Advanced Biomedical Engineering最新文献

{"title":"A Prototyping of Penile Tumescence Continuous Observation Device","authors":"S. Matsumoto, Y. Takeuchi","doi":"10.14326/abe.9.167","DOIUrl":"https://doi.org/10.14326/abe.9.167","url":null,"abstract":"In this study, we attempted to develop a wireless real-time continuous observation device for penile tumescence and/or stiffness for veri cation of nocturnal penile tumescence (NPT) and for diagnosis and classi cation of erectile dysfunction (ED). Unlike conventional mechanically wired method, the patient is not constrained by the device and is able to use the device by himself in his own living environment. A soft silicone ring that ts the penis is equipped with a built-in variable inductance, variable frequency oscillator and a onetime use micro-battery. The inductance (hence oscillating frequency) is responsible for the internal stress of the ring, which represents the tumescence and/or stiffness. A non-contact leakage ux coupled to the variable inductor allows proximity telemetry of the phenomenon overnight, or up to the battery life. Our prototype device was successfull in a feasibility test using a desktop model and in a simulated ex vivo test. Now, preparation for pre-clinical trial in healthy volunteer(s) is underway.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"9 1","pages":"167-171"},"PeriodicalIF":1.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007267","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":"Hyperparameter Optimization for Deep Learning-based Automatic Melanoma Diagnosis System","authors":"T. Nagaoka","doi":"10.14326/abe.9.225","DOIUrl":"https://doi.org/10.14326/abe.9.225","url":null,"abstract":"Deep learning is widely used in the development of automatic diagnosis systems for melanoma. However, there are some parameters called hyperparameters which should be set arbitrarily. Optimum setting of hyperparameters is challenging. The dermoscopic images on the database are trained on GoogLeNet. The hyperparameters verified in this study were random seed, solver type, base learning rate, epoch, and batch size. By using a genetic algorithm, these hyperparameters were optimized to obtain higher validation accuracy than other methods such as brute force or Bayesian optimization. The highest validation accuracy was 89.75%. The best hyperparameter settings were: 2 for random seed, RMSProp for solver type, 0.0001 for base learning rate, 30 for epoch, 32 for batch size, and 368 seconds for training time. Using the genetic algorithm, we successful-ly set the hyperparameters for efficient deep learning. Using the system developed in this study, we plan to search for a broader range of hyperparameters and identify multiple groups including lesions other than melanoma.","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":"67007978","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":"Swallowing Pattern Classification Method Using Multichannel Surface EMG Signals of Suprahyoid and Infrahyoid Muscles","authors":"Masahiro Suzuki, M. Sasaki, Katsuhiro Kamata, Atsushi Nakayama, Isamu Shibamoto, Yasushi Tamada","doi":"10.14326/abe.9.10","DOIUrl":"https://doi.org/10.14326/abe.9.10","url":null,"abstract":"The ability to fine-tune the movement of swallowing-related organs and change the swallowing pattern to fit the volume of a bolus, texture and the physical properties of the food to be swallowed is referred to as the swallowing reserve. In other words, it is the response capability of food swallowing to avoid choking and aspiration. Herein, we focus on the coordination of the suprahyoid and infrahyoid muscles activities, which are closely related to swallowing movement, as a first step to develop a method to evaluate swallowing reserve, which declines due to neuromuscular disease, muscle weakness caused by aging, to mention a few. First, using two 22-channel electrodes, we measured the surface electromyography (sEMG) signals of suprahyoid and infrahyoid muscles during the following four swallowing conditions: combining two bolus volumes (3 and 15 mL water) and two techniques (normal and effortful swallow). Then, we verified whether the difference in swallowing patterns based on swallowing conditions can be classified from sEMG signals using three machine learning methods; namely, the real-time classification, comprehensive classification, and image recognition method. In the real-time classification method, the mean classification accuracy (MCA) for the four swallowing conditions was as low as 81.5%, indicating that the difference between swallowing conditions performed in a period of approximately 1 s cannot be classified sufficiently by this method. In the comprehensive classification method that applies a majority decision to all the classification results from the start to the end of swallowing, which can be obtained every 16 ms, MCA was 95.1%. Furthermore, in the image recognition method, the change of a series of sEMG signals in the swallowing movement was converted into swallowing pattern image, and the images were classified using a combination of deep convolutional neural networks and support vector machine (SVM). Compared with the comprehensive classification method, the number of training samples for the image recognition method was only 1 / 26, but the MCA reached 95.7%. This method, which can noninvasively evaluate swallowing patterns that change slightly based on swallowing conditions, could be applied to early detection of reduced swallowing function or a state of frailty (dysphagia potential) in aged individuals.","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.9.10","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007129","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":"Finite Element Predictions of Sutured and Coupled Microarterial Anastomoses","authors":"R. Wain, Nicolas J Gaskell, A. Fsadni, J. Francis, J. Whitty","doi":"10.14326/ABE.8.63","DOIUrl":"https://doi.org/10.14326/ABE.8.63","url":null,"abstract":"Simulation using computational methods is well-established for investigating mechanical and haemodynamic properties of blood vessels, however few groups have applied this technology to microvascular anastomoses. This study, for the first time, employs analytic and numeric models of sutured and coupled mi-croarterial anastomoses to evaluate the elastic and failure properties of these techniques in realistic geometries using measured arterial waveforms. Computational geometries were created of pristine microvessels and mi-croarterial anastomoses, performed using sutures and a coupling device. Vessel wall displacement, stress, and strain distributions were predicted for each anastomotic technique using finite element analysis (FEA) software in both static and transient simulations. This study focussed on mechanical properties of the anastomosis im-mediately after surgery, as failure is most likely in the early post-operative period. Comparisons were also drawn between stress distributions seen in analogous non-compliant simulations. The maximum principal strain in a sutured anastomosis was found to be 84% greater than in a pristine vessel, whereas a mechanically coupled anastomosis reduced arterial strain predictions by approximately 55%. Stress distributions in the su-tured anastomoses simulated here differed to those in reported literature. This result is attributed to the use of bonded connections in existing studies, to represent healed surgical sites. This has been confirmed by our study using FEA, and we believe this boundary condition significantly alters the stress distribution, and is less representative of the clinical picture following surgery. We have demonstrated that the inertial effects due to motion of the vessel during pulsatile flow are minimal, since the differences between the transient and static strain cal-culations range from around 0.6–7% dependent on the geometry. This implies that static structural analyses are likely sufficient to predict anastomotic strains in these simulations. Furthermore, approximations of the shear strain rate (SSR) were calculated and compared to analogous rigid-walled simulations, revealing that wall compliance had little influence on their overall magnitude. It is important to highlight, however, that SSR variations here are taken in isolation, and that changing pressure gradients are likely to produce much greater variation in vessel wall strain values than the influence of fluid flow alone. Hence, a formal fluid-structure interaction (FSI) study would be necessary to ascertain the true relationship.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/ABE.8.63","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41935365","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":"Changes in Brain Perfusion in Patients with Unilateral Lower-limb Paresis, before and after Training on a Pedaling Wheelchair: A Feasibility Study","authors":"T. Sekiya, K. Seki, Y. Handa","doi":"10.14326/ABE.8.99","DOIUrl":"https://doi.org/10.14326/ABE.8.99","url":null,"abstract":"Our aim was to evaluate the effects of a 4-week training program using a self-powered pedaling wheelchair on brain perfusion in patients presenting with lower limb hemiparesis due to stroke, brain injury, or spinal cord injury. Our cross-sectional observational study included seven patients with lower limb hemiparesis ( ve men, two women; mean age, 68.3 ± 17.5 years), due to the following causes: cerebral hemorrhage (n = 1), stroke (n = 4), brain contusion (n = 1), and spinal cord injury (n = 1). The control group consisted of eight healthy participants (3 men, 5 women; mean age 62 ± 8 years). The training program consisted of ve bouts of 3-min continuous pedaling per day (total, 15 min/day). The outcome variable of interest was blood ow velocity in the middle cerebral artery (time average peak [TAP], cm/s) measured using Doppler. TAP was measured at rest and after a 3-min pedaling bout, before and after the training program. In the patient group, TAP was signi cantly greater after the 3-min bout than at rest, both before and after the training program (p < 0.05). There was no effect of pedaling identi ed in the control group. In the patient group, TAP increased signi cantly (p < 0.05) after training, both at rest (36.9 ± 16.9 to 47.6 ± 13.8 cm/s), and after the 3-min bout (43.3 ± 13.3 to 50.5 ± 15.1 cm/s). Our pedaling wheelchair provided a safe and effective intervention to improve brain perfusion in this patient population.