Hieyong Jeong

A New Four-Fingered Robot Hand with Dual Turning Mechanism

This paper newly proposes the four-fingered robot hand with dual turning mechanism where two and two other fingers can independently rotate inner and outer circles with the common center, respectively. Due to this mechanical configuration, it has the particular rotating axis where the manipulation around the axis can be completely decomposed into the velocity control around the axis and the internal force control in the contact plane. We achieved a manipulation task around the axis with the time of 0.8[sec] for one rotation, while it is relatively slow for another axis.

Analysis of Difference in Center-of-Pressure Positions Between Experts and Novices During Asymmetric Lifting

Although numerous studies have analyzed the relationship between manual material handling (MMH) and the forces acting on the lumbar spine, the difference in the MMH between experts and novices through the analysis of measured data has not been well studied. The purpose of this paper was to analyze the difference in the MMH positions between ten skilled experts working at a freight transport company (Group 1) and five unskilled novices without any experience (Group 2) during asymmetric lifting. All the human subjects performed asymmetric lifting experiments with closed eyes; the experiments involved moving loads (6 and 18 kg) to the left side. Time series data of the vertical ground reaction force were measured, using a Wii Balance Board, and then, the center-of-pressure (CoP) trajectories were calculated. The balance board was used for the measurement, because it was reliable, inexpensive, and portable and provided good repeatability even on rough surfaces, and all the information pertaining to the load and worker under various conditions was captured without any omissions. Under the 18 kg load condition, the CoP positions for Group 2 were located on the same side during left asymmetric lifting; however, those for Group 1 were located on the opposite side during left asymmetric lifting (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}

Experimental evaluation of human postural balance through lifting loads

P <0.001

Improvement of touch sensitivity by pressing

\end{document}). Furthermore, under the 6 kg load condition, the load weight influenced asymmetric lifting for most subjects of Group 2 such that the CoP positions were located on the opposite side (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}

A study on estimating blood pressure during body postural change based on pulse transit time

P <0.001

Frequency response dependence to vibration sensitivity by pressing

\end{document}). Based on the simulation and electromyography measurement results, we inferred that the difference in the CoP positions between the two different groups could be attributed to the difference in the hip positions. Most skilled experts position their hips in such a way that their CoP trajectories move toward the opposite side during left asymmetric lifting. Although the skillful characteristics of experts may be responsible for the lightening of the burden on the waist during asymmetric lifting, there are still two points that this paper does not clarify: the relationship between the experts’ adjustment of the hip position and the load of the weight, and the influence of an imbalance of the CoP position on the forces acting on the lumbar spine.

Analysis of Center of Pressure Location during Asymmetric Lifting

We have an interest in the relationship between the human postural balance and back injuries. Although back injuries are the number-one problem facing the workforce in the industry of carrying loads, there appears to be no firm idea on how this will deal with in practice. It is known that the brain plays an important role in maintenance of standing posture. In this paper, we focus on evaluating how the human postural balance is affected under three conditions of lifting loads. Especially, we evaluate the human postural balance during the rising time. We use the spectrum analysis for evaluating the postural balance by using the Nintendo Wii balance board. Through all of experiments, we found the tendency that the heavier loads are, the faster and larger the body swing for balancing the posture during the rising time is. Additionally, the case excluding bending the knee shows the larger swing than that including bending the knee. From all of results, we could hypothesize that an expert of carrying loads may make a balance for the posture during rising time as soon as possible by using the smaller swing motion. We show all of experimental results.

Linear discriminant analysis for symmetric lifting recognition of skilled logistic experts by center of pressure trajectory

It is really interesting to know how a blood flow has an influence on a touch sensitivity during human fingertip exploration over an environment. In this paper, we examine experimentally how the touch sensitivity is changed under the condition that the blood flow is interrupted compulsorily by pressing the proximal phalange of human finger. Through the weight discrimination test based on Webers Law, we found that the touch sensitivity improves temporarily with the statistical significance test of below 0.1 %, when a finger proximal phalange is bound and pressed. Experimental results also show that there exists a meaningful correlationship between the stiffness of fingertip and the touch sensitivity.

Effectiveness of surface enhanced Raman spectroscopy of tear fluid with soft substrate for point-of-care therapeutic drug monitoring

We are interested in healthcare for a bed ridden patient. Although a bed ridden patient in the hospital can be led to a circulatory disorder or a serious secondary disease, it is still difficult to give an adequate healthcare service for the patient due to side effects. Thus, we focus on the method of measuring the continuous and non-invasive bio signal in order to provide important insight into the patients overall physical condition. In this paper, we estimate the blood pressure during the change of body posture based on the pulse transit time. Accordingly, we newly propose the measurement system and the equation for estimating the blood pressure, and then prove the effectiveness through the experiment of changing the body posture. Through all of results, we found that it is possible to estimate the blood pressure during the change (45 and 75 deg) of body posture with the continuous (5 min) and non-invasive method by monitoring the condition of patient.

Continuous non-invasive blood pressure during continuous repositioning by pulse transit time

We are interested in estimating whether the harder skin affects the frequency response to vibration sensitivity or not. While there is the difference among individuals, it is well known that the threshold to vibration sensitivity as a function of frequency yields a U-shaped curve that reaches a maximum of sensitivity in the region of 250 Hz as shown in Fig.1. By focusing on this fact, we can evaluate which the vibration sensitivity is changed under the normal condition and the harder skin conditions caused by pressing the proximal phalange of finger forcibly. Through measuring the vibration sensitivity by the psychophysical method, we found that the vibration sensitivity at the frequency of 80 Hz and 120 Hz improves with the statistical significance test (p-value) of below 10 %, but no effect was showed at the frequency of 10 Hz and 30 Hz.