ニューラル ネットワーク オ モチイタ ジキ ウンドウ ケイソク システム

物体の空間内での位置及び向きを非接触で多自由度でけいそくすることは、工業計測 や生態運動計測等の様々な分野で重要であり、種々の方法により計測が試みられて いる。特に磁界を利用した方法は原理的に非接触計測が可能であるため、計測その ものによって影響を受けやすい生体各部の運動等に対しても適用することが可能で ある。制御対象の周辺に磁束を歪める磁性体が無ければ、物体によって遮蔽され、 不可視な測定対象の運動測定にも適用可能である。現在使用されている磁界を用い た多自由度運動計測には変動磁界とセンサコイルを併用するものがほとんどである。 原理的にはセンサコイルに誘起される誘導電流が各自由度毎に位相の違いとして検 出できるよう周波数や振幅、位相の異なる変動磁界を生成し、その中にセンサコイルを 置く方法が用いられる。一方永久磁石を使う方法は位置のみまたは特定方向の 回転のみといった自由度自由度の小さい運動の計測にしか用いられない。これは小型磁石 の位置と向きから周辺の磁束密度分布を求める問題は、逆問題の1種であり一般に 解くことができないためである。 本論では小型永久磁石周辺の磁束密度分布から磁石の位置と向きを求める逆問題 に、任意関数の汎用近似器としてバックプロパゲーション・ニューラルネットワーク を用いることにより、高速、高精度に多自由度運動計測が可能なシステムを提案 し、計算機シミュレーションを用いてその有用性を検討した。その結果、上記の 逆問題の解の近似を位置、向きついてそれぞれ平均で0.4％、0.04度程度の精度で行う ことが可能であることが確認された。これにより例えば多次元ポインティングデバ イス等へ本システムを適用可能であるものと思われる。 生体運動計測の一種として古くから盛んに計測が試みられているものに顎運動計測 がある。これは顎運動が咬合機能の解明や顎関節症等の診断等に関する様々な情報 を含んでいると考えられるためである。しかし測定対象である下顎骨が皮膚によ り覆い隠されており外部から見ることができないこと、下顎運動が6自由度を持って いること、測定による下顎運動への影響が出やすいこと、数10μm、0.1度程度の 精度が必要なことなど生体運動計測の中でも特に困難な部類に入る。従来の計測法 には、機械的計測法、光学的計測法そして磁気的計測法が用いられてきたが上のよう な条件を全て満たすものはほとんど無い。本論文で提案した運動計測システムは測 定対象に小型の磁石を固定するだけで良く顎運動にも制限を加えないことから、下 顎の運動計測への応用は特に有用を思われる。測定空間を下顎前肢部計測用に最適化 するなどして、計算機シミュレーションにより検討した結果、位置、向きついてそれ ぞれ平均で7μ、0.002度程度の制度で測定可能なネットワークを構築することが できた。これは制度的には下顎運動計測システムとして実用可能であると思われる

Automatic Bowel Motility Evaluation Technique for Noncontact Sound Recordings

Information on bowel motility can be obtained via magnetic resonance imaging (MRI)s and X-ray imaging. However, these approaches require expensive medical instruments and are unsuitable for frequent monitoring. Bowel sounds (BS) can be conveniently obtained using electronic stethoscopes and have recently been employed for the evaluation of bowel motility. More recently, our group proposed a novel method to evaluate bowel motility on the basis of BS acquired using a noncontact microphone. However, the method required manually detecting BS in the sound recordings, and manual segmentation is inconvenient and time consuming. To address this issue, herein, we propose a new method to automatically evaluate bowel motility for noncontact sound recordings. Using simulations for the sound recordings obtained from 20 human participants, we showed that the proposed method achieves an accuracy of approximately 90% in automatic bowel sound detection when acoustic feature power-normalized cepstral coefficients are used as inputs to artificial neural networks. Furthermore, we showed that bowel motility can be evaluated based on the three acoustic features in the time domain extracted by our method: BS per minute, signal-to-noise ratio, and sound-to-sound interval. The proposed method has the potential to contribute towards the development of noncontact evaluation methods for bowel motility

BP ニューラル ネットワーク オ モチイタ サーカディアン リズムゲン ノ システム ドウテイ

Almost all land animals coordinate their behavior with circadian rhythms, matching their functions to the daily cycles of lightness and darkness that result from the rotation of the earth corresponding to 24 hours. Through external stimuli, such as dairy life activities or other sources from our environment may influence the internal rhythmicity of sleep and waking properties. However, the rhythms are regulated to keep their activity constant by homeostasis while fluctuating by incessant influences of external forces. A modeling study has been developed to identify homeostatic dynamics properties underlying a circadian rhythm activity of sleep and wake data measured from normal subjects, using an MA (Moving Average) model associated with backpropagation (BP) algorithm. As a result, we found out that the neural network can capture the regularity and irregularity components included in the data. The order of MA neural network model depends on subject’s behavior. The last two data are usually dominant in the case without strong external forces. The adaptive changes of the dynamics are evaluated by the change of weight vectors, a kind of internal representation of the trained network. The dynamics is kept in a steady state for more than 20 days. Identified properties reflect the subject’s behavior, and hence may be useful for medical diagnoses of disorders related to circadian rhythms

