Week 9 Activation and Programming Flashcards
what all is included in the post-op physical exam
- imaging
- –pre- CT and MRI
- –post= x-ray
- activation day and every appointment after:
- –otoscopy (MEE is common up to 3-6 weeks post-op)
- –incision
- –coil placement
how to select a magnet
- want to make sure it is not too weak or too strong
- children, women, and elderly have a mostly thin skin flap
- middle aged men and obese patients have a mostly thin skin flap
- dont fall for parent request because they would ask for a strong magnet for their active child–you are the expert
- make sure it is the right strength because if it falls off with pt movement it is too weak but if it snaps on when being held 1/2 inch away it is too strong
what are the 4 main steps to programming
1) impedance measures
- –deactivate any abnormal electrodes
2) select a coding strategy
3) measure stimulation levels: threshold and USL
4) adjust parameters
how to select a coding strategy
- generally use the manufacturers recommended (ACE, HiRes Optima, FS4)
- –for adults base it off of trials meaning start with recommended strategy and then if the pt has poor benefit try another strategy and see if it helps
- –for children again start with manufacturer default and then if not improving try to address the issues and can change strategy to so this
review of each manufacturers threshold basic
- Med-El (THR): highest level not heard 100% of time–generally estimate
- Cochlear (T-Level): lowest level heard 100% of time–measure
- AB(T-Level):lowest level heard 50% of the time–estimate
- —–with kids it can go good to measure threshold across manufacturers
review of each manufacturers USL basic
- Mel-EL (MCL): loud but not uncomfortable
- Cochlear (C-level): loud but comfortable
- AB (M-level): most comfortable
Ways to measure CI threshold in adults
- do as you would audiometric threshold
- begin with apical electrodes because normally easier for the pt to perceive
- procedures:
- –ascending-descending
- –count the beeps while altering the # of beeps
- –psychophysical scale
- –estimation
- could use ling sounds ans see it the patient could detect them
what happens if the threshold for the CI is set too low
T-levels set too low leads to pt having issues with soft levels and general processing of speech signals because a lot of it will end up outside of the electrode range you are trying to stimulate
(below their actual threshold)
what happens if the threshold for the CI is set too high
T-levels too high leads to pt not having access to soft level sounds
what is a t-tail
- a problem that is only identified when using a psychophysical scale
- –you keep increasing the level but the pt does not notice a change in loudness level
- —–eventually it will seem louder to them
- —–poses a problem because the pt ends up with a wide electrodynamic range ad then levels will overall be too soft and the pt will have problems with speech sounds
- in cases of t-tail, want to set up the threshold right at the point the loudness perception starts increasing
ways to measure CI threshold in children
- BOA: breathing, sucking (typically supra-threshold)
- VRA around 6 months
- conditioned play audiometry ages 2+
- activities during the session
- step size would want to be bigger to be quicker and use electrode hopping meaning one apex one basal and middle and s on so even if testing stops you have info from the full range
- within a month post activation: aided soundfield want 30 dB in FL, 25 dB in middle, and 25 dB in high freqs
- can use estimation however large EDR or limited responses to soft sounds means we should measure
- –actually with kids its recommended to measure threshold
measuring USL in adults
- it is important to not over or under estimate the USL
- procedures:
- –loudness scaling chart
- –global adjustment using live speech and balancing
- –ESRT
- —–measured in up to 85%
- —–0.79 to 0.85 correlation between objective and behavioral USL
- —–performance= actually give better maps than the chart measured USL
what happens if you overestimate the USL
painful sounds for the pt or discomfort
what happens if you underestimate the USL
narrow the dynamic range leading to distortion because of more “compression” of the speech into smaller range
- EDR on average is:
- –cochlear= 40-50 CL
- –AB= M-level between 150-250 CU
- –med-el= MCL 10-25 CU
- —–really dont want to go over these set values for the USL
measuring the USL in children
- procedures:
- –ESRT is generally the best because it does not rely on behavioral responses
- —–set USL within 10% below the response
- –loudness scaling chart for kids 8+
- —–there are simpler charts for kids ages 4+
- –observation in younger kids (increase level and see when child starts blinking)
- –live speech
- be careful because over stimulation will make them not want to wear the CI
balancing of CI
- 80-90% of the DR
- –do the apical electrode first
- –should be done at one week post-activation
- –starting at 7 yrs old, dont do younger children
- –absent ESRT means super important to do because ESRT normally creates a more balanced map than behavioral
- –procedure: ask pt how the perceive loudness of electrode 1 and 2 then move to 2 and 3
- —–always adjust the 2nd electrode so by time you get to the base all electrodes are compared to the apical one
