PubMed Health⌕ Search

Biomedical subjects

Julia Williams

Publications and source records attributed to Julia Williams.

2 recordsLinked to original sources

Comparing machine learning classifiers for diagnosing glaucoma from standard automated perimetry.

PURPOSE: To determine which machine learning classifier learns best to interpret standard automated perimetry (SAP) and to compare the best of the machine classifiers with the global indices of STATPAC 2 and with experts in glaucoma. METHODS: Multilayer perceptrons (MLP), support vector machines (SVM), mixture of Gaussian (MoG), and mixture of generalized Gaussian (MGG) classifiers were trained and tested by cross validation on the numerical plot of absolute sensitivity plus age of 189 normal eyes and 156 glaucomatous eyes, designated as such by the appearance of the optic nerve. The authors compared performance of these classifiers with the global indices of STATPAC, using the area under the ROC curve. Two human experts were judged against the machine classifiers and the global indices by plotting their sensitivity-specificity pairs. RESULTS: MoG had the greatest area under the ROC curve of the machine classifiers. Pattern SD (PSD) and corrected PSD (CPSD) had the largest areas under the curve of the global indices. MoG had significantly greater ROC area than PSD and CPSD. Human experts were not better at classifying visual fields than the machine classifiers or the global indices. CONCLUSIONS: MoG, using the entire visual field and age for input, interpreted SAP better than the global indices of STATPAC. Machine classifiers may augment the global indices of STATPAC.

Diagnosis, Computer-Assisted↗

Psychological considerations in gastrointestinal nursing.

Body image changes and psychological adaptation are often associated with patients who have gastrointestinal disease due to the potential alteration to physical appearance through the very nature of the disease process or treatment. This article describes some of the psychological issues highlighted by patients with gastrointestinal disease, including loss of bowel control, withdrawal and concealment. It highlights altered image difficulties and adaptation through the patients' journey and treatment with illustrations from patients' narratives. In doing so, it explores the nurse's role and stresses the necessity for nurses to seek training to become skillful in counselling this group of patients towards exploring and identifying their individual psychological problems.

Activities of Daily Living↗