著者
中山 敦 嶋脇 聡 酒井 直隆 中林 正隆
出版者
一般社団法人 日本機械学会
雑誌
茨城講演会講演論文集 2013.21 (ISSN:24242683)
巻号頁・発行日
pp.219-220, 2013-09-06 (Released:2017-06-19)

When human hand grasping an object, nail will support and restrain the deformation of finger pulp. Object is able to be grasped firmly due to the adaptation of finger pulp to the shape of grasped object. So, the nail is considered to be playing an important role in every motion of the fingertip. But the study case regarding the nail structure and it's mechanical properties are very rare. We used guitar string and applied to ways of doing experiment, such as pressing and flipping on the string.
著者
嶋脇 聡 須田 拓也 中林 正隆 杉本 英治
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.84, no.862, pp.18-00131, 2018 (Released:2018-06-25)
参考文献数
37

The neck is an important body part that links the head and chest sections. However, very few analyses of cervical movement derived from muscle contractions have been conducted with numerical simulation. This study aimed to construct a multi-body model of the neck comprising the bones, muscles, and ligaments (including the intervertebral disc) and to apply flexion and extension movements to analyze the behavior of each cervical segment. We created bone models (including cervical vertebrae C1-C7) from X-ray computed tomography (CT) images of the upper half of the human body. Each bone model was bound by 17 types of ligaments constructed as 51 wire models. We set six types of muscles as the protagonists for neck flexion and 12 types for the neck extension. Muscle strength was defined with a parallel contraction element model and an elastic element model. The intervertebral discs represented five spring models with repulsion characteristics on compression and attraction characteristics on extension. The neck section could flex up to 38.1° and extend up to 61.0° with contraction in the flexor and extensor models. The maximum cervical segment angles on flexion and extension were measured at C0-C1 and C4-C5, and their contribution rates were 20.7% and 19.3%, respectively. Each cervical segment angle when flexing and extending closely matched the experimental results measured by other studies. The centers of rotation for cervical segments from C2-C3 to C4-C5 on maximum flexion were different from those in previous experimental result. This may be because of the settings pertaining to the interspinous ligament, nuchal ligament and supraspinous ligament. On the other hand, our results for maximum extension were consistent with past experimental result. An improved neck model will allow the analysis of cervical segment movement through the joint restrictions based on damage to the ligaments and muscles or arthrodesis when flexing and extending.
著者
嶋脇 聡 吉田 和樹 中林 正隆
出版者
一般社団法人 日本機械学会
雑誌
日本機械学会論文集 (ISSN:21879761)
巻号頁・発行日
vol.83, no.856, pp.17-00063-17-00063, 2017 (Released:2017-12-25)
参考文献数
36

Arterial endothelial function is known as a factor that correlates with progression of arteriosclerosis. This is measured by flowmediated dilatation (FMD) testing. This test is performed by measuring the brachial artery diameter with an ultrasound system or by measuring digital pulse volumes. Technical and cost-related problems have been pointed out for both methods. We came up with an idea to apply the near-infrared light-based vascular visualization to the measurement of changes in vessel diameter. So, at first, we investigated whether the FMD reaction can be detected with near-infrared transmission images. Next, we derived the estimated values that is considered to correspond to the FMD reaction from the vascular image change. We aimed to determine if these estimated values correlate with brachial-ankle pulse wave velocity (baPWV), which is related to arteriosclerosis. In 50 adult males varying in age, the right upper arm was compressed with a cuff at 200 mmHg for 5 min to cause the FMD reaction after the cuff release. In a 11-min period including time points before and after the cuff compression, near-infrared (wavelength: 850 nm) transmission images near the bilateral finger joints were taken with a CCD camera. The mean brightness was calculated from the images. While no major temporal changes in mean brightness were observed before cuff release, the mean brightness of the hyperemic finger sharply decreased after cuff release. This result suggested that the FMD reaction can be detected with near-infrared transmission images. When the brightness decrease ratio (BDR1) before and after cuff release were compared among age groups, BDR1 at age 50 over years group was significantly smaller than that at age 20-29 years group (p<0.05). BDR1 showed a significant negative correlation with baPWV (R=0.34). This measurement method is considered to have a possibility of estimating FMD reaction and arterial endothelial function.