A team of UK scientists has developed a resistor based on a ruthenium oxide/glass system for use in portable devices for the treatment of heart attacks, it has been reported.

Research scientists from Northampton-based Welwyn Components have developed a new high-voltage planar resistor for use in automated external defribrillators (AEDs), which will enable emergency services to administer an electric charge in defribrillation treatment in field situations.

As a result, delays to treatment of victims of cardiac arrest will be significantly reduced, leaving them with a better chance of survival.

Crucial to the success of the technology was that the resistor needed to allow the user to control the charge administered to the patient and that the charge is stable and repeatable.

Meanwhile, just as critical is that it is durable under voltage stress and outdoor environments and has excellent linearity, expressed by voltage coefficient.

However, according to a report in Engineer Live, Welwyn's team managed to develop a resistor fulfilling these criteria by utilising a printed thick-film resistor ink, based on a ruthenium oxide/glass system, which is itself then encapsulated with high-density epoxy - providing for improved environmental performance compared with protection offered by a traditional porous conformal coat.

Sources:

High voltage resistor used in defibrillator charge control circuit, 03/07/07
http://www.engineerlive.com/european-electronics-engineer/components-and-sub-assemblies/18094/high-voltage-resistor-used-in-defibrillator-charge-control-circuit.thtml

Resistors For Medical Applications
http://www.welwyn-tt.com/pdf/application_notes/Medical.pdf


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