Effect of Carbonated Water Swallowing Volume on the Acoustic Characteristics of Swallowing Sounds in Healthy Adult Subjects

成人健常者における炭酸水嚥下量が嚥下音の音響特性に与える影響

Carbonated beverage-based sensory stimulation affects swallowing movements and contributes to safe swallowing. Although the effects of carbonated beverages on swallowing movements have been reported using swallowing sounds, small amounts of swallowing have not been investigated. In this study, we extracted the acoustic characteristics from swallowing sounds acquired when 15 healthy adults swallowed 3mL, 5mL, and 10mL of water or carbonated water five times each. Consequently, we confirmed that the acoustic features of the swallowing sound in time domain, i.e., peak intensity and energy, marginally significantly reduced when swallowing carbonated water compared to water, regardless of the quantity. Even with a mouthful volume of 3mL of carbonated water, this trend was confirmed. Therefore, the potential evaluation of swallowing and rehabilitation through the swallowing of small amounts of carbonated water, which has a lower risk of aspiration for dysphagia, was considered.

Transactions of the Japanese Society for Medical and Biological Engineering


Peak-Frequency Histogram Similarity of Bowel Sounds for the Evaluation of Intestinal Conditions


Auditory Property-Based Features and Artificial Neural Network Classifiers for the Automatic Detection of Low-Intensity Snoring/Breathing Episodes


UV-LED irradiation reduces the infectivity of herpes simplex virus type 1 by targeting different viral components depending on the peak wavelength.

Herpes simplex virus type 1 (HSV-1) is an enveloped virus that mainly infects humans. Given its high global prevalence, disinfection is critical for reducing the risk of infection. Ultraviolet-light-emitting diodes (UV-LEDs) are eco-friendly irradiating modules with different peak wavelengths, but the molecules degraded by UV-LED irradiation have not been clarified. To identify the target viral molecules of UV-LEDs, we exposed HSV-1 suspensions to UV-LED irradiation at wavelengths of 260-, 280-, 310-, and 365-nm and measured viral DNA, protein, and lipid damage and infectivity in host cells. All UV-LEDs substantially reduced by inhibiting host cell transcription, but 260- and 280-nm UV-LEDs had significantly stronger virucidal efficiency than 310- and 365-nm UV-LEDs. Meanwhile, 260- and 280-nm UV-LEDs induced the formation of viral DNA photoproducts and the degradation of viral proteins and some phosphoglycerolipid species. Unlike 260- and 280-nm UV-LEDs, 310- and 365-nm UV-LEDs decreased the viral protein levels, but they did not drastically change the levels of viral DNA photoproducts and lipophilic metabolites. These results suggest that UV-LEDs reduce the infectivity of HSV-1 by targeting different viral molecules based on the peak wavelength. These findings could facilitate the optimization of UV-LED irradiation for viral inactivation.

Journal of Photochemistry and Photobiology B: Biology


Evaluation of Temperature Increase from Joule Heat in Numerical Tooth Model by Applying 500 kHz Current for Apical Periodontitis Treatment Effect of applied voltage and tooth conductivity

For apical periodontitis treatments, a new method with the insertion of an electrode into the root canal of a tooth and application of a current at 500 kHz to sterilize the area by Joule heat has attracted attention. However, few studies have quantified the temperature increase in the root canal. This study aimed to investigate the basic characteristics of the temperature increase in a simple and standard tooth model when energizing a current at 500 kHz to the numerical tooth model with typical electrical and physical properties. We developed a numerical model of a standard tooth (dentin) and periodontal tissues consisting of an alveolar bone, cortical bone, and gingiva, and physiological saline in a root canal and calculated the temperature increase inside the numerical model by a coupled analysis of current and heat when a voltage was applied across the electrodes. The calculated results for the different applied voltages showed a temperature increase at the apical portion of the root canal, which increased with the applied voltage even for the same total supplied energy. The temperature increase occurred at the apical portion of the root canal as the tooth conductivity decreased. When the tooth conductivity was high, a current passed through the dentin, which led to a decrease in the temperature at the apical portion of the root canal. However, a chemical solution with a higher conductivity in the root canal tended to increase the temperature at the apical portion of the root canal, regardless of the tooth conductivity. More efficient approaches for increasing the spatial and temporal temperature for the tooth model target are needed. © 2021 Bioelectromagnetics Society.


