In this paper, the ratio of powers in the frequency bands of β2 and θ waves in EEG signals (termed as the β2/θ -ratio) was introduced as a potential enhancement in measuring anesthesia depth. The β2/θ -ratio was...In this paper, the ratio of powers in the frequency bands of β2 and θ waves in EEG signals (termed as the β2/θ -ratio) was introduced as a potential enhancement in measuring anesthesia depth. The β2/θ -ratio was compared to the relative β-ratio which had been commercially used in the BIS monitor. Sensitivity and reliability of the β2/θ -ratio and EEG measurement locations were analyzed for their effectiveness in measuring anesthesia depth during different stages of propofol induced anesthesia (awake, induction, maintenance, and emergence). The analysis indicated that 1) the relative β -ratio and β2/θ-ratio derived from the prefrontal, frontal, and the central cortex EEG signals were of substantial sensitivity for capturing anesthesia depth changes. 2) Certain channel positions in the frontal part of the cortex, such as , had the combined benefits of substantial sensitivity and noise resistance. 3) The β2/θ-ratio captured the initial excitation, while the relative β -ratio did not. 4) In the maintenance and emergence stages, the β2/θ -ratio showed improved reliability. Implications: The ratio of powers in EEG frequency bands and derived from the frontal cortex EEG channels has combined benefits of substantial sensitivity and noise resistance in measuring anesthesia depth.展开更多
A new approach to estimating level of uncon-sciousness based on Principal Component Analysis (PCA) is proposed. The Electroen-cephalogram (EEG) data was captured in both Intensive Care Unit (ICU) and operating room, u...A new approach to estimating level of uncon-sciousness based on Principal Component Analysis (PCA) is proposed. The Electroen-cephalogram (EEG) data was captured in both Intensive Care Unit (ICU) and operating room, using different anesthetic drugs. Assuming the central nervous system as a 20-tuple source, window length of 20 seconds is applied to EEG. The mentioned window is considered as 20 nonoverlapping mixed-signals (epoch). PCA algorithm is applied to these epochs, and larg-est remaining eigenvalue (LRE) and smallest remaining eigenvalue (SRE) were extracted. Correlation between extracted parameters (LRE and SRE) and depth of anesthesia (DOA) was measured using Prediction probability (PK). The results show the superiority of SRE than LRE in predicting DOA in the case of ICU and isoflurane, and the slight superiority of LRE than SRE in propofol induction. Finally, a mixture model containing both LRE and SRE could predict DOA as well as Relative Beta Ratio (RBR), which expresses the high capability of the proposed PCA based method in estimating DOA.展开更多
Objective To detect the change of brain activity under different depth of anesthesia (DOA) noninvasively. Methods The Lempel-Ziv complexity C(n) was used to analyze EEG and its four components (delta, theta, alpha, be...Objective To detect the change of brain activity under different depth of anesthesia (DOA) noninvasively. Methods The Lempel-Ziv complexity C(n) was used to analyze EEG and its four components (delta, theta, alpha, beta), which was recorded from SD rats under different DOA. The relationship between C(n) and DOA was studied. Results The C(n) of EEG will decrease while the depth of anesthesia increasing and vice versa. It can be used to detect the change of DOA sensitively. Compared with power spectrum, the change of C(n) is opposite to that of power spectrum. Only the C(n) of delta rhythm has obvious variations induced by the change of DOA, and the variations of delta is as similar as the EEG's. Conclusion The study shows that the desynchronized EEG is replaced by the synchronized EEG when rat goes into anesthesia state from awake, that is just the reason why complexity and power spectrum appear corresponding changes under different DOA. C(n) of delta rhythm dynamic change leads to the change of EEG, and the delta rhythm is the dominant rhythm during anesthesia for rats.展开更多
