Transactions of Japanese Society for Medical and Biological Engineering
Online ISSN : 1881-4379
Print ISSN : 1347-443X
ISSN-L : 1347-443X
Volume Annual58 , Issue Proc
Showing 1-31 articles out of 31 articles from the selected issue
  • Makoto Yoshizawa, Norihiro Sugita, Emi Yuda, Akira Tanaka, Noriyasu Ho ...
    2020 Volume Annual58 Issue Proc Pages 542-543
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Video plethysmogram (VPG) can easily be obtained from video images taken by ordinary video cameras that are installed in personal computers or smartphones. In this article, the wide application possibilities of the VPG, its problems and limitations will be discussed after introducing basic characteristics and methods of extracting the VPG signals.

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  • Shinji Deguchi, Honghan Li, Tsubasa Matsui, Daiki Matsunaga, Foncham J ...
    2020 Volume Annual58 Issue Proc Pages 544-545
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Recent progress in understanding the essential roles of mechanical forces in regulating various cellular functions expands the field of biology to one where interdisciplinary approaches with mechanical engineering techniques become indispensable. Cellular traction forces (CTF) - that are present in proliferative cells including cancer cells due to the activity of ubiquitous nonmuscle myosin II (NMII) - are one of such mechanical forces (or signal regulators), but because NMII works downstream of diverse signaling pathways, it is often difficult to predict how the CTF changes upon perturbations to particular molecules such as gene mutations and drugs. Here I will talk about our unique bioengineering technology with a high-throughput data analysis capability to determine whether the endogenous CTF is upregulated or downregulated.

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  • Akinori Ueno
    2020 Volume Annual58 Issue Proc Pages 546-547
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    This paper presents electrocardiogram (ECG) measurement systems that involve capacitively coupled electrodes. Two of three systems presented are non-wearable types and the other is wearable type. The non-wearable systems are in-bed and on-seat systems, respectively. Capacitive ECG (cECG) measured by these systems provided clearly visible R and T waves even in realistic measuring conditions. Moreover, the wearable-type system using elastic bandage electrodes also provided stable cECG recordings in treadmill exercise test, compared with directly measured NASA-lead ECG.

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  • Ryoma Seto, Ryosuke Hosaka
    2020 Volume Annual58 Issue Proc Pages 548-549
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In the era of Society 5.0, two study groups have been discussing the direction of business reform using inpatient devices in order to make nurses more capable. A questionnaire survey was conducted with nursing managers to understand their views on this issue. As a result, it was found that there was a certain level of understanding in implementing a motion detection system using RFID and an observation system using face recognition in hospital wards. On the other hand, there was a strong sense of resistance to leaving the nurses' own behavior log as compared to the patient's behavior, suggesting the need to strengthen privacy protection.

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  • Tomohiro Kuroda, Risa Sakurai, Yoshimoto Shunsuke, Hideo Nakamura, Mas ...
    2020 Volume Annual58 Issue Proc Pages 550-552
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Japan has introduced Clinical Trials Act in April 2018 with unique definition of "clinical trials". Once defined as a clinical trial, the research has to be conducted by ones with medical doctor license. As a result, the act discourages medical and biomedical engineering researchers, mostly engineering-origin researchers without medical doctor license, to engage in research activities. In order to promote medical and biomedical engineering researches, Japanese Society for Medical and Biomedical Engineering issued guideline for researchers to check whether a particular research is classified as clinical trial under the clinical trial act definition on October 2019. Although the guideline provides general classification criteria, contributions of members to develop detailed criteria should be given for each research approach, such as electric-stimuli, motor-assistance, etc. is expected. Keywords: The Clinical Trials Act of Japan, Guideline, Classification Criteria.

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  • Hiroya Takada, Nao Wakabayashi, Atsushi Sakai, Takayuki Hoshi, Hidenor ...
    2020 Volume Annual58 Issue Proc Pages 553-554
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    We elucidated the molecular mechanism of angiogenesis effects of non-contact compression force based on phased-array ultrasonic technologies. Endothelial cells cultured on type I-A collagen gel were induced to differentiate and form tube-like structures concomitant with the cyclic compression at apical cell-surface. Additionally, cyclic compression induced high-frequency Ca2+ oscillations which were reduced with the removal of compression. Cyclic compression by our device accelerated wound healing in an acute murine wound model. Compression-stimulated wounds demonstrated significantly accelerated wound healing: their mean area decreased significantly faster relative to control wounds. The histochemical staining indicated the facilitation of collagen proliferation and proangiogenesis in the treatment group. Gene expression profiling revealed similarities between the in vitro and in vivo. Notch ligand and Notch signaling that were involved in angiogenesis were sequentially and transiently upregulated in the early stage after starting treatment. Compression may stimulate to accelerate early angiogenesis mediated by Notch ligand upregulation.

