Shigeru Sakurazawa

Orientation of protein crystals grown in a magnetic field

Abstract Three crystal forms of hen egg-white lysozyme, and ribonuclease A and met-myoglobin crystals exhibited orientation in a magnetic field of

Entertainment feature of a game using skin conductance response

There are many computer games in the world, but generally game players challenge either the computer, or real players in the case of many person games. In view of the strong connectivity advocated between communication and entertainment in the field of entertainment computing, the use of biological signals for computer games is of interest. Here, a novel type of game using biological signals was developed as an entertainment device. The change in skin conductance caused by sweating was measured as a signal reflecting the players agitation during the game. This type of game incorporates various characteristics relating to communication. First, players of the game challenge themselves because they are able to view their detected biological signals. In this situation, a kind of self-reference system is constructed. Second, the environments in which the game is played changed how the game was enjoyed. Third, the game system reveals differences of context between player and observer. From these characteristics, it is considered that the use of biological signals is attractive for entertainment computing.

Detection of Muscle Fatigue by the Surface Electromyogram and Its Application

The muscle is moved by muscle fiber contraction receiving command from the brain. But, energy that moves muscle is not infinity. If muscle get into energy shortage, no matter how send command from the brain, muscle is not moved. Such a temporary muscular dysfunction is muscle fatigue. If muscle becomes excess fatigue condition, it may decrease work efficiency, or muscle strain. If we are able to measure muscle fatigue objectively, improve work efficiency, or avert muscle strain. Therefore, it is necessity to measure muscle fatigue. It is able to objectively measure with a surface electromyogram (EMG). The feature of muscle fatigue are increase in amplitude and make the transition from high frequency spectrum to low frequency spectrum. We evaluate muscle fatigue Mean Power Frequency (MPF). to evaluates frequency of surface EMG. We assume muscle recovery process is converse phenomenon from muscle fatigue, and it is able to evaluate elevated MPF. The purpose of the present study is to design of system that effective training, or improve work efficiency, or avert muscle strain uses feature of muscular fatigue and muscle recovery process.

Finger Motion Classification Using Surface-Electromyogram Signals

The finger movement has the information about force, speed to bend and the combination of fingers. If these information is estimated, the many degrees of freedom interface can apply it. In this study, we aimed for the many degrees of freedom finger movement classification. We tried each fingers classification and the estimate of the flexural finger force using surface-electromyogram signals. In the technique, amount of characteristic are a cepstral coefficient of EMG signals and an integral calculus EMG signals. A support vector machine performs learning and classtification. Therefore, I propose the classification technique and inspected a classification each finger and the combination of fingers by offline data handling using surface EMG signals.

Wearable Biomedical Monitoring System Using TextileNet

We developed and tested a biomedical monitoring system using TextileNet, a flexible conductive garment for wearable computing. TextileNet detects biological signals while simplifying communication and power supply wiring. TextileNet also acts as an electromagnetic interference (EMI) shield, which makes it possible to use simpler amplifiers in the system. Using TextileNet, a huge amount of biological information can be processed simultaneously.

Entertainment Feature of a Computer Game Using a Biological Signal to Realize a Battle with Oneself

A novel computer game was developed in which a player challenges him- or herself using the skin conductance response to make the player aware of his or her own agitation. This game was developed as a paradoxical system in which their desire to win makes it more difficult to win. This type of game was found to have the following characteristics. First, players find uncontrollable themselves due to viewing their biological signals. In this situation, a kind of self-reference system is constructed. Second, the environments changed how the game was enjoyed. Third, the game system reveals differences of context between player and observer. From these characteristics, it is thought that the use of biological signals is attractive for entertainment computing.

Motion estimation of five fingers using small concentric ring electrodes for measuring surface electromyography

Recently, new interfaces for bionic arm using surface electromyography (EMG) have been developed. To control bionic arms, the motion identification of five fingers using forearm muscle is required. However, estimation of independent muscle activity on five fingers is difficult because differential electrodes between two points have low spatial selectivity. On the other hand, small concentric ring electrodes have high spatial selectivity. Therefore, in this research, we showed possibility of independent measurement of EMG corresponding to each fingers movement using small concentric ring electrodes. Also, we compared Signal-Noise Ratio (SNR) of EMG for each fingers using differential electrodes between two points and a virtual concentric ring electrode by an array electrode (3×3).

Preliminaly Study on Coordinated Movement Mechanism of Multiple Muscle Using Wavelet Coherence Analysis

Movement of the human is achieved by coordinated movements of several muscles. In this paper, measuring the EMG during exercise. After that, we did wavelet coherence analysis. Thereby, we can presume which coordinative relationship between multiple muscles is important. We also have experimented with the same exercise under unstable conditions to investigate the effect of disturbance. As a result of the analysis, correlation is increasing in frequency region of 10 ~ 70 Hz. In addition, I compared the three groups (biceps and biceps, biceps and triceps, triceps and triceps). As a result of the comparison, biceps and triceps group showed highest correlation. At the end, I compared the stable condition and unstable condition. As a result of the comparison, there is a tendency of stable condition showed higher correlation than instability condition. Conclusion of this study is that, (1) coordinated movement between agonist muscle and antagonist muscle is important. (2) there is a tendency of stable condition showed higher correlation than instability condition.

Microcapsule formation in self-assembly of thermal heterocomplex molecules from amino acids

Solid microspheres that were phase-separated in aqueous suspensions of thermal heterocomplex molecules made by heating a mixture of proline and aspartic acid transformed into husk-like microcapsules as pH increased. The transformation from solid microspheres into microcapsules proceeded at two different time scales. Rapid dissolution of thermal heterocomplex molecules from the outer surfaces only during a short period was followed by slow dissolution of those molecules from their inside. The difference of the rates of dissolution led to the formation of microcapsules carrying smaller inner kernels as remnants.

Adsorption of monomers on microspherical structures of thermal heterocomplex molecules from amino ACIDS

The surface of a microspherical structure formed in the aqueous suspension of thermal heterocomplex molecules made by heating aspartic acid and proline can adsorb basic amino acids such as histidine, lysine and arginine. It can also adsorb adenine, cytosine, adenosine and cytidine. Electrostatic interactions acting between those monomers to be adsorbed and the adsorbing surface are responsible for the adsorption.