78 research outputs found

    Requiring factors in structural model of the blood vesselfor the principle analysis of measurement of blood pressure waveform by applanation tonometry.

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    生体内の血圧脈波を非侵襲的に計測する手法として,「トノメトリ法」が知られており,近年,この計測手法を用いて得られた血圧脈波波形から,動脈硬化などの循環器系疾患のスクリーニングや予防診断に役立てようという動きが活発である。しかしながら,組織内の血管を圧迫した場合の血管の変形挙動については,十分な解析は行われていない。そこで本研究では,生体中のトノメトリ状態を解析可能な数値解析モデルを構築することを目的とした。この結果, トノメトリ法による血圧脈波計測の原理解析を行うための血管断面構造の応力解析モデルには,以下の要件が求められることが明らかとなった。・センサ部と皮膚表面はそれぞれ独立な要素としてモデル化し,これらの接触部においては摩擦を考慮しなければならない。・応力の定量的な解析を行うためには,素材の非線形的な機械的特性を考慮する必要がある。さらに,実験結果と計算結果を一致させるためには,初期形状を正確にモデル化することが必要であることがわかった。"Applanation tonometry" is well known method as the technique which measures blood pressure waveform in vivo non-invasively. Recently, utilizing for screening and prevention diagnosis of circulatory system diseases such as the arteriosclerosis from the blood pressure waveform gotten by this measurement technique is very actively being investigated. However, the sufficient analysis is not carried out on the deformation behavior of the blood vessel in real human body. Consequently, the purpose of this paper is to construct the analyzable numerical model in respect of the applanation tonometry. As this result, following factors are necessary in the numerical analysis model of cross sectional structure of blood vessel for the principle analysis of the blood pressure waveform measurement for applanation tonometry. 1) Sensor block and skin surface must have the independent structure, and it must consider the friction in the contact area. 2) For the quantitative analysis, it is necessary to consider the hyper-elasticity which is a nonlinear material property. In addition, it is necessary to accurately model the initial shapes of the material

    Supportive intervention using a mobile phone in behavior modification

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    The authors previously developed a mobile ecological momentary assessment (EMA) system as a real-time data collection device using a mobile phone. In this study, a real-time advice function and real-time reporting function were added to the previous system as a supportive intervention. The improved system was found to work effectively and was applied to several clinical cases, including patients with depressive disorder, dizziness, smoking habit, and bronchial asthma. The average patient compliance rate was high (89%) without the real-time advice and higher (93%) with the advice. The trends in clinical data for patients using a mobile EMA with/without the new function were analyzed for up to several months. In the case of dizziness, an improving trend in its clinical data was observed after applying the real-time advice, and in the case of depressive disorder, a stabilizing trend was observed. The mobile EMA system with the real-time advice function could be useful as a supportive intervention in behavior modification and for motivating patients in self-management of their disease.</p

    Antioxidant Activity and Oxidation Products of 1,2,3,4- Tetrahydroquinoxalines in Peroxyl Radical Scavenging Reactions, Part I

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    This paper studies the antioxidant activity of 1,2,3,4-tetrahydroquinolines, 3,4-dihydro-2H-benzo[1,4]thiazines and 1,2,3,4-tetrahydroquinoxalines in the inhibition of the peroxidation of tetralin induced by an azo initiator. Neither 1,2,3,4- tetrahydroquinoline nor 3,4-dihydro-2H-benzo[1,4]thiazine alone acted as an antioxidant, but when they have an electron-donating group at the para position to the NH group, they act as potent antioxidants. On the other hand, 1,2,3,4- tetrahydroquinoxaline on its own showed good antioxidant activity. However, 1,2,3,4-tetrahydroquinoxalines with methyl and methoxy groups in the phenyl ring have reactivities similar to or less than that of unsubstituted 1,2,3,4-tetrahydroquinoxaline. The induction periods of 1,2,3,4-tetrahydroquinoxalines with an alkyl group or phenyl group at the 2-position were all longer than the value for the unsubstituted 1,2,3,4-tetrahydroquinoxaline, except for a compound with a t-butyl group. The oxidation of 1,2,3,4-tetrahydroquinoxalines by peroxyl radicals generated from an azo initiator in tetralin or benzene yields quinoxalines and a dimer product of quinoxalines, 6-(1,2,3,4-tetrahydroquinoxalin-1-yl)-quinoxaline