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  • Yuichi Makino, Satoshi Yamamoto, Taichi Shimizu, Shinya Onogi, Kohji M ...
    2020 Volume Annual58 Issue Proc Pages 555-556
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In this study, for the control of a small object in blood vessel by acoustic radiation force, a therapeutic ultrasonic transducer is controlled. The objective of this research is to develop a position / posture calibration control to maintain ultrasonic irradiation position accuracy and to apply to a parallel link robot. We have verified the performance of calibration control using a parallel link robot. As a result, the robot achieved positioning even when there were trackers could not be detected by the optical 3D position sensor during position control of the transducer, where the usefulness of the system was suggested. In this calibration control, the position and posture of the robot are calculated using an optical 3D position sensor and inertial sensor, and calculate the error from the command value at that moment. Then, maintaining ultrasonic irradiation position accuracy by subtracting from the command value at the next moment.

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  • Yutaro Kobayashi, Junya Takano, Kansai Okadome, Kohji Masuda
    2020 Volume Annual58 Issue Proc Pages 557-558
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    We are currently developing a research to control a thin catheter by forming acoustic radiation force. In an actual medical practice, positioning of the transducers on body surface is limited due to various shape of body surface or blood vessel on each patient. The purpose of this study to examine with various spatial placement conditions of the transducer to bend a thin catheter. Acoustic radiation force were produced to bend of the catheter in the direction perpendicular to the sound axis with various placement of transducers in line or point symmetrically. Focal position of the sound field was arranged with a step by 0.2 mm to measure the displacement of the catheter. We found that more displacement was obtained with a line symmetric arrangement rather than a point symmetric arrangement. Also, we compared the superiority of each arrangement condition through the obtained displacement.

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  • Masaki Yoshida, Yuichi Miyamoto, Masahiro Toida
    2020 Volume Annual58 Issue Proc Pages 559-561
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    PDT (photodynamic therapy) is the cancer treatment. But PDT is not adapted to advanced cancers. 405nm is the peak absorption wavelength of Laserphyrin® and it does not penetrate into tissues deeply interfered with hemoglobin absorption and scattering attenuation in tissues. The next peak absorption wavelength 664nm is used for PDT now. Since the absorption rate at 405nm of Laserphyrin® is very high, the effect of two-photon excitation at 810nm can be expected. In this study, we investigate a feasibility of two-photon excitation PDT using near infrared light and compared at 810nm and 1328nm. We have developed Nd:YAG SHG pumped KTP-OPO that oscillate at both wavelengths by replacing the output coupler and adjusting phase matching angle with high peak power. In this paper, we report KTP-OPO configuration and optical properties at these wavelengths. We have accomplished 200kW peak power 20ns pulse width 50Hz repetition rate at both wavelengths.

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  • Misuzu Yoneyama, Masaya Watada, Akira Mori
    2020 Volume Annual58 Issue Proc Pages 562-563
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In stage 1 5-year survival rate of breast cancer is more than 90%. So, early detection is important for breast cancer, and it is effective to have regular examination for breast cancer.But, inspect accuracy depends on inspector skills because it is difficult to keep the probe vertical. And, the size and position of cancer is unclear.The aim of our study is to keep the probe by the auxiliary equipment.Here we describe operation verification of auxiliary equipment. In the guidelines of breast cancer screening, it needs to find minimum 5mm object on ultrasound image. The goal of this study was to detect object of minimum 5mm. Next, we consider image acquisition method. When auxiliary equipment scans, the phantom was deformed by the probe. We suggest new scanning method. It can prevent to deform the phantom and to obtain ultrasound image. We describe the result of operation verification.

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  • Akane Yamamoto, Takamasa Shimada
    2020 Volume Annual58 Issue Proc Pages 564-565
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In the previous study, the method of extracting brain regions from the MR brain image was proposed. That method uses Snake to detect the position of the scalp and remove scalp and skull automatically. In this study, we propose the method for automatic placement of initial contour of snake. At first, the MR brain image is divided into several small areas. Each area could be classified into the area with no object, and the area with brain parenchyma, and Composite area by considering the average and the standard deviation of histogram of the image. The position of the contour of snake can be initialized automatically by place it in the area with no object. As a future, we will apply the proposing method of placing the initial contour of Snake to several MR head images and estimate the effect by comparing with the conventional manual methods.