Biomedical telemetry: technology and applications

Telemetry is a technology that allows the remote measurement and reporting of information of interest to the system designer or operator. Telemetry typically refers to wireless communications, but can also refer to data transferred over other media, such as a telephone or computer network or via an optical link. This book provides a brief overview of the telemetric technique and how it has evolved over the years as well as its numerous applications. By providing the geographical location of animals, and sometimes concurrently allowing the registration of other parameters (e.g. activity, temperature), this technique is often used to study home-range size and shape, habitat selection etc. Medical telemetry may be defined as "the measurement and recording of physiological parameters and other patient-related information via radiated bi- or unidirectional electromagnetic signals." This book discusses the telemetric devices that can be coupled with biosensors and microsensors that generate electrical signals related to electrochemical processes. The engagement of fisheries and polar biologists in acoustic telemetry studies on inshore polar fish is explored by sharing their experiences of the issues surrounding environmental constraint, equipment limitations, tracking protocols, choice of species, and safety in the field. Different steps taken for the telemetric system to record the electroencephalogram (EEG) from adult freely moving rats are described. This novel telemetric system was also used to record brain activity in small animals. The development of a cost-effective telemetric system is addressed, through a combination of a wireless microphone for signal transmission and a computer sound card for recording of signals in the audible range. Finally, the telemetry of body temperature for long-term recordings of breathing is described

Visceral fat accumulation influenced blood flow velocity in hypertensive subjects

Arterial function measurements are widely used as surrogate markers of cardiovascular disease. However, it is unknown whether non-pathological factor may influence these measurements in particularly blood velocity function. The aim of current study was to investigate the relationship between visceral fat (VF) accumulation and hypertension incidence. The study evaluated the changes of blood velocity waveforms among normotensive and hypertensive subjects. One hundred twenty six individuals were classified into three groups which are lower VF, middle VF and higher VF regarding on their VF level. Resistive index (RI), velocity reflection index (VRI) and vascular elastic recoil index (VEI) were calculated from the 3 minutes assemble average of envelope waveform. The VF accumulation was higher in hypertensive than normotensive subjects. Peak systolic (S1), peak diastolic (D), VRI and VEI modulated significantly (P < 0.05) in higher VF compared to lower VF groups. RI and VRI show significantly different in hypertensive compared to normotensive groups. In conclusion, increased VF influences hypertension incidence and blood velocity regulation

Basic study of a diagnostic modality employing a new electrical impedance tomography (EIT) method for noninvasive measurement in localized tissue

The objective of this study is to develop a device for noninvasive local tissue electrical impedance tomography (EIT) using divided electrodes with guard electrodes and to validate its effectiveness using bioequivalent phantoms. For this purpose, we prepared a measurement device and bioequivalent phantoms, measured the electrical characteristics of the phantoms, and validated the method using the phantoms. Monolayer phantoms mimicking the brain and muscle and bilayer phantoms consisting of muscle and brain layers were prepared. The relative differences between the measured electrical conductivities of the monolayer brain and muscle phantoms and the true values determined by the 4-electrode method were both less than 10%. The relative differences between the measured and true values in the bilayer phantoms were less than 20% in both layers. The biological impedance measurement device that we developed was confirmed to be effective for impedance measurement in bilayer phantoms with different electrical impedances. To develop a device for the early diagnosis of breast diseases, the development of a multi-layer phantom and demonstration of the effectiveness of the device for its examination are necessary. If the device that we developed makes impedance measurement in breast tumors possible, it may be used as a new diagnostic modality for breast diseases

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

Ultraviolet (UV) irradiation is used to disinfect water and food and can be classified as UVA (detected at wavelengths 320–400 nm), UVB (280–320 nm), and UVC (<280 nm). We developed a method for UVA sterilization of equipment with a UVA-light-emitting diode (LED); however, a high rate of fluence was needed to promote pathogen inactivation. The aim of this study was to identify genes associated with UVA sensitivity with the goal of improving UVA-LED-mediated bactericidal activity. We constructed a transposon-mutant library of Vibrio parahaemolyticus and selected six mutants with high sensitivity to UVA irradiation. Genes associated with this phenotype include F-type H+-transporting ATPases (atp), as well as those involved in general secretion (gsp), and ubiquinone and terpenoid-quinone biosynthesis (ubi). Gene complementation resulted in decreased sensitivity to UVA-LED. The atp mutants had lower intracellular adenosine triphosphate (ATP) concentrations than the wild-type treatment, with 20 mM L-serine resulting in elevated ATP concentrations and decreased sensitivity to UVA-LED. The gsp mutants exhibited high levels of extracellular protein transport and the ubi mutants exhibited significantly different intracellular concentrations of ubiquinone-8. Taken together, our results suggest that the protein products of the atp, gsp, and ubi genes may regulate sensitivity to UVA irradiation

青色発光ダイオードはオプシン3を介し大腸癌細胞のオートファジーを誘導する

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/cm2 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 Gi/o 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

Inactivation of ESBL-E. coli

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

Vegetable Surface Sterilization System Using UVA Light Emitting Diodes

Surface sterilization of fresh produce has been needed in the food manufacturing/ processing industry. Here we report a UVA-LED (Ultra Violet A-Light Emitting Diode) system for surface sterilization that is safe, efficacious, low cost, and apparently harmless to fresh produce. To test the system, Escherichia coli strain DH5α was spot-inoculated onto vegetable tissues, and treated under UVA-LED. Tissues were homogenized and bacteria quantified by colony-forming assay. Possible effects of UVA-LED on vegetable quality were evaluated by HPLC. Tissue weight changes were checked after treatment at 4℃, 15℃, and 30℃. Bacterial inactivation by UVA-LED radiation was observed after a 10 min treatment and increased with increasing time of irradiation. The log survival ratio reached -3.23 after a 90 min treatment. Bacterial cells surviving treatment grew slowly compared to non-irradiated control cells. Cabbage tissue lost weight over time after treatment, and weight loss increased with increasing incubation temperature, but there was no difference between losses by UVA-LED treated and control tissues at any temperature tested. In addition, no differences of Vitamin C content in cabbage tissue were detected by HPLC after UVA-LED treatment. These results suggest that UVA-LED treatment has great potential for vegetable surface sterilization in the food manufacturing/processing industry