To investigate the reproducibility of computed tomography (CT) imaging quality in respiratory-gated radiation treatment planning is essential in radiotherapy of movable tumors. Seven series of regular and six series of irregular respiratory motions were performed using a thorax dynamic phantom. For the regular respiratory motions, the respiratory cycle was changed from 2.5 to 4 s and the amplit...

PURPOSE To develop a three-dimensional (3-D) volumetric registration algorithm to estimate the intra-fractional lung tumor motion between respiratory phases for improving the accuracy of radiotherapy treatment. METHODS The 3-D thoracic CT volumes (512×512×160 voxels, with dimensions 0.97×0.97×2.5 mm3 ) in different respiratory phases were acquired on a General Electric Optima T580 scanner in ...

In order to characterize the variability and correlation properties of spontaneous breathing in humans, the breathing pattern of 16 seated healthy subjects was studied during 40 min of quiet breathing using opto-electronic plethysmography, a contactless technology that measures total and compartmental chest wall volumes without interfering with the subjects breathing. From these signals, tidal ...

OBJECTIVE The pathophysiology of shrinking lung syndrome (SLS) is poorly understood. We sought to define the structural basis for this condition through the study of pulmonary mechanics in affected patients. METHODS Since 2007, most patients evaluated for SLS at our institutions have undergone standardized respiratory testing including esophageal manometry. We analyzed these studies to define...

Helium pulsed balloons are integral components of several cardiovascular devices, including intraaortic balloon pumps (IABP) and a novel intravenous respiratory support catheter. Effective use of these devices clinically requires full inflation and deflation of the balloon, and improper operating conditions that lead to balloon under-inflation can potentially reduce respiratory or cardiac suppo...

The gas delivery characteristics during simulated spontaneous ventilation of a non-rebreathing adaptation of the Bain circuit were examined. Tidal volumes were varied from 200 to 600 ml and respiratory rate from 8 to 20 breaths per minute obtaining characteristics for a minute volume range from 2.4 to 12 litres/minute. The minimum inspired oxygen concentration with 1 litre/minute 100% oxygen fr...

In this issue of RESPIRATORY CARE, a report by Borg and Thompson1 examines an aspect of the measurement of static lung volumes according to recommendations in the 2005 American Thoracic Society (ATS)/European Respiratory Society (ERS) Standardisation of Lung Function Testing.2-6 The procedure for measuring absolute lung volumes begins with establishing functional residual capacity, followed by ...

In the last few years a tremendous amount of study has been directed toward the etiology and pathogenesis of respiratory disease. Quantitative studies of respiratory infection by t.he cloud chamber method require that the respiratory volume of test. animals be known in order to calcu late the dose of agent used. Because data in the literature on respiratory volume of laboratory animals are very...