Bowel sound-based features to investigate the effect of coffee and soda on gastrointestinal motility

Biomedical Signal Processing and Control


Polygonally Meshed Dipole Model Simulation of the Electrical Field Produced by the Stomach and Intestines

Cutaneous electrogastrography (EGG) is used in clinical and physiological fields to noninvasively measure the electrical activity of the stomach and intestines. Dipole models that mathematically express the electrical field characteristics generated by the stomach and intestines have been developed to investigate the relationship between the electrical control activity (ECA) (slow waves) shown in EGG and the internal gastric electrical activity. However, these models require a mathematical description of the movement of an annular band of dipoles, which limits the shape that can be modeled. In this study, we propose a novel polygonally meshed dipole model to conveniently reproduce ECA based on the movement of the annular band in complex shapes, such as the shape of the stomach and intestines, constructed in three-dimensional (3D) space. We show that the proposed model can reproduce ECA simulation results similar to those obtained using conventional models. Moreover, we show that the proposed model can reproduce the ECA produced by a complex geometrical shape, such as the shape of the intestines. The study results indicate that ECA simulations can be conducted based on structures that more closely resemble real organs than those used in conventional dipole models, with which, because of their intrinsic construction, it would be difficult to include realistic complex shapes, using the mathematical description of the movement of an annular band of dipoles. Our findings provide a powerful new approach for computer simulations based on the electric dipole model.

Computational and Mathematical Methods in Medicine


Identification of Genes Associated with Sensitivity to Ultraviolet A (UVA) Irradiation by Transposon Mutagenesis of Vibrio parahaemolyticu


医工・病学・多職種連携による胸腹水濾過濃縮専用装置の研究開発.

医工・病学・多職種連携による胸腹水濾過濃縮専用装置の研究開発.

Cell-free and concentrated ascites reinfusion therapy(CART)is an effective and safe therapy for patients with refractory ascites or pleural effusion. CART was initially indicated for cirrhotic ascites, and has come to be widely used for malignant ascites. Recently, cancer therapy that applies cancer cells obtained by filtration process is considered, and CART attracts attention as one of the important therapies to support future cancer therapy. However, the numbers of CART in Japan is not sufficient because the equipment for CART is high price and large. Additionally, the specialized medical staff such as clinical engineers is necessary for CART because of complicated operation. Therefore, we think that development of next-generation type equipment for CART that can be performed safely, easily, and reliably is necessary. We could develop the exclusive equipment for CART according to the project management by multifarious worker cooperation in five years.


Inactivation of Extended-spectrum β-Lactamase (ESBL)-producing Escherichia Coli by UVA-LED Irradiation System.

The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is increasing rapidly and spreading worldwide, particularly in Asia, compared to other regions. In the last ten years, in our hospital, in particular, there has been a < 30% increase. To prevent the spread of ESBL in hospitals and the community, the ultraviolet (UV) A-light-emitting diode (LED) irradiation device was used to inactivate ESBL-E. coli in human livestock and the environment. ESBL-E. coli and E. coli bacterial samples were collected from patients at Tokushima University Hospital (Tokushima City, Japan). The UVA-LED irradiation system had 365 nm single wavelength, and the current of the circuit was set to 0.23 or 0.50 A consistently. Results demonstrated that UVA-LED was useful for the inactivation of ESBL-E. coli and E. coli. The minimum energy dosage required to inactivate ESBL-E. coli and E. coli was 40.76 J/cm2 (45 min) in the first type of UVA-LED and 38.85 J/cm2 (5 min) in the second type. There were no significant differences between ESBL-E. coli and E. coli. The inactivation of ESBL-E. coli was dependent on energy. These findings suggest that UVA-LED with 365 nm single wavelength could be useful for surface decontamination in healthcare facilities. J. Med. Invest. 67 : 163-169, February, 2020.

The Journal of Medical Investigation : JMI


Effectiveness of visible and ultraviolet light emitting diodes for inactivation of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli: A comparative study.

Malaysian Journal of Fundamental and Applied Sciences


Adaptive resources allocation algorithm based on modified PSO for cognitive radio system.


多波長植物専用LED照射装置を用いた完全制御型水耕栽培システム

多波長植物専用LED照射装置を用いた完全制御型水耕栽培システム

LED総合フォーラム2019 in 徳島 論文集

LED総合フォーラム2019 in 徳島 論文集


Bacterial Contamination of Hemodialysis Devices in Hospital Dialysis Wards.