Conjunctive use of anesthetic agents results in drug interactions which can alter or influence multiple patient outcomes such as anesthesia depth,and cardiorespiratory parameters which can also be altered by patient c...Conjunctive use of anesthetic agents results in drug interactions which can alter or influence multiple patient outcomes such as anesthesia depth,and cardiorespiratory parameters which can also be altered by patient conditions and surgical procedures.Using artificial intelligence technology to continuously gather data of drug infusion and patient outcomes,we can generate reliable computer models individualized for a patient during specific stages of particular surgical procedures.This data can then be used to extend the current anesthesia monitoring functions to include future impact prediction,drug administration planning,and anesthesia decisions.展开更多
BACKGROUND Wavelet index(WLi)and pain rating index(PRi)are new parameters for regulating general anesthesia depth based on wavelet analysis.AIM To investigate the safety and efficacy of using WLi or PRi in sevoflurane...BACKGROUND Wavelet index(WLi)and pain rating index(PRi)are new parameters for regulating general anesthesia depth based on wavelet analysis.AIM To investigate the safety and efficacy of using WLi or PRi in sevoflurane anesthesia.METHODS This randomized controlled trial enrolled 66 patients scheduled for elective posterior lumbar interbody fusion surgery under sevoflurane anesthesia between September 2017 and February 2018.A random number generator was used to assign the eligible patients to three groups:Systolic blood pressure(SBP)monitoring group,WLi monitoring group,and PRi monitoring group.The main anesthesiologist was aware of the patient grouping and intervention used.The primary endpoint was anesthesia recovery time.Secondary endpoints included extubation time,sevoflurane consumption,number of unwanted events/interventions,number of adverse events and postoperative visual analogue scale for pain.RESULTS A total of 62 patients were included in the final analysis(SBP group,n=21;WLi group,n=21;and PRi group,n=20).There were no significant differences among the three groups in patient age,gender distribution,body mass index,American Society of Anesthesiologists class,duration of surgery,or duration of anesthesia.Anesthesia recovery time was shorter in the WLi and PRi groups than in the SBP group with no significant difference between the WLi and PRi groups.Extubation time was shorter in the WLi and PRi groups than in the SBP group.Sevoflurane consumption was lower in the WLi and PRi groups than in the SBP group.Nicardipine was more commonly needed to treat hypertension in the WLi and PRi groups than in the SBP group.CONCLUSION Regulation of sevoflurane anesthesia depth with WLi or PRi reduced anesthesia recovery time,extubation time and sevoflurane consumption without intraoperative unwanted events.展开更多
文摘In this paper, the ratio of powers in the frequency bands of β2 and θ waves in EEG signals (termed as the β2/θ -ratio) was introduced as a potential enhancement in measuring anesthesia depth. The β2/θ -ratio was compared to the relative β-ratio which had been commercially used in the BIS monitor. Sensitivity and reliability of the β2/θ -ratio and EEG measurement locations were analyzed for their effectiveness in measuring anesthesia depth during different stages of propofol induced anesthesia (awake, induction, maintenance, and emergence). The analysis indicated that 1) the relative β -ratio and β2/θ-ratio derived from the prefrontal, frontal, and the central cortex EEG signals were of substantial sensitivity for capturing anesthesia depth changes. 2) Certain channel positions in the frontal part of the cortex, such as , had the combined benefits of substantial sensitivity and noise resistance. 3) The β2/θ-ratio captured the initial excitation, while the relative β -ratio did not. 4) In the maintenance and emergence stages, the β2/θ -ratio showed improved reliability. Implications: The ratio of powers in EEG frequency bands and derived from the frontal cortex EEG channels has combined benefits of substantial sensitivity and noise resistance in measuring anesthesia depth.
