Search PubMed⌕ Search

Biomedical subjects

R Schmukler

Publications and source records attributed to R Schmukler.

4 recordsLinked to original sources

A brief history of bioelectrodes.

The history of bioelectrodes is intimately associated with electrochemistry in general, through studies on electrode polarization. Electrode polarization was first recognized and studied in the early 1800s, and scientific studies in this area have continued since that time. Experimental and theoretical work on bioelectrodes, electrode polarization, and relevant electrochemistry of electrode phenomena, is traced from 1826 to Schwan's recent electrode work.

Electrochemistry↗

Biocompatibility considerations at stimulating electrode interfaces.

The choice of biocompatible stimulating electrodes for various biomedical applications varies with the type of electrode-tissue interface, biomolecules present, electrolyte background, preparation of electrode, interfacial potential, current density, electrode material, porosity, geometry, and inflammatory response. Illustrative examples are given to demonstrate the importance of these parameters. Topics discussed are: A) DC electrodes applied to partially keratinized epithelial membranes; B) Variation of the electrical impedance and biocompatibility of stimulating electrodes with electrode potential and surrounding pH; C) Influence of electrode geometry, porosity and pore size on biocompatibility; D) Body defense mechanisms at the sites of implantable stimulating electrodes; E) Thrombus formation at stimulating electrode interfaces and F) Sterilization of electrodes to ensure biocompatibility.

Animals↗

Rapid deoxygenation of red cells and hemoglobin solution using hollow capillary fibers.

A newly designed capillary deoxygenator has been constructed by using microporous polypropylene hollow fibers sealed into an airtight plexiglass housing. Oxygenated red cell suspensions and hemoglobin solutions flowing through the hollow fibers were subjected to deoxygenation with a gas mixture composed of 95 percent N2 and 5 percent CO2 passed through the housing. At a given flow rate of the oxygenated fluid, the outgoing fluid pO2 varied directly with hematocrit and inversely with the residence time. With a deoxygenator composed of 144 parallel 100-micrometers fibers with an active length of 10 cm, 2 ml of blood at 10 percent hematocrit can be converted from arterial to venous pO2 in approximately 1 min. The design of this deoxygenator provides a method for rapid deoxygenation of blood without red cell membrane damage or hemolysis.

Blood Gas Analysis↗

Effects of anticoagulants on packed cell volume measurement.

A comparison was made of different types of anticoagulants on packed cell volume determinations of canine, feline, rabbit, and human blood. It was found that the use of excessive amounts of anticoagulant alters the packed cell volume when measured by the standard centrifuge method. It was also found that the results vary significantly when different anticoagulants are used. The effects are not seen when the packed cell volume is indirectly measured using an electronic cell counter. A balanced combination of ethylenediaminetetraacetic acid salts ameliorates the concentration-dependent effects.

Animals↗