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  • Miho Kanbayashi, Takahiro Toma, Motoshi Tanaka, Sho Muroga, Saito Kats ...
    2020 Volume Annual58 Issue Proc Pages 566-567
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In order to investigate an evaluation method of lighting space by parameters of brain waves, EEG measurement and opinion test were done in a room with a color lighting. The color lighting with 64 Organic-LED panels was located in front of a subject, with a distance of 2.8 m and a height of 1 m. Color was changed such as red, green, etc. with interval of 90 s. The opinion test about "Comfortableness", "Feeling", etc. was done with five-grade scale. Thirteen subjects (21-23 ages) provided written informed consent.In the case when color changed from green to red, mean opinion score (MOS) of "Comfortableness" decreased, and a correspondence with fast-alpha-wave power component was observed. In some cases, the relationship with MOS and the component was not observed depending on the color change. However, these results indicate the feasibility of using of EEG information to evaluate the lighting space.

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  • TADAYOSHI MIYAMOTO, GO ITO, HIDEHIRO NAKAHARA
    2020 Volume Annual58 Issue Proc Pages 568-569
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Background: High intensity interval training (HIT) is more effective than continuous training in enhancing cardio-respiratory function and symptom severity in chronic heart failure (CHF). We examined how HIT affects ventilatory regulation. Methods: In 7 healthy subjects, at rest and during exercise at light and heavy intensities, we separately characterized respiratory controller and plant (subsystems) of chemoreflex by changing inspiratory CO2 fraction and by making subjects alter ventilation (VE), respectively. Results: HIT did not affect both subsystems at rest and during light intensity exercise. During heavy intensity exercise, rightward shift of central controller characteristics mainly attributed to lower VE (-9.4%, p<0.01) and higher end tidal PCO2 (+4.4%, p<0.05) after HIT. Conclusion: Weekly high intensity interval training attenuates the respiratory drive during heavy exercise through desensitization of the respiratory central controller. Such mechanism may contribute to favorable effects of HIT in CHF.

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  • GO ITO, HIDEHIRO NAKAHARA, TADAYOSHI MIYAMOTO
    2020 Volume Annual58 Issue Proc Pages 570-571
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    There is strong evidence that exercise intensity mediates central and peripheral cardiovascular and respiratory adaptations to exercise and improvements in maximum aerobic capacity (VO2max). However, the effects of different exercise intensity on once-a-week interval training are uncertain for dynamic cardio-respiratory responses to exercise. 16 male college student athletes divided into 2 groups of 95% or 80% intensity (TG95%, TG80%,), trained weekly for 8 weeks. The training consisted of three bouts of exercises to volitional fatigue at TG95% or TG80% maximum work rate.Regardless different of training intensity, increased VO2max and maximal exercise performance in both training groups were observed after training program (P <0.01). TG95% induced cardiac adaptation in enhancing heart rate during maximal exercise. The present results indicate that high intensity interval training markedly induces training intensity-dependent specific cardiorespiratory response at the onset of exercise through changes in autonomic neural regulation.

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  • Taichi Shimizu, Satoshi Yamamoto, Yuichi Makino, Shinya Onogi, Koji Ma ...
    2020 Volume Annual58 Issue Proc Pages 572-573
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    The purpose of this study is to create a therapeutic plan on human body to induce a micro object through blood vessel considering of human body. First, based on the image analysis of 3D blood vessel network, the system calculates the possible area ultrasonic transducers with respect to shape of the body surface and the position of ribs using an optical positon sensor. Next, by applying 2D-3D registration in echogram, 3 dimensional blood vessel movement is acquired using body surface, rib positon and blood vessel movement. We created a therapeutic plan to guide a thin catheter, where 2D-3Dregistration of human liver was performed. As the result, we suggested the usefulness of the therapy planning software.

