Temporal-spatial Filtering in the Preprocessing of Clinical EEG Signals

EEG spot-recording for clinical patients in the bed is always advocated due to easing patients and making them comfortable. But EEG signals recorded in the ward exposed to various noisesand interference is less effective in the EEG analysis. Atemporal-spatial filter is designed for noise removing of clinical EEG signals, the first filtering is temporal filtering using band-pass filter, and the second filtering is spatial filtering with ICA-based spatial filter. Experimental results indicate that various noises and interferences, such as power interference, blinking, eyes movements, muscle moments, ECG artifacts, etc., are removed effectively, individually or simultaneously.     

二甲苯胺噻唑神经药理作用的研究

本实验对二甲苯胺噻唑(静松灵)的镇静、镇痛、肌松、安定和抗惊厥等中枢抑制作用进行了较为系统的研究;观察了该药对大鼠自发性脑电变化的影响;对该药的作用机理作了初步探讨。结果:(1)二甲苯胺噻唑具有良好的镇静、镇痛和松肌作用,较大剂量有一定的安定作用,但安全性差;(2)对戍四氮、士的宁和苦味毒所致惊厥反应无对抗作用;(3)对神经于神经冲动的传导具有阻断效应,(4)可诱导大鼠脑电出现高幅慢波,惊醒反应消失,妥拉苏林和育亨宾对此有拮抗作用;(5)妥拉苏林和育亨宾对二甲苯胺噻唑制动大有催醒作用,且可缓解该药的中毒反应。结果提示,中枢性α_2—肾上腺素能受体参与了二甲苯胺噻唑中枢抑制作用的产生过程。     

Signal Processing of Electroencephalogram and It''s Application

Electroencephalogram (EEG) signals are the electrical activities in the cortex or on the surface of scalp caused by the physiological activities of the brain which play a key role in the diagnosis of brain and the functional determination of brain. The authors discuss some methods for processing EEG signals from the view of the frequency domain and time domain, especially introduce some time-frequency analysis methods such as Wigner distribution, wavelet transform and matching pursuit etc. , ANN and non-linear analysis for EEG signals processing.     

Electroencephalographic evaluation of gold wire implants inserted in acupuncture points in dogs with epileptic seizures

The purpose of this study was to evaluate both, clinically and with electroencephalographic (EEG) recordings, the effect of gold wire implants in acupuncture points in dogs with uncontrolled idiopathic epileptic seizures. Fifteen dogs with such diagnosis were enrolled in the study. A first EEG recording was performed in all dogs under anaesthesia with xylazine (1 mg/kg) and propofol (6 mg/kg) before the treatment protocol, and a second EEG was performed 15 weeks later. Relative frequency power, intrahemispheric coherence available through EEG, number of seizures and seizure severity were compared before and after treatment using a Wilcoxon signed-rank test. There were no significant statistical differences before and after treatment in relative power or in intrahemispheric coherence in the EEG recording. However, there was a significant mean difference in seizure frequency and seizure severity between control and treatment periods. After treatment, nine of the 15 dogs (60%) had at least a 50% reduction in seizures frequency during the 15 weeks established as follow-up of this treatment.     

Electroencephalographic alterations in a mare with presumed intermittent neuroglycopenia caused by severe hypoglycaemia-associated with nonislet cell tumour

The focus of this report was to document the electroencephalogram (EEG) findings associated with nonislet cell tumour-induced hypoglycaemia (NICTH) in a racing Thoroughbred mare subsequently diagnosed with renal carcinoma and carcinomatosis. We evaluated cortical cerebral activity and confirmed paroxysmal activity consistent with subclinical seizures by performing an EEG prior to onset of clinical signs of seizures. We showed that the electrical activity pattern progressed in a similar fashion as in humans with severe, progressive hypoglycaemia and presumed neuroglycopenia. The glycaemic threshold for abnormalities detected in EEG showed that abnormal electrical cortical activity appeared when blood glucose dropped to 44 mg/dL (2.4 mmol/L) and paroxysmal activity spread, becoming generalised when blood glucose dropped to 23 mg/dL (1.3 mmol/L). NICTH is an uncommon paraneoplastic phenomenon in several species. In horses, NICTH has been reported most frequently in primary renal tumours, followed by primary hepatic tumours. This report highlights the importance of investigating the possibility of hypoglycaemia in cases of horses that present altered state of consciousness with or without intermittent seizures. This case report also highlights that the diagnostic work-up for horses presenting with episodic hypoglycaemia should comprise investigation of possible neoplasia, as paraneoplastic hypoglycaemia should be included in the list of differentials of horses with hypoglycaemia.     

