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Biomedical subjects

M Kumashiro

Publications and source records attributed to M Kumashiro.

At least 37 records · Page 2Linked to original sources
PubMed1987

[Instabilities in tactile, visual and auditory sense--application of stochastic catastrophe model].

As a fundamental study on management of the working environment, instabilities in tactile, visual and auditory sense are discussed. The effects of localized vibration on the ability to discriminate the surface roughness are analyzed by means of the stochastic cusp catastrophe model. Also, bistable perception of the ambiguous man/girl figure is modelled in the same way. Furthermore, the instable phenomenon of a pure tone when heard under the masking noise is pointed out and analyzed by the catastrophe model.

Adult↗
PubMed1986

Effects of listening to music with headphones on hearing--especially under noisy conditions.

The purpose of this experiment was to clarify the effects of exposure to music using headphones under noisy conditions on hearing. The most comfortable loudness (MCL) for three kinds of music (Rock, Popular, Japanese songs) decided by two normal hearing subjects was measured under 6 noisy conditions (Train, Subway, Tram, Bus, Underground, Street) in a soundproof room. In the same manner, the MCL of favorite tunes of five subjects were measured. Temporary threshold shift 2 min after exposure (TTS2) to music for 30 min at the highest MCL was obtained. Furthermore, the characteristics such as spectral structures in one-third octave band or level fluctuations (coefficient of variation) were obtained for noise and music and compared. Statistical analysis revealed that MCL in Street was significantly higher than under other conditions and there was no significant differences in MCL among the various types of music. However, the highest MCL was found for Rock. About 20 dB of TTS was observed in one ear and the hazardous of headphones use in noisy conditions was suggested.

Adult↗
PubMed1986

[Anxiety symptoms and their association with work environment and other factors].

Anxiety symptoms and their association with work, work environment, family environment and physical health were studied by mailed questionnaire in 1379 male and 1427 female employees working in a Tokyo-based company and a Kyushu branch of a government-subsidized corporation. Subjective anxiety symptoms were found to increase with poor physical health, poor marital relationship and physical work overload and when the employee felt his superior(s) difficult to deal with. They were little influenced by whether the employee felt his work environment dangerous or not.

Adult↗
PubMed1986

[Health check on radiation workers in the nuclear energy industry using Todai Health Index].

In the nuclear energy industry, the plants are located far from urban areas and the working environments are generally separate from each other for radiation protection purposes. The health investigation on radiation workers in the nuclear energy industry was carried out using the Todai Health Index questionnaire in 1982, 1983 and 1984. As a control study non-radiation workers on the other several working fields were investigated in the same manner. The results showed that the status of radiation workers in the nuclear energy industry is similar to that of the workers in the other working fields and the THI questionnaire is useful to know health and working status of a group of workers.

Adult↗
PubMed1984

[Workers' subjective feeling of fatigue and attitudes towards work--effects of age and job difference].

The present study is an attempt to assess attitudes towards work and subjective feelings of fatigue. To discover the relationships between these factors, a field study was conducted in a large-sized electric company. The subjects were 1376 male workers. The results of the 30 questions concerning subjective feelings of fatigue published by the Japan Association of Industrial Health showed that the complaint rate of fatigue in younger workers (18-29 yrs.) was higher than that of older workers (30-66 yrs.). In the middle aged (44-49 yrs.), feelings of fatigue in the administrative group were lower than that of the non-administrative group. Finally, workers who had a high complaint rate of fatigue were less favourably disposed towards their work and felt an increase in boredom, loneliness and monotony. Overall, the results indicated that the difference of labor mode exerts an influence on the onset of self-reported stress.

Adolescent↗
PubMed1984

[Effects of visual and mental strain on VDT (visual display terminal) performance].

The progression of visual and mental strain in VDT work was investigated through an experimentally-designed VDT task providing a number of stressors including pacing, repetition, judgment and output decisions. We measured the effects of CFF (critical fusion frequency), TAF (the ability to maintain concentration), EEG (electroencephalogram) and near-point accommodation of various changes in the duration of the testing period. The subjects were seven male university students who performed single multiplication problems at a rate of 60 per minute. The problems were presented to them on a CRT screen and on paper for periods of 90 min each. The results obtained were as follows; CFF values and near-point accommodation of VDT performance were significantly decreased compared to Non-VDT's as a control. The TAF test showed that the mental strain in a VDT task is greater than that in a Non-VDT task. CFF values of VDT performance showed a tendency to decline in the 30th min after commencement, but in the 60th min and thereafter a significant lowering was noticed. In TAF and near-point accommodation of VDT performance, the greatest decline was in the 60th min, and this was significantly reduced only immediately after the work period. CFF values and near-point accommodation were not recovered after 60 min from the end of a 90 min VDT task. However, TAF X L values recovered in the 30th min after VDT performance. The peak level of alpha waves from the parietal region moved toward the slow alpha band with the elapse of VDT task time, but returned [or reverted] to the initial state 30 min after the test period ended.

