Raman Spectroscopic Evaluation of Composition of Matrix Synthesized by Osteoblasts under Microvibration Stimulation


Evaluation of the basic designs of a micro device that provides vibration stimulation to cells


Difference in the osteoblastic calcium signaling response between compression and stretching mechanical stimuli


Cyclical Stretching Induces Excess Intracellular Ca2+ Influx in Human Keloid-Derived Fibroblasts In Vitro

The incidence of keloids is higher in the case of darker skin. It is more common in the parts exposed to stretching (thorax, abdomen, and joints). Cyclical stretching reportedly induced each Ca2+ spike through differential mechanosensitive channels in human synovial and dermal fibroblasts. Therefore, the authors hypothesized that cyclical stretching also induces a specific Ca2+ spike in keloid-derived fibroblasts. This in vitro study compared the intracellular calcium dynamics induced by cyclical stretching between control (human dermal fibroblasts) and keloid (human keloid-derived fibroblasts) groups. Each group was exposed to two-dimensional stretch using an originally developed stretch microdevice. Intracellular Ca2+ was observed for 5 minutes, including 30 seconds of baseline, under a fluorescent confocal laser microscope. The intracellular Ca2+ concentration was evaluated every 0.5 second using the fluorescence intensity ratio. A positive cellular response was defined as a rise of the ratio by greater than or equal to 20%. The normal response cutoff value was determined by receiver operating characteristic analysis. The keloid groups were significantly more responsive than the control groups (15.7% versus 8.2%; P = 0.029). In the cellular response-positive cells, the keloid groups reached significantly higher intracellular Ca2+ concentration peaks than the control groups (2.20 versus 1.26; P = 0.0022). The cutoff value was 1.77, and 10.4% of the keloid-derived fibroblasts exhibited a hyper-Ca2+ spike above the normal range. Keloid-derived fibroblasts with a hyper-Ca2+ spike might constitute a keloid-specific subpopulation. Hereafter, the authors will study whether the normalization of excessive intracellular Ca2+ concentration leads to keloid treatment in vivo. This study result provided a clue to the onset mechanism of keloids, which the authors hope will lead to the development of new therapy in the future.


Development of vibration mechanical stimuli loading device for live cell fluorescence microscopy

Bone metabolism is regulated by mechanical stimuli such as gravity and exercise. If bone formation can be promoted by artificial mechanical stimulation, the quality of life of the aging society can be improved, such as by reducing the progression of osteoporosis and preventing patients from being bedridden. Micro-vibration stimulation with frequencies of 15 Hz to 90 Hz and acceleration amplitudes of 0.1 g to 0.3 g is effectively promotes bone formation in animal models. However, the mechanism of how these weak vibrations are sensed by bone cells and are used to regulate bone metabolism is unknown. In this study, we developed a device to apply micro-vibration stimuli to osteoblasts cultured on a glass bottom dish and observed the cell response to the stimuli using a confocal laser scanning fluorescence microscope. The device performance was confirmed using driving tests, and the calcium signaling response of osteoblasts to micro-vibration stimuli was observed in real time and in situ. The calcium signaling response characteristics of the cells differed when the cells were subjected to 45 Hz and 90 Hz micro-vibration stimuli, even under a constant acceleration amplitude of 0.2 g.

Journal of Biomechanical Science and Engineering


Quantitative evaluation of both histological and mechanical recovery in injured tendons using Fourier-transform second-harmonic-generation microscopy

IEEE Journal of Selected Topics in Quantum Electronics


Quantitative in situ time-series evaluation of osteoblastic collagen synthesis under cyclic strain using second-harmonic-generation microscopy

The aim of this study is to provide an in situ method to non-invasively monitor osteoblastic collagen synthesis under mechanical stimulation. We applied second-harmonic-generation (SHG) microscopy to monitor the collagen fibers produced by osteoblast-like cells. To evaluate the influence of mechanical stimulation on collagen synthesis and maturation, we compared SHG images of osteoblast-produced collagen fibers with and without a cyclic stretch stimulus. Image analysis of the average SHG intensity indicated that the amount of osteoblastic collagen synthesis was significantly enhanced by the cyclic stretch. Furthermore, the maturity of the collagen fibers was not affected in the early stage of bone formation by the mechanical stimulus.© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.


Evaluation of initiating characteristics of osteoblastic calcium signaling response to stretch by video rate time-course observation


Scan-less confocal phase imaging based on dual-comb microscopy

Confocal laser microscopy (CLM) is a powerful tool in life science research and industrial inspection because it offers two-dimensional optical sectioning or three-dimensional imaging capability with micrometer depth selectivity. Furthermore, scan-less imaging modality enables rapid image acquisition and high robustness against surrounding external disturbances in CLM. However, the objects to be measured must be reflective, absorptive, scattering, or fluorescent because the image contrast is given by the optical intensity. If a new image contrast can be provided by the optical phase, scan-less CLM can be further applied for transparent non-fluorescent objects or reflective objects with nanometer unevenness by providing information on refractive index, optical thickness, or geometrical shape. Here, we report scan-less confocal dual-comb microscopy offering a phase image in addition to an amplitude image with depth selectivity by using an optical frequency comb as an optical carrier of amplitude and phase with discrete ultra-multichannels. Our technique encodes confocal amplitude and phase images of a sample onto a series of discrete modes in the optical frequency comb with well-defined amplitude and phase to establish a one-to-one correspondence between image pixels and comb modes. The technique then decodes these images from comb modes with amplitude and phase. We demonstrate confocal phase imaging with milliradian phase resolution under micrometer depth selectivity on the millisecond timescale. As a proof of concept, we demonstrate the quantitative phase imaging of standing culture fixed cells and the surface topography of nanometer-scale step structures. Our technique for confocal phase imaging will find applications in three-dimensional visualization of stacked living cells in culture and nanometer surface topography of semiconductor objects.