Chronic care patients undergoing hemodialysis for treatment of end-stage renal failure experience higher rates of bloodstream-associated infection due to the patients' compromised immune system and management of the bloodstream through catheters. Staphylococcus species are acommon cause of hemodialysis catheterrelated bloodstream infections. We investigated environmental bacterial contamination of dialysis wards and contamination of hemodialysis devices to determine the source of bacteria for these infections. All bacterial samples were collected by the swab method and the agarose stamp method. And which bacterium were identified by BBL CRYSTAL Kit or 16s rRNA sequences. In our data, bacterial cell number of hemodialysis device was lower than environment of patient surrounds. But Staphylococcus spp. were found predominantly on the hemodialysis device (46.8%), especially on areas frequently touched by healthcare-workers (such as Touch screen). Among Staphylococcus spp., Staphylococcus epidermidis was most frequently observed (42.1% of Staphylococcus spp.), and more surprising, 48.2% of the Staphylococcus spp. indicated high resistance for methicillin. Our finding suggests that hemodialysis device highly contaminated with bloodstream infection associated bacteria. This study can be used as a source to assess the risk of contamination-related infection and to develop the cleaning system for the better prevention for bloodstream infections in patients with hemodialysis. J. Med. Invest. 66 : 148-152, February, 2019.


A computer simulation of the metallic artifacts in MRI caused by dental magnetic attachments

Dental magnetic attachments, which are relatively simple to use and provide good retention and stability, have been increasingly used as dental prostheses. These attachments are composed of ferromagnetic stainless-steel keepers and magnetic assemblies embedded in the denture. The use of magnetic resonance imaging (MRI) to investigate lesions in the oral and maxillofacial areas is quite common. When a patient with a magnetic keeper undergoes MRI examination of the oral or maxillofacial area, however, the keeper is considered a metallic artifact (MA). Depending on the location of the lesion requiring diagnosis, the patient may be required to remove the keeper. The extent of the MA is known to be related to the hardware and pulse sequence parameters and the magnetic properties of the keeper. In this study, we propose a new method to estimate the extent of the MA in MR images caused by a keeper placed in the MRI, approximating the keeper with a magnetic dipole. This method should allow us to express the relationship among the hardware and pulse sequence parameters, the magnetic properties of the keeper and the extent of the MA in the MR image. To evaluate the validity of the method, we compare the MA in MR images produced by the proposed method with those in any experimental MR images taken in the existing study. Via our computer simulations, we show that the proposed method outperformed the existing approach and can estimate the extent of the MA based on the hardware and pulse sequence parameters and the magnetic properties of the keeper. By estimating the extent of the MA in the MR image by using our method before the MRI examination, depending on the location of the lesion requiring diagnosis, it may not be necessary to remove the keeper.

歯科用磁性アタッチメントの利用が広がっているが，口腔内に取り付けるキーパーは磁性材料を含むためMRI検査時の金属アーチファクトが問題となる．本研究ではキーパーによる金属アーチファクトの大きさを評価するための手法を提案し，計算機シミュレーションおよび既存の研究結果を用いて有用性を検討している．キーパーはMRIの界磁で磁化するが，キーパーの大きさが解析領域に対して小さい場合は磁気ダイポールにより近似することができる．金属アーチファクトの大きさはキーパーの大きさ・材質およびパルスシーケンスに関係することが示された．

Biomedical Physics & Engineering Express


Detection of sleep breathing sound based on artificial neural network analysis

Biomedical Signal Processing and Control


Automatic Bowel Motility Evaluation Technique for Noncontact Sound Recordings


LED光を用いた対外循環照射モデルの構築.

LED光を用いた対外循環照射モデルの構築.

電子情報通信学会研究技術報告(MEとバイオサイバネティックス)

電子情報通信学会研究技術報告(MEとバイオサイバネティックス)


Comparison of standard light-emitting diode (LED) and 385 nm ultraviolet A LED (UVA-LED) for disinfection of Escherichia coli


Evaluation of human bowel motility using non-contact microphones


Automatic snore sound extraction from sleep sound recordings via auditory image modeling


Combined treatment of UVA irradiation and antibiotics induces greater bactericidal effects on Vibrio parahaemolyticus.

