Issues : JET is a peer-reviewed, open-access scientific journal : Journal of Ergonomic Technology (JET)

Journal of Ergonomic Technology (JET)
ISSN 2432-1575

Issues

A proposal for frequency analysis method of unevenly spaced time series data
Publish Date : 2004/04/01  Vol.4
Authors : 
Tu YUXIN, Shigeyuki KON, Satoshi HONDA, Department of Instrumentation Engineering, Faculty of Science and Technology, Keio University
Report Outline : 
Original article
Appeared on Ergonomics of Human System Interaction, Vol. 4, No.1, 27/30, 1999.

A novel method for unevenly spaced time series is proposed. Since Fast Fourier Transform (FFT) method cannot Fourier transform unevenly space time series, such as heart rate, respiratory rate, etc., we have had to precondition the data for frequency analysis. With the present method a direct discrete Fourier transform is performed. We compared the conventional FFT and the present methods numerically, and found that the conventional method showed lower power spectrum in high frequency region, whereas the present one showed the correct power spectrum. As an example, heart rate variability was investigated in frequency domain, and the results were compared with those of conventional methods, and found that in respiratory frequency range (0.2-0.4 Hz), the present method gave better spectrum estimate.

Keywords: Frequency analysis, Unevenly sampled time series, Heart rate variability, Stress
Count : 116
Center of gravity measuring system for nursing
Publish Date : 2004/04/01  Vol.4
Authors : 
Nobuaki AGETSUMA, Koichi OGAWA, Tokyo Denki Universit
Report Outline : 
Original article
Appeared on Ergonomics of Human System Interaction, Vol. 4, No.1, 21/26, 1999.

This study aims to develop a new measuring system for the analysis of nursing motion. The system obtains reaction forces, the center of gravity, its locus, and the foot positions to measure nursing motions, such as transferring a patient from a bed to a wheel chair, or assisting a patient from lying positon to sitting position. Instead of using a large force plate, we used a pair of shoe-size force plates, which we call ‘force-shoe’, tow displacement sensors, four potentiometers, a dynamic strain meter, and the error is five millimeters.

Keywords: Center of gravity, Ground reaction force, Nursing posture, Area of base
Count : 114
The study of the effect of touch
Publish Date : 2004/04/01  Vol.4
Authors : 
Naoko SAITO, National Cancer Center Hospital
Yukari TAKEHANA, Hideaki SHIMADU, Chizuko OHGAWARA, Faculty of Health Science, Kyorin University
Report Outline : 
Original article
Appeared on Ergonomics of Human System Interaction, Vol. 4, No.1, 13/20, 1999.

The purpose of this study is to obtain the basic data on the effect of touch in nursing care. This study involved two experiments. The subjects in this study were 15 female students. These experiments examined the effect of touch during fixed painful stimulation. In the first experiment, we measured R-R interval and skin blood flow rate as physical indices. Then, we examined the State-Trait Anxiety Inventory (STAI) and responses to a questionnaire about changes in pain degree b y a touch as mental indices. In the next experiment, we measured these thresholds.
As a result, these experiments suggest that the touch with abundant susceptibility in each case may ease the mind and body, but not affect patient’s condition.
We thought that this study suggested the availability of touch for nursing care.

Keywords: Touch, R-R interval, Skin blood flow, STAI, Painful stimulation
Count : 126
Biomechanical analysis of lifting actions for nursing
Publish Date : 2004/04/01  Vol.4
Authors : 
Tadao ISAKA, Kenji SHIGETSHI, Ritsumekan University
Yasuhiro HAYAKAWA, Nara National College of Technology
Sadao KAWAMURA, Ritsumekan University
Report Outline : 
Original article
Appeared on Ergonomics of Human System Interaction, Vol. 4, No. 1, 8/12, 1999.

This study was designed to obtain the basic information about the machine of nursing and instruction methods of lifting actions for nursing. The subjects who participated in this study consisted of one skilled person working in a hospital and two unskilled students. They were requested to perform the nursing lifts in some conditions such as in case of low or high height beds. From the comparison between the skilled and unskilled persons, the characteristics of lifting actions in the skilled person were shown as follows; (1) the skilled person utilize the larger range of motion in the knee and hip joints, (2) the skilled person could reduce the vertical load (Fp) by the increasing the impulse in the horizontal plane, and (3) the muscle activities in the lower limb were totally used in well-balanced without a local intense muscle activity by using the multi-joint movement shown in the skilled person. From the obtained results, it is necessary to consider the teaching system of the technique in efficient lifting movements, and to develop the lifting machine which have a interface between nurses and patients.

Keywords: Lifting for nursing, Joint kinematics, Ground reaction force, Biomechanics
Count : 131
Perception of apparent depth in stereogram: an effect of horizontal rotation of cube on apparent depth
Publish Date : 2004/04/01  Vol.4
Authors : 
Tesuya KAJITANI, Bunka Women’s University
Report Outline : 
Original article
Appeared on Ergonomics of Human System Interaction, Vol. 4, No. 1, 1/7, 1999.

The experiment in this paper gives clear examples showing two cubes of different depth. Apparent depth is regarded here as the degree of recognizing the difference of two objects. The objects, cubes in this case, are deformed in depth in increments of 0.5% to  2%. Using this method, two kinds of experiments were carried out, namely, one using a pair of stationary cubes and the other using a pair of rotating cubes. The test was conducted on 30 average females of age between 10 and 23.
As a result, they could better recognize the difference of depth on a pair of rotating cubes than stationary ones.

Keywords: Stereopsis, Apparent depth, Motion parallax, Parallax, CAD, Computer
Count : 112
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