Development of micro mechanical device having two-dimensional array of micro chambers for cell stretching

This paper presents a novel cell stretching micro device having two-dimensional array of micro chambers. It enables an in situ time-lapse observation of stretched cell by using an optical microscope with high measurement efficiency. The presented device consists of a cell culture dish and the array of micro chambers made of silicone elastomer and extension structures made of photocurable resin, and is fabricated with MEMS technology. The fabrication process of the thin micro chamber array combines photoresist mold and lift-off process based on conventional photolithography. The fabricated device has 134micro chambers in 5μm or less thickness. It was demonstrated that the fabricated micro device could be used to make in-situ time-lapse observation of cell responses to stretching under optical microscopy. In addition, the influence of the chamber thickness to the quality of the microscope image observed was evaluated. It is confirmed that the proposed device having two-dimensional array of the thin micro chambers makes it possible to observe cell response for stretch stimuli with high quality and efficiency.


In situ observation and measurement of actin stress fiber deformation in stretched osteoblast like cell

Advances in Bioscience and Biotechnology


Evaluation of Orientation Performance of Attention Patterns for Blind Person

Tactile walking surface indicators (TWSIs) are installed on footpath to support independent travel for the blind. There are two types of TWSIs, attention patterns and guiding patterns. The attention pattern is usually installed at the crosswalk entrances. The direction of the crossing can be acquired by the row of the projection of the attention pattern through the soles of the shoes. In addition, truncated domes or cones of the attention pattern were arranged in a square grid, parallel or diagonal at 45 degrees to the principal direction of travel. However, the international standard organization (ISO) allows a wide-ranging size. In this research, the direction indicating performance was compared at the same intervals for the five diameters specified by the international standard. As a result of the experiment, the diagonal array does not indicate the direction of travel, but the projection row does indicate the direction of travel in the parallel array. When the attention pattern is installed at a crosswalk entrance, a parallel array should be installed in the direction of the crossing.

Studies in Health Technology and Informatics


Observation of Tendon Healing with Second-harmonic-generation (SHG) Microscopy

第2高調波発生光(SHG)顕微鏡を用いた腱修復の観察

Tendon rupture is a traumatic injury that is difficult to recover to the condition before injury. In previous studies, histological staining and tensile testing have been widely used to evaluate histological and mechanical healing. However, since both methods are destructive and invasive, it is difficult to apply these methods to clinical diagnosis. If the degree of healing can be visualized nondestructively and noninvasively, new findings may be obtained regarding mechanisms of the tendon healing process. In this study, we used second-harmonic-generation (SHG) microscopy to evaluate the degree of healing of ruptured tendon in a rabbit model. SHG microscopy has high selectivity and high image contrast with respect to the structural maturity, density, and aggregates of collagen molecule, without the need for histological sectioning and staining. Furthermore, since SHG light intensity sensitively reflects the structural maturity of collagen molecule and its aggregates, it has the potential to be a good indicator for the degree of healing of the injured tendon. By comparing the SHG images between 4-week-healing tendons and normal tendons in the animal model, we confirmed that SHG light intensity of the healing tendon was significantly lower than that of the normal tendon, indicating that the collagen structure in the healing tendon is still immature. Furthermore, we performed image analysis based on 2D Fourier transform of the acquired SHG images, and confirmed a significant difference in collagen distribution depending on the sample. These results indicate that SHG microscopy has the unique potential as an indicator of tendon healing.

Transactions of the Japanese Society for Medical and Biological Engineering


This study aimed to evaluate the histological and mechanical features of tendon healing in a rabbit model with second-harmonic-generation (SHG) imaging and tensile testing. A total of eight male Japanese white rabbits were used for this study. The flexor digitorum tendons in their right leg were sharply transected, and then were repaired by intratendinous stitching. At four weeks post-operatively, the rabbits were killed and the flexor digitorum tendons in both right and left legs were excised and used as specimens for tendon healing (n = 8) and control (n = 8), respectively. Each specimen was examined by SHG imaging, followed by tensile testing, and the results of the two testing modalities were assessed for correlation. While the SHG light intensity of the healing tendon samples was significantly lower than that of the uninjured tendon samples, 2D Fourier transform SHG images showed a clear difference in collagen fibre structure between the uninjured and the healing samples, and among the healing samples. The mean intensity of the SHG image showed a moderate correlation (R(2) = 0.37) with Young's modulus obtained from the tensile testing. Our results indicate that SHG microscopy may be a potential indicator of tendon healing.Cite this article: E. Hase, K. Sato, D. Yonekura, T. Minamikawa, M. Takahashi, T. Yasui. Evaluation of the histological and mechanical features of tendon healing in a rabbit model with the use of second-harmonic-generation imaging and tensile testing. Bone Joint Res 2016;5:577-585. DOI: 10.1302/2046-3758.511.BJR-2016-0162.R1.


In situ time-series monitoring of collagen fibers produced by standing-cultured osteoblasts using a second-harmonic-generation microscope.

In bone tissue engineering and regeneration, there is a considerable need for an unstained method of monitoring collagen fibers produced by osteoblasts. This is because collagen fibers play an important role as a bone matrix and continuous monitoring of their temporal dynamics is important in clarifying the organization process toward forming bone tissue. In the work described here, using a second-harmonic-generation (SHG) microscope, we performed in situ time-series monitoring of collagen fibers produced by cultured osteoblasts without the need for staining. Use of the 19 fs near-infrared pulsed light enables us to visualize the temporal dynamics in a thin layer of collagen fibers produced by a single layer of osteoblasts in high-contrast SHG images. While the collagen fibers were produced and stored inside the osteoblasts at an early stage of culturing, the network structure of collagen fibers was formed and locally condensed at a late stage. Furthermore, we extracted a quantitative parameter of collagen maturity degree in the cultured sample by use of image analysis based on a two-dimensional Fourier transform of the SHG image. The proposed method will be useful for in situ quality and quantity control of collagen fibers in bone tissue engineering and regeneration.