The presence of antibiotics in the environment and their subsequent impact on the development of multi-antibiotic resistant bacteria has raised concerns globally. Consequently, much research is focused on a method to produce a better disinfectant. We have established a disinfectant system using UVA-LED that inactivates pathogenic bacteria. We assessed the bactericidal efficiency of a combination of UVA-LED and antibiotics against Vibrio parahaemolyticus. Combined use of antibiotic drugs and UVA irradiation was more bactericidal than UVA irradiation or antibacterial drugs alone. The bactericidal synergy was observed at low concentrations of each drug that are normally unable to kill the bacteria. This combination has the potential to become a sterilization technology. J. Med. Invest. 63: 63-67, February, 2016.

The Journal of Medical Investigation : JMI


The Real-Time Monitoring System of Blood Flow Velocity Using Doppler Ultrasound for Healthcare Application

Doppler ultrasound is a widely used and reliable noninvasive device for blood flow waveform measurement. However, the commercialized blood flow devices are usually in hospital with limited access for public, required monitoring by competent staff and not easily transported. The aim of current study is to examine the potential of a portable blood flow velocity (BFV) Doppler ultrasound system for healthcare application. The effects of visceral fat (VF) level, blood pressure (BP) level (hypertension), aging, regular exercise and exercise-trained programme toward blood flow waveforms and its indices are determined. The peak systolic (S1) velocity and resistive index (RI) are significantly higher (p<0.05) in older population who exercise regularly than who does not. There are significant differences (p<0.05) in the RI and velocity reflection index between normotensive and hypertensive groups. The S1 and peak diastolic (D) are decreased significantly (p<0.05) from normotensive to hypertension groups. Low VF group has significantly increase vascular elasticity than high VF group. In contrast, low VF group has decrese reflected wave velocity. Our findings have broad implication in prevention and monitoring of cardio-related healthproblem that possibly early detection by frequent measurement of BFV, BP and electrocardiogram using this portable device.


Signal shape feature for automatic snore and breathing sounds classification

In this study we focus on this problem and propose an automated method to classify snore and breathing sounds based on the novel feature, 'positive/negative amplitude ratio (PNAR)', to measure the shape of the sound signal. The performance of the proposed method was evaluated using snore and breathing recordings (snore: 22 643 episodes and breathing: 4664 episodes) from 40 subjects. Receiver operating characteristic (ROC) analysis showed that the proposed method achieved 0.923 sensitivity with 0.918 specificity for snore and breathing sound classification on test data. PNAR has substantial potential as a feature in the front end of a non-contact snore/breathing-based technology for sleep studies.

この論文では，新規信号形状特徴を用いた，いびき•呼吸音の自動分類法を提案する．提案法の性能評価を行った結果，提案法は感度:0.923，特異度:0.918の高精度自動抽出が行える事が分かった．さらに，提案法は，既存法よりも優れた性能を有する事が分かった．


体外循環療法中に腎臓で行われる水分の再吸収効率の推定

体外循環療法中に腎臓で行われる水分の再吸収効率の推定


Evaluation of blood flow velocity waveform in common carotid artery using multi-branched arterial segment model of human arteries

Arteriosclerosis is considered to be a major cause of cardiovascular diseases, which account for approximately 30% of the causes of death in the world. We have recently demonstrated a strong correlation between arteriosclerosis (arterial elasticity) and two characteristics: maximum systolic velocity (S1) and systolic second peak velocity (S2) of the common carotid artery flow velocity waveform (CCFVW). The CCFVW can be measured by using a small portable measuring device. However, there is currently no theoretical evidence supporting the causes of the relation between CCFVW and arterial elasticity, or the origin of the CCFVW characteristics. In this study, the arterial blood flow was simulated using a one-dimensional systemic arterial segments model of human artery in order to conduct a qualitative evaluation of the relationship between arterial elasticity and the characteristics of CCFVW. The simulation was carried out based on the discretized segments with the physical properties of a viscoelastic tube (the cross-sectional area at the proximal and terminal ends, the length, and the compliance per unit area of the tube (CS)). The findings obtained through this study revealed that the simulated CCFVW had shape similar characteristics to that of the measured CCFVW. Moreover, when the compliance CS of the model was decreased, the first peak of the simulated-CCFVW decreased and the second peak increased. Further, by separating the anterograde pulse wave and the reflected pulse wave, which form the CCFVW, we found that the decrease in the first peak of the simulated CCFVW was due to the arrival of a reflected pulse wave from the head after the common carotid artery toward the arrival of a anterograde pulse wave ejected directly from the heart and that the increase in the second peak resulted from the arrival of the peak of the reflected pulse wave from the thoracic aorta. These results establish that the CCFVW characteristics contribute to the assessment of arterial elasticity.