Accommodation, Ocular↗
PubMed1983

The present state of ergonomics in Japan.

The purpose of this study was to investigate the state of ergonomics teaching in Japan and the research interests of those concerned with this teaching. The name "Ergonomics" became well known between 1965 and 1969. Most Japanese researchers in ergonomics came from an engineering background and most teaching and research were carried out at Departments of Industrial Management. The next largest group of researchers came from Departments of Psychology, but in their teaching or research they were not necessarily carrying out research in ergonomics in those departments even though many of them were conducting ergonomics projects before 1959. University courses in ergonomics were first launched in 1953; 1967 was a turning point, and they have rapidly become more popular since then. However, the courses of ergonomics are optional at the majority of universities, taught over a period of only one term at half of the universities and one year at the other half. Furthermore, there were very few experiments which were separate from the courses of the lectures. Most of the work of Japanese researchers is in the areas of "Man as a system component" and "Methods, techniques and equipment in ergonomics". These are also the main subjects of undergraduate and graduate theses and experiments.

Education↗
PubMed1980

[The recent status of vibration hazards among workers at the state forests in Hokkaido (author's transl)].

In order to make clear the recent status of vibration hazards among workers belonging to the national forestry bureau in northern Hokkaido, a special health examination was carried out on 417 chain saw operators and 443 bush cutter operators. The results obtained are as follows: 1. Seven point seven percent of chain saw operators and 5.6% of bush cutter operators were diagnosed as suffering from vibration hazards. Distribution of the cases in chain saw operators was 50% in grade I, 31.2% in grade II and 18.8% in grade III, while in bush cutter operators it was 20% in grade I, 60.0% in grade II and 20.0% in grade III. 2. Six new patients were found in this special health examination. 3. Twenty-two of 76 authorized patients, who had been treated with periodical therapy and prohibited from the operation of vibratory tools until this special health examination, were diagnosed as having recovered their health because of the existance of no symptoms concerning vibration hazards. 4. Pains on pressure of the muscles were complained of at the upper arm, forearm, chest and at the back in 12.4% of chain saw and bush cutter operators. Deformities of the elbow, hand and finger joints were recognized in 12.6% of the workers, and ulnar nerve paralysis was recognized in 1.0% of them. 5. Occupational hearing loss and lumbago were diagnosed in 20.2% and 14.7% of the chain saw and bush cutter workers, respectively.

Adult↗
PubMed1980

[Studies of the propriety of the items adopted for the special health examination of vibration hazards at present (author's transl)].

Skin temperature, vibratory sense, nail press test and pain sense are customarily used as the items in the special health examination for finding vibration hazards at present. These items are measured under the condition of room temperature at 20 to 23 degrees c and after 10-minute immersion in cold water at 5 degrees C or 10 degrees C. In this report, the propriety of these items was investigated on the basis of measurements in 274 healthy chain saw operators and 294 healthy bush cutter operators. The 10-minute immersion test in cold water at 10 degrees C was adopted in this experiment. The results obtained are as follows: Skin temperatures of the chain saw and bush cutter operators did not show any significant difference by age under the condition at the room temperature, but the recovery in the subjects in the twenties was faster than in the other. Skin temperatures at the 10th minute after the 10-minute immersion test in cold water at 10 degrees C showed very wide deviations among the subjects. Vibratory senses of the aged subjects markedly lowered in comparison with those of the younger subjects. Recovery of vibratory sense after the immersion in cold water showed a tendency which is faster than that of the skin temperature. Correlation between the skin temperature and the vibratory sense at the 10th minute after the immersion was statistically significant. Most of the subjects showed the recovery time within 2 sec with the nail press test under the condition of the room temperature and at the 10th minute after the immersion. Above 95% of subjects complained pain sense with one gram weight at the measurement under the all conditions except immediately after the 10-minute immersion test. From the above results, it should be considered that the value of these measurement may be dominated by the age of the subjects and that the immersion test in cold water to the tests of vibratory sense and pain sense may not have important role in the diagnosis of vibration hazards.

Adult↗