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007024","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":"Observation and Proposed Measurements of Three-dimensional Tortuous Capillary Pores with Depth for Hollow Fiber Hemoconcentrator Membrane Using Dynamic Force Microscopy","authors":"M. Fukuda, Hitoshi Saomoto, Taisei Shimizu, K. Namekawa, K. Sakai","doi":"10.14326/ABE.8.145","DOIUrl":"https://doi.org/10.14326/ABE.8.145","url":null,"abstract":"A hemoconcentrator is installed as a part of cardiopulmonary bypass to concentrate the blood by removing excess water and unnecessary electrolytes from the blood diluted with myocardial protection uid. The hemoconcentrator must remove water from diluted blood ef ciently and quickly and remove proin ammatory cytokines and other unwanted molecules, without losing useful proteins such as albumin. Especially, the pore diameter and diameter distribution of the innermost surface greatly affect the pure water permeability and sieving coef cient of the solutes. In this study, the pore structure of the inner surface of the membrane was observed, and pore measurement of hollow ber hemoconcentrator membranes was attempted using a scanning probe microscope (SPM). The samples studied were commercially available hemoconcentrator membranes PUREMA A and B (JMS Co. Ltd., Japan) having asymmetric structures. A SPM was used using the dynamic force microscopy (DFM), cyclic contact mode. The deep and tortuous pore structure on the inner surface of the hemoconcentrator membrane was observed for the rst time using DFM. The pores had an elliptical shape, elongated in the longitudinal direction. When the elliptical area on the inner surface of the hemoconcentrator membrane was larger, pure water permeability was higher, showing a correlation between the elliptical area and membrane functions. The mean major pore diameters and minor pore diameters as well as the equivalent pore diameter calculated from the tortuous capillary pore model were consistent. Using DFM, the three-dimensional tortuous capillary pores at the inner surface of a hollow ber hemoconcentrator membrane could be studied, and pore diameter and distribution could be measured by image analysis. The results were supported by the tortuous capillary pore model. In the future, we need to clearly show the further superior innovations or creative/ ingenious techniques related to this study. Further the state of new ndings which contribute to development of a new hemoconcentrator and other semipermeable membranes will help to increase the value of this paper. This study is one of the key studies to achieve the targeted function for the transport phenomena through semipermeable membranes including hemoconcentrator.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/ABE.8.145","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67006953","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":"Measurements of Isometric Strength and Electromyography of Elbow Flexors under Active and Passive Conditions","authors":"M. Higa, N. Araki, Shintaro Nakatani, H. Toji","doi":"10.14326/ABE.8.124","DOIUrl":"https://doi.org/10.14326/ABE.8.124","url":null,"abstract":"The aim of this study was to measure maximum isometric force under two different conditions: active and passive conditions. The electromyograms (EMGs) were also measured. The elbow exors of healthy subjects were studied. Six healthy subjects took part in this study. The isometric maximum force and the EMGs of the elbow exors were measured under two contrasting conditions. The rst was a standard isometric measurement in which a subject actively pulled a xed wire using their elbow exor at 100% effort (active). In the second case, the subject tried to keep their elbow at 90 degrees of exion for as long as possible against external forces produced by an electric motor (passive). The highest force values were extracted during the isometric phase when the elbow angles were kept constant. Hence, the elbow angles were also monitored by an electric goniometer in the later measurement. The passive condition resulted in higher forces than the active condition in 4 of 6 subjects. For a subject who showed different maximum forces under the two conditions, the mean (standard deviation) measured maximum forces under active and passive conditions were 285.2 (11.0) N and 300.2 (14.1) N, respectively (p < 0.01). For the EMG, there were no signi cant differences between the two conditions. In conclusion, the passive condition used in this study enhanced isometric maximum forces compared to that obtained under standard isometric conditions.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/ABE.8.124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67006343","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":"Differences in Regional Brain Activities during Memory Acquisition Depending on Individual Working Memory Capacity","authors":"H. Gan, Tatsuya Suzuki, K. Yokosawa, Y. Ono","doi":"10.14326/ABE.8.23","DOIUrl":"https://doi.org/10.14326/ABE.8.23","url":null,"abstract":"Individual capacity of recall memory varies greatly even among healthy young adults. Nevertheless, the difference in brain circuitry underlying varied memory capacity has yet to be fully investigated. We acquired electroencephalographic measurements from 43 healthy young adults while performing a demanding working memory task and studied the changes in regional cortical activity in relation to different levels of memory performance. The memory task involved sequentially presenting seven arrow pictures to a participant during the encoding period, who was then asked to recall the direction of one of the arrows in the sequence within the retrieval period. We divided the participants into three groups of high, intermediate, and low performance based on the weighted hierarchical grouping method. Regional brain activities were source-localized using multiple sparse priors method in the highand low-performance groups, and group differences were determined by non-parametric permutation tests. Our ndings showed that participants with higher memory performance exhibited wider distribution of cortical activity including the prefrontal and parieto-posterior cortices, whereas lower performance participants only exhibited stable activations across occipital regions. The results implied the importance of selective attention in order to attain optimal individual working memory performance. Furthermore, we suggest the potential role of the angular gyrus as an interplay between the prefrontal and posterior regions for the management of stimulus ow and signal control. Future works should focus on conducting more thorough connectivity analysis to investigate the relationship of cortical activations with individual working memory performance.