Electrodes Flashcards
Describe the electrode evolution.
Spiral Electrode (1990-1997)
Spiral Electrode with Positioning System (1998-1999/2000)
HiFocus Electrode with Positioning (1999-2000)
HiFocus Electrode (present)
How do previous electrode designs differ?
Wiring of electrode contacts
Location and shape of the contacts
Curvature of the elctrode carrier.
How are electrodes stimulated?
Stimulated in pairs with one active and one ground electrode.
How can electrodes be coupled?
Monopolar (what AB uses)-stimulating/active electrode is intracochlear and the ground electrode is extracochlear
**Allows the ability to recruit more nerve fibers to obtain adequate loudness levels with less current.
Bipolar-both stimulating/active electrode and ground electrode are intracochlear. This can allow more accurate stimulation and recruits fewer nerve fibers, which requres more current to obtain adequate loudness levels. *Power hungry
What was the most recently released HiFocus Electrode?
Mid Scala
What is unique about the HiFocus MidScala Electrode?
Designed for MidScala placement
Designed to be inserted with minimal trauma to the delicate structures of the cochlea
Smaller Pre-curved electrode
Designed for hearing preservation…but we can’t say that per FDA
In what year did AB initiate a voluntary recall after observing a small number of failed devices due to moisture?
September 2004
What did AB do after voluntary recall 2004 to improve manufacturing process?
Bake test and helium test
Describe the Vendor B feedthru issue.
In 2006, after manufacturing processes had been improved, a high number of ex planted devices showed moisture ingress. After investigation vendor b was found to be the source of a bad feedthru. The glass insulator used was too porous and over time found to corrode and leak body fluid in to the casing.
What year did AB stop using Vendor b?
- All vendor b devices were recalled and pulled off the shelves.
What is the 7 year CSR?
98.31
