This paper investigates impact of noise and signal averaging on patient control in anesthesia applications, especially in networked control system settings such as wireless connected systems, sensor networks, local ar...This paper investigates impact of noise and signal averaging on patient control in anesthesia applications, especially in networked control system settings such as wireless connected systems, sensor networks, local area networks, or tele-medicine over a wide area network. Such systems involve communication channels which introduce noises due to quantization, channel noises, and have limited communication bandwidth resources. Usually signal averaging can be used effectively in reducing noise effects when remote monitoring and diagnosis are involved. However, when feedback is intended, we show that signal averaging will lose its utility substantially. To explain this phenomenon, we analyze stability margins under signal averaging and derive some optimal strategies for selecting window sizes. A typical case of anesthe-sia depth control problems is used in this development.展开更多
目的：探讨无创性经食管信号叠加直接记录窦房结电位(SNP)的技术。方法：对8只犬进行了系统实验研究，并对256例食管电生理检查窦房结传导时间(SACT)和窦房结恢复时间(SNRT)均在正常范围的患者，其中男142例、女114例，年龄10～74(44.2&...目的：探讨无创性经食管信号叠加直接记录窦房结电位(SNP)的技术。方法：对8只犬进行了系统实验研究，并对256例食管电生理检查窦房结传导时间(SACT)和窦房结恢复时间(SNRT)均在正常范围的患者，其中男142例、女114例，年龄10～74(44.2±12.4)岁进行检测。采用自制三导心电微电位检测仪将食管导联的信号放大(增益达到100_μV/cm)、滤波(0.1～50Hz)，16位模/数(A/D)转换，系统采样频率2kHz，对信号进行叠加，189例(74%)记录到食管 SNP。结果：所测信号叠加食管 SNP 为 P 波前的低幅、低频波，可见有两种形态：园顶型(60%)和上斜型(40%)。所测窦房传导时间为(83.3±26.7)ms，分布范围为(23～118)rm；波幅为3.5～27.7μV；dv/dt为0.43～1.93mV/s。结论：我们认为在适当的滤波、高增益和抗基线漂移技术条件下，利用经食管信号叠加技术，大多数窦房结功能正常的患者可直接记录到食管 SNP。展开更多
目的将相位整序信号平均技术(phase-rectified signal averaging,PRSA)应用于全麻术中,观察其评价自主神经活动变化的可行性。方法选择口腔颌面外科择期手术患者110例,男63例,女47例,年龄18~65岁,ASAⅠ或Ⅱ级。手术全程采集心电信号。...目的将相位整序信号平均技术(phase-rectified signal averaging,PRSA)应用于全麻术中,观察其评价自主神经活动变化的可行性。方法选择口腔颌面外科择期手术患者110例,男63例,女47例,年龄18~65岁,ASAⅠ或Ⅱ级。手术全程采集心电信号。从连续的心电信号中截取三个5min时段:术前(T0):患者麻醉前的清醒状态;术中(T1):手术开始25~30 min;术后(T2):手术结束,患者意识恢复。计算三个时间段心率变异性(heart rate variability,HRV)各项指标:心率减速力(deceleration capacity of heart rate,DC)、RR间期差值的均方根(RMSSD)、RR间期的标准差(SDNN)、散点图短轴(SD1)、散点图长轴(SD2)、总功率(total power,TP)、低频功率(low frequency power,LF)、高频功率(high frequency power,HF)。结果与T0时比较,T1、T2时DC、RMSSD、SDNN、SD1、SD2明显缩短,logTP、logLF和logHF明显减小(P<0.05);与T1时比较,T2时DC、RMSSD、SDNN、SD1、SD2明显延长,logTP、logLF和logHF明显增大(P<0.05);DC与RMSSD、SD1、logHF呈正相关(r=0.905、0.909、0.932,P<0.01)。结论基于PRSA技术5分钟的DC值,与迷走神经活动性具有较好的相关性,用于术中观察自主神经活动是可行的。展开更多
文摘This paper investigates impact of noise and signal averaging on patient control in anesthesia applications, especially in networked control system settings such as wireless connected systems, sensor networks, local area networks, or tele-medicine over a wide area network. Such systems involve communication channels which introduce noises due to quantization, channel noises, and have limited communication bandwidth resources. Usually signal averaging can be used effectively in reducing noise effects when remote monitoring and diagnosis are involved. However, when feedback is intended, we show that signal averaging will lose its utility substantially. To explain this phenomenon, we analyze stability margins under signal averaging and derive some optimal strategies for selecting window sizes. A typical case of anesthe-sia depth control problems is used in this development.
文摘目的：探讨无创性经食管信号叠加直接记录窦房结电位(SNP)的技术。方法：对8只犬进行了系统实验研究，并对256例食管电生理检查窦房结传导时间(SACT)和窦房结恢复时间(SNRT)均在正常范围的患者，其中男142例、女114例，年龄10～74(44.2±12.4)岁进行检测。采用自制三导心电微电位检测仪将食管导联的信号放大(增益达到100_μV/cm)、滤波(0.1～50Hz)，16位模/数(A/D)转换，系统采样频率2kHz，对信号进行叠加，189例(74%)记录到食管 SNP。结果：所测信号叠加食管 SNP 为 P 波前的低幅、低频波，可见有两种形态：园顶型(60%)和上斜型(40%)。所测窦房传导时间为(83.3±26.7)ms，分布范围为(23～118)rm；波幅为3.5～27.7μV；dv/dt为0.43～1.93mV/s。结论：我们认为在适当的滤波、高增益和抗基线漂移技术条件下，利用经食管信号叠加技术，大多数窦房结功能正常的患者可直接记录到食管 SNP。
文摘目的将相位整序信号平均技术(phase-rectified signal averaging,PRSA)应用于全麻术中,观察其评价自主神经活动变化的可行性。方法选择口腔颌面外科择期手术患者110例,男63例,女47例,年龄18~65岁,ASAⅠ或Ⅱ级。手术全程采集心电信号。从连续的心电信号中截取三个5min时段:术前(T0):患者麻醉前的清醒状态;术中(T1):手术开始25~30 min;术后(T2):手术结束,患者意识恢复。计算三个时间段心率变异性(heart rate variability,HRV)各项指标:心率减速力(deceleration capacity of heart rate,DC)、RR间期差值的均方根(RMSSD)、RR间期的标准差(SDNN)、散点图短轴(SD1)、散点图长轴(SD2)、总功率(total power,TP)、低频功率(low frequency power,LF)、高频功率(high frequency power,HF)。结果与T0时比较,T1、T2时DC、RMSSD、SDNN、SD1、SD2明显缩短,logTP、logLF和logHF明显减小(P<0.05);与T1时比较,T2时DC、RMSSD、SDNN、SD1、SD2明显延长,logTP、logLF和logHF明显增大(P<0.05);DC与RMSSD、SD1、logHF呈正相关(r=0.905、0.909、0.932,P<0.01)。结论基于PRSA技术5分钟的DC值,与迷走神经活动性具有较好的相关性,用于术中观察自主神经活动是可行的。