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  • Kaoru Sawasaki, Yuta Horie, Masanori Nakamura, Naoyuki Kimura, Koji Ka ...
    2020 Volume Annual58 Issue Proc Pages 574-575
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Aortic Valve Stenosis (AS) has been associated with aneurysm, and dissection of the ascending aorta. In this study, we tested the hypothesis that impinging jet blood flow due to AS is suggested to disrupt endothelial integrity, contributing to the formation of the aortic diseases. After cultured vascular endothelial cells (ECs) were exposed to impinging jet flow using a custom-made flow circuit, cell-cell junction proteins, VE-cadherin and PECAM-1 were fluorescently stained. As a result, detachment of ECs and a decrease in PECAM-1 expression were observed only in the area where higher wall shear stress and dynamic pressure exerted, while VE-cadherin expression was not changed. These results suggest that EC cell-cell adhesion, known to be important in endothelial integrity, is affected by the mechanical environment caused by impinging jet flow.

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  • jun sasaki, Tomohiko Utsuki
    2020 Volume Annual58 Issue Proc Pages 576-581
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    A mathematical model of brain's physiological condition was constructed in consideration of the inter relation of intracranial pressure, cerebral blood flow, brain temperature, and cerebral metabolism. This model is necessary for designing and verifying the automatic control system of brain's physiological condition which is being developed to evolve the brain resuscitation.In this paper, the constructed model was analyzed using the almost normal parameters in order to verify the adequacy to use it as a substitute for patients. As the parameters used in this analysis were obtained from more than 10 papers and a few mechanisms of regulating brain's physiological condition were not considered yet in the model, the several analyzed values were inescapably different from the measured value in the previous papers. However the analysis result totally showed no contradiction from the viewpoint of anatomy and physiology. Therefore this model can qualitatively represent normal brain's physiological condition at least.

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  • Michihiko Fukunaga, Hisato Okubo
    2020 Volume Annual58 Issue Proc Pages 582-583
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Rotating a crank by legs is the popular way to transform manpower to rotative power, as used for bicycles. Thus ergometers or pedaling wheelchairs are used for the elderly or patients who have weakened muscles because it is useful for their training or rehabilitations. Then, how to design the crank or saddle lengths for these users? We confirmed it by musculoskeletal model simulations. The lower limb and crank were modeled as a four-bar linkage, fixing an ankle joint. Hip and knee joints were driven by the six muscles around thigh. We compared four types of subjects; the healthy people, quadriceps weakened, hamstrings weakened and all the muscles weakened. As a result, in all the cases, the high saddle was the best to extend the knee at bottom dead center. The optimal crank length was longer by weakened quadriceps and was shorter by weakened hamstrings.

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  • Yoichi Mori, Yutaro Yoshioka, Taiga Yamasaki, Xin Xin, Shinsaku Izumi
    2020 Volume Annual58 Issue Proc Pages 584-585
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Conventional models of human motor control can-not always possible to provide a clear understanding of the mechanism for controlling nonlinear dynamics of the musculoskeletal systems. In this study, we propose a model that combines the feedback linearization of the musculoskeletal system with an intermittent controller. This model can compatibly realize the nonlinear control of the musculoskeletal system and the simple motion planning in the workspace based on the minimum jerk criterion. Here, we show an example of a musculoskeletal model with a single joint.

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  • Hazuki Masuda, Shima Okada, Naruhiro Shiozawa, Masaaki Makikawa
    2020 Volume Annual58 Issue Proc Pages 586-589
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    The conditioning for athletes depends on their self-management or the experiences of their coaches. We focused on circadian rhythm which is related to physical and mental condition. The conventional method for estimating circadian rhythm is not suitable for daily measurement because of the measurement for more than 24 hours and restricting exercise in the daytime. Hence, we developed an algorithm for estimating circadian rhythm by using Electrocardiogram (ECG) during sleep. We evaluated the effectivity of this algorithm as compared with circadian rhythm measured by core temperature as the reference data. Both were related to strong positive correlation in data without first-night effect. Further the average of the error time (difference in the lowest time calculated by deep forehead temperature and ECG) was only 20 minutes. As the results, we succeeded in estimation of the time and heart rate value to reach the lowest point in circadian rhythm in normal sleep.

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  • Hajime Nagasawa, Motoaki Sano
    2020 Volume Annual58 Issue Proc Pages 590-591
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Heart rate measurement is stressful for the subject because most of the measuring devices need to bring sensors into contact with body. In addition, remote heart rate measurement is necessary in such case as Judo, in which wearing a rigid object is prohibited. Therefore, we are conducting research to accurately measure the heart rate of a moving human from several meters. In this study, we photographed the palm of right hand with a web camera (Logicool Qcam Pro 9000) and examined about the measurement of the heart rate by the change of the pixel value. The palm was fixed on a stand so as not to move, and the distance between the camera and the palm was about 5 cm. In order to increase accuracy, an arithmetic mean of 480 × 480 pixels was taken. As a result, periodic fluctuations synchronized with the heartbeat was observed in the G component.

