该文提出一种基于单基站六角单极定向天线阵列的到达角(Angle Of Arrival,AOA)估计方法,用于超宽带(UWB)室内精确定位。该文设计的AOA估计方法是通过测量各天线接收脉冲幅度信息,结合加入了动态参数的天线阵列的波束方向图,从而获得AOA...该文提出一种基于单基站六角单极定向天线阵列的到达角(Angle Of Arrival,AOA)估计方法,用于超宽带(UWB)室内精确定位。该文设计的AOA估计方法是通过测量各天线接收脉冲幅度信息,结合加入了动态参数的天线阵列的波束方向图,从而获得AOA,避免了传统多基站定位系统中采用测量脉冲到达时间差的方法带来的部署困难以及精度不足问题。仿真结果显示,使用该文提出的AOA估计方法,估计误差小于1°的概率可达到96%,在IEEE802.15.4a CM3信道下,当定位距离为10 m时,定位误差小于15 cm的概率可达80%。因此,基于该文单基站AOA估计方法的UWB定位系统部署简单,并且可提供精确的定位精度,是一种有效的定位方法。展开更多
Purpose: To investigate intraocular pressure (IOP) and ocular haemodynamics fo llowing small incision cataract surgery. Methods: Systemic and ocular haemodynam ics, and IOP, were measured pre-operatively and 1 month p...Purpose: To investigate intraocular pressure (IOP) and ocular haemodynamics fo llowing small incision cataract surgery. Methods: Systemic and ocular haemodynam ics, and IOP, were measured pre-operatively and 1 month post-operatively, in 2 5 eyes of 25 patients (mean age 72.6±7.9 years) scheduled for small incision ca taract surgery and intraocular lens implantation; these values were compared to an untreated age-matched healthy group (n=25, mean age 72.3±5.0 years). For ea ch eye, the Ocular Blood Flow Analyser (OBFA, Paradigm Inc., UT, USA) was used t o obtain measurements of IOP, pulsatile ocular blood flow (POBF), pulse volume ( PV), ocular pulse amplitude (PA), and pulse rate (PR). Systemic blood pressure m easurements were obtained at each visit. Pre-and post-operative values for the cataract group were compared using repeated measures analysis of variance, and compared to the normal group using analysis of variance. Results: Pre-operative ly, IOP was significantly higher in the cataract group compared to the age-matc hed normal control group (P < 0.001). Cataract surgery resulted in a significant 16.7%reduction in IOP (P=0.001). Consequently, the post-operative IOP in the cataract group was similar to that of the normal group (P > 0.05). Both pre-and post-operative POBF and PV values for the cataract groupwere significantly low er than for the normal age-matched group (P < 0.0125). Small incision cataract surgery led to an 8.3%post-operative increase in POBF (P=0.0118) and 15.5%inc rease in PV (P < 0.001). No changes in PA or PR were evident. Conclusion: These data suggest that cataract patients exhibit higher IOP and reduced ocular perfus ion characteristics compared to an age-matched normal healthy group. Following cataract surgery, IOP reduced and ocular pulsatility improved.展开更多
文摘Purpose: To investigate intraocular pressure (IOP) and ocular haemodynamics fo llowing small incision cataract surgery. Methods: Systemic and ocular haemodynam ics, and IOP, were measured pre-operatively and 1 month post-operatively, in 2 5 eyes of 25 patients (mean age 72.6±7.9 years) scheduled for small incision ca taract surgery and intraocular lens implantation; these values were compared to an untreated age-matched healthy group (n=25, mean age 72.3±5.0 years). For ea ch eye, the Ocular Blood Flow Analyser (OBFA, Paradigm Inc., UT, USA) was used t o obtain measurements of IOP, pulsatile ocular blood flow (POBF), pulse volume ( PV), ocular pulse amplitude (PA), and pulse rate (PR). Systemic blood pressure m easurements were obtained at each visit. Pre-and post-operative values for the cataract group were compared using repeated measures analysis of variance, and compared to the normal group using analysis of variance. Results: Pre-operative ly, IOP was significantly higher in the cataract group compared to the age-matc hed normal control group (P < 0.001). Cataract surgery resulted in a significant 16.7%reduction in IOP (P=0.001). Consequently, the post-operative IOP in the cataract group was similar to that of the normal group (P > 0.05). Both pre-and post-operative POBF and PV values for the cataract groupwere significantly low er than for the normal age-matched group (P < 0.0125). Small incision cataract surgery led to an 8.3%post-operative increase in POBF (P=0.0118) and 15.5%inc rease in PV (P < 0.001). No changes in PA or PR were evident. Conclusion: These data suggest that cataract patients exhibit higher IOP and reduced ocular perfus ion characteristics compared to an age-matched normal healthy group. Following cataract surgery, IOP reduced and ocular pulsatility improved.