Emitting LED block at crosswalk entrance for visually impaired persons

Visually impaired persons require tactile walking surface indicators (TWSIs) for independent walking. However, if these blocks are installed following guidelines for constructing TWSIs, it's unkind to users. Therefore, we propose LED blocks installed at crosswalk entrances for blind and visually impaired persons. These blocks can be detected through the soles of shoes and through use of residual vision. This study conducted an experiment with amblyopic examinees in which we evaluate the visibility of the LED blocks.


Development of Augmentative and Alternative Communication Assessment Tools for Patients with ALS

Amyotrophic lateral sclerosis (ALS) is a progressive, intractable disease that causes the body to gradually become weaker. A communication device for the handicapped with a high degree of disability (see Fig. 1) is often used for a seriously ill ALS patient. However, the degree of the symptoms differs in each patient, so it is necessary to select a suitable input switch. Moreover, the selection of the switch is greatly influenced by differences in knowledge and experience, so support is often advanced preceded by a subjective evaluation [1]-[6]. This research developed an evaluation apparatus capable of measuring the movement of the finger from the displacement of the lever using a sensor built into the input switch. As a result, appropriate support is expected to evaluate patient's remaining function based on objective data when the input switch is selected.

筋萎縮性側索硬化症(ALS)は，身体機能が徐々に衰えていく進行性の難病である．重度のALS患者には，重度障害者用意思伝達装置が用いられることが多い．しかし，症状の度合いが患者ごとに異なるため，適した入力スイッチを選定する必要がある．また，スイッチの選定は知識・経験の差に大きく影響されるため，主観的な評価で支援が進められることが多い．本研究では，入力スイッチにセンサを組み込むことでレバーの変位から指の動きを計測できる評価器具の開発を行った．これにより，入力スイッチの選定を行う際に，患者の残存機能を客観的なデータ根拠に基づいて評価し，適切な適合支援が可能になることが期待される．


Walking Characteristics of Persons with Visually Impairment Crossing Intersections with Audible Pedestrian Signals

The authors have been continuously researching tactile walking surface indicators and audible pedestrian signals used for crossing intersections. A pedestrian walks to the opposite side of the crosswalk using audible pedestrian signals. The position where the audible pedestrian signal is set up clearly influences the pedestrian's path. We performed an intersection crossing experiment with road noise for different positions where the audible pedestrian signal was set up. Vehicle road noise is thought to influence walking pedestrians. However, we could not clearly separate the difference of where the audible pedestrian signal was set up from the influence of the road noise. We therefore conducted the experiment with no road noise in the intersection to determine the difference of the position where the audible pedestrian signal was set up. The research results were compared with and without road noise to specify the road noise influence.


Visibility of LED Blocks Mounted on Crosswalk Boundaries for low Visual Capacity

According to the WHO, about 80% of visually impaired persons in the world are with low visual capacity. It is considered that LVs' safe independent mobility will be improved as employing Tactile Walking Surface Indicators (TWSIs). In the night, guidelines for constructing warning blocks, a kind of tactile surface indicator, have not been well established. Therefore, crossing crosswalks is one of the most dangerous situations for visually impaired persons. We thus developed novel LED blocks that indicate crosswalk boundaries between sidewalks and roadways. This study addresses the LED blocks under various environmental illuminations and illumination from the opposite side of the crossing.


Strain magnitude dependent intracellular calcium signaling response to uniaxial stretch in osteoblastic cells

In osteoblast cells, cells change their intracellular Ca2+ concentration ([Ca2+]i) as the response to mechanical stimuli. Although it has been reported that osteoblast cells responded to many kinds of mechanical stimuli including stretch of substrate, shear stress in fluid flow, direct indentation of glass microneedle and hydrostatic pressure etc., the detail of the characteristics of intracellular calcium signaling response to substrate stretch still remains unclear because motion artifact during stretch application causes out of focus plane and observation area, and complicates the in situ time lapse observation of change in [Ca2+]i in a single cell level. In this study, we combined our originally developed cell stretching MEMS device with the ratiometric microscopy method with two kinds of visible wavelength calcium indicator dyes. The cell stretching micro device and the ratiometric method reduce the influence of motion artifact during stretch application, and enable us to quantitatively evaluate the characteristics of cellular calcium signaling response to stretch. MC3T3-E1 osteoblastic cells were plated onto the cell stretching micro device and fluorescently labeled by Ca2+ indicator Fluo 3 and Fura Red. A uniaxial stretch with three magnitudes of strain 5%, 10% and 15% with constant strain rate were applied to the cells, and in situ time lapse observation of cellular calcium signaling response to stretch was conducted with high temporal and spatial resolution. We succeeded in obtaining time lapse fluorescent image sequences during stretch application without excessive out of focus and blank time. The results revealed that MC3T3-E1 cells change the intensity of calcium signaling response to stretch according to the stretch strain magnitude. As stretch strain magnitude was increased, the amount of change in fluorescent ratio value of Ca2+ indicators in stretched cells also increased. This result suggests the possibility that osteoblastic cells can sense the magnitude of mechanical stimuli at upstream of mechanotransduction pathway such as influx of extracellular Ca2+.

