RESUMO
In the present study, a prototype 106Ru/106Rh source was fabricated using high level liquid waste from reactor fuel, fixed in a stainless steel housing with a window and backing made of silver. The study involves measurement of the operational quantities Hp(0.07), Hp(3) and the percentage depth dose (PDD) using an extrapolation chamber. It also involves determination of necessary correction factors to arrive at Hp(0.07) and Hp(3) following International Organisation for Standardisation (ISO) and methods suggested in literature. The study facilitates incorporation of the 106Ru/106Rh source as a beta reference source for quality assurance programme in TLD personnel monitoring as per the guidelines of ISO.
Assuntos
Dosimetria Fotográfica/instrumentação , Monitoramento de Radiação/métodos , Radioisótopos/análise , Ródio/análise , Radioisótopos de Rutênio/análise , Partículas beta , Dosimetria Fotográfica/métodos , Humanos , Doses de RadiaçãoRESUMO
Impedance plethysmograms were recorded from thoracic region in 254 normal subjects, 183 patients with coronary artery disease, 391 patients with valvular heart disease and 107 patients with congenital septal disorder. The data in 18 normal subjects and 55 patients showed that basal impedance decreases markedly during exercise in patients with ischaemic heart disease. Estimation of cardiac index by this technique in a group of 99 normal subjects has been observed to be more consistent than that of the stroke volume. Estimation of systolic time index from impedance plethysmograms in 34 normal subjects has been shown to be as reliable as that from electrocardiogram, phonocardiogram and carotid pulse tracing. Changes in the shape of plethysmographic waveform produced by valvular and congenital heart diseases are briefly described and the role of this technique in screening cardiac patients has been highlighted.