TAS showed greater effects against drinking bigger amount of Japanese wine than a little of it, i.e. the larger the amount of alcohol the greater the effect of TAS.

三交代高温作業者のフリツカー値と季節

Change of flicker values according to seasons was studied on sixty healthy men, 18 to 38 years of age working in three 8-hour shifts under hot environment. Thermal conditions of the environment of the workshop were: in summer, air temperatures 28 to 40°C., relative humidities 80 to 85%, wind velocity 0 and in winter, 28 to 30°C, 75 to 80%, and 0, respectively. Followings are the summary of the results. 1) In the morning shift, ficker values before work are lower than those after work, in winter; on the contrary, in summer, such difference was not significant. In the night shift, values after work were lower than those before work in both summer and winter, especially in summer. 2) In each shift, the flicker values both before and after work were lower in summer than in winter. 3) Sleeping hours of these workers were shorter in summer than in winter. Therefore, the flicker value may be affected by the change of sleeping hours, temperature, and others.

アスパラギン酸カリウム及びマグネシウム塩の疲労に及ぼす影響

A group of 14 male medical students, having nearly the same daily life, was the subjects, and the effects of a mixture of potassium and magnesium aspartates were observed on the reaction time to light, the flicker value and the threshold of patellar reflex. Of the subjects, 9 received 40 ml in 10% solution of the mixture per day and the rest 5 were used as the controls, receiving the placebo. The main results obtained were: 1. Reaction time to light indicates no great difference between the two sets of subjects, though the administered showed somewhat more reliability in the reponse, i.e. the values observed were less scattered. 2. Flicker value was decisively enhanced from day to day in the administered, while all the controls remained unchanged. 3. Patellar reflex showed, in the administered, slow and later more faster lowerings in the threshold which settled somewhere around on the 3rd day; on the other hand, the controls registered increased threshold with the lapse of days. To sum up, the mixture looks to be effective for the recovery from fatigue, especially the nervous fatigue. The use of this may be recommended for the prevention of the accumulated fatigue.

Photic Flicker Value on Workers in the Warm Environment under 3-Time Shift System and Season

Photic Flicker Value on Workers in the Warm Environment under 3-Time Shift System and Season

不眠と疲労

There are usually many experiences that the sleep is very important to recover the fatigue. In recent times, various industries are developing more and more which maintain 24 hours operation. As a result, workers having more chances to work at night. The investigation about the relation between fatigue and the insufficient sleep was experimentally designed. The flicker test was done on office work and the flicker value was found to be declined in the next morning after all-night working. In a petroleum manufacturing factory, the flicker value declined most severely at work of nightshift, in comparison with day-shift and evening-shift, and the decline of flicker value became more severe day by day. These facts mean that the insufficient sleep influences the brain functions making to decline its the level. And the variations of flicker value by insufficient sleep should be considered on the basis of physiological diurnal fluctuation of functions, that is to say 24 hours rhythm. The investigation was planned as follows (I) subjects: 5 students, (2) duration of sleep: 2, 4, 6, and 8 hours, (3) time to go to bed: 22:00 o'clock, (4) functions tested: sublingual temperature, pulse rate, flicker value, and subjective drowsiness, (5) follow up after awake until evening. Ranking of the levels of function at 8:00 to 10:00 o'clock after various duration of sleep showed that after 0 or 2 hours' sleep the level is lower compared with 4, 6, or 8 hours' sleep and that the ascending of the sublingual temperature after meal is higher with sufficient sleep. Further results could be summarized as follows: (1) With insufficient sleep, ascending of functions is the next morining is disturbed, and descending of functions continues until next evening. (2) If dietetic descending of sublingual temperature is detectable, it means descending of replacement. (3) Subjective drowsiness on the next day means the semisleeping condition. (4) This semisleeping condition is a situation of insufficient efficiency and sleeping. (5) This situation is fatiugue that is carried over to the next day. This condition means of insufficient changing of the higher level of functions at daytime to the lower at night.

フリッカー値による夜間, 昼間の作業負荷および夏季冷房効果の分析

In order to examine fluctuations of the flicker value due to work loads and temperature, the author selected 7 different occupations engaged by male employees, namely, full time Judo and Kendo (Japanese fencing) trainers (57 persons), motorcycle policemen (37 persons), printers (12 persons), selecters (8 persons), clerical workers (50 persons), night-shift members of the communication headquarters (47 persons) and the same of the car patrol section (50 persons). At the same time, 3 different occupations engaged by female empolyees such as clerical workers (20 persons), key-punchers (14 persons) and Japanese letter typists (19 persons) were also selected. On the male employees the influence by work loads was observed, while on the female wokers the influence of air conditioning was observed utilizing the key-punchers' room of which temperature was always kept at 24°C. The male employees were between 20 and 35 years of age and the female were between 20 and 25 years and unmarried. The results obtained through the above test are summarized as follows. 1. The nightshift work proved to be an usually strong stress on human body compared with the day-time work. 2. In the case of the nightshift patrol car policemen, the flicker value of 24 hours period showed an warped curve indicating a disorder of the physiological fluctuation. However, no such tendency was observed in case of the nightshift employees of the communication headquarters. This seems to mean that the former work is heavier than the latter. 3. The day-time occupations engaged by the male employees were classfied into the heavy and the medium labor according to the results. On the other hand, no difference could by marked between the medium and the light labors. 4. Among the nightshift occupations, the flicker value of car patrol policemen converged to 36.0 cyl/sec and that of the members of communication headquarters to 36.4 cyl/sec. The daytime occupations (except the full time Judo and Kendo trainers) showed constancy superimposed with repeated fluctuations. It took about 4 days for motorcycle policemen to converge to the orginal value. Such phenomena seem to indicate the fluctuational function of the human body to maintain homeostasis. 5. In the case of the female employees, room temperature of 24°C maintained high flicker values.

