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Biomedical subjects

H O'Neill

Publications and source records attributed to H O'Neill.

28 records · Page 2Linked to original sources
PubMed1985

Skin blood flow changes and tissue deformations produced by cylindrical indentors.

Since skin blood flow as a function of applied pressure depends on many factors, one may find different curves within each group of subjects, making separation of groups difficult. A dimensional analysis has been out which indicates that the percent decrease in skin blood flow associated with external loading is primarily a function of only three variables: the ratios of bone depth and bone diameter to indentor diameter, and percent compression of the tissue overlying the bone. The load itself is found to be unimportant. It is concluded that measurement of bone depth, bone diameter, and tissue deformation are more important than pressure measurements. Measurements of skin displacement and average indentor pressure for four male subjects indicate that tissue stiffness increases with age, regardless of disability, so that higher pressures are required to produce the same displacement in older subjects.

Adult↗
PubMed1984

Development and evaluation of a universal contoured cushion.

A new wheelchair seat cushion has been developed which reduces the ischaemia producing forces and redistributes them to the more tolerant areas of the posterior thighs and lateral gluteal muscles. The cushion is fabricated of foam materials and designed to stabilise the pelvis and promote proper spinal-pelvic alignment. Pressure measurements were recorded at the skin cushion interface for 66 subjects while seated on the cushion in their own wheelchair. The cushion was considered effective if maximum interface pressures recorded were: coccyx: less than 20 mmHg, ischii: less than 65 mmHg, trochanters: less than 70 mmHg, and posterior thighs: less than 80 mmHg. The cushion was considered ineffective if the interface pressure at any one location exceeded these criteria. The cushion was found effective for 52 of the subjects. The cushion was more effective (90 per cent versus 58 per cent) for subjects without certain skeletal deformities (pelvic obliquity, bony resections). Eighty-three per cent of the respondents who were followed on the cushion reported that they preferred the cushion to their previous cushions with improved posture, balance and comfort being the most commonly cited reasons. This study has shown the cushion to be a preferred alternative to other commercially available wheelchair cushions for those who are paraplegic.

Adult↗
PubMed1983

Aetiology of chronic constrictive pericarditis.

In a consecutive series of 32 cases of chronic constrictive pericarditis treated by pericardiectomy during the past 25 years, four were attributable to rheumatoid disease, two to trauma, one to sarcoidosis, and four, at a maximum, to tuberculosis. In the remaining 21 cases of undetermined aetiology there was no evidence of tuberculosis. It appears, therefore, that tuberculosis was not a common cause of chronic constrictive pericarditis during the period under review, which included the 1950s and early 1960s when tuberculosis was widespread.

Adolescent↗
PubMed1982

Problems in the management of patients with artificial valves during pregnancy.

During the past 15 years, 12 patients with prosthetic valves were treated during 18 pregnancies in the four Dublin maternity hospitals. These patients were on long-term anticoagulants and their pregnancies were reviewed to assess the problems associated with anticoagulation. One baby had warfarin embryopathy, six pregnancies ended in spontaneous abortions and there were two intrauterine deaths. On the basis of the findings a policy on the most appropriate anticoagulant regimen in such cases was formulated.

Abortion, Spontaneous↗
PubMed1982

Haemodynamic effects of pregnancy in patients with heart failure.

Four patients, who were maintained on a constant regimen of treatment, developed congestive cardiac failure during pregnancy. They were examined regularly and carefully during the course of pregnancy to assess the progress of their failure. All four demonstrated unequivocal improvement during the third trimester attributable to obstruction of the inferior vena cava restricting venous return to the right side of the heart. This resulted in a fall in venous pressure in the neck and the resulting fall in right ventricular output could be very valuable in patients with left ventricular failure.

Cardiac Output↗