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Biomedical subjects

R Dwarakanath

Publications and source records attributed to R Dwarakanath.

3 recordsLinked to original sources

A circle system with a rotating wick vaporizer.

The humidity output of a circle system was raised to 28 mg H2O/l by the use of a modified rotating wick vaporizer placed in the center of the soda lime canister and coaxial inspiratory and expiratory limbs. Both the fresh gas inflow and the expired gases passed through the lime and reached a compartment below it. The bag/ventilator connector, bearing a pressure relief valve, opened on the lateral wall of that compartment. Gases returning to the inspiratory valve passed: (1) through a tube in the canister connecting the inferior compartment to the vaporizer above water level, (2) through the upper portion of the vaporizer and around the rotating wick, and (3) through a tube emerging from the top of the vaporizer to reach the inspiratory valve. Thus inspired gases were humidified by the rotating wick constantly replenishing its water content warmed by the reaction of neutralization. The use of coaxial inspiratory and expiratory limbs reduced water condensation outside the canister.

Anesthesiology↗

A percolator vaporizer heated by reaction of neutralization of lime by carbon dioxide.

To improve the humidification of anesthetic gases without use of electricity and its associated dangers the principle of the coffee percolator has been applied to a new vaporizer. Coffee percolators work by introducing steam-driven spurts of boiling water into a perforated coffee container. A water vaporizer, which functions on this principle, was used substituting the fresh gas inflow of an anesthesia machine as the driving gas. The vaporizer was placed in the center of the lime canister of a circle system with coaxial-valved respiratory limbs. The gas-water mixture percolated through a multiple wire mesh gauze filter that prevented the introduction of water droplets into respiratory channels. All gases emerging from the bottom of the canister and reaching the inspiratory valve passed through the vaporizer above water level. The circuit delivered gases containing 4 to 9 mg of H2O/L above saturated values at ambient temperature (20.5 mg of H2O/L) within 15 minutes, if the fresh gas inflow was set at 2.5 L/min.

Anesthesiology↗