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  • Yuki Sogabe, Motoaki Sano
    2020 Volume Annual58 Issue Proc Pages 592-593
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Respiratory rate can be measured in a variety of ways such as nasal temperature, breath sounds, and chest and abdominal movements. However, many instruments used in clinical practice today are of the type that attach sensors to the body. Therefore, when a screening test for sleep apnea syndrome (SAS) is performed at home, for example, the subject may not sleep well because the sensor is attached, and there is a concern that no symptoms appear. Further, especially in the case of a child, there is a possibility that the sensor or the wiring is disconnected or entangled due to turning over. Therefore, in this research, we aim to develop a device that can measure the respiratory rate of patients without contact. This time, using an infrared camera, we measured the temperature change of the body surface or blanket due to respiration, and examined whether the respiration rate could be measured.

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  • Margarette Kozuka, Motoaki Sano
    2020 Volume Annual58 Issue Proc Pages 594-595
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In this study, we conducted a study on tonometry using acoustic radiation pressure. We created a device using a parametric speaker, and thought that it would be possible to measure intraocular pressure by measuring the frequency of the surface vibration by applying acoustic radiation pressure to an object. In the measurement, the object was set to a water balloon, and the vibration of the surface was measurement by observing the reflection of an irradiated laser beam using a high-speed camera. And the data was subjected to Fourier transform to measure the eigenfrequency. Then the relationship between the eigenfrequency and the pressure in the water balloon was discussed.

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  • Kansai Okadome, Ikumu Yasuda, Takuya Katai, Kosuke Watamabe, Yoshihiro ...
    2020 Volume Annual58 Issue Proc Pages 596-597
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    We are working to visualize 3D human blood vessel using ultrasound for an active drug delivery. The purpose of this study is improving the structural analysis method of blood vessel network (BVN) of human liver by applying three-dimensional extension to investigate BVN deformation. For the structural analysis in a BVN, bifurcation points were extracted using point cloud. And for the extension, the connected part was clarified using the position of the probe recorded by a position sensor. In the proposed method, since more accurate structure of BVNs was obtained, a wider liver BVNs from the right lobe to the left lobe could be obtained, where the maximum total path length was about 1200 mm in the largest BVN. Furthermore, we evaluated the deformation of BVNs quantitatively under the specific conditions as changing the subject's posture or breathing state.

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  • Takanori Uchiyama, Yuri Ogura
    2020 Volume Annual58 Issue Proc Pages 598-599
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    The purpose of this study is to propose a novel method to estimate natural frequency using a myotonometer with the aid of a system identification technique. A myotonometer is an instrument that measures muscle hardness based on an indentation method. The myotonometer applies a mechanical rectangular pulse to an object and records the acceleration of the indenter. This method showed the dependency of the natural frequency on the rectangular pulse width. Our proposed method extracted the acceleration that was not affected by the rectangular pulse. The extracted acceleration was regarded as an output of a system from the mechanical pulse to the acceleration. The system was identified, and then the natural frequency was calculated. We applied the method to edtimate the natural frequency of a gel-like object mimicking human soft tissue. The proposed method provided a smaller standard deviation of the natural frequency than the built-in program of the myotonometer.

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  • Toshio Sato, Ryoya Suzuki, Hiroki Makita, Tomoko Oku, Shinobu Yamauchi ...
    2020 Volume Annual58 Issue Proc Pages 600-601
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    With the objective of proposing ideal chamber configurations for prevention of blood coagulation during hemodialysis, we focused on quantitatively elucidating the effects of the three related factors of: (1) chamber length LP, (2) inlet flow angle θ, and (3) filtration filter configuration. In the simulation by acid addition to milk, casein coagulates were formed and then captured by the filtration filter, effectively simulating blood coagulation and a steady rise in blood circuit pressure. When this simulation of coagulate growth by acid addition to milk was applied to investigate the time to coagulation completion (TCOAG) in the six constructed chamber types, it was found that, with mesh-type filtration filtering, TCOAG lengthened with shortening of the chamber length (LP).