Journal of Biomechanical Science and Engineering


Preference Analysis Method Applying Relationship between Electroencephalogram Activities and Egogram in Prefrontal Cortex Activities --- How to collaborate between engineering techniques and psychology

This paper introduces a method of preference analysis based on electroencephalogram (EEG) analysis of prefrontal cortex activity. The proposed method applies the relationship between EEG activity and the Egogram. The EEG senses a single point and records readings by means of a dry-type sensor and a small number of electrodes. The EEG analysis adapts the feature mining and the clustering on EEG patterns using a self-organizing map (SOM). EEG activity of the prefrontal cortex displays individual difference. To take the individual difference into account, we construct a feature vector for input modality of the SOM. The input vector for the SOM consists of the extracted EEG feature vector and a human character vector, which is the human character quantified through the ego analysis using psychological testing. In preprocessing, we extract the EEG feature vector by calculating the time average on each frequency band: theta, low-beta, and high-beta. To prove the effectiveness of the proposed method, we perform experiments using real EEG data. These results show that the accuracy rate of the EEG pattern classification is higher than it was before the improvement of the input vector.

本論文では，前頭前野脳波分析技術を用いて嗜好を分析する手法を紹介する．脳波分析では，脳波の周波数特性を定量化する．脳波に含まれる個人差を緩和するために，エゴグラムを用いてヒトの性格を定量化する．これら脳波の特徴量とエゴグラムの得点を特徴ベクトルとし，嗜好パターン分類の問題適用することで，提案手法の有効性を検証する．パターン分類識別機には自己組織化マップを用いる．実験検証の結果，提案手法の有用性が確認できた．

International Journal of Advances in Psychology


Preference Classification Method Using EEG Analysis Based on Gray Theory and Personality Analysis

This paper introduces a method to classify the preference patterns of sounds on the basis of an electroencephalogram (EEG) analysis and a personality analysis. We analyze the EEG of the left prefrontal cortex by single-point sensing. For EEG recording, a dry-type sensor and few electrodes were used. The proposed feature extraction method employs gray relational grade detection on the frequency bands of EEG and egogram. The gray relational grade is used for extracting the EEG feature. The egogram is extracted for quantifying the subject's personality. The preference patterns generated when the subject is hearing a sound are classified using the nearest neighbor method. To show the effectiveness of the proposed method, we conduct experiments using real EEG data. These results show that the accuracy rate of the preference classification using the proposed method is better than that using the method that does not to consider the subject's personality.

本論文では，音刺激に対する嗜好パターンを脳波分析技術を用いて検出する手法を提案する．脳波分析では，脳波の周波数帯域間の関連性を灰色理論に基づいて分析し，灰色関連度を算出し，脳波の特徴量とみなす．脳波に含まれる個人差を緩和するために，ヒトの性格をエゴグラムを用いて定量化する．脳波の特徴量とエゴグラムを特徴ベクトルとし，嗜好パターンを分類する．実験検証の結果，提案手法の有効性を示すことが出来た．

The Online Journal on Computer Science and Information Technology, OJCSIT


Electroencephalogram Analysis of Mechanisms Underlying Brain Activity during Voluntary Movement

This paper proposes an electroencephalogram (EEG)-based method for identifying the mechanism underlying brain activity during a voluntary movement. Our final goal is to develop a rehabilitation assistance system that can be used on a daily basis by observing a patients degree of functional recovery. In order to assist in ambulation rehabilitation, the mechanism related to the voluntary movement need to be identified. As a first step, we elucidated the mechanism underlying brain activity. The proposed method involves EEG recording, blind source separation, noise reduction, and feature enhancement. The EEG device has dry-type sensors. Independent component analysis is used to delink the signal. Median morphological filters are used to reduce EEG noise and emphasize the feature signal. To demonstrate the effectiveness of the proposed method, we conducted experiments using real EEG data.

ブレイン・コンピュータ・インタフェースによる歩行アシストシステム構築のために，随意運動時における大脳皮質の活動メカニズムを分析する手法を提案する．提案手法は，独立成分分析とメディア・モルフォロジーフィルタを用いてノイズ除去および特徴を強調する．実験検証の結果，提案手法の有効性が示され，かつ，随意運動時の大脳皮質活動にも個人差が含まれることが確認できた．

International Journal of Bioscience, Biochemistry, Bioinformatics (IJBBB)


Development of higly precise cell stretching microdevice and in-situ observation of stretched cell

高精度細胞伸展マイクロデバイスの開発と引張りを受ける細胞のその場観察

This paper presents a cell stretching microdevice for in-situ observation of stretched cell. In a conventional cell stretching device, it was difficult to observe the initial and in-situ cellular response to stretching. The presented device consists of an elastic culture chamber and leaf springs by which uniaxial stretch is applied to the culture chamber. The device is produced by a micro three-dimensional structure fabrication process using multiple exposures to the photoresist. The device permits the observation of cellular responses to stretching in real time because it is made of transparent materials when observed by optical microscope. We demonstrated the fundamental characteristics of a microdevice, and observed the cellular response behavior by a fabricated microdevice. The amount of the culture chamber deformation was controlled by the amount of the stretching arm displacement. Also, we demonstrated the culture chamber during stretching was not deformed toward the optical axis. Moreover, in-situ observation of transition of the cellular calcium signaling response to stretching succeeded by optical microscopy using fabricated microdevice. These results indicated that this device can be used to observe and evaluate the initial cellular response and micro-strain field on a cell membrane during uniaxial stretching.

IEEJ Transactions on Sensors and Micromachines

電気学会論文誌E (センサ・マイクロマシン部門誌)


Difference in Road Surface Recognition by Disease and Grades of The Low Vision

In our previous studies, Lateral Bands that were placed in both side of Tactile Walking Surface Indicators, and the result of clinical testing of Lareral Bands indicated the effectiveness for the Low Vison to show walking way. In this paper, relation between visibility and miss-recognition was studied from the different point of view in date of the previous study. Influence both by the difference in visual impairment and the difference in grades of disability was also studied. As the results, it was suggested that 30% of luminance contrast was the optimum value for both keeping visibility of Tactile Walking Surface Indicators with Lateral Bands and producing no miss-recognition.

