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Biomedical subjects

S R Topaz

Publications and source records attributed to S R Topaz.

21 records · Page 2Linked to original sources
PubMedDate not supplied

Molded double lumen silicone skin button for drivelines to an artificial heart.

A one-piece transfer molded double skin button allows two drivelines to pass through the skin and reduces the penetration area by 44%. The use of elastomer HP-100 (Dow Corning) without a reinforcing mesh allows some additional features not possible with hand lay-up techniques. These include "S" curved passages for the lines, double sealing rings within the passages, a sleeve, and a flange, all as one piece of silicone. The sealing rings prevent the leakage of air, create a pocket for a glue seal, and anchor the air line. The sleeve prevents the air lines from putting necrosis-causing pressure on the skin. The flange keeps the button from being pulled out, is covered with Dacron velour, and is a barrier against infection. The shape of the device allows the air lines to be tunneled under the skin and exited parallel to the skin.

Catheters, Indwelling↗
PubMedDate not supplied

The development of a valveless cardiac assist device attached to the ventricular apex.

Konstantinov et al, in October, 1991, published a novel way to bridge a patient for heart transplantation. They proposed to cut off both ventricles high under the atrioventricular groove, leaving the atria, aorta, and pulmonary artery and their valves intact and to attach pneumatically driven, valveless pulsating pouches to assist the heart until a donor could be found. The removal of the ventricles just below the atrioventricular groove is called the "high cut"; it, however, destroys the chordae tendineae rendering the mitral and tricuspid valves insufficient. These have to be replaced by tissue inflow valves. We chose to cut off the ventricles at a lower level (the "low cut") to leave the papillary muscles on both sides intact, thereby saving the integrity of the mitral and tricuspid valves. Pulsating pouches were made to fit the heart at this lower level. They can be easily connected to the remaining heart after a specially disigned cuff has been sutured over the ventricular stumps. The pouches were pumped during the systole of the natural heart, but the myocardium may have to be electrically stimulated during systole to prevent undue distension. If the turgor is too weak to prevent distension, a sleeve over the ventricles is provided. To find the best location for these pouches, human cadaver implantations were done and the pre peritoneal cavity was found to be the most suitable. In vitro testing to determine how much flow could be pumped was done by attaching the pouches to fresh pig hearts and connecting them to a double sided mock circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