Health Record Management System in Visual Electroencephalograph

Visual Electroencephalograph (VEEG) is a new type of digital, information electroencephalograph. As an important part of Visual Electroencephalograph, Health Record Management System(HRMS)is integrant to store electroencephalographic data plentifully, show and edit their waveforms, analyze the data on line or off line. By the most popular and steady Relational-Database technology, ADO Application Programming Interface (API) and Visual C++ programming tool, the system has the friendly interactive interface and the functions of adding, updating, deleting, recalling, counting health record information, etc. Integrated with other parts of VEEG, HRMS ameliorates traditional EEG and overcomes some disadvantages of it such as discommodious to record, difficult to read and hard to get useful information. This paper introduces main functions, structure design and components of Health Record Management System.     

Detecting EEG Sleep Spindles by Digital Filtering with Zero Phase Error

EEG signal is a kind of very complex non stationary signal. It is of important clinical values for using EEG most efficiently to distinguish all kinds of components in EEG or getting needed components to judge some pathology features effectively. The phase moving of the system can change the relative phase relation between the components in the inputed signal, so there can be a great change of the feature in time domain of inputed signal. The FRR and RRF digital filtering methods and their realization are discussed. By using these methods, the system can be of the feature of zero phase error, and the filtering of EEG signals with zero phase error can be realized. Based on the definition of sleep spindles, we can detect sleep spindles in time domain directly by using digital filtering with zero phase error.     

Comparison of analgesic techniques for antler removal in halothane-anaesthetized red deer (Cervus elaphus): electroencephalographic responses

OBJECTIVE: To provide evidence for an analgesic effect of antler pedicle compression or lidocaine 'ring block' by comparing changes in median and spectral edge frequencies and total electroencephalographic (EEG) power during the application of each technique followed by antler removal. ANIMALS: Twenty-nine 2-year-old red deer (Cervus elaphus) stags weighing 106-131 kg each were used in this study. Stags were carrying immature growing antler suitable for commercial harvest. MATERIALS AND METHODS: Anaesthesia was induced using propofol (8.25 +/- 1.28 mg kg(-1)) and ketamine (2.18 +/- 0.15 mg kg(-1)) and maintained with halothane in oxygen. End-tidal halothane (Fe'HAL), expired CO(2) tension (Pe'CO(2)), SpO(2), EEG, ECG, and direct arterial blood pressures were recorded continuously. Respiratory rate and somatic responses were recorded at specific time points. After stabilization of anaesthesia (Fe'HAL was approximately 0.8%) baseline data were recorded. Stags were randomly allocated to one of three treatment groups; control, local anaesthesia, or compression band. One antler was removed 4 minutes after the application of treatment. Electroencephalographic responses to application of treatment and antler removal were analysed using area under the curve (AUC) analysis. Mean AUC was compared between groups using anova, and when significant differences were found, groups were compared post hoc with two-tailed t-tests. Significance levels were set at p EEG power (P(tot)) was decreased in the removal period in the control group. In the compression group, P(tot) was decreased in the removal period. In the lidocaine group, P(tot) was decreased in the application period. There were no significant differences in EEG variables between antler removal in the control group and application of compression (p = 0.19-0.96). CONCLUSIONS: These data suggest that lidocaine 'ring block' of the antler pedicle provides adequate analgesia for velvet antler removal. The use of antler pedicle compression bands represents a noxious stimulus in its own right and is not as protective as lidocaine 'ring block' against the noxious stimulus of surgical antler removal. CLINICAL RELEVANCE: Compression of the antler pedicle has been recommended as an alternative to lidocaine 'ring block' for velvet antler removal. The results of this study suggest that antler pedicle compression is noxious. In addition, antler pedicle compression offers less effective analgesia than lidocaine 'ring block'.     

EEG changes in 4-week-old lambs in response to castration, tail docking and mulesing

OBJECTIVE: To interpret changes in EEG in relation to perceived pain of castration, mulesing and docking in lambs. DESIGN: Analysis of covariance (randomised block design) to determine the effects of treatment on eight bandwidths of the EEG frequency spectrum. PROCEDURE: Ninety-eight, 3- to 4-week-old lambs were subjected to one of seven treatments: castration, tail docking, mulesing, ear tagging, sham shearing, formalin injection (to induce lameness) and handling. EEG was recorded for 15 min before treatment, during treatment, and for 15 min after treatment. RESULTS: Consistently lower mean power values across all bandwidths of the EEG were found at the time of mulesing and docking than at handling and shearing (P < 0.01). Formalin injection resulted in lower power values than handling and shearing (P < 0.01). Castration had lower power values than handling and shearing. Similarly, for 15 min after treatment, mulesing and formalin injection had significantly lower power values than handling, shearing, ear tagging and castration (P < 0.05). CONCLUSION: The consistent effects associated with mulesing, docking and castration compared to handling, shearing and ear tagging suggest that mulesing at both the time of treatment and during 15 min after treatment results in a response that is similar to that of induced lameness. Docking and castration result in a response at the time of treatment that is similar to induced lameness and mulesing, but during 15 min after treatment is similar to the non-noxious control treatments. However, the depressing effects on the mean power values are the reverse of that anticipated from a previously developed pain model, highlighting the need for further research to develop this technology to evaluate pain associated with husbandry procedures.