    Distinct associations of different sedentary behaviors with health-related attributes among older adults

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    Objective: Leisure-time sedentary behaviors (LTSBs) have been associated adversely with health outcomes. However, limited research has focused on different categories of LTSB. We aimed at identifying categories of LTSBs and examining their separate associations with indices of health among Japanese older adults. Methods: A postal survey collected data on self-reported health, psychological distress, body mass index, moderate-to-vigorous physical activity (MVPA), LTSBs (five behaviors) and socio-demographic characteristics from 1,580 Japanese older adults (67% response rate; 65-74 years) in 2010. Exploratory factor analysis was used to classify LTSBs. Odds ratios (ORs) were calculated for associations of LTSB categories with self-reported health, psychological distress, overweight, and lower MVPA. Data were analyzed in 2013. Results: Two categories of LTSB: passive sedentary time (consisting of TV time, listening or talking while sitting, and sitting around) and mentally-active sedentary time (consisting of computer-use and reading books or newspapers) were identified. Higher passive sedentary time was associated with a higher odds of being overweight (OR: 1.39, [95% CI: 1.08-1.80]), and lower MVPA (1.26, [1.02-1.54]). Higher mentally-active sedentary time was associated with lower odds of lower MVPA (0.70, [0.57-0.86]). Conclusions: Two types of sedentary time-passive and mentally-active-may play different roles in older adults' well-being

    Development of intramuscular probe for local muscle function

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    臨床においては,筋機能や機能不全を診断するために,表面筋電図や針筋電図,筋生検などが行われている。しかし,これらの方法では筋機能や筋収縮メカニズムを連続的に測定することは難しい。本研究では新たに筋内挿入型プローブと測定システムを開発した。測定プローブは光ファイバと6本の白金細線から構成されている。光ファイバを用いて筋の局所血流量と筋内圧力を測定し,6個の電極を用いて運動単位活動電位を測定した。プローブと測定システムの基礎特性を確認した後,麻酔下のラットの排腹筋において,安静時および局所虚血時の活動電位,血流量,筋内圧力を測定した。また脛骨神経を電気刺激し,活動電位波形から伝播速度を算出したところ,プローブは正常に動作していることが確認できた。さらに筋小胞体からのカルシウム放出チャネルを抑制するdantroleneを筋注すると,筋内圧力波形は大きく減少したが,活動電位波形はほとんど変化しないことがわかった。In order to diagnose muscle function or dysfunction, surface/needle electromyograms, muscle biopsy, biochemical markers inspection, muscle tone, etc. are carried out. It is difficult to measure muscle function continuously by using these methods. In this study, an intramuscular probe and measurement system were developed. The probe is composed of optical fibers and six small platinum electrodes. The probe, the tip of which is protected by epoxy resin, is inserted in a cannula of 1.26mm in diameter. By using the fibers, the local blood flow in a muscle and the intramuscular pressure were measured. By using six electrodes (50μm in diameter), a motor unit action potential was measured. The time-course changes of the action potential, blood flow and intramuscular pressure were measured in the gastrocnemius muscle of rats under the resting and the local ischemia. The tibial nerve was stimulated electrically using the current of the unipolar and negative polarity with 50μs pulse duration every 2 seconds and the propagation velocity of the action potential was calculated from the potential waves. The animal tests using rats were carried out in order to verify the developed probe and system. Under the local ischemia, the action potential, the blood flow and the intramuscular pressure decreased and the propagation velocity became slower. When dantrolene sodium was injected, which inhibits the calcium release channel of the sarcoplasmic reticulum, the intramuscular pressure decreased but the action potential wave was still detectable

