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Biomedical subjects

G G Gardner

Publications and source records attributed to G G Gardner.

At least 19 recordsLinked to original sources
PubMed1996

Automatic detection of diabetic retinopathy using an artificial neural network: a screening tool.

AIMS: To determine if neural networks can detect diabetic features in fundus images and compare the network against an ophthalmologist screening a set of fundus images. METHODS: 147 diabetic and 32 normal images were captured from a fundus camera, stored on computer, and analysed using a back propagation neural network. The network was trained to recognise features in the retinal image. The effects of digital filtering techniques and different network variables were assessed. 200 diabetic and 101 normal images were then randomised and used to evaluate the network's performance for the detection of diabetic retinopathy against an ophthalmologist. RESULTS: Detection rates for the recognition of vessels, exudates, and haemorrhages were 91.7%, 93.1%, and 73.8% respectively. When compared with the results of the ophthalmologist, the network achieved a sensitivity of 88.4% and a specificity of 83.5% for the detection of diabetic retinopathy. CONCLUSIONS: Detection of vessels, exudates, and haemorrhages was possible, with success rates dependent upon preprocessing and the number of images used in training. When compared with the ophthalmologist, the network achieved good accuracy for the detection of diabetic retinopathy. The system could be used as an aid to the screening of diabetic patients for retinopathy.

Diabetic Retinopathy↗
PubMed1994

The mathematical modelling of thermal responses of normal subjects and burned patients.

A model of the human thermoregulatory system has been developed for normal subjects and burned patients treated in the intensive care room at Aberdeen Royal Infirmary. The human body is split into eleven segments, each having core, muscle, fat and skin layers. Heat transport through blood flow and conduction are simulated, and surface heat loss is separated into radiative, convective and evaporative components. Measurement of skin temperature and evaporation of moisture have been made from all sections of the body for 22 normal subjects over a range of environmental temperatures from 20 degrees C to 40 degrees C. The model has been refined to fit the data through manipulation of heat flow commands and temperature set points controlling sweating and shivering. The model has been adapted to describe the responses of burn patients by the introduction of skin layer destruction, increased body metabolism and fluid loss from wounds. Predictions have been compared with measurements made on six patients. The model shows that the ambient temperature at which sweating occurs increases with the area of burn injury, which is confirmed by clinical observations. It has been used to predict optimum environmental temperatures for treatment of patients with burn wounds of varying extent.

Adult↗
PubMed1992

Infrared emissivity of burn wounds.

Emissivities of burn wounds and tissue samples have been measured in the wavelength range 8-14 microns using a non-contact method. Emissivities of wound tissues studied were in the range 0.976-0.992, greater than those of intact skin by 0.01-0.03. This will result in underestimates of the difference in temperature between wounds and normal skin of 0.1-0.2 degrees C.

Burns↗
PubMed1978

Hypnotherapy in the management of childhood habit disorders.

Hypnotherapy may sometimes be helpful in treating childhood habit disorders, provided that it is used with the same caution as are other treatment modalities. This paper clarifies some common misconceptions about hypnosis with children, notes indications and contraindications, describes a patient in whom hypnotherapy was used to treat hair pulling, and offers information about training in hypnosis and locating qualified hypnotherapists.

Child↗
PubMed1978

Some guidelines for uses of hypnotherapy in pediatrics.

Hypnotherapy has many uses in pediatrics, and its value, not only as a adjunct but also as a primary therapy for certain conditions, justifies its inclusion in pediatric training programs. Suggestion and expectation have long been related to therapeutic outcomes in medicine, but not all physicians know how to apply them constructively and systematically in communication with patients. In pediatrics there is a tendency to overlook opportunities in which hypnosis might be the treatment of choice. Because children engage in imagination and fantasy easily without the cognitive inhibitions of adults, they are able to use hypnosis more readily than adults. More research into the imaginative skills of children may facilitate understanding of learning mechanisms and make it possible for professionals to prevent the loss of the natural imaginative capacities in children and, therefore, enhance the ability of mature members of society to use these skills. In addition to reduction of specific symptoms through hypnotherapy, children benefit by the sense of mastery which they acquire, a sense which is surely needed to overcome the feelings of hopelessness, loss of control, and depression induced by many diagnostic and therapeutic procedures in medicine.

Adolescent↗
PubMed1977

Psychological issues in bone marrow transplantation.

We studied the psychological and emotional problems experienced by seven children and their families who underwent bone marrow transplantation at the University of Colorado Medical Center from 1973 to 1975. These problems included (1) anxiety and depression relating to isolation, fear of death, and painful procedures; (2) an overdependence associated with a feeling of helplessness; (3) anger directed toward both the staff and the parents; (4) a reduced tolerance for medical procedures; and (5) periodic refusal to cooperate. Initially we had been concerned that patients might become agitated, psychotic, or even suicidal. These did not occur. Severe anxiety over bodily changes was not a problem. We did not encounter prolonged refusal to cooperate, refusal to remain in isolation, or drug addiction. Important aspects in management included an honest, straightforward, and direct discussion of all aspects of transplantation, including the potential complications and the risks of death from the underlying disease or from complications of transplantation. A firm but understanding approach to the patients appeared to be the most effective method to develop their continuing cooperation. The opportunity for patients to express verbally their fears of procedures and of death was essential. The donors needed help in working through their feelings of guilt if a transplant was not successful. The parents needed continuing psychological support for the many personal, social, and psychological difficulties which they had to face.

Adolescent↗