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2007 1

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Evaluation of the relative risk of stroke in patients with hypertension using cerebrovascular hemodynamic accumulative

HUANG Jiuyi, WANG Guiqing, GUO Jiping, CAO Yifeng, WANG Yan, YANG Yongju, YU Xuehai

《医学前沿(英文)》 2007年 第1卷 第3期   页码 274-278 doi: 10.1007/s11684-007-0052-0

摘要: The relative risk (RR) of stroke in patients with hypertension was evaluated by using synthetic index of cerebrovascular hemodynamics. A total of 7,371 patients with hypertension with ages ≥40 years were selected from a population-based cohort study of the risk factors for stroke. The data on the baseline investigation of risk factors, the determination of cerebrovascular hemodynamic parameters (CVHP), and stroke follow-up were analyzed. The RR of stroke in patients with hypertension was evaluated by CVHP scores. Univariate analysis indicated that hypertension, complicated by other risk factors, had significant statistical association with the onset of stroke. RRs for stroke when hypertension complicated with decrease of hemodynamic scores, heart disease, cigarette smoking and alcohol consumption were 4.93 (95%CI, 3.26–7.45), 1.90 (95%CI, 1.36–2.66), 1.99 (95%CI, 1.42–2.79) and 1.73 (95%CI, 1.19–2.53) respectively. In multivariate analysis, hemodynamic score, age, sex, cigarette smoking, family history of stroke and systolic blood pressure were selected by the Cox regression for inclusion in the final analysis. Among them, the RR of hemodynamic score was highest. The analysis of doseresponse relationships indicated that when the hemodynamic scores in patients with hypertension were lower than 75 points, the RR of stroke at 75, 60, 45, 30 and 15 points were 2.85, 4.43, 4.54, 5.40 and 9.88, respectively. The risk of stroke in patients with hypertension is closely asso ciated with hemodynamic impairment and the hemodynamic score may be used for quantitative evaluation of relative risks of stroke.

关键词: inclusion     quantitative evaluation     cerebrovascular     relative     decrease    

Bi-modes alternation stepping ultrasonic motors

JIN Jiamei, ZHAO Chunsheng

《机械工程前沿(英文)》 2008年 第3卷 第1期   页码 101-105 doi: 10.1007/s11465-008-0018-1

摘要: Based on the principle of alternative operation of two bending vibration modes in an annular stator, this paper presents a standing-wave stepping ultrasonic motor characterized by no accumulative errors driven by an open-loop control circuitry. The driving forces are generated from the motions of projections on the stator in two modes. The positioning of the motor is achieved by the cooperation between the stator projections and rotor teeth, and the number of the rotors determines the stepping angle of the motor. Two-phase sinusoidal signals corresponding to the two modal frequencies drive the motor bi-direction stepping rotation via a switch unit. The prototype runs steadily without miss-step on trial. The single-step angle displacement of the motor is 2.5°.

关键词: miss-step     bi-direction     Two-phase sinusoidal     positioning     accumulative    

标题 作者 时间 类型 操作

Evaluation of the relative risk of stroke in patients with hypertension using cerebrovascular hemodynamic accumulative

HUANG Jiuyi, WANG Guiqing, GUO Jiping, CAO Yifeng, WANG Yan, YANG Yongju, YU Xuehai

期刊论文

Bi-modes alternation stepping ultrasonic motors

JIN Jiamei, ZHAO Chunsheng

期刊论文