    Physical activity environment and Japanese adults’ body mass index

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    Evidence about the impacts of the physical activity environment on adults’ weight in the context of Asian countries is scarce. Likewise, no study exists in Asia examining whether Walk Score®—a free online walkability tool—is related to obesity. This study aimed to examine associations between multiple physical activity environment measures and Walk Score® ratings with Japanese adults’ body mass index (BMI). Data from 1073 adults in the Healthy Built Environment in Japan study were used. In 2011, participants reported their height and weight. Environmental attributes, including population density, intersection density, density of physical activity facilities, access to public transportation, and availability of sidewalks, were calculated using Geographic Information Systems. Walk Scores® ratings were obtained from the website. Multiple linear regression analysis was conducted to examine the association between each environmental attribute and BMI. Adjusting for covariates, all physical activity environmental attributes were negatively associated with BMI. Similarly, an increase of one standard deviation of Walk Score® was associated with a 0.29 (95% confidence interval (CI) of –0.49-–0.09) decrease in BMI. An activity-friendly built environment was associated with lower adults’ BMI in Japan. Investing in healthy community design may positively impact weight status in non-Western context

    Dog-walking in dense compact areas: The role of neighbourhood built environment

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    There is a dearth of evidence about how high-density living may influence dog-walking behaviour. We examined associations between neighbourhood built environment attributes and dog-ownership and dog-walking behaviour in Japan. Data from 1058 participants were used. The dog-ownership was 18.8%. All neighbourhood built attributes (excluding availability of parks) were negatively associated with dog-ownership. Among dog-owners, these same attributes were positively associated with any dog-walking in a usual week and with achieving 150-min per week of physical activity through dog-walking alone. These findings provided evidence on the importance of neighbourhood built environment attributes on dog-ownership and dog-walking behaviour in dense and compact areas. The urban design and public health implication of these findings is that the built environment attributes in high-density living areas may have different impacts on dog-ownership and dog-walking: while living in a walkable neighbourhood may not be conducive to dog-ownership, it may support dog-walking in such areas. Programs targeting dog-owners in high-density areas might be needed to encourage them to walk their dogs more. If successful, these programs could contribute to higher physical activity levels among dog-owners

    Physical Activity Environment and Japanese Adults’ Body Mass Index

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    Evidence about the impacts of the physical activity environment on adults’ weight in the context of Asian countries is scarce. Likewise, no study exists in Asia examining whether Walk Score®—a free online walkability tool—is related to obesity. This study aimed to examine associations between multiple physical activity environment measures and Walk Score® ratings with Japanese adults’ body mass index (BMI). Data from 1073 adults in the Healthy Built Environment in Japan study were used. In 2011, participants reported their height and weight. Environmental attributes, including population density, intersection density, density of physical activity facilities, access to public transportation, and availability of sidewalks, were calculated using Geographic Information Systems. Walk Scores® ratings were obtained from the website. Multiple linear regression analysis was conducted to examine the association between each environmental attribute and BMI. Adjusting for covariates, all physical activity environmental attributes were negatively associated with BMI. Similarly, an increase of one standard deviation of Walk Score® was associated with a 0.29 (95% confidence interval (CI) of −0.49–−0.09) decrease in BMI. An activity-friendly built environment was associated with lower adults’ BMI in Japan. Investing in healthy community design may positively impact weight status in non-Western contexts

    Walkable Urban Design Attributes and Japanese Older Adults\u27 Body Mass Index: Mediation Effects of Physical Activity and Sedentary Behavior

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    Purpose: The purposes of this study were to examine associations between objectively measured walkable urban design attributes with Japanese older adults’ body mass index (BMI) and to test whether objectively assessed physical activity and sedentary behavior mediated such associations. Design: Cross-sectional. Setting: Matsudo City, Chiba Prefecture, Japan. Participants: Participants were 297 older residents (aged 65-84 years) randomly selected from the registry of residential addresses. Measures: Walkable urban design attributes, including population density, availability of physical activity facilities, intersection density, and access to public transportation stations, were calculated using geographic information systems. Physical activity, sedentary behavior, and BMI were measured objectively. Analysis: The relationships of walkable urban design attributes, Walk Score®, and BMI were examined by multiple linear regression with adjustment for covariates in all models. Mediation effects of the physical activity and sedentary behavior variables in these relationships were tested using a product-of-coefficients test. Results: Higher population density and Walk Score® were associated with lower BMI. Light and moderate-to-vigorous physical activities partially mediated the relationships between these walkable urban design attributes and BMI. Conclusions:Developing active-friendly environmental policies to (re)design neighborhoods may not only promote active transport behaviors but also help in improving residents’ health status in non-Western contexts
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