フリッカー値による自動車, 自動二輪車乗務作業の分析

It is reported that the flicker value shows physiologically a sine curve with 24 hours as a period and this fluctuation is influenced in accordance with the work loads and other factors. (Oshima and others) The author, in order to examine these points, selected nightshift members of car patrol section for studying conditions of physiological fluctuation, and dayshift members of motorcycle policemen for examining the maximum limit of actual working hours as indicated from the disturbance of fluctuation. Total members of the car patrol section were 53 male persons of the age between 25 and 35 years while the motorcycle policemen were in all 70 male persons of the age between 23 and 28 years. The former examination was conducted in May and the later in November. The results obtained could be summarized as follows. 1. In the case of car patrol section members, no remarkable distrubance on the physiological fluctuation of the flicker value was observed. 2. In the case of motorcycle policemen, both daily and weekly flicker values showed a heavy decrease. 3. In order to avoid such disturbances it is recommended that the actual working hours of the motorcycle policemen should be restricted to 3 hours and 18 minutes in a day.

The Influence of the Room Brightness on the Flicker Value

The Influence of the Room Brightness on the Flicker Value

Change of the Photic Flicker Value as well as Electric Flicker Value during Musclar Exercis

Change of the Photic Flicker Value as well as Electric Flicker Value during Musclar Exercis

Effects of pure tone and noise on values of electric flicker.

By means of Motokawa's method of electric flicker (EF), we measured variations of electric flicker values (EFV) of 5 subjects caused by exposure to pure tones or noise. The pure tones used were 500, 1000, 2000, 4000 and 6000 cps. 1. 4 subjects were exposed to a tone of 500 cps and 70 db for 30 minutes. EFVs increased and reached a highest level in about 5-10 minutes and continued so long as the stimulus lasted. 2. Measurements of EFVs in exposure to each of 5 pure tones of 70 db were made in 4 subjects. EFVs in response to tones of 500 and 6000 cps were remarkably great in comparison with those to tones of 1000 and 2000 cps. 3. In 3 subjects similar measurements were made at various intensity levels of tones, and it was found that the higher the intensity, the greater the change of EFV caused. 4. Hearing loss caused by two kinds of ear plugs A and B were investigated by an audiometer. With A hearing loss occurred above 2000 cps and with B over the whole range of frequencies. EFVs measured with the ear plug A were found to be remarkably low in comparison with control over the frequency range higher than 2000 cps. This finding corresponds with the audiometric one mentioned above. 5. In 3 subjects, the relation between intensity of noise and EFVs was investigated, and it was found that the larger the intensity of noise, the greater the change of EFV caused by exposure to noise.

Effects of Hyperpnea on Values of Electric Flicker

By means of Motokawa's method of electric flicker (EF), we measured variations of electric flicker values (EFV) of 5 subjects caused by hyperpnea, the inhaled gases being air, 100% O2 and 1% CO2 in 2. Measurements by an ear oximeter were carried out in parallel. 1. During 5 minutes' deep breathing of air, both EFV and oximeter values (Oxi-V) increased. 2. Also by deep breathing of pure oxygen, both kinds of values increased. 3. In case of 100% O2 inhalation (normal breathing), Oxi-V increased, but no change occurred in EFV. 4. In case of hyperpnea of 1% CO2 in O2, Oxi-V increased, while no change could be found in EFV. From these findings it was concluded that the change in EFV by hyperpnea is due to acapnia.

The influence of retinal adaptation on the electric flicker values.

The electrical threshold of the eye was measured by the alternating current of 20 c. p. s. with flicker sensation caused by it as an index under various adaptation states. 1. The threshold-time curve during complete dark adaptation following light adaptation of 10 minutes to illumination of 9, 800 lux shows the following course: At first the threshold remained low for about 8 minutes, and then increased rapidly to attain a constant level in about 15 minutes. Thus, the curve showed an inflection at about 8 minutes. 2. The curve suffered from a modification when the retina was constantly exposed to a small point of light of 40' in visual angle following the same light adaptation as above. The inflection at the middle stage became more obscure and the final level lower as local illumination was moved farther towards the periphery of the retina. 3. The effect of similar local illumination was investigated with colored lights. When blue, green and red lights were used for local illumination, it was found that the red light showed an effect similar to white light confined to the fovea, but that the green and blue light acted as white light illuminating the periphery of the retina. 4. Next the effect of exposure to broad illumination was investigated upon the curve following the same light adaptation as above. The curves by illumination of 0.1 lux, 1 lux and 10 lux were low and almost steady, but those by 100 and 1, 000 lux were generally much higher. From these experiments it is likely that the threshold as determined by the A. C. of 20 c. p. s. is lowered when visual cells, especially rods are excited to some extent.