Power Source/Battery
•PPM:
lithium (anode)
iodine (cathode)
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•ICD:
all anodes: lithium
cathodes: silver, vanadium-oxide (SVO), carbon monofluride (CFx), SVO and CFx hybrid or manganese dioxide (MnO2)
Circuitry
•Sensing circuit
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•Output circuit
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•Timing circuit
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•Microprocessor capabilities
•ROM (read only memory): operates sensing & output functions of device
•RAM (random access memory): used in diagnostic functions
Header
•See history of CIEDs: header types for further info
Zenor Diodes
•protects circuity from high external voltages by shunting excess voltage back through the leads to the myocardium
Capacitor
stores charged energy for ICDs
•Oxide layer formed on inside of anode surface
•This layer can degrade through chemical & physical processes overtime, resulting in capacitor deformation, heating & even explosion
•Capacitor reformation performed to avoid deformation