The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillator＇s phase...The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillator＇s phase trajectory in a small- scale periodic state are analyzed by introducing the theory of stopping oscillation system. Based on this approach, a novel Duffing oscillator weak wide-band signal detection method is proposed. In this novel method, the reference signal is discarded, and the to-be-detected signal is directly used as a driving force. By calculating the cosine function of a phase space angle, a single Duffing oscillator can be used for weak wide-band signal detection instead of an array of uncoupled Duffing oscillators. Simulation results indicate that, compared with the conventional Duffing oscillator detection method, this approach performs better in frequency detection intervals, and reduces the signal-to-noise ratio detection threshold, while improving the real-time performance of the system.展开更多
目的:探讨重症监护病房(intensive care unit,ICU)获得性肌无力(ICU acquired weakness,ICUAW)患者肌肉超声回声与血浆炎性因子的相关性,以及其对ICUAW的诊断价值和预后的预测价值。方法:选择重庆市急救医疗中心ICU住院患者,分别在第1、...目的:探讨重症监护病房(intensive care unit,ICU)获得性肌无力(ICU acquired weakness,ICUAW)患者肌肉超声回声与血浆炎性因子的相关性,以及其对ICUAW的诊断价值和预后的预测价值。方法:选择重庆市急救医疗中心ICU住院患者,分别在第1、3、7天使用床旁超声检测患者肌肉回声,获得的总体肌肉回声评分(global muscle echogenicity score,GEM),测定血清白细胞介素-6(interleukin-6,IL-6)和降钙素原(procalcitonin,PCT)浓度,采用医学研究理事会肌力评分法(medical research council scales,MRC-ss)评估肌肉力量。根据患者入ICU第7天MRC-ss评分将患者分为ICUAW组和非ICUAW组,分析比较2组患者GEM、IL-6、PCT的差异及各指标的相关性。利用受试者工作特征(receiver operator characteristic,ROC)曲线分析以上参数对ICUAW诊断效能,分析GEM、IL-6、PCT对ICUAW患者的预测预后价值。结果:ICUAW组第3天GEM、第7天IL-6浓度、GEM高于非ICUAW组(P<0.05)。GEM与第7天IL-6水平呈正相关(r=0.221),第7天GEM与MRC-ss评分呈负相关(r=-0.581)。ROC曲线分析显示,第7天GEM对ICUAW有诊断预测价值,ROC曲线下面积(area under the curve,AUC)为0.838,使用GEM、IL-6、PCT联合诊断,AUC=0.885(P<0.05)。ICUAW组Barthel指数评分(Barthel index,BI)低于非ICUAW组,ICUAW组中总体肌肉超声回声评分(global muscle echogenicity score,GEM)高的患者BI低于GEM低的患者(P<0.05)。结论:ICU住院患者GEM与IL-6、PCT浓度相关,其对ICUAW具有一定的诊断价值,并能够预测ICUAW患者的预后。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61673066)
文摘The conventional Duffing oscillator weak signal detection method, which is based on a strong reference signal, has inherent deficiencies. To address these issues, the characteristics of the Duffing oscillator＇s phase trajectory in a small- scale periodic state are analyzed by introducing the theory of stopping oscillation system. Based on this approach, a novel Duffing oscillator weak wide-band signal detection method is proposed. In this novel method, the reference signal is discarded, and the to-be-detected signal is directly used as a driving force. By calculating the cosine function of a phase space angle, a single Duffing oscillator can be used for weak wide-band signal detection instead of an array of uncoupled Duffing oscillators. Simulation results indicate that, compared with the conventional Duffing oscillator detection method, this approach performs better in frequency detection intervals, and reduces the signal-to-noise ratio detection threshold, while improving the real-time performance of the system.
文摘目的:探讨重症监护病房(intensive care unit,ICU)获得性肌无力(ICU acquired weakness,ICUAW)患者肌肉超声回声与血浆炎性因子的相关性,以及其对ICUAW的诊断价值和预后的预测价值。方法:选择重庆市急救医疗中心ICU住院患者,分别在第1、3、7天使用床旁超声检测患者肌肉回声,获得的总体肌肉回声评分(global muscle echogenicity score,GEM),测定血清白细胞介素-6(interleukin-6,IL-6)和降钙素原(procalcitonin,PCT)浓度,采用医学研究理事会肌力评分法(medical research council scales,MRC-ss)评估肌肉力量。根据患者入ICU第7天MRC-ss评分将患者分为ICUAW组和非ICUAW组,分析比较2组患者GEM、IL-6、PCT的差异及各指标的相关性。利用受试者工作特征(receiver operator characteristic,ROC)曲线分析以上参数对ICUAW诊断效能,分析GEM、IL-6、PCT对ICUAW患者的预测预后价值。结果:ICUAW组第3天GEM、第7天IL-6浓度、GEM高于非ICUAW组(P<0.05)。GEM与第7天IL-6水平呈正相关(r=0.221),第7天GEM与MRC-ss评分呈负相关(r=-0.581)。ROC曲线分析显示,第7天GEM对ICUAW有诊断预测价值,ROC曲线下面积(area under the curve,AUC)为0.838,使用GEM、IL-6、PCT联合诊断,AUC=0.885(P<0.05)。ICUAW组Barthel指数评分(Barthel index,BI)低于非ICUAW组,ICUAW组中总体肌肉超声回声评分(global muscle echogenicity score,GEM)高的患者BI低于GEM低的患者(P<0.05)。结论:ICU住院患者GEM与IL-6、PCT浓度相关,其对ICUAW具有一定的诊断价值,并能够预测ICUAW患者的预后。
