Seizure detection in subdural recordings using nonlinear decision functions

This dissertation proposed a new approach to seizure detection in intracranial EEG recordings using nonlinear decision functions. It implemented well-established features that were designed to deal with complex signals such as brain recordings, and proposed a 2-D domain of analysis. Since the features considered assume both the time and frequency domains, the analysis was carried out both temporally and as a function of different frequency ranges in order to ascertain those measures that were most suitable for seizure detection. In retrospect, this study established a generalized approach to seizure detection that works across several features and across patients. ^ Clinical experiments involved 8 patients with intractable seizures that were evaluated for potential surgical interventions. A total of 35 iEEG data files collected were used in a training phase to ascertain the reliability of the formulated features. The remaining 69 iEEG data files were then used in the testing phase. ^ The testing phase revealed that the correlation sum is the feature that performed best across all patients with a sensitivity of 92% and an accuracy of 99%. The second best feature was the gamma power with a sensitivity of 92% and an accuracy of 96%. In the frequency domain, all of the 5 other spectral bands considered, revealed mixed results in terms of low sensitivity in some frequency bands and low accuracy in other frequency bands, which is expected given that the dominant frequencies in iEEG are those of the gamma band. In the time domain, other features which included mobility, complexity, and activity, all performed very well with an average a sensitivity of 80.3% and an accuracy of 95%. ^ The computational requirement needed for these nonlinear decision functions to be generated in the training phase was extremely long. It was determined that when the duration dimension was rescaled, the results improved and the convergence rates of the nonlinear decision functions were reduced dramatically by more than a 100 fold. Through this rescaling, the sensitivity of the correlation sum improved to 100% and the sensitivity of the gamma power to 97%, which meant that there were even less false negatives and false positives detected. ^

A descriptive study of the empowerment process of mothers of children who have disabilities

The purpose of this study was to examine the phenomenological aspect in the empowerment process of mothers of children with disabilities, and to determine if the coding categories used by Dunst & Trivette (1996) could be replicated. Three mothers of children with disabilities agreed to participate in the study. A semistructured interview was used to determine the specific events that lead to empowerment. Interviews were audio-taped and transcribed by the researcher. Fifteen coding categories and four majors themes of empowerment were identified. Triangulation was used to assure reliability and validity. The findings demonstrated that the coding stages of empowerment as outlined by Dunst & Trivette (1996) are reproducible, as well as the envisionment of the future for their children is the essence of empowerment for these mothers. Specific suggestions are made by which occupational therapists can facilitate the empowerment process of mothers who have children with disabilities.

A descriptive study of the ratio of approval to disapproval demonstrated by music teachers and classroom teachers in first, second, and third grades

The purpose of this study was to determine the approval to disapproval ratios of feedback given by music and classroom teachers to first, second and third grades. Eight teachers from a South Florida Elementary School were selected for this study. Twelve 20-minute videos were taken for further examination. Analyses of data using percentage formulas were used to determine the ratio of each of the teacher reinforcement. Classroom teachers gave 2.3% social approval feedback, 59% academic approval feedback, 22% social disapproval feedback, 16.5% academic disapproval feedback, and 0% errors. Music teachers gave .7% social approval feedback, 67% academic approval feedback, 22% social disapproval feedback, 10% academic disapproval feedback, and 0% errors. Today's teachers are 8% more academically approving than thirty years ago. Results also show that today's music teachers are still more approving than classroom teachers.