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"13 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/ABE.8.23","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007101","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":"Heat Enhances Ex Vivo Paclitaxel Delivery to Porcine Carotid Artery Wall","authors":"R. Homma, Machiko Shinozuka, N. Shimazaki, E. Ogawa, T. Arai","doi":"10.14326/ABE.8.30","DOIUrl":"https://doi.org/10.14326/ABE.8.30","url":null,"abstract":"We investigated the delivery of rhodamine B and Oregon Green®-labeled paclitaxel (OGLP) in ex vivo porcine carotid artery wall (CAW) samples after heating the reagents to 50–70°C for 15 s. When the isolated CAW samples were placed in the heated uorophore solutions, the penetration depth of the hydrophobic rhodamine B increased signi cantly compared with reference solution at 37°C. The penetration depth of OGLP also tended to increase upon heating to 70°C for 15 s. We also studied the mechanism of this agent delivery enhancement by observing the inner surface structure and hydrophobicity of the CAW samples after heating. An expanded mesh structure at the inner surface of the heated CAW samples was observed upon heating above 70°C, and the mean hydrophobicity of the media layer also increased signi cantly. We hypothesize that heating at 60–70°C for 15 s enhances the delivery of uorophores to CAW samples as a result of an expanded mesh structure at the inner surface of the CAW, along with a simultaneous increase in hydrophobicity.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67007119","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":"Photoelectric Dye-Coupled Polyethylene Film: Photoresponsive Properties Evaluated by Kelvin Probe and In Vitro Biological Response Detected in Dystrophic Retinal Tissue of Rats","authors":"T. Matsuo, M. Sakurai, Keiko Terada, T. Uchida, Koichiro Yamashita, Tenu Tanaka, K. Takarabe","doi":"10.14326/ABE.8.137","DOIUrl":"https://doi.org/10.14326/ABE.8.137","url":null,"abstract":"Electrodes that output electric current as conduction current are widely used to stimulate nerves and cardiac cells in human body. We designed a photoelectric dye-coupled polyethylene lm for use as a thin lm device to stimulate nerve cells by electric potential changes. The aim of this study was to measure its photoresponsive properties and to record in vitro biological response. When measured using a Kelvin probe system, the photoelectric dye-coupled lm showed rapid rise and fall of surface electric potential in response to light-on-and-off. Light-evoked surface electric potential of the dye-coupled lm increased in response to increasing light intensity. In vitro biological response to the dye-coupled lm was assessed in isolated rat retinal tissues using a multielectrode array recording system. As positive control, electroretinogram-like waves were recorded in response to light from normal rat retinal tissue placed with the inner retinal surface at the bottom of the multielectrode array dish. In contrast, no light-elicited wave was recorded from degenerative retinal tissue isolated from retinal dystrophic Royal College of Surgeons (RCS) rats. When the dye-coupled lm was simply overlaid on the degenerative retinal tissue with the inner retinal surface placed at the bottom of the multielectrode array dish, electroretinogram-like waves were elicited in response to light projected from the bottom. Plain polyethylene lm without photoelectric dye coupling was used as negative control, and did not yield light-elicited response when placed on the degenerative retinal tissue. For detailed recordings of action potential spikes high-passed at 100 Hz, a nylon mesh anchor was placed on top of the preparation to ensure close contact between the multielectrode array and the retinal tissue with or without the dye-coupled lm. In this experimental setting, the degenerative retinal tissue alone showed spontaneous action potential spikes as numerous small trivial amplitudes in the background noise, while the degenerative retinal tissue overlain with the dye-coupled lm showed action potential spikes with increased amplitude in response to light against the background of spontaneous spikes. This study con rmed that the photoelectric dye-coupled polyethylene lm is able to stimulate degenerative retinal tissue that has lost photoreceptor cells, and may function as a novel type of retinal prosthesis. Electric potential changes, probably as displacement current or capacitive current, may be an alternative approach to stimulate nerves in human body.","PeriodicalId":54017,"journal":{"name":"Advanced Biomedical Engineering","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14326/ABE.8.137","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67006938","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}