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Biomedical subjects

N R Silverman

Publications and source records attributed to N R Silverman.

At least 19 recordsLinked to original sources
PubMed1977

Differences in the velocity-displacement relationship of systolic contraction of normal and ischemic canine myocardium.

In the canine model there exist major differences in the velocity-displacement relationships of systolic contraction between normal and ischemic myocardium. These differences are noninvasively measurable in vivo from video recordings of the fluoroscopic image of the heart, and can be detected within the time period of one cardiac cycle. Velocity data is plotted against the corresponding wall displacement on orthogonal axes (phase-space), producing characteristic loops which give an immediate visual indication of myocardial dysfunction.

Animals↗
PubMed1976

Pulmonary videodensitometry in the diagnosis of carcinoma of the lung.

Pulmonary videodensitometry permits the detection of vascular pulsations of the lung caused by the incremental blood flow to the lung associated with systole. These pulsations may be diminished or absent in a segment of the lung affected by carcinoma. Of 46 patients evaluated, 12 had carcinoma. The technique is discussed and representative amplitude changes are demonstrated. This technique should prove useful in the detection of processes which alter the pulmonary vascular pulsations.

Absorptiometry, Photon↗
PubMed1975

Localised aneurysms of the descending thoracic aorta.

The clinical, roentgenographic and aortographic data were reviewed in 12 patients with localised descending, thoracic aortic aneurysms. The current study indicates that arteriosclerotic peripheral vascular disease not infrequently produced localised saccular aneurysms of the descending thoracic aorta. Characteristic symptomatology was unusual; most aneurysms were detected as incidental roentgenographic findings. The aneurysms projected from the posteroloteral aspect of the aorta and roentgenographically appeared as left hilar masses or left retrocardiac masses when located in the mid and lower descending thoracic aorta, respectively. Specific rim calcification or vertebral erosion was not encountered in any case. During aortography only a small portion of the aneurysm was outlined with contrast material due to partial obliteration of the aneurysmal cavity with thrombus.

Adult↗
PubMed1975

Evaluation of a videodensitometric method for monitoring the left ventricular contractile state.

Videodensitometry of the margins of the fluoroscopic image of the left ventricle (LV) was used to evaluate LV wall motion. Differentiation of the wall motion signal reflected the velocity of LV contraction (dv/dt) during various inotropic interventions in 6 anesthetized dogs. Alterations in dv/dt were similar to changes in simultaneously measured LV peak dP/dt and the quotient of dP/dt and developed LV pressure, two widely accepted parameters of LV contractile state.

Analog-Digital Conversion↗