Designing a new computer mouse and evaluating some of its functional parameters

This study aimed to design a new mouse and evaluate some of its functional parameters. The prototype of an ergonomic mouse was made according to design principles. The study was conducted from 2011 to 2013 in the Department of Ergonomics in Shiraz University of Medical Science. Functional parameters including Movement Time [MT] and error rate of the new mouse were evaluated by 10 participants based on ISO 9241-9 standard. The application of design principles in the new mouse resulted in improving MT and error rate so that they could be comparable to those of a standard mouse. MT, in both the standard and the new mouse was 0.846 and 0.864 s, respectively. Error rate of the standard and the new mouse was reported as 13% and 19%, respectively. Statistical analysis showed no significant difference between the two mice from these perspectives. Apparently, the studied functional parameters of the new mouse were similar to those of the standard one. The new mouse could be an appropriate substitution for the standard mouse without losing its positive characteristics

Alterations of visual reaction time and short term memory in military radar personnel

Radar transmitters emit high-power radiofrequency radiation by creation of a high-voltage and high-frequency alternating electrical current. Health effects of occupational exposure to military radar were investigated. Visual reaction time was recorded with a simple blind computer-assisted-visual reaction time test. To assess the short-term memory, modified Wechsler Memory Scale test was performed. The mean +/- SD reaction time in radar works [N=100] and the control group [N=57] were 238.58 +/- 23.47 milliseconds and 291.86 +/- 28.26 milliseconds [P<0.0001], respectively. The scores of forward digit span in radar works and the control group were 3.56 +/- 0.77 and 4.29 +/- 1.06 [P<0.0001], while the scores of backward digit span in radar works and the control group were 2.70 +/- 0.69 and 3.62 +/- 0.95 [P<0.0001]. The scores of word recognition in radar works and the control group were 3.37 +/- 1.13 and 5.86 +/- 1.11 [P<0.0001]. Finally, the scores of paired words in radar works and the control group were 13.56 +/- 1.78 and 15.21 +/- 2.20 [P<0.0001]. It can be concluded that occupational exposures to radar radiations decreases reaction time, which may lead to a better response to different hazards. To the best of our knowledge, this is the first study to show that occupational exposure to radar microwave radiation leads to decreased reaction time and the lower performance of short-term memory. Altogether, these results indicate that occupational exposure to radar microwave radiations may be linked to some non-detrimental and detrimental health effects