我々の以前の研究で，視覚障害者誘導用ブロックの両側に置かれた側帯と側帯の医学的な実験結果は視覚障害者が道を歩いていて見つけるために有効であることが示された．本論文では，視認性と誤識別の関係を前の研究のデータを異なった観点から検証した．視覚障害者の症状の違いと等級の違いによる影響も検証した．結果として，30%の輝度コントラストが側帯と製造された点字ブロックの視認に誤識別しないことを担保するための最適値であることが示された．


Verification of LED Blocks used at Crosswalk Entrances for Persons with Visually Impairment

The eyesight of a person with low visual capacity (LV) might decrease remarkably under low-light conditions such as the morning, evening, and nighttime, decreasing their opportunities to go out. Research and development underway to ensure safe walking for LVs examined a walking guidance system in which LED blocks are embedded into the road at edges of warning blocks installed at crosswalk entrances. The LED block can be detected with the LVs residual vision. The detectability of this LED block was evaluated by subjective experiments performed by visually impaired and blind persons.

ロービジョン者の中には，朝夕や夜間などの低照度環境下において視力による視認性が著しく低下する場合がある．このことが，ロービジョン者の外出の機会の減少させる一因となっている．視覚障害者の安全な歩行を確保するため，視覚障害者誘導支援システムに関する様々な研究・開発が行われている．本研究では，LED発光ブロックを路面に埋め込む歩行誘導システムについて検討した．横断歩道口用発光ブロックを横断歩道口の注意喚起ブロックの端に設置した．この発光ブロックはロービジョン者にとっては，残存視力で知覚することができる．この発光ブロックの知覚に関する性能特性を被験者実験によって評価した．被験者実験はロービジョン者と盲人によって実施した．


Research on the Occupational Ability Evaluation Technique in the Group Work of Intellectually/Mentally Handicapped Persons by MODAPTS Method

The first objective is to analyze the characteristics of the intellectually/mentally disabled more deeply in order to help the government and companies to understand them and the employment rate to increase. The second objective is to review the work evaluation method of the intellually/mentally disabled anew through this evaluation in order to trigger the research on the intellectually/mentally disabled to be activated. The result of the verification performed by this research has showed that the success or failure in a continuous company employment is more significantly related to the factors of ``surrounding healthy persons'' which are external factors than the factors arising from the disability of a disabled person.

本研究の第一の目的は，政府と会社が彼らを理解し就職率が増加することより深く支援するために，知的/精神障害者の特性を分析することである．第二の目的は，知的/精神障害者が活動的になることを研究が引き金になってこの評価を新たに通して，知的/精神障害者の作業評価方法を見直すことである．本研究の検証の結果，会社の雇用の阻害要因が障害者の障害から起こる要素より外部の要素である「強周囲の健康な人」の要素にかなり関連するのを示した．


Continuity of Tactile Walking Surface Indicators and Audible Pedestrian Signals at Crosswalks

Crossing an intersection is one of the most risky actions for a visually impaired person. A visually impaired pedestrian is guided to the crosswalk entrance by the tactile walking surface indicators "TWSIs". It is then important that he/she safely and smoothly cross the intersection using the audible pedestrian signal. However, neither connectivity nor the continuity between the TWSIs and the audible pedestrian signal travel support systems has been verified. The purpose of this research is to verify this connectivity and continuity. It should be possible to acquire basic scientific data for developing guidelines from the findings of this research.

視覚障害者が交差点を横断するのは，最も危険な行動の1つである．視覚障害を持つ歩行者は視覚障害者誘導用ブロック「TWSIs」によって横断歩道入り口に誘導される．視覚障害者が歩行者用音響信号を利用して安全にかつ円滑に交差点を横断することが重要です．しかしながら，TWSIsと音響式歩行者信号との歩行支援システム間の接続性や連続性が確保させていない．本研究の目的は，この接続性と連続性について確かめることある．本研究の知見から指針設計のための基本的なの科学的データを取得することが可能となる．


Visualization Method to Confirm Relationships among Optimal Solutions

This paper proposes method to visualize the relationship between the gene and objective values of all individuals in a Pareto solution. The gene and objective values are expressed as color and gray scales, respectively. The rules of visualization apply three normalization techniques for coloring the gene values and the objective function values, respectively. The gene values normalize using maximum and minimum values over all gene of all suboptimal solutions, in each gene and in each individual, respectively. The objective values normalize using maximum and minimum values in each objective function. We define the visualization space based on the visualization rules. The information visualization technique in this paper has the advantage of indicating the Pareto solution and its details in one frame. To show the effectiveness of the proposed method, we apply the proposed method to benchmark problems. We found that it is possible to confirm the Pareto solution, its details and relationships among those easily in one frame.

パレート最適解間の関連性を可視化する手法を提案する．提案手法では，個体の適応度と個体の遺伝子の値を見える化することで，最適解間の関連性を一目で把握可能になる．見える化技術には疑似カラー法を適用している．提案手法の有効性検証するために，多目的ナップサック問題を適用した結果，提案手法の有用性が確認できた．


Myosin-II-mediated directional migration of dictyostelium cells in response to cyclic stretching of substratum

Living cells are constantly subjected to various mechanical stimulations, such as shear flow, osmotic pressure, and hardness of substratum. They must sense the mechanical aspects of their environment and respond appropriately for proper cell function. Cells adhering to substrata must receive and respond to mechanical stimuli from the substrata to decide their shape and/or migrating direction. In response to cyclic stretching of the elastic substratum, intracellular stress fibers in fibroblasts and endothelial, osteosarcoma, and smooth muscle cells are rearranged perpendicular to the stretching direction, and the shape of those cells becomes extended in this new direction. In the case of migrating Dictyostelium cells, cyclic stretching regulates the direction of migration, and not the shape, of the cell. The cells migrate in a direction perpendicular to that of the stretching. However, the molecular mechanisms that induce the directional migration remain unknown. Here, using a microstretching device, we recorded green fluorescent protein (GFP)-myosin-II dynamics in Dictyostelium cells on an elastic substratum under cyclic stretching. Repeated stretching induced myosin II localization equally on both stretching sides in the cells. Although myosin-II-null cells migrated randomly, myosin-II-null cells expressing a variant of myosin II that cannot hydrolyze ATP migrated perpendicular to the stretching. These results indicate that Dictyostelium cells accumulate myosin II at the portion of the cell where a large strain is received and migrate in a direction other than that of the portion where myosin II accumulated. This polarity generation for migration does not require the contraction of actomyosin.


