Advanced Biomedical Engineering最新文献

{"title":"Overview of Magnetoencephalography—Brief History of its Sensors and Hardware","authors":"K. Yokosawa","doi":"10.14326/abe.9.217","DOIUrl":"https://doi.org/10.14326/abe.9.217","url":null,"abstract":"# Abstract Magnetoencephalography (MEG) has advanced dramatically in the past 50 years, since the first neuromagnetic recording in 1968. Recent MEGs have both high spatial resolution of a few millimeters and high temporal resolution in the order of millisecond. MEG is applied not only clinically, but also in many academic fields including physiology and psychology. In this article, the basic principle and structure of MEG, and the brief history of development are","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanism of Electrical Defibrillation: Current Status and Future Perspective","authors":"N. Shibata, S. Inada, K. Nakazawa, Naoki Tomii, M. Yamazaki, Hiroshi Seno, H. Honjo, I. Sakuma","doi":"10.14326/abe.9.125","DOIUrl":"https://doi.org/10.14326/abe.9.125","url":null,"abstract":"Ventricular fibrillation (VF) is currently a major cause of sudden cardiac death (SCD). To cure VF, electrical defibrillation is the only therapy. However, strong energy is required. Thus, to reduce the energy or develop a new method is desired. The mechanism of how the electric shock sweeps VF is still controversial. In this article, we summarize evidence and remaining problems of this topic. There are three issues in time sequence of VF: how to initiate, how to continue, and how to terminate. Many investigations to achieve VF-free heart have been reported, but there are currently no definite methods to prevent VF. Thus, to terminate VF is one of the big challenges to prevent SCD. There are two strategies to improve electrical defibrillation: elucidate the substantial mechanism and reduce the energy. (1) Substantial mechanism proposed: In a failed defibrillation episode, at the energy level of the near defibrillation threshold, the initial activation site is related to the repolarization phase of the location. However, it is still not clear whether it is part of the continuous VF activity or initiation of re-VF. It is well known that strong field electric shock (including cathodal and anodal stimuli) has many effects on the cardiac tissue, such as electroporation, virtual electrode effects, and electrophysiological responses, which are influenced by tissue geometry (including fiber orientation and bifurcation of tissues). These phenomena should modify the defibrillation effect. Finally, the characteristics of dynamic spiral wave (SW; the sources of continuity of re-entries) influence the continuity of VF. (2) Efforts to reduce the defibrillation energy: To reduce the defibrillation energy, biphasic pulse, regional cooling, modified stimuli programs, and automated local stimuli to SW are proposed. The superiority of biphasic pulse to monophasic pulse was established in the late 20th century; however, the mechanism is still not well understood. Cooling of some region of the heart ventricles widens the route of SW trajectory and terminates SW. Programming high frequency stimulus or double stimuli according to computer simulation of the heart model could reduce the defibrillation threshold. Automated local stimulus to the site between the tail of SW activation and the next activation front could terminate the SW.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationships among Electromyogram, Displacement and Velocity of the Center of Pressure, and Muscle Stiffness of the Medial Gastrocnemius Muscle during Quiet Standing","authors":"T. Uchiyama, Gai Kondo","doi":"10.14326/abe.9.138","DOIUrl":"https://doi.org/10.14326/abe.9.138","url":null,"abstract":"Medial gastrocnemius muscle stiffness was estimated using a system identification technique. The medial gastrocnemius muscle was electrically stimulated using surface Ag-AgCl electrodes and the center of pressure fluctuation in the forward-backward direction was measured with a force plate. Electrically induced fluctuation of the center of pressure was classified according to the displacement and velocity of the center of pressure. The classified steps of displacement and velocity were 0.2 cm and 0.2 cm / s, respectively. The ranges of the classes were ± 0.15 cm and ± 0.15 cm / s. The classified fluctuations were synchronously averaged and the averaged fluctuation was regarded as an output signal of the transfer function from the electrical stimulation to the fluctuation. The transfer function was identified as an estimate of muscle stiffness using a singular value de-composition method. The average muscle stiffness of eight young male participants ranged from 56.7 to 75.9 N / m. Muscle stiffness was high when the displacement of the center of pressure was positive and the velocity was negative. These characteristics resembled the preceding 0.3 s of the electromyogram. This preceding high muscle activity probably contributed to muscle stiffness. Muscle stiffness was well approximated with a multiple linear regression plane, in which the explanatory variables were the displacement and velocity of the center of pressure.