Applications of the electric potential sensor for healthcare and assistive technologies

The work discussed in this thesis explores the possibility of employing the Electric Potential Sensor for use in healthcare and assistive technology applications with the same and in some cases better degrees of accuracy than those of conventional technologies. The Electric Potential Sensor is a generic and versatile sensing technology capable of working in both contact and non-contact (remote) modes. New versions of the active sensor were developed for specific surface electrophysiological signal measurements. The requirements in terms of frequency range, electrode size and gain varied with the type of signal measured for each application. Real-time applications based on electrooculography, electroretinography and electromyography are discussed, as well as an application based on human movement. A three sensor electrooculography eye tracking system was developed which is of interest to eye controlled assistive technologies. The system described achieved an accuracy at least as good as conventional wet gel electrodes for both horizontal and vertical eye movements. Surface recording of the electroretinogram, used to monitor eye health and diagnose degenerative diseases of the retina, was achieved and correlated with both corneal fibre and wet gel surface electrodes. The main signal components of electromyography lie in a higher bandwidth and surface signals of the deltoid muscle were recorded over the course of rehabilitation of a subject with an injured arm. Surface electromyography signals of the bicep were also recorded and correlated with the joint dynamics of the elbow. A related non-contact application of interest to assistive technologies was also developed. Hand movement within a defined area was mapped and used to control a mouse cursor and a predictive text interface

The Validity of Child and Adolescent Depression Diagnoses in the Danish Psychiatric Central Research Register

OBJECTIVE This study examined the validity of childhood depression diagnoses in the Danish Psychiatric Central Research Register (DPCRR) and identified predictors of validity. METHODS A nationwide random sample of 500 children (6-17 years) diagnosed with depression between 1996 and 2016 was identified in the DPCRR. Psychiatric hospital records were reviewed and rated using an online checklist. The primary outcome was, whether depressive symptoms and functional impairment documented in hospital records justified a depressive disorder diagnosis based on ICD-10 or DSM-5 diagnostic criteria. Diagnostic validity was calculated as the positive predictive value. Binary logistic regression analysis was used to identify potential predictors of diagnostic validity and these were included in a multiple logistic regression. RESULTS Psychiatric hospital records were available for 393 patients (78.6%). The documentation in the records justified an ICD-10 depressive episode diagnosis in 72.8%, and DSM-5 major depressive disorder in 73.3% of the patients registered with a depression diagnosis. We identified three predictors of diagnostic validity; 1) The validity increased almost linearly from 2000-2016 (OR 1.14, 95% CI 1.07-1.20, p<0.001), 2) antidepressant use was associated with increased diagnostic validity (OR 2.27, 95% CI 1.35-3.82, p=0.002), and 3) emergency department admission predicted low diagnostic validity (OR 0.33, 95% CI 0.12-0.93, p=0.036). CONCLUSION Childhood depression diagnoses registered in the DPCRR show a satisfactory validity according to both ICD-10 and DSM-5 diagnostic criteria. Diagnostic validity increased steadily from 2000-2016 and was positively correlated to antidepressant use. Depression diagnoses assigned in emergency departments had low diagnostic validity

The Validity of Child and Adolescent Depression Diagnoses in the Danish Psychiatric Central Research Register

This study examined the validity of childhood depression diagnoses in the Danish Psychiatric Central Research Register (DPCRR) and identified predictors of validity.; A nationwide random sample of 500 children (6-17 years) diagnosed with depression between 1996 and 2016 was identified in the DPCRR. Psychiatric hospital records were reviewed and rated using an online checklist. The primary outcome was whether depressive symptoms and functional impairment documented in hospital records justified a depressive disorder diagnosis based on ICD-10 or DSM-5 diagnostic criteria. Diagnostic validity was calculated as the positive predictive value. Binary logistic regression analysis was used to identify potential predictors of diagnostic validity, and these were included in a multiple logistic regression.; Psychiatric hospital records were available for 393 patients (78.6%). The documentation in the records justified an ICD-10 depressive episode diagnosis in 72.8%, and DSM-5 major depressive disorder in 73.3% of the patients registered with a depression diagnosis. We identified three predictors of diagnostic validity: (i) The validity increased almost linearly from 2000 to 2016 (OR 1.14, 95% CI 1.07-1.20, p < 0.001), (ii) antidepressant use was associated with increased diagnostic validity (OR 2.27, 95% CI 1.35-3.82, p = 0.002) and (iii) emergency department admission predicted low diagnostic validity (OR 0.33, 95% CI 0.12-0.93, p = 0.036).; Childhood depression diagnoses registered in the DPCRR show a satisfactory validity according to both ICD-10 and DSM-5 diagnostic criteria. Diagnostic validity increased steadily from 2000 to 2016 and was positively correlated with antidepressant use. Depression diagnoses assigned in emergency departments had low diagnostic validity