総頸動脈血流速度波形と動脈弾性の関係について，1次元流体解析モデルを用いて検討している．動脈モデルはヒトの全身の主要な動脈を多枝セグメントモデルとして構築したものを用い，動脈弾性を変化させた時の総頸動脈の血流速度波形を求めた結果，動脈弾性の変化により血流速度波形が変化することを示した．これにより総頸動脈の血流速度波形を調べることにより動脈硬化を評価することができる可能性を示した．


ARMA based spectral bandwidth for evaluation of bowel motility by the analysis of bowel sounds

In this study we propose a novel simple automatic method to detect the bowel sound(BS)s based on the 3 dB bandwidth of the frequency peaks in the autoregressive moving average spectrum. We use the measure, sound-to-sound interval (SSI) obtained by the proposed method, to capture bowel motility. In this paper, we show that the proposed method for automatic detection could achieve a sensitivity of 87.8±5.88%, specificity of 91.7±4.33% and area under the curve of 0.923 when working on 16 healthy volunteers during mosapride administrations. Furthermore, we show that the measured SSI averaged over a period of 30 min can clearly capture bowel motility. Our findings should have the potential to contribute toward developing automated BS-based diagnosis of IBS.

ARMAスペクトルピークの3dB帯域幅を用いて自動的に腸蠕動音を検出する方法を提案する．提案法の性能評価の結果，提案法は感度:87.8±5.88%，特異度:91.7±4.33%およびAUC:0.923の高精度な自動抽出が行える事が分かった．被験者16人に対して薬剤負荷試験を行い，腸蠕動促進剤摂取前後における腸運動性を腸蠕動音の発生頻度をもとに評価できることが分かった．


Artificial neural networks for breathing and snoring episode detection in sleep sounds

In this paper, we propose a fundamentally novel approach based on artificial neural network (ANN) technology to detect snore and breathing sound episodes(SBE). Working on clinical data, we show that the proposed method can detect SBE at a sensitivity and specificity exceeding 0.892 and 0.874 respectively, even when the signal is completely buried in background noise (SNR < 0 dB). We compare the performance of the proposed technology with those of the existing methods (short-term energy, zero-crossing rates) and illustrate that the proposed method vastly outperforms conventional techniques.

この論文では，ニューラルネットワークを用いたいびき•呼吸音検出法を提案する．提案法はSNR<0dBの状況下でも精度良く，感度:0.892，得意度:0.874で，いびき•呼吸音を検出できることが分かった．さらに，提案法は，既存法よりも優れた性能を有する事が分かった．


High Frequency Region of the Snore Spectra Carry Important Information on the Disease of Sleep Apnea

The traditional approach over the years has been to record snore sounds at a bandwidth of < 5 kHz. In this paper, we compute the power spectra of snores in three different bands defined as: low-frequency band (LFB: < 5 kHz); middle-frequency band (MFB: 5-10 kHz) and high-frequency band (HFB: 10-20 kHz). We illustrate that there is a significant difference between non-OSA snorers (Apnoea Hypopnoea Index (AHI) < 10) and OSA snorers (AHI > 10) in the region > 5 kHz. We then develop a feature to diagnose obstructive sleep apnoea (OSA) based on the spectral differences in the high frequency region and evaluate its performance on a database of 20 subjects.

いびきの周波数スペクトルは5kHz以下で特徴付けられると考えられ，その範囲でOSAいびきと単純いびきが分類できると報告されている．本研究では5kHz以上の高い周波数成分を調査することによりOSAいびきと単純いびきを分類できるかどうか検討を行う．高周波帯域に関する周波数スペクトルの違いを表現する方法を開発し，20人の患者から得られたいびきに対して，その性能の評価を行った．結果として，5kHz以上の周波数帯域にOSAと単純いびき症を識別できる違いがある事を示した．

Journal of Medical Engineering & Technology


Testing the system non-linearity in snoring sound via neural networks

Snoring has been analyzed for the clinical diagnosis of obstructive sleep apnea(OSA). Snores are likely to have diagnostically relevant non-linearities that cannot be captured by linear techniques. In this paper, we investigate the non-linearity of snores and develop a novel measure, as a possible characterisation index. The method is based on artificial neural networks (NN). The developed method was tested on a database of 27 subjects.

