Charge Density
The amount of electrical charge delivered per unit area of electrode surface, a critical safety parameter in neurostimulation.
Full Definition
Charge density represents the electrical charge delivered per unit area of electrode surface, typically expressed in microcoulombs per square centimeter (μC/cm²). This parameter is fundamental to neurostimulation safety as excessive charge density can cause tissue damage, electrode corrosion, and toxic electrochemical reactions. Safe charge density limits vary based on electrode materials, with platinum electrodes generally considered safe below 30 μC/cm² per phase for chronic stimulation. Charge density is calculated by multiplying current amplitude by pulse width and dividing by the geometric surface area of the active electrode contact. Modern neurostimulation devices incorporate charge density monitoring and limiting algorithms to prevent unsafe stimulation parameters.
Usage
Usage note: Always specify units (μC/cm²) and distinguish from total charge per pulse.
In Context
- "The programming software displayed a warning when charge density exceeded the recommended safety threshold." — Device programming session
- "Electrode design considerations include optimizing surface area to maintain safe charge density limits." — Engineering specification