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  • Masaya Mitsuhori, Tomoko Oku, Shinobu Yamauchi, Yuka Motohashi, Toshio ...
    2020 Volume Annual58 Issue Proc Pages 602-603
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    In previous studies, we measured swallowing sounds using acceleration sensors attached to the neck, and performed time-frequency analysis on the swallowing sounds obtained. We also quantitatively assessed swallowing function by finding the envelope of the swallowing sound signals via cubic spline interpolation and calculating a parameter, Swallowing Function Parameter (SFP), that indicates the subject's swallowing function. In this report, after examining methods for measuring swallowing sounds surely, we investigated the effects of water jelly at different temperatures on swallowing function. As a result, we came to be able to measure swallowing sounds surely in both men and women. In addition, from the results of the texture test and the measurement of the swallowing sound of the water jelly, it was found that the SFP value decreased most at 20°C.

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  • Kazuma Sasaki, Yoshimasa Shinne, Tomoko Oku, Shinobu Yamauchi, Yuka Mo ...
    2020 Volume Annual58 Issue Proc Pages 604-605
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Shunt murmurs are believed to be generated when turbulent flow, which is generated as a large amount of blood passes quickly through the anastomosis site of the VA, causes the vascular wall to vibrate. In this report, the pseudo shunt murmurs generated in the AVF models with different diameter stenosis rates was measured, and the flow in these models were visualized using particle image velocimetry (PIV). As a result, in the several model with a low diameter stenosis rate, the flows were laminar, and the frequency component of the pseudo shunt murmurs were mainly composed of low frequency components. As a result, it was considered that the change in the flow in the blood vessels by stenosis may have an effect on the acoustic characteristics of the shunt murmurs.

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  • Hiroko Suzuki, Yukino Sasaki, Tomoko Oku, Shinobu Yamauchi, Yuka Motoh ...
    2020 Volume Annual58 Issue Proc Pages 606-607
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    The double-lumen catheter (DLC) for hemodialysis is widely used as a means of vascular access (VA) for blood purification in emergency and acute medical care. In the clinical use of DLCs, however, blood removal failure tends to occur and may impede therapy continuation. In such cases, continuation of therapy may be possible by reversing the DLC connection in the blood circuit from the normal connection. Despite the resolution of sticking phenomenon to the vessel wall, however, this interchange between the blood removal port and the retransfusion port gives rise to recirculation and markedly reduces dialysis efficiency. In the present study, to decrease sticking phenomenon by optimizing DLC tip shape, we focused on pressure change in blood removal and construction of a system that can quantitatively assess the effect of various DLC tip shape parameters on sticking phenomenon.

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  • Shinobu Yamauchi, Tomoko Oku, Yuka Motohashi, Toshio Sato
    2020 Volume Annual58 Issue Proc Pages 608-609
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Cavitation occurring in an artificial cardio-pulmonary device blood circuit is reported with a cause of hemolysis. In this study, it is intended to visualize cavitation occurring in an artificial cardio-pulmonary device blood circuit. Visualize cavitation by observing luminescence of the luminol by cavitation. After having circulated luminol solution in a blood circuit, we let a blood circuit occlude using some forceps. Occurring air and luminescence were recorded by using a digital single-lens reflex camera. As a result, we were able to observe the bubbles, but was not able to observe the luminescence. However, it was the experiment using the sonoreactor and was able to observe luminescence in flow. Because luminescence was not observed as for the bubbles occurred in the blood circuit, it was suggested that we did not have energy like acoustic cavitation.

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  • TOMOKO OKU, Shinobu Yamauchi, Yuka Motohashi, Toshio Sato, Tetsuzo Agi ...
    2020 Volume Annual58 Issue Proc Pages 610-611
    Published: 2020
    Released: August 05, 2020
    JOURNALS FREE ACCESS

    Most recent methods of blood purification therapy prioritize blood purification efficiency. However, it has been reported that a disparity arises between the set blood removal flow rate and the actual flow rate when thinner indwelling needles are used, reducing blood purification efficiency. Therefore, With the aim of developing indwelling needles that can achieve a sufficient blood removal flow rate even with a thin needle, we have used computational fluid dynamics (CFD) to perform theoretical examinations. In the present study, we compared straight type with high flow type indwelling needle, investigated the optimum shape of the flow path. Comparing the actual flow rates, we found that the high flow type had superior blood removal properties, and that the difference between the set flow rate and the actual flow rate was small. Based on the results, we plan to perform further investigations of the optimal shape of indwelling needles.

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