Analysis of Individual Difference in EEG using Self-organizing Map

自己組織化マップを用いた聴覚刺激時における脳波に含まれる個人差に関する一考察

This paper introduces a method to analyze an individual difference in an electroencephalogram (EEG) using a self-organizing map (SOM). The EEG recording position is a left prefrontal pole (Fp1) in the international 10-20 system. The device for recording the EEG uses dry-type sensor and a small number of electrodes. The EEG data is analyzed through the FFT and EEG features are extracted by calculating the time average of the power spectrum of five frequency bands which are theta, low-alpha, high-alpha, low-beta and high-beta, respectively. In order to confirm the individual difference in the EEG, the EEG patterns are classified using the SOM. The EEG patterns are based on human responses on sounds listened to. Finally, we conduct experiments using real EEG data. The experimental results suggest that it is possible to express the individual differences in the EEG using SOM.

本論文では，自己組織化マップ(self-organizing map: SOM)を用いて脳波の個人差を見える化し，聴覚刺激時における脳波の個人差に関して考察する手法を紹介する．脳波の計測箇所は左前頭極付近とし，周波数分析の結果を脳波の特徴量とする．紹介する手法の有効性を検証するために，聴取音に対するヒトの嗜好を分類する問題に適用する．実験的検証の結果，紹介手法の有用性が確認できた．


Interindividual Difference Analysis in Prefrontal Cortex EEGs Based on the Relationship with Personality

In this study, we propose a method to analyse interindividual differences in electroencephalograms (EEGs) taken while a subject listened to music, which is based on the relationship of these EEGs to human personality. The frequencies of the EEGs that are analysed have components that contain both significant and immaterial information as well as different levels of importance. We express the different levels of importance through the weight values of frequencies using a real-coded genetic algorithm. Then, the EEG patterns, which are determined based on the evaluation of the impression on the music, are detected using the $k$-nearest neighbour method. We assume that differences between detection results for EEG patterns with the highest and lowest recognition accuracies show interindividual differences. Moreover, ego analysis based on psychological testing is used to analyse personality, and the ego score is determined using a questionnaire. Finally, we discuss the relationship between personality and interindividual differences observed in experimental EEGs. An interesting tendency of a person with a combined ego type is that he or she has a unique response to negative stimuli compared with that of positive stimuli.

聴取音楽に対する感受性の違いを分析する方法を提案する．提案手法は脳波分析部，パーソナリティ分析部，および聴取音楽の印象分類ぶで構成される．脳波分析部では，遺伝的アルゴリズムを用いて脳聴取音楽の印象分類に有用な周波数帯域を選定する．パーソナリティ分析部では，心理テストを用いてヒトの性格を定量化する．印象分類部では，k近傍法を用いて聴取音楽に対する印象を分類する．個体間差を分析するために，脳波による聴取音楽の印象分類結果と定量化された性格との関連性を分析した．その結果，ネガティブな印象の検出が容易な被験者は，内向的な性格である可能性が示唆された．


Lower back pain survery during care work and Bed care load assessment --- 富山県腰痛予防対策推進研修会腰痛アンケート結果から考えられるベッド介助作業負担の評価

介助作業中の腰痛調査とベッド介助負担評価 --- 富山県腰痛予防対策推進研修会腰痛アンケート結果から考えられるベッド介助作業負担の評価

We conducted a questionnaire about lower-back-pain to the participants at the Toyama lower-back-pain measure promotion study session (1925 persons). The question asked the presence of lower back pain and investigated what kind of lower back pain they had in respect of a care work place. Furthermore, the IEMG and the breathing gas analyzing apparatus analyzed the weight load (10kg) in the position which changed the height in the bed depended for lifting. About 60 percent of caregivers had a lower-back-pain person by a caregiver. When the persons who had lower back pain in the past were included, about 80 percent of them had lower back pain. Caregivers often felt lower back pain when engaging in care work at the bedside. The causation of the onset of chronic lower back pain was "the work which kept their body with half-sitting posture for a long time." In care work with a bed, work in the height of the waist reduced the load for a line active mass and breathing gas volume. The present care work had the high risk of causing lower back pain. To decrease the risk, the care worker should do bed care work at the height of the waist. This result should be adopted as a job standard.

