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Biomedical subjects

D Wright

Publications and source records attributed to D Wright.

At least 127 records · Page 7Linked to original sources
PubMed1996

Realistic animation of human figures using artificial neural networks.

We describe a new approach to the animation of human figures which can produce realistic animation and based on artificial neural networks (ANN). A fully connected ANN is trained with inputs and outputs of key frames obtained from image analysis and key postures and parameters of standing, walking and running. A behaviour index is introduced as an input to the ANN. Each index is unique to each behaviour. Other inputs include speed, cycle history and subsystem index. The subsystem index refers to the different subsystem of the human figure e.g. the right leg is a subsystem referred to by an index. The outputs are the joints displacements. The ANN is trained using the back propagation method. The ANN was able to generate realistic animations of walking and running and could merge three different behaviours, standing, walking and running. The proposed method should enable design evaluations, human factors analysis, task simulation and motion understanding easier for non-animation experts.

Biomechanical Phenomena↗
PubMed1996

Psychological symptoms, somatic symptoms, and psychiatric disorder in chronic fatigue and chronic fatigue syndrome: a prospective study in the primary care setting.

OBJECTIVE: This study assessed relationships among psychological symptoms, past and current psychiatric disorder, functional impairment, somatic symptoms, chronic fatigue, and chronic fatigue syndrome. METHOD: A prospective cohort study was followed by a nested case-control study. The subjects, aged 18-45 years, had been in primary care for either clinical viral infections or a range of other problems. Questionnaire measures of fatigue and psychological symptoms were completed by 1,985 subjects 6 months later; 214 subjects with chronic fatigue were then compared with 214 matched subjects without fatigue. Assessments were made with questionnaires, interviews, and medical records of fatigue, somatic symptoms, psychiatric disorder, and functional impairment. RESULTS: Subjects with chronic fatigue were at greater risk than those without chronic fatigue for current psychiatric disorder assessed by standardized interview (60% versus 19%) or by questionnaire (71% versus 31%). Chronic fatigue subjects were more likely to have received psychotropic medication or experienced psychiatric disorder in the past. There was a trend for previous psychiatric disorder to be associated with comorbid rather than noncomorbid chronic fatigue. Most subjects with chronic fatigue syndrome also had current psychiatric disorder when assessed by interview (75%) or questionnaire (78%). Both the prevalence and incidence of chronic fatigue syndrome were associated with measures of previous psychiatric disorder. The number of symptoms suggested as characteristics of chronic fatigue syndrome was closely related to the total number of somatic symptoms and to measures of psychiatric disorder. Only postexertion malaise, muscle weakness, and myalgia were significantly more likely to be observed in chronic fatigue syndrome than in chronic fatigue. CONCLUSIONS: Most subjects with chronic fatigue or chronic fatigue syndrome in primary care also meet criteria for a current psychiatric disorder. Both chronic fatigue and chronic fatigue syndrome are associated with previous psychiatric disorder, partly explained by high rates of current psychiatric disorder. The symptoms thought to represent a specific process in chronic fatigue syndrome may be related to the joint experience of somatic and psychological distress.

Adolescent↗
PubMed1996

Telemedicine and developing countries.

A committee was established by the International Telecommunication Union in 1994 to study telemedicine, with particular reference to developing countries. A questionnaire was used to gather data. Fifty-eight responses were received, two-thirds from developing countries. In most developing countries the user did not pay for the telemedicine service, at least not directly. There were few instances of a commercial telemedicine service, and in most countries the telemedicine service was subsidized by the government or another party. The telemedicine 'value chain' describes how equipment suppliers, telecommunications operators and health-care professionals deliver their products or services to the client, who is eventually the ultimate user. Quite different configurations are conceivable, and an analysis of what could be a sustainable, cost-effective value chain in developing countries is required. It is clear that the rapidly growing interest in telemedicine challenges the leaders of the medical establishment to rethink the ways they provide their services and to address the medical needs of areas where such services are absent or in short supply.

Cost-Benefit Analysis↗
PubMed1996

Ergonomic data of elderly people and their application in rehabilitation design.

The population of the First World is ageing, and as it does so elderly people are becoming an increasingly significant consumer group. This process has important ramifications for the ergonomics and design professions. The demand for products that have been developed with consideration for the elderly consumer will require designers to develop new skills and ergonomists to supply new data. This paper highlights the inadequacy of current design data pertaining to the elderly. Anthropometric studies which have been carried out within the fields of ergonomics and rehabilitation are reviewed, and their usefulness to the product designer discussed. Recommendations are made regarding future needs for the collection and dissemination of further data.

Activities of Daily Living↗
PubMed1996

Molecular weights and isoelectric points of sperm antigens relevant to autoimmune infertility in men.

