Volume 3 Issue 3
Authors: Kyung-Hwa Kim; Jong-Beum Choi; Gi-Beum Kim
Abstract: The water flow characteristics in the implantable artificial lung (IAL) were evaluated by in vitro experiments. The 50-fiber modules were of different lengths but contained well-spaced fibers; and the 300-fiber module had a volume fraction of 0.9. A lower number of tired hollow fibers produce a higher water-side film coefficient of oxygen transfer at a constant velocity of water-side flow. The area of the water flow decreases with increasing hollow fiber packing density, thus if water is induced to flow uniformly in the IAL module, the oxygen transfer rate should monotonously increase with the packing density. The water flow in the IAL is not uniform and depends on the hollow fiber packing density. The stagnation of the water flow occurs in the bundle of the hollow fibers at the water inlet.
Keywords: Implantable Artificial Lung; Hollow Fiber Membranes; Mass Transfer Coefficient; Gas Diffusion
Authors: Satoshi Shimawaki; Yohei Kobayashi; Masataka Nakabayashi; Naotaka Sakai
Abstract: This paper investigated whether a simple, non-invasive blood vessel visualization technique using near-infrared light is suitable for determining serum cholesterol levels. Six-week-old male Wistar rats were divided into 6 groups (n = 10/group) and were fed either control diet alone or control diet with 0.5%, 1.0%, 1.25%, 1.5%, or 2.0% cholesterol for 8 weeks. A cuff was subsequently placed on the proximal part of the tail (cuff pressure, 80 mmHg), the tail distal to the compression site was exposed to near-infrared light (wavelength, 850 nm), and transmitted light was photographed. Near-infrared transmission images were acquired before and after cuff inflation, and hemoglobin and haematocrit levels in veins distal to the compression site were determined. Increased dietary cholesterol levels resulted in increased total serum cholesterol levels. Before cuff inflation, rats that were fed the 2.0% cholesterol diet had significantly lower hemoglobin levels than those that fed the control diet (P < 0.01). There were no significant differences in hemoglobin and haematocrit levels at 5 min after cuff inflation. From the association between total serum cholesterol levels and differences in hemoglobin levels, the differences in hemoglobin levels were almost constant when total serum cholesterol levels increased to near 150 mg/dL, but the differences significantly elevated at total serum cholesterol levels >150 mg/dL (r = 0.449, P < 0.001). The correlation between total serum cholesterol levels and relative changes in near-infrared light transmission significantly adhered to that between total serum cholesterol levels and differences in hemoglobin levels (r = 0.452, P < 0.005). At total serum cholesterol levels >150 mg/dL, increased cholesterol levels affected erythrocyte membranes and probably reduced their deformability, resulting in decreased hemoglobin levels (anemia) with erythrocyte destruction in the spleen as the rate-determining factor. This decrease was detected as changes in near-infrared light transmission.
Keywords: Near-Infrared Light; Cholesterol; Hemoglobin; Cuff Inflation
Authors: Feng Liu; Wei Liu; Xiaoyi Li; Shiyu Wang; Jiajia Fan
Abstract: Medicine imaging plays a more and more important role in illness detection and treatment. Various imaging skills, including CT imaging, MR imaging, ultrasound imaging and so on are in application and under research nowadays, and those images could be got from medicine databases in hospitals, clinical cases or volunteers. Since the biomedical researches are attracting more and more attention in China, our group investigated papers on biomedical published in the last 3 years in China and referenced 35 papers here. From different views, we investigated methods applied in image resources, image preprocessing, image registration, image segmentation, and their application fields. By reviewing those papers, we aim at getting a brief view of the current biomedical research trend in China.
Keywords: Bio-Medical Imaging; Image Resource; Image Preprocessing; Image Segmentation; Image Registration