いびきは既存の線形手法で捉えることの出来ない非線形性を有すると考えた．ニューラルネットワーク(NN)を用いていびきの非線形性を調査する方法を開発し，開発した方法が閉塞型睡眠時無呼吸(OSA)いびきと単純いびきに対して検定を行った．27人の患者から得られたいびきに対して非線形性の検定を行うことにより，OSAいびきは単純いびきに比べて，強い非線形性を示すことが分かった．現在までに，いびき解析に基づOSA診断法が提案されているが，非線形性検定はこの方法の更なる性能向上に役立つと思われる．

International Journal of Medical Engineering and Informatics


The removal of EMG in EEG by neural networks

In this paper, it is presented that electromyography (EMG) is a shot noise based on the generation of EMG. A novel filter is proposed by applying a neural network (NN) ensemble where the noisy input signal and the desired one are the same in a learning process. Both incremental and batch mode are applied in the learning process of NNs that is better than generalized NN filters. This NN ensemble filter not only reduces additive and multiplicative white noise inside signals, but also preserves the signals' characteristics. In clinical EEG and EMG signals processing, the filter is capable of reducing EMG in the clinical EEG, and it is proved that there is randomness in EMG.

EEGとEMGが混在する信号から，EMGを軽減するための新規フィルタを提案する．提案フィルタはニューラルネットワークを用いて作成される．提案フィルタの有効性が周波数スペクトル上で表現される．


Discriminating apneic snorers and benign snorers based on snoring formant extracted via a noise-robust linear prediction technique

Snoring is the earliest and the most common symptom of Obstructive Sleep Apnea (OSA) . Quantitative analysis of snoring, however, is not used at present in the clinical diagnosis of the disease. Several researchers have reported differences in the formant frequencies of Apneic and benign snoring sounds (SS) based on linear prediction coding (LPC) analysis. However, SS is complex signal and at local low signal to noise ratio (SNR) . This signal complexity should reduce the accuracy of formant estimation. In this paper, we propose a novel approach to the diagnosis of OSA based on the formants of SSs, extracted via a noise-robust linear prediction technique. The proposed method and existing LPC-based method are compared via a measure, ς which indicates the standard deviation of first formant frequencies. The performance of the proposed method was evaluated on a database of clinical snoring sounds recorded overnight in the laboratory of a hospital sleep diagnostic center. Compared with existing LPC-based method, we show that the proposed method can differentiate (sensitivity: 88.9%, specificity: 88.9%, AUC: 0.85) between benign snoring (Apnea Hypopnea Index, AHI=6.0±3.2 event/h; 6188 episodes) and apneic snoring (AHI=40.7±20.2 event/h; 14066 episodes) .

この論文では，自己相関関数の雑音低減能力を用いて，いびきのホルマント周波数抽出法の雑音耐性を向上させる方法を提案する．18人の患者のいびきに対して，提案法の有効性を確認する事が出来た．ROC解析を用いて，いびきの第一ホルマント周波数に基づく閉塞型睡眠時無呼吸(OSA)の診断における診断能の評価を行い，高い診断能(感度:88.9%，特異度:88.9%，AUC:0.85)を得ることができた．

Transactions of the Japanese Society for Medical and Biological Engineering


Linear neural networks for spectral envelope estimation

The spectral envelope is mainly determined by the shape of vocal tract and it is generally represented by linear estimation methods such as an autoregressive (AR) modeling. Neural network (NN) is general tools for modeling nonlinear function. Nonlinear aspects of NN have been emphasized. However, in this study, a novel approach to spectral estimation, which is based on the use of a linear feed-forward NN is discussed. Example of the linear network for estimating the spectral envelope of vowel sound is presented. The proposed linear NN technique leads to interesting new paradigms which could not have been considered in advance.

線形ニューラルネットワークを用いてスペクトル包絡を推定する方法を提案する．母音を用いて，提案法の有効性が評価される．


Tracking the states of a nonlinear and nonstationary system in the weight-space of artificial neural networks

The new proposed method uses the connection-weight-space (CWS) of the neural network(NN) to extract information about the signal generator mechanism. We define a novel feature to measure the separation of two arbitrary states in the CWS and use it to track the state changes of the generating system. The performance of the method is examined via synthetic signals and clinical EEG. Synthetic data indicates that the feature can track the system down to a SNR of 3.5 dB. Clinical data obtained from three patients undergoing carotid endarterectomy of the brain showed that EEG could be modeled by the proposed method, and the blood perfusion state of the brain could be monitored via feature, with small NNs.