PURPOSE: We determined the molecular weights and isoelectric points of antigens in the uncapacitated and capacitated spermatozoa of fertile men binding to the serum immunoglobulin G (IgG) from 8 autoimmune infertile men and 8 fertile nonautoimmune men. MATERIALS AND METHODS: We used double fluorochrome cytotoxicity and immunobead binding assays to determine the sperm antibody status of the study subjects. 2-Dimensional gel electrophoresis and Western blot analysis were used to determine the molecular weights and isoelectric points of sperm antigens binding to serum IgG from these men. Amino acid sequencing of the digested peptides of chosen proteins was accomplished. Immune reactivity to the proteins in autoimmune infertile men was further verified. RESULTS: Serum IgG from fertile men failed to react significantly. Serum IgG from all autoimmune men (100%) showed significant binding to proteins with a molecular weight of 92 kDa. and isoelectric points of 3.5 to 4.0 in the capacitated spermatozoa. Six of 8 infertile men (75%) had serum IgG binding to capacitated sperm antigens with a molecular weight of 18 kDa. and isoelectric points of 4.5 to 5.2. Amino acid sequencing of peptides of the 92 kDa. protein matched complement component 1 (C1) inhibitor, with noted differences in the amino acid sequencing from the latter. The 18 kDa. protein matched calmodulin. We verified that serum IgG from autoimmune infertile men bound with C1 inhibitor and ascertained that the 92 kDa. protein in the spermatozoa was C1 inhibitor-like protein. CONCLUSIONS: Significant antibody responses to C1 inhibitor-like protein and calmodulin were noted in autoimmune men. Both of these proteins may be of testicular origin and these autoimmune responses may be highly relevant to infertility.

Amino Acid Sequence↗
PubMed1996

Learning and generating human natural behaviours for design evaluation using artificial neural networks.

Biomechanical consideration is becoming very important when designing a product. Animation and strength prediction tools are available to perform the necessary analysis. However with most of these tools, animation is achieved via a sequence of key frames constructed by manipulating the human model to the desired position in each key frame. The resulting motion is therefore unnatural. Most strength predictions are based on static strength measurements of a selected population. Existing prediction tools are not flexible so as to allow data from other populations and/or additional parameters such as dynamic strength to be included in the prediction equations. In this paper we present an approach using neural networks that will allow learning and generation of natural human behaviours. We also propose using neural networks for strength prediction because of the flexibility in specifying inputs and outputs and the ability to map non-linear relationships.

Behavior↗
PubMed1996

An analysis of the impact of a management system on patients waiting for cardiac surgery.

The Cardiac Surgery Management System (CSMS) was developed in the Central West region of Ontario to support patients who are waiting for cardiac surgery. This management system provides a consistent mechanism to communicate preoperative information to patients and their families. A questionnaire was developed to analyze the impact of the CSMS on patients waiting for elective surgery in this health region. This descriptive study assesses the patients' perception of the assistance they received preoperatively, through the nurse coordinator. One hundred and fifty study patients were randomly selected from patients who had undergone elective surgery during the previous calendar year and these subjects received questionnaires. The final response rate was 81%. Ninety-three percent of respondents had telephone contact with the coordinator, and 89% of these patients received information/education by mail. Sixty percent of respondents admitted to some degree of anxiety, and 46% of these patients discussed their feelings with the coordinator. Increased levels of anxiety were associated with an increased likelihood of a patient-initiated contact with the coordinator. This contact was associated with decreased levels of anxiety. Patients waiting for surgery demonstrated preoperative anxiety, and opportunities to discuss this should be provided. Patients also feel they benefit from receiving educational material preoperatively. The use of the nurse in an expanded role needs to be maximized, with focus on the nurse as a facilitator for problem solving.

Adaptation, Psychological↗
PubMed1995

Magnetic brain stimulation: safety studies.

We describe short-term and long-term safety studies after low repetition rate magnetic brain stimulation in 10 normal subjects. We obtained quantitative EEG data, psychometric test results, serum prolactin and cortisol levels before and after brain stimulation. EEG and psychometric data were also obtained in 5 of these subjects 16-24 months after the initial experiment. Short- and long-term studies did not show any deleterious effects. Randt delayed recalls, however, showed a transient reduction in the score immediately after stimulation which resolved on retesting in 2 weeks. To address the question of fatigue we repeated Randt tests in 4 subjects before and after magnetic brain stimulation but without the other extensive psychometric, EEG and blood tests. Pre- and post-stimulation scores on this occasion showed no significant difference in these 4 subjects suggesting that the transient changes in the previous Randt score were related to fatigue. We conclude that single-pulse magnetic brain stimulation has no deleterious effects after magnetic brain stimulation.

Adult↗
PubMed1995

Influence of physical, psychological and behavioural factors on consultations for back pain.

Over 34,000 questionnaires were used to study occurrence and consultations for back pain in the community. The 12-month period prevalence was 24% and 13% of the sample consulted a doctor. Elderly women were at greatest risk of back pain. The consultation rate increased in both sexes throughout middle age, but declined in men over the age of 55 yr. Back pain was associated with the Goldberg General Health Health Questionnaire score suggesting psychiatric morbidity [odds ratio (OR) = 2.05; confidence interval (CI) 1.89-2.23], obesity (OR = 1.59; CI 1.40-1.79), and cigarette smoking (OR = 1.52; CI 1.36-1.70). Vigorous daily activity was positively associated with back pain in men aged 18-39 yr (OR = 1.37; CI 1.02-1.85), and women aged 18-39 yr (OR = 1.50; CI 1.08-2.09), but was negatively associated with back pain in women aged over 65 yr (OR = 0.35; CI 0.16-0.76). Alcohol consumption was also negatively associated with back pain (OR = 0.72; CI 0.62-0.85). The prevalence of arthritis, constipation and respiratory disorders was increased in those who consulted for back pain corrected for the other variables. Thus back pain was substantially more common in women compared to men over 55 yr. Psychiatric morbidity, cigarette smoking and obesity were associated with back pain at all ages, but the effect of physical exercise appeared to change with age. Further studies are required to explain the sex differences and nature of the associations.

Adolescent↗