文摘A new approach to estimating level of uncon-sciousness based on Principal Component Analysis (PCA) is proposed. The Electroen-cephalogram (EEG) data was captured in both Intensive Care Unit (ICU) and operating room, using different anesthetic drugs. Assuming the central nervous system as a 20-tuple source, window length of 20 seconds is applied to EEG. The mentioned window is considered as 20 nonoverlapping mixed-signals (epoch). PCA algorithm is applied to these epochs, and larg-est remaining eigenvalue (LRE) and smallest remaining eigenvalue (SRE) were extracted. Correlation between extracted parameters (LRE and SRE) and depth of anesthesia (DOA) was measured using Prediction probability (PK). The results show the superiority of SRE than LRE in predicting DOA in the case of ICU and isoflurane, and the slight superiority of LRE than SRE in propofol induction. Finally, a mixture model containing both LRE and SRE could predict DOA as well as Relative Beta Ratio (RBR), which expresses the high capability of the proposed PCA based method in estimating DOA.
文摘Objective To detect the change of brain activity under different depth of anesthesia (DOA) noninvasively. Methods The Lempel-Ziv complexity C(n) was used to analyze EEG and its four components (delta, theta, alpha, beta), which was recorded from SD rats under different DOA. The relationship between C(n) and DOA was studied. Results The C(n) of EEG will decrease while the depth of anesthesia increasing and vice versa. It can be used to detect the change of DOA sensitively. Compared with power spectrum, the change of C(n) is opposite to that of power spectrum. Only the C(n) of delta rhythm has obvious variations induced by the change of DOA, and the variations of delta is as similar as the EEG's. Conclusion The study shows that the desynchronized EEG is replaced by the synchronized EEG when rat goes into anesthesia state from awake, that is just the reason why complexity and power spectrum appear corresponding changes under different DOA. C(n) of delta rhythm dynamic change leads to the change of EEG, and the delta rhythm is the dominant rhythm during anesthesia for rats.
文摘Conjunctive use of anesthetic agents results in drug interactions which can alter or influence multiple patient outcomes such as anesthesia depth,and cardiorespiratory parameters which can also be altered by patient conditions and surgical procedures.Using artificial intelligence technology to continuously gather data of drug infusion and patient outcomes,we can generate reliable computer models individualized for a patient during specific stages of particular surgical procedures.This data can then be used to extend the current anesthesia monitoring functions to include future impact prediction,drug administration planning,and anesthesia decisions.
基金Supported by Key Research and Development(R&D)Projects of Shanxi Province,China,No.201803D31135.
文摘BACKGROUND Wavelet index(WLi)and pain rating index(PRi)are new parameters for regulating general anesthesia depth based on wavelet analysis.AIM To investigate the safety and efficacy of using WLi or PRi in sevoflurane anesthesia.METHODS This randomized controlled trial enrolled 66 patients scheduled for elective posterior lumbar interbody fusion surgery under sevoflurane anesthesia between September 2017 and February 2018.A random number generator was used to assign the eligible patients to three groups:Systolic blood pressure(SBP)monitoring group,WLi monitoring group,and PRi monitoring group.The main anesthesiologist was aware of the patient grouping and intervention used.The primary endpoint was anesthesia recovery time.Secondary endpoints included extubation time,sevoflurane consumption,number of unwanted events/interventions,number of adverse events and postoperative visual analogue scale for pain.RESULTS A total of 62 patients were included in the final analysis(SBP group,n=21;WLi group,n=21;and PRi group,n=20).There were no significant differences among the three groups in patient age,gender distribution,body mass index,American Society of Anesthesiologists class,duration of surgery,or duration of anesthesia.Anesthesia recovery time was shorter in the WLi and PRi groups than in the SBP group with no significant difference between the WLi and PRi groups.Extubation time was shorter in the WLi and PRi groups than in the SBP group.Sevoflurane consumption was lower in the WLi and PRi groups than in the SBP group.Nicardipine was more commonly needed to treat hypertension in the WLi and PRi groups than in the SBP group.CONCLUSION Regulation of sevoflurane anesthesia depth with WLi or PRi reduced anesthesia recovery time,extubation time and sevoflurane consumption without intraoperative unwanted events.
