The passage of red blood cells （RBCs） through capillaries is essential for human blood microcirculation. This study used a moving mesh technology that incorporated leader-follower pairs to simulate the fluid-structu...The passage of red blood cells （RBCs） through capillaries is essential for human blood microcirculation. This study used a moving mesh technology that incorporated leader-follower pairs to simulate the fluid-structure and structure-structure interac- tions between the RBC and a microvessel stenosis. The numerical model consisted of plasma, cytoplasm, the erythrocyte membrane, and the microvessel stenosis. Computational results showed that the rheology of the RBC is affected by the Reynolds number of the plasma flow as well as the surface-to-volume ratio of the erythroeyte. At a constant inlet flow rate, an increased plasma viscosity will improve the transit of the RBC through the microvessel stenosis. For the above reasons, we consider that the decreased hemorheology in microvessels in a pathological state may primarily be attributed to an increase in the number of white blood cells. This leads to the aggregation of RBCs and a change in the blood flow structure. The present fundamental study of hemorheology aimed at providing theoretical guidelines for clinical hemorheology.展开更多
Hypoxia leads to increased red blood cells and blood viscosity at high altitude while moderate trauma increases coagulation in blood. Under the above-mentioned conditions, venous sinus thrombosis is more likely to occ...Hypoxia leads to increased red blood cells and blood viscosity at high altitude while moderate trauma increases coagulation in blood. Under the above-mentioned conditions, venous sinus thrombosis is more likely to occur. A patient suffering bilateral acetabular fractures together with the gradual disturbance of consciousness was admitted to our hospital. Though computed tomography arteriogram （CTA） of the brain displayed normal blood vessels; bilateral thalamus and brainstem infarction were found on head computed tomography （CT} and Galen vein thrombosis on cerebral computed tomography venography （CTV）. Dehydration and tracheotomy were immediately conducted with antiplatelet, anticoagulant and neurotrophic medicine administered to the patient. After three days＇ treatment, the patient＇s con- sciousness gradually improved and eventually became clear enough to leave the hospital. On follow-up, no dysfunction was documented.展开更多
Objective: To develop an on line system for the measurement of blood viscosity and hematocrit. The dynamic changes of the macrovascular blood volumes, microvascular blood volumes and the total blood volume were observ...Objective: To develop an on line system for the measurement of blood viscosity and hematocrit. The dynamic changes of the macrovascular blood volumes, microvascular blood volumes and the total blood volume were observed by means of calculating from the testing result. Methods: Applying traditional viscosity measurement principle and specific wavelength optic density measurement method, an on line system for the measurement of blood viscosity and hematocrit was developed, and the A/D multifunctional board and the testing circuit were designed by ourselves. The system was validated by experiments both in vitro and in vivo. Therapeutic effects of hypertonic saline dextran solution (HSD) and Lactatic Ringers solution at the early stage after burn blast combined injury were compared by this method. Results: The results showed that the system has attained the goal of the design. The changes of the blood viscosity and hematocrit could be detected effectively and continuously. The changes of macrovascular, microvascular and total blood volume could be calculated approximately. Conclusions: The system and the method can continuously on line test the blood viscosity and hematocrit, and reveal the change and distribution of blood volumes more accurately and clearly in the therapy process by estimatng changes of the macrovascular, microvascular and total blood volumes, respectively. It has confirmed that HSD treatment could increase blood pressure and attenuate tissue edema by significantly increasing total blood volume, improving macrocirculatory and microcirculatory blood volumes. This study suggested that it could be desirable to develop an experiment technique based on the method mentioned above.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.10672090)the National High Technology Research and Development Program of China (Grant No.2006AA02Z4E8)
文摘The passage of red blood cells （RBCs） through capillaries is essential for human blood microcirculation. This study used a moving mesh technology that incorporated leader-follower pairs to simulate the fluid-structure and structure-structure interac- tions between the RBC and a microvessel stenosis. The numerical model consisted of plasma, cytoplasm, the erythrocyte membrane, and the microvessel stenosis. Computational results showed that the rheology of the RBC is affected by the Reynolds number of the plasma flow as well as the surface-to-volume ratio of the erythroeyte. At a constant inlet flow rate, an increased plasma viscosity will improve the transit of the RBC through the microvessel stenosis. For the above reasons, we consider that the decreased hemorheology in microvessels in a pathological state may primarily be attributed to an increase in the number of white blood cells. This leads to the aggregation of RBCs and a change in the blood flow structure. The present fundamental study of hemorheology aimed at providing theoretical guidelines for clinical hemorheology.
文摘Hypoxia leads to increased red blood cells and blood viscosity at high altitude while moderate trauma increases coagulation in blood. Under the above-mentioned conditions, venous sinus thrombosis is more likely to occur. A patient suffering bilateral acetabular fractures together with the gradual disturbance of consciousness was admitted to our hospital. Though computed tomography arteriogram （CTA） of the brain displayed normal blood vessels; bilateral thalamus and brainstem infarction were found on head computed tomography （CT} and Galen vein thrombosis on cerebral computed tomography venography （CTV）. Dehydration and tracheotomy were immediately conducted with antiplatelet, anticoagulant and neurotrophic medicine administered to the patient. After three days＇ treatment, the patient＇s con- sciousness gradually improved and eventually became clear enough to leave the hospital. On follow-up, no dysfunction was documented.
文摘Objective: To develop an on line system for the measurement of blood viscosity and hematocrit. The dynamic changes of the macrovascular blood volumes, microvascular blood volumes and the total blood volume were observed by means of calculating from the testing result. Methods: Applying traditional viscosity measurement principle and specific wavelength optic density measurement method, an on line system for the measurement of blood viscosity and hematocrit was developed, and the A/D multifunctional board and the testing circuit were designed by ourselves. The system was validated by experiments both in vitro and in vivo. Therapeutic effects of hypertonic saline dextran solution (HSD) and Lactatic Ringers solution at the early stage after burn blast combined injury were compared by this method. Results: The results showed that the system has attained the goal of the design. The changes of the blood viscosity and hematocrit could be detected effectively and continuously. The changes of macrovascular, microvascular and total blood volume could be calculated approximately. Conclusions: The system and the method can continuously on line test the blood viscosity and hematocrit, and reveal the change and distribution of blood volumes more accurately and clearly in the therapy process by estimatng changes of the macrovascular, microvascular and total blood volumes, respectively. It has confirmed that HSD treatment could increase blood pressure and attenuate tissue edema by significantly increasing total blood volume, improving macrocirculatory and microcirculatory blood volumes. This study suggested that it could be desirable to develop an experiment technique based on the method mentioned above.
