PubMed Health⌕ Search

Biomedical subjects

D T Reid

Publications and source records attributed to D T Reid.

9 recordsLinked to original sources
PubMed2005

Two-photon optical-beam-induced current solid-immersion imaging of a silicon flip chip with a resolution of 325 nm.

We report high-resolution subsurface imaging of a silicon flip chip by detection of the photocurrent generated by the two-photon absorption of 1530-nm light from a femtosecond Er:fiber laser. The technique combines the focal sensitivity of two-photon excitation with the enhanced optical resolution of high-numerical-aperture solid-immersion imaging. Features on a sub-1-microm scale are clearly resolvable with high contrast, showing a resolution of 325 nm.

Journal Article↗
PubMed2003

Low-threshold femtosecond optical parametric oscillator based on chirped-pulse frequency conversion.

We report what is to our knowledge the first demonstration of a femtosecond optical parametric oscillator based on chirped-pulse frequency conversion in a long crystal of aperiodically poled potassium titanyl phosphate. The minimum pump threshold power was 15 mW, and a signal slope efficiency of 35% was achieved. Continuous tuning from 1190 to 1450 nm was obtained for an average pump power of 800 mW.

Journal Article↗
PubMed2001

Relating familial stress to the psychosocial adjustment of adolescents with Duchenne muscular dystrophy.

Adolescence is a time that offers significant challenges to families dealing with Duchenne muscular dystrophy (DMD). A major developmental task in the adjustment process for the adolescent is the achievement of a sense of self-identity. Mastering stress in families of adolescents with DMD has also been shown to be a major task in the adjustment process for the family. In this study, the relationships between familial stress and psychosocial adjustment in adolescents with DMD were investigated. The study participants (36 caregivers and 32 adolescents) were all registered with the Muscular Dystrophy Association of Canada and all resided in the province of Ontario. The Offer Self-Image Questionnaire for Adolescents (Offer et al., 1982, 1989) was used to measure psychosocial adjustment of adolescents with DMD. Family stress was measured by the Questionnaire on Resources and Stress (Holroyd, 1987). All but a few of the participants were interviewed and completed self-report instruments in their own homes. The other families were interviewed in other settings (e.g., clinic, adolescent's school). The results indicate that, overall and in several specific areas, the adolescents demonstrate lower levels of psychosocial adjustment than their normal reference group. The results also indicate that familial stress is not related to sociodemographic variables, but is associated with psychosocial adjustment in the adolescent (P = 0.0004), and with intellectual function of the adolescent (P = 0.001). In fact, the results of a regression analysis show that the level of stress experienced by the family predicts the degree of psychosocial adjustment of the adolescent with DMD (R2 = 0.38, P = 0.0003). These findings underscore the importance of a holistic approach with these families. Limitations of the study, and implications of the results, are discussed in terms of clinical practice and future research.

Adaptation, Psychological↗
PubMed1996

The effects of the saddle seat on seated postural control and upper-extremity movement in children with cerebral palsy.

A repeated-measures experimental cross-over study was conducted with school-aged children with spastic cerebral palsy (spastic CP) to compare the effects of flat-bench versus saddle-bench seating on postural control and reaching motions. The saddle bench allowed significantly better postural control as measured by the clinical rating scale Sitting Assessment for Children with Neuromotor Dysfunction and by a study-defined variable, Spinal Extension. No statistically significant differences were found for any other variables using aggregate data-analysis techniques. However, the group results and those of single-subject data analysis suggest that the saddle seat may help such children to develop and maintain seated postural control and upper-extremity movement patterns.

Arm↗
PubMed1992

Influences of a hand positioning device on upper-extremity control of children with cerebral palsy.

The aim of this study was to investigate the effects of a hand positioning device on aspects of upper-extremity movement control and muscular activity during a reaching task, and on visual-motor performance in a group of ten children with cerebral palsy. A three-dimensional (3D) motion analysis tracking system was used to monitor hand movement. The 3D path length, movement latency, movement time, average velocity, and the number of accelerations and decelerations (movement units) were measured. Muscle onset latencies of the anterior deltoid, triceps, brachioradialis, extensor carpi radialis, and flexor carpi ulnaris muscles were recorded by electromyography (EMG). A pencil-paper test specifically designed for this study was used to evaluate visual-motor function. Each subject was tested under two conditions (device on and device off). No significant results were found by comparing any parameter between conditions for all subjects combined, however, individual subject data revealed a trend towards an increased number of movement units, slower movement times, and decreased average velocity during the 'on' condition as compared to the 'off' condition. The average onset latencies for the EMG activity of the arm muscles showed differences between the on and off conditions, showing a more normalized muscle activation pattern for the 'on' condition. Furthermore, individual data inspection showed improved performance in the test of visual-motor function during the 'on' as compared to 'off' condition for most subjects. The potential clinical impact of the use of the device for some children with cerebral palsy, as well as directions for future research, are discussed.

Arm↗
PubMed1991

Effects of anterior-tipped seating on respiratory function of normal children and children with cerebral palsy.

The purpose of this study was to compare the respiratory parameters of tidal volume, respiration rate, and minute ventilation of a group of six normal children and a group of six children with spastic cerebral palsy, in response to two seat base positions: (1) flat, and (2) anterior-tipped. Respiratory inductance plethysmography was used to record respiratory parameters. The results demonstrated significant differences in tidal volume and minute ventilation between the groups in the anterior-tipped seat condition. No significant differences in respiratory parameters could be attributed to seat base position within either the normal or cerebral palsied subjects. Implications are discussed in relation to the anterior seat base design, group data analysis methods and individual data profiles, and the impact of these results for future research and practice.

Cerebral Palsy↗
PubMed1991

Memory retraining to support educational reintegration.

A memory retraining package specifically designed to facilitate reintegration of head injured patients into an educational environment is described. Two adolescent patients who had severe head injuries were administered the memory retraining package approximately three months postinjury. A single case study and multiple baseline design was used to evaluate the efficacy of the memory retraining program. The results suggested that this is a promising avenue for improving memory functioning and facilitating educational reintegration, but only where moderate rather than severe memory deficits are involved. Studies involving groups of patients and the collection of data on generalization are required to confirm usefulness.

Adolescent↗