信号を生成するシステムをモデルしたニューラルネットワーク(NN)の結合荷重空間において，2つの状態を分離する方法を提案する．提案法はSNR=3.5dBの環境下でさえ，システムの状態を捉える事が示唆された．提案法を用いて，動脈内膜切除中のEEG信号をモデルすることにより，血液かん流の状態をモニタリングできることが分かった．

Medical and Biological Engineering and Computing


一般照明および植物育成照明に応用できる新しいLED照明方法の開発

一般照明および植物育成照明に応用できる新しいLED照明方法の開発

LED総合フォーラム2018 in 徳島 論文集

LED総合フォーラム2018 in 徳島 論文集


Blue light-emitting diodes induce autophagy in colon cancer cells by Opsin 3.

Light emitting-diodes (LED) have various effects on living organisms and recent studies have shown the efficacy of visible light irradiation from LED for anticancer therapies. However, the mechanism of LED's effects on cancer cells remains unclear. The aim of the present study was to investigate the effects of LED on colon cancer cell lines and the role of photoreceptor Opsin 3 (Opn3) on LED irradiation in vitro. Human colon cancer cells (HT-29 or HCT-116) were seeded onto laboratory dishes and irradiated with 465-nm LED at 30 mW/cm for 30 minutes. Cell Counting Kit-8 was used to measure cell viability, and apoptosis and caspase 3/8 expression were evaluated by AnnexinV/PI and reverse transcription-polymerase chain reaction (RT-PCR), respectively. Autophagy and expression of LC-3 and beclin-1 were also evaluated by autophagy assays, RT-PCR and Western blotting. We further tested Opn3 knockdown by Opn3 siRNA and the G G-protein inhibitor NF023 in these assays. Viability of HT-29 and HCT-116 cells was lower in 465-nm LED-irradiated cultures than in control cultures. LC-3 and beclin-1 expressions were significantly higher in LED-irradiated cultures, and autophagosomes were detected in irradiated cells. The reductive effect of cancer cell viability following blue LED irradiation was reversed by Opn3 knockdown or NF023 treatment. Furthermore, increased LC-3 and beclin-1 expression that resulted from blue LED irradiation was suppressed by Opn3 knockdown or NF023 treatment. Blue LED irradiation suppressed the growth of colon cancer cells and Opn3 may play an important role as a photoreceptor.


Effect of light irradiation by light emitting diode on colon cancer cells.

Recent studies have demonstrated the efficacy of irradiation from light emitting diodes (LED) for wound healing, anti-inflammation and anticancer therapies. However, little is known about the effects of visible light in colon cancer cells. The purpose of this study was to evaluate the biological response (including gene expression changes) of human colon cancer cells to different wavelengths of LED irradiation. Human colon cancer cells (HT29 or HCT116) were seeded onto laboratory dishes that were then put on LED irradiation equipment with a 465 nm-, 525 nm-, or 635 nm-LED. Irradiation at 15 or 30 mW was performed 10 min/day, each day for 5 days. The cell counting kit8 was then used to measure cell viability. Apoptosis and expression of several mRNAs (caspase, MAPK and autophagy pathway) in HT29 cultures irradiated with 465 nm LED were evaluated via AnnexinV/PI and RT-PCR, respectively. Viability of HT29 and HCT116 cells was lower in 465 nm-LED irradiated cultures than in control cultures, but viability of HT29 cells did not differ between control cultures and 525 nm-LED or 635 nm-LED irradiated cultures. Moreover, the expression of FAS, caspase-3, capase-8, and JUK were significantly higher in 465 nm-LED irradiated cultures than in control cultures, and expression of ERK1/2 and LC3 was lower in blue-irradiated cells. LED irradiation at 465 nm inhibited the proliferation of HT29 cells and of HCT116 cells. Notably, LED irradiation at 465 nm promoted apoptosis inHT29 cultures via the extrinsic apoptosis pathway and the MAPK pathway.


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The Journal of Japanese Society of Stomatognathic Function


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