Publications (56) View all
-
Article: Development of a compact wireless laplacian electrode module for electromyograms and its human interface applications.
[show abstract] [hide abstract]
ABSTRACT: In this study, we developed a compact wireless Laplacian electrode module for electromyograms (EMGs). One of the advantages of the Laplacian electrode configuration is that EMGs obtained with it are expected to be sensitive to the firing of the muscle directly beneath the measurement site. The performance of the developed electrode module was investigated in two human interface applications: character-input interface and detection of finger movement during finger Braille typing. In the former application, the electrode module was combined with an EMG-mouse click converter circuit. In the latter, four electrode modules were used for detection of finger movements during finger Braille typing. Investigation on the character-input interface indicated that characters could be input stably by contraction of (a) the masseter, (b) trapezius, (c) anterior tibialis and (d) flexor carpi ulnaris muscles. This wide applicability is desirable when the interface is applied to persons with physical disabilities because the disability differs one to another. The investigation also demonstrated that the electrode module can work properly without any skin preparation. Finger movement detection experiments showed that each finger movement was more clearly detectable when comparing to EMGs recorded with conventional electrodes, suggesting that the Laplacian electrode module is more suitable for detecting the timing of finger movement during typing. This could be because the Laplacian configuration enables us to record EMGs just beneath the electrode. These results demonstrate the advantages of the Laplacian electrode module.Sensors 01/2013; 13(2):2368-88. · 1.74 Impact Factor -
Article: Sympathetic neurons modulate the beat rate of pluripotent cell-derived cardiomyocytes in vitro.
[show abstract] [hide abstract]
ABSTRACT: Although stem cell-derived cardiomyocytes have great potential for the therapy of heart failure, it is unclear whether their function after grafting can be controlled by the host sympathetic nervous system, a component of the autonomic nervous system (ANS). Here we demonstrate the formation of functional connections between rat sympathetic superior cervical ganglion (SCG) neurons and pluripotent (P19.CL6) cell-derived cardiomyocytes (P19CMs) in compartmentalized co-culture, achieved using photolithographic microfabrication techniques. Formation of synapses between sympathetic neurons and P19CMs was confirmed by immunostaining with antibodies against β-3 tubulin, synapsin I and cardiac troponin-I. Changes in the beat rate of P19CMs were triggered after electrical stimulation of the co-cultured SCG neurons, and were affected by the pulse frequency of the electrical stimulation. Such changes in the beat rate were prevented when propranolol, a β-adrenoreceptor antagonist, was added to the culture medium. These results suggest that the beat rate of differentiated cardiomyocytes can be modulated by electrical stimulation of connected sympathetic neurons.Integrative Biology 10/2012; · 4.51 Impact Factor -
Article: Temporal change in IL-6 mRNA and protein expression produced by cyclic stretching of human pulmonary artery endothelial cells.
[show abstract] [hide abstract]
ABSTRACT: The time courses of interleukin (IL)-6 gene expression and protein production were examined in human pulmonary artery endothelial cells (HPAECs) subjected to cyclic stretching. IL-6 protein was increased even in cells without stretching. Fold changes determined by dividing the level of IL-6 protein in stretched cells by that in unstretched cells at the same sampling times indicated that IL-6 protein was increased by stretching. At least 1 h of stretching was necessary to elicit an increase of IL-6 protein, and the levels peaked at 3 h after the start of stretching. After withdrawal of stretching, there was no further increase of IL-6 protein. The expression levels of the IL-6 gene were significantly increased by stretching and peaked at 30 min after the start of stretching. The difference in the peak times of IL-6 gene and protein expression likely reflects the process of protein synthesis after the appearance of IL-6 mRNA.International Journal of Molecular Medicine 06/2012; 30(3):509-13. · 1.98 Impact Factor -
Article: Genomewide Analysis of Expression of Genes Located near miRNAs in Humans and Mice
[show abstract] [hide abstract]
ABSTRACT: MicroRNAs (miRNAs) are 20- to 22-nucleotide RNAs that regulate the transcription and translation of genes. In our previous studies, we reported that a miRNA has the potential to affect the transcription of genes located near it. The number of miRNAs recorded in databases continues to increase. However, the effects of the miRNAs, including newly found miRNAs, on the transcription of genes located near them have not yet been analyzed. In this study, we investigated the effects in humans and mice. The average expression levels are increased in the 104 bp vicinity of miRNA in all the datasets investigated. Many of the newly found miRNAs are located in an intron, exon or untranslated region (UTR) of host genes. When a host gene is transcribed, the miRNA located in such a region of the host gene is also transcribed. In addition, recent reports indicate that some noncoding RNAs, including miRNAs, can upregulate the expression of genes that have the complement sequences of the noncoding RNA in their promoter regions. Therefore, if genes having complement sequences of miRNAs are located around these miRNAs, the expression levels of these genes could be increased. These phenomena may be the reasons for the increased average expression levels around miRNAs.Sensors and Materials 01/2012; 24(6):303–310. · 0.34 Impact Factor -
Article: Feasibility of Capacitive Sensing of Surface Electromyographic Potential through Cloth
[show abstract] [hide abstract]
ABSTRACT: A capacitive sensing method was developed for sensing surface electromyographic potential (sEMG) through a thin cloth. The method is based on capacitive coupling involving fabric electrodes, the cloth, and the skin of the subject. A proposed measuring device was assembled by modifying the previously developed instrument for electrocardiographic potential. Experimental results showed that sEMG obtained with the proposed system was clearly visible and showed firings synchronized with sEMG simultaneously measured with a commercial device and that the spectral powers of both sEMGs were almost identical. These results demonstrated the potential of the proposed method to measure sEMG through cloth. The method enables the discomfort due to conventional skin-to-electrode coupling to be eliminated, although the signal quality, such as the signal-to-noise ratio (S/N), is slightly decreased with the cloth barrier.Sensors and Materials 01/2012; 24(6):335-346. · 0.34 Impact Factor
About
Now retired from Kitasato University.