本調査研究では，腰痛アンケート調査(1,925名)を実施し，腰痛の有無と介助作業場面でどのような腰痛が発生するかについて介助動作場面の問題点を調査した上で，その結果からベッド介助作業での高さを変えた位置での持ち上げによる重量負荷(10kg)を筋電計と呼気ガス分析装置を用いて分析した．結果介護者の腰痛発症者が6割近くあり，既往者を含めると8割近くが腰痛を訴えていた．腰痛が発生しやすい介助動作は，ベッドでの介助場面であった．腰痛発生の原因は，中腰で長く続く作業であり，ベッドでの介助作業は腰の高さでの作業が筋活動量・呼気ガス量ともに負担を減らすことになった．ベッド介助作業は腰痛へのリスクが高く，リスクを減少させるには，腰の高さのベッド介助作業を作業標準とすべきであることがわかった．


Evaluation of the dependence of tensile strength and fracture strain of PLA film on machining method

ポリ乳酸フィルムの引張強度および破断ひずみにおける加工法依存性の評価

Transactions of The Japan Society of Mechanical Engineers, Series C

日本機械学会論文集(C編)


Mis-recognition of Road Surface by The Low Vision

The low vision sometimes miss-recognize road surface as holes or ditches. The purpose of our research is to find parameters of road surface that causes this kind of miss-recognition. As the preliminary result of our research, this paper describes how the low vision recognizes road surface incorrectly. Fifty-nine low vision persons were participated as subjects in these experiments. Visibility of road surface's line that have different parameters in width, luminance contrast, and illumination was experimentally studied. One of the three experiment, eight lines that have different parameters respectively were showed to a subject at a time. The lines were arranged in ascending order. At the end of each experiment, comments from a subject were obtained.

弱視者は時々路面を穴や溝として誤識別する．この場合の誤識別に起因する路面の要因を見つけることが本研究の目的である．本研究の予備結果として，本論文は弱視者がどのように路面を誤認識するかを説明する．弱視者59名を被験者として実験に参加した．幅，輝度比，および照明の異なったパラメータの路面の線の視認性を実験で検証を行った．三つの内の一つの実験では，被験者にそれぞれ異なったパラメータを持った8本の線を一度に見てもらう．線は昇降順に配置されている．それぞれの実験の終わりに，被験者からの回答を得た．


An evaluation of tactile walking surface indicators for the visually impaired

Tactile Walking Surface Indicators (TWSIs) are a vital walking aid for the visually impaired, especially those with complete blind person, but the blocks are still not available on all walkways. This study was performed with visually inpaired person to determine to what degree TWSI (in particular, blocks with raised parts to indicate caution) contribute to direction determination, with the goal of improving the utility of TWSIs. By comparing drift after 5m of straight line travel, significant differences were seen between the existence and nonexistence of border elevation for both square and zigzag patterns, confirming that determining direction when using square patterns over zigzag patterns.

視覚障害者誘導用ブロック(TWSIs)は視覚障害者，特に全盲者のための重要な歩行支援用品である．しかし，点字ブロックがすべての歩道で有効ではない．本研究はTWSI(特に，注意喚起ブロック)が方向の決定に貢献する割合を決定するため視覚障害者で検証を行った．TWSIsの形状を改善することが目的である．直線を5m歩行した後，その偏軌を比較することによって，正方配列と千鳥配列の方向提示性能の違いがあるかの検証を行う．方向提示性能は千鳥配列より正方配列が有意であることが確認できた．


Development of a flexible microprobe using strip line structure for MR Imaging

ストリップ線路構造を用いたMRI用フレキシブルマイクロプローブの開発

Inspection by the MRI is also thought to be promising as well as the supersonic catheter and so on for the details inspection of the plaque inside the blood vessel wall. MR probe that can detect MR signal in just near the lesion site is necessary to observe it about 2 mm deep with high resolution. In this research, we have developed MR microprobes that have a shielded-loop type coil of which change in Q-value by the load is small. The shielded-loop was made by using strip line. It is flexible because it is made by stacking the thin films on which the wiring is formed. The coil part of this microprobe can be rolled into compact size and can be inserted into a catheter. Its coil expands outside of the catheter and can be used for imaging large area. We designed and made the microprobes and measured their fundamental electrical characteristics. Then, they were tested by using MR scanner and the resolution of MR images were evaluated. The thin microprobe that could be inserted into the 6 Fr (1 Fr = Ø0.33 mm) catheter was made and evaluated. Its Q-value was 22.7, and the resolution of MR image was 160 μm when sample was kiwi fruit.

Transactions of the Japanese Society for Medical and Biological Engineering


Development of microstretching device to evaluate cell membrane strain field around sensing point of mechanical stimuli

International Journal of Mechanical Sciences


Simultaneous observation of calcium signaling response and membrane deformation due to localized mechanical stimulus in single osteoblast-like cells

Biochemical signals related to a mechanosensory mechanism by which cells sense mechanical stimuli have been gradually clarified by biological approaches such as blocking specific signaling pathways; however, mechanical signals such as deformation/strain, which is transduced into biochemical signals through this mechanism, particularly at the cellular structural component level in a single cell, have not yet been clearly understood. This in vitro study focuses on an intracellular calcium signaling response to an applied localized deformation in a single osteoblast-like MC3T3-E1 cell, and observed localized deformation of a cell membrane and the calcium ion flux from an extracellular medium. The localized deformation was applied to a cell by indenting a microsphere onto the cell membrane using a glass microneedle. The cellular calcium signaling response and cell membrane deformation were simultaneously observed using fluorescent dyes in a vertical section under a confocal laser-scanning microscope with high spatial and temporal resolutions. Our results observed in the vertical section showed that the initiation point of the calcium ion flux is collocated at the displaced microsphere around which stretch membrane deformation was observed.

Journal of the Mechanical Behavior of Biomedical Materials


Local disassembly of actin stress fibers induced by selected release of intracellular tension in osteoblastic cell

In adherent cells, such as osteoblasts and endothelial cells, the actin stress fiber structure is dynamically reorganized under changes in the surrounding mechanical environment such as cyclic stretch deformation or extracellular fluid flow. Although many studies have been conducted to clarify the biochemical signaling pathways in the reorganization process, details of the reorganization mechanism are still not clearly understood. In addition, to known biochemical mediators, intracellular tension has been proposed as a candidate mechanical mediator for stress fiber reorganization. In previous studies, it was reported that the release of intracellular tension by contracting the cell body induced the disassembly of the stress fiber as an initial phase of the reorganization process. However, in these experimental systems, deformation or force was applied to the entire cell body, so that it was difficult to directly discuss the relationship between the individual mechanical condition of stress fibers and the disassembling phenomenon. In this study, we have designed a novel experimental system by which local contraction was applied to a single osteoblast-like cell and intracellular tension in the targeted stress fiber was selectively released. The dynamic change in stress fiber structure was observed in the EGFP-tagged actin expressed osteoblast-like cell MC3T3-E1. The results indicated that only tension-released stress fibers were selectively disassembled and disappeared in a single cell. This result suggests that the existence of intracellular tension is essential for the dynamical stability of the stress fibers in osteoblast-like cells.