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimum Sterilization Methods of Biocompatible Hybrid Material for Artificial Organs","authors":"Y. Inoue, Ayaka Tashiro, Y. Kawase, T. Isoyama, I. Saito, T. Ono, Shintaro Hara, K. Ishii, Terumi Yurimoto, Y. Shiraishi, A. Yamada, T. Yambe, Y. Abe","doi":"10.14326/abe.9.83","DOIUrl":"https://doi.org/10.14326/abe.9.83","url":null,"abstract":"We previously reported the development of a new hybrid medical material comprising bio-based materials with high biocompatibility and artificial materials with characteristics of excellent strength and pro-cessability. This material shows sufficient biocompatibility and excellent stability in vivo . Moreover, when applied to the surface of an implantable sensor, the biological reaction on the sensor function surface can be well controlled. For commercialization and widespread use of hybrid materials with such superior properties, sterilization and storage are critical considerations, given that hybrid materials must be processed outside the body prior to application as medical materials in vivo , thus posing a risk of contamination despite best efforts. There-fore, the aim of the present study was to establish an optimal sterilization method that will not impair the biocompatibility of the hybrid material. Toward this end, we tested six sterilization methods for the hybrid material: autoclave (121 (cid:155) C, 20 min), dry heat (160 (cid:155) C, 120 min), ethylene oxide gas (37 (cid:155) C, 120 min), hydrogen peroxide plasma (45 (cid:155) C, 45 min), and gamma ray (25 kGy) with and without lyophilization. After sterilization, the material was cultured with vascular endothelial cells to evaluate the engraftment rate, and was observed with light and scanning electron microscopy to determine shape and structure changes. The results demonstrated that gamma sterilization without lyophilization was the best sterilization method for this material, which preserved the collagen network and showed no change in number of adhered vascular endothelial cells compared to the pre-sterilized material. These findings are useful to promote the commercialization of this hybrid material with combined advantages of synthetic and bio-based materials for widespread clinical application in the engineering of artificial organs.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67008331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance Improvement of Automated Melanoma Diagnosis System by Data Augmentation","authors":"Kana Kato, M. Nemoto, Yuichi Kimura, Y. Kiyohara, H. Koga, N. Yamazaki, G. Christensen, C. Ingvar, K. Nielsen, A. Nakamura, T. Sota, T. Nagaoka","doi":"10.14326/abe.9.62","DOIUrl":"https://doi.org/10.14326/abe.9.62","url":null,"abstract":"Color information is an important tool for diagnosing melanoma. In this study, we used a hyper-spectral imager (HSI), which can measure color information in detail, to develop an automated melanoma diagnosis system. In recent years, the effectiveness of deep learning has become more widely accepted in the field of image recognition. We therefore integrated the deep convolutional neural network with transfer learning into our system. We tried data augmentation to demonstrate how our system improves diagnostic performance. 283 melanoma lesions and 336 non-melanoma lesions were used for the analysis. The data measured by HSI, called the hyperspectral data (HSD), were converted to a single-wavelength image averaged over plus or minus 3 nm. We used GoogLeNet which was pre-trained by ImageNet and then was transferred to analyze the HSD. In the transfer learning, we used not only the original HSD but also artificial augmentation dataset to improve the melanoma classification performance of GoogLeNet. Since GoogLeNet requires three-channel images as input, three wavelengths were selected from those single-wavelength images and assigned to three channels in wavelength order from short to long. The sensitivity and specificity of our system were estimated by 5-fold cross-val-idation. The results of a combination of 530, 560, and 590 nm (combination A) and 500, 620, and 740 nm (com-bination B) were compared. We also compared the diagnostic performance with and without the data augmentation. All images were augmented by inverting the image vertically and/or horizontally. Without data augmentation, the respective sensitivity and specificity of our system were 77.4% and 75.6% for combination A and 73.1% and 80.6% for combination B. With data augmentation, these numbers improved to 79.9% and 82.4% for combination A and 76.7% and 82.2% for combination B. From these results, we conclude that the diagnostic performance of our system has been improved by data augmentation. Furthermore, our system suc-ceeds to differentiate melanoma with a sensitivity of almost 80%. (Less)","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67008625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diffuse Speckle Contrast Analysis (DSCA) for Deep Tissue Blood Flow Monitoring","authors":"Kijoon Lee","doi":"10.14326/abe.9.21","DOIUrl":"https://doi.org/10.14326/abe.9.21","url":null,"abstract":"Assessing blood ow, as well as blood volume and oxygen saturation, is of utmost importance for health monitoring. Assessing microcirculation, as opposed to macrocirculation, is especially important for assessing the local tissue viability. Many optics-based modalities have been developed recently such as laser speckle contrast imaging (LSCI), laser Doppler owmetry (LDF), diffuse correlation spectroscopy (DCS), and diffuse speckle contrast analysis (DSCA), which all share the advantage of non-invasive measurement of blood ow using non-ionizing radiation. This paper offers a review of these modalities centered around DSCA, which was developed most recently and is considered one of the fastest and most affordable deep tissue perfusion probes.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/abe.9.21","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards a Medical Oriented Social Network Service: Analysis of Instant Messaging Communication among Emergency Physicians","authors":"Kensuke Morris, Osamu Sugiyama, Goshiro Yamamoto, Manabu Shimoto, G. Kato, S. Ohtsuru, Masayuki Nambu, T. Kuroda","doi":"10.14326/abe.9.35","DOIUrl":"https://doi.org/10.14326/abe.9.35","url":null,"abstract":"The use of social network service (SNS) applications for health communication has revolutionized communication between physicians in recent years. We performed an unrestricted retrospective study focusing on emergency physicians (EPs) in Kyoto University Hospital (KUHP) since timely communication is important during emergencies. EPs used LINE, a popular SNS application in Japan. EPs (n = 22) sent 1752 messages from April 2017 to March 2018. Most messages sent contained text data (82.1%), the remaining contained media (17.9%); media included images (72.6%), LINE stamps (22.9%), LINE albums (2.3%) and les (1.6%). Content analysis by two coders produced 13 categories (n = 1438); these were ‘miscellaneous’, ‘patient’, ‘team’, ‘treatment’, ‘event’, ‘situation’, ‘reference’, ‘announcement’, ‘schedule’, ‘resource’, ‘policy’, ‘transport’ and ‘unknown’. The top ve message categories were related to miscellaneous chat (22.5%), patient (19.1%), team (14.3%), treatment (11.8%) and event (6.6%). The largest number of messages among EPs were sent on Monday and Friday. The numbers of messages sent among EPs during day-shift and night-shift were similar. The categories identi ed in uenced our proposal of medical oriented SNS platform features: structured tagging system for messages related to relevant categories (F1); inquiry broadcast system for speci c inquiries using structured tagging (F2); image tagging system for images shared within groups (F3) and summarized noti cations (F4). Features that need consideration are (1) an opt-in location sharing system between physicians and (2) physicians’ access to patient records from the SNS application. In this study, messages discussed by EPs were categorized and the resulting categories in uenced our proposal of a physician-centered SNS platform customized to EPs’ roles. Since physicians prefer using SNS applications compared to traditional mobile phones, their information needs should be considered. Designing a medical oriented SNS platform that is physician-centered should rst include an understanding of topics discussed by physicians. Based on the categories classi ed, the proposal of physician-centered features for designing a medical oriented SNS platform is also discussed in this paper.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"9 1","pages":"35-42"},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the Impact of White Matter Conductivity Anisotropy on Reconstructing EEG Sources by Linearly Constrained Minimum Variance Beamformer","authors":"N. Samadzadehaghdam, B. Makkiabadi, S. Masjoodi","doi":"10.14326/abe.9.53","DOIUrl":"https://doi.org/10.14326/abe.9.53","url":null,"abstract":"EEG source imaging aims to reconstruct the neural activities of the brain accountable for the recorded scalp potentials. This procedure requires solving two problems, namely, forward and inverse problems. For the forward problem, the head is modeled as a volume conductor and the Poisson ʼ s equation that describes the relation between neural activities and the observed EEG signals is solved. In this study, we enhanced the forward model by considering the white matter anisotropic conductivity tensor estimated from diffusion-weight-ed images. The second step is to solve the inverse problem in which the activity of the brain sources is estimated from measured data using the forward solution obtained in the previous step. Spatial filtering, also called beamforming, is an inverse method that reconstructs the time course of the source at a particular location by a linear combination of the sensor space data. We evaluated quantitatively the impact of the enhanced anisotropic forward model on linearly constrained minimum variance beamformer for both superficial and deep sources in a simulation environment, in terms of normalized mean squared error. Results showed that the anisotropic head forward model moderately enhanced the reconstruction of the sources, especially deep thalamic and olfactory sources.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/abe.9.53","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67008496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of Portal Vein by Three-dimensional Ultrasound Image Tracking and Registration: Toward Hands-free Monitoring of Internal Organs","authors":"Iori Terada, Yuki Togoe, Toshiki Teratoko, Tomohiro Ueno, K. Ishizu, Y. Fujii, T. Shiina, N. Sugimoto","doi":"10.14326/abe.9.1","DOIUrl":"https://doi.org/10.14326/abe.9.1","url":null,"abstract":"Ultrasound is a convenient non-invasive imaging modality used for the diagnosis or detection of various diseases and assessment of therapeutic effects. However, when imaging internal organs, the ultrasound probe must be handled by an operator. The ability to perform hands-free ultrasound imaging of internal organs is likely to offer an unprecedented advantage in various situations such as internal organ monitoring during exercise tests and prolonged monitoring. Toward this end, we have developed a new method of hands-free monitoring using three-dimensional (3D) ultrasound and used this method in portal vein monitoring, which is important for functional evaluation of hepatic and gastrointestinal systems. In previous studies, we developed a hand-made probe holder and used it to capture images of the portal vein, using image tracking and registration to compare the same position of the portal vein. In this study, we first used an abdomen phantom to assess image tracking qualitatively and quantitatively. After validating the method on the phantom, we monitored the portal vein in three healthy subjects using our 3D ultrasound method. Image tracking and registration of the portal veins in three subjects were successfully performed offline. Finally, respiratory analysis and vein diameter measurement were performed based on the image tracking results. The respiratory analysis quantified the respiration-induced portal vein movements. The vein diameter showed changes that might be induced by respiration and heartbeat. These results indicate that our 3D ultrasound method is a potentially useful tool for hands-free monitoring of internal organs.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/abe.9.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smoothing of Mammogram Using an Improved Gradient based Technique","authors":"R. ByraReddyG, H. PrasannaKumar","doi":"10.14326/abe.9.202","DOIUrl":"https://doi.org/10.14326/abe.9.202","url":null,"abstract":"","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"9 1","pages":"202-208"},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}