Journal of Biomechanical Science and Engineering


Measurement of local strain on cell membrane at initiation point of calcium signaling response to applied mechanical stimulus in osteoblastic cells.

In adaptive bone remodeling, it is believed that bone cells such as osteoblasts, osteocytes and osteoclasts can sense mechanical stimuli and modulate their remodeling activities. However, the mechanosensing mechanism by which these cells sense mechanical stimuli and transduce mechanical signals into intracellular biochemical signals is still not clearly understood. From the viewpoint of cell biomechanics, it is important to clarify the mechanical conditions under which the cellular mechanosensing mechanism is activated. The aims of this study were to evaluate a mechanical condition, that is, the local strain on the cell membrane, at the initiation point of the intracellular calcium signaling response to the applied mechanical stimulus in osteoblast-like MC3T3-E1 cells, and to investigate the effect of deformation velocity on the characteristics of the cellular response. To apply a local deformation to a single cell, a glass microneedle was directly indented to the cell and moved horizontally on the cell membrane. To observe the cellular response and the deformation of the cell membrane, intracellular calcium ions and the cell membrane were labeled using fluorescent dyes and simultaneously observed by confocal laser scanning microscopy. The strain distribution on the cell membrane attributable to the applied local deformation and the strain magnitude at the initiation point of the calcium signaling responses were analyzed using obtained fluorescence images. From two-dimensionally projected images, it was found that there is a local compressive strain at the initiation point of calcium signaling. Moreover, the cellular response revealed velocity dependence, that is, the cells seemed to respond with a higher sensitivity to a higher deformation velocity. From the viewpoint of cell biomechanics, these results provide us a fundamental understanding of the mechanosensing mechanism of osteoblast-like cells.


Quantitative evaluation of threshold fiber strain that induces reorganization of cytoskeletal actin fiber structure in osteoblastic cells.

The cytoskeletal stress fiber structure plays essential roles in various kinds of cellular functions such as shape maintenance, active motility and mechanosensing, and its structure is dynamically reorganized under each functional process. In known reorganization mechanisms of the stress fibers, a change in its mechanical condition has been suggested as one of the key mediators that affect the reorganization process. Some experimental studies have clarified that tension release in the stress fibers induces fiber depolymerization that is considered to be the initial phase of the reorganization process. However, quantitative mechanical values such as strain or stress that induce depolymerization have still not been evaluated. This study is aimed at the quantitative evaluation of the mechanical value that induces stress fiber depolymerization, to gain a basic understanding of the reorganization phenomenon from a mechanical viewpoint. Osteoblastic cells (MC3T3-E1) were cultured on prestretched silicone rubber substrate. Compressive deformation was applied to the cells by uniaxially releasing the prestretched substrate strain and change in the stress fiber structure was observed. The results indicated that the compressive strain magnitude, not in the whole cell body but in the stress fiber itself, is important to induce disassembly of the stress fiber structure. The existence of a threshold strain magnitude for initiating fiber disassembly was also suggested; the threshold strain magnitude was evaluated as approximately -0.20.


細胞接着マイクロパターニングとアクチン細胞骨格の配向制御 --- 原子ビームを用いた基板表面改質の試み

Journal of the Japanese Association for Crystal Growth


Cell Micro-Patterning by Atom Beam Exposure

原子ビームを用いた細胞接着パターンの作成

This study aimed to develop a new cell micro-patterning method by controlling material surface affinity of the cell using atomic oxygen beam exposure. Surfaces of low-density polyethylene (LDPE) and tetrafluoroethylene-hexafluoropropylene (FEP) were exposed to the atomic oxygen beam. On the LDPE surface, the roughness measured by atomic force microscopy (AFM) did not change much, however, the oxygen concentration on the surface measured by X-ray photoelectron spectroscopy (XPS) significantly increased that resulted in increase in wettability. Contrary to this, on the FEP surface, the oxygen concentration showed no significant change, but roughness of the surface remarkably increased and the wettability decreased. As a result of the surface modification, affinity of the osteoblastic cells on the FEP surface increased, which was also confirmed by increase in the cell area. Finally, cell micro-patterning on the FEP surface was carried out based on difference in the affinity between modified and unmodified surfaces patterned by a masking method.

Transactions of The Japan Society of Mechanical Engineers, Series A

日本機械学会論文集(A編)


Research on continuity among assistive devices for personal mobility of visually impaired persons around crossings

Tactile walking-surface indicators (TWSIs) are necessary for visually impaired persons to walk independently. Audible pedestrian signals are also necessary for them to cross intersections. TWSIs support approaching the intersection, and audible pedestrian signals support crossing the intersection. However, the support of audible pedestrian signals may not necessarily be related to the support of the TWSIs. This research sought to verify how visually impaired persons are guided by different positions where the audible pedestrian signals are set up.

視覚障害者誘導用ブロックは視覚障害者の単独歩行には重要である．音響式方向者信号は同様に交差点の横断するために重要である．点字ブロックは交差点までを誘導し，音響式方向者信号機は交差点を横断することを支援する．しかしながら，音響式歩行者信号機の支援は点字ブロックの支援と連携をとっていないことがある．本研究では，音響式歩行者信号機を設置される場所の異なる位置で視覚障害者が如何に誘導されるかを検証することである．