Programming and Coding Flashcards

1
Q

Telemetry

A

Confirms proper communication between the processor and the electrodes
AB and Cochlear:”impedance”
Medel: “telemetry”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Neural response assessment

A

Electrophysiology response from nerve in response to electrode stim

Useful for pediatrics who can’t give subjective measurements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T levels

A

Measures threshold for sound on each electrode (only cochlear devices)

Measures the lowest amount of electricity needed to be perceived as sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

C or M levels

A

Comfort levels measured using a scale

-Upper loudness levels.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Speech strategies

A

Different methods of stimulation that can produce diff perceptions from the patient

  • sequential
  • simultaneous
  • both
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Connecting equipment

A

You’ll need:

  • computerized processing unit/ interface (cpu/cui); the “pod” that allows the computer to communicate with the processor
  • implant
  • processor
  • the patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Prepare equipment: AB

A
  1. Verify connection of components: coil to cable to processor
  2. Initialize processor
    - which ear, modality of use (bilateral, unilateral, bimodal)
    - do this when loading/reassigning a processor
  3. Condition electrode array
    Stimulate all channels at the same time
    Gets rid of buildup around array
    Perform this at activation, 1wk follow-up, returning on channel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Prepare equipment: Cochlear and medel

A
  1. Verify connection of components: coil to cable to processor
  2. Reset processor as needed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Impedance

A

Stimulus parameters: current, voltage, stim. Width

Material of electrode surface: (an inverse relationship) narrower contact, more impedance

Nature of the medium of transmission is specific to each electrode: air vs tissue

Measures the opposition to electrical, current flow
Impedance (kiloOhms)=voltage/current

Voltage= impedance x current
When current is cons at increase in impedance will increase voltage

More resistance to flow = higher impedance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Deactivated electrodes

A

Short electrodes (-<1kOhmn)

  • wires touching and likely to send stim across channels
  • always in pairs
  • turn off and leave off forever

Abnormally high impedance (>30kOhmn)

  • broken wire
  • air bubble; current can’t travel through air—> remeasure post stimulation
  • may decrease with use or by increasing the pulse width
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

NRT

A

Neural Response Telemetry
-Cochlear specific
-use of the electrically evoked compound action potential
—gross potential that reflects synchronous firing of a large # of electrically stimulate n8 fibers
—-reflective of wave I of acoustic ABR and comfort levels or upper dynamic range

AB: Neural response imaging (NRI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Auto NRT

A

Cochlear Specific
Steps:
1. Select # of channels to run (3, 5,9) a low, mid and high. Running all will take a long time

  1. Click measure
  2. Watch measurements and pt reaction
  3. Prepare to skip channels if pt. Reports discomfort
  4. Software will move on to next channel if stimulation reaches compliance w/o achieving a response

Auditory neuropathy won’t have NRT
No need to measure later because they should be stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Terminology

A

Programming/mapping: Measuring thresholds, tolerance levels, assessing implant status

MAPs: configurations of current units (CU); processing strategies; stimulation rate

Programs: configurations of MAPs; similar of hearing aid programs;use of different programs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Flex NRI

A

AB specific
NRI= Neural Response Imaging
1. Select channels to stimulate on (avoid most basal @ activation- build up)
2. Recording channel is 2 apical from stim
3. Select level of ordering
–low to high (awake pt.)
–high to low (sedated/surgery in OR)
4. Set min and max stim levels (100-250 uV)
-look for 3 repations of response per channel
5. Crates EP Growth FUnction (best regression line)
6. tNRI corresponds to M levels (not as nicelys to C levels for Cochlear)

NRI/NRT not in MedEl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Clinical Utility of NRT/NRI

A
  • Stable over time
  • Used w/ impedances to see if change in performance is due to device function or neural responsiveness; Pt not doing well and impedances are weird, recheck this and if abnormal, may indicate a soft failure.
  • Measure w/in first few months of stim (baseline)–> annually/bi-annually afterwords
  • loosely correlates with Ms/Cs as a guide to max comfort levels
  • Can assess pitch at activations “same vs diffierent” or high vs low
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Terminology per company

A

Cochlear:
Ts and Cs are required
AB/MedEL: Ts are optiona (will be interpolated from Ms) l and Ms are required

SF thresholds per compant
Cochlear: 20-25 (slight)
AB/M: 30-35 (mild)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Challenges of NRT/NRI

A

Highly influenced by

  • neural survival and synchronous activity
  • nerve survival re: measuring electrode

To reduce noise

  • remove contra CI
  • Increase high level and # of averages (AB)
  • decrease sample per data point
18
Q

ESRT

A

-electrically evoked spatial reflex thresholds

-Electrical stimulation to implant
Measure SRT in nonimplanted ear
—immittance bridge or in OR w/ bridge
-ESRT occurs at or near max levels used by processor
-Not recorded in 25-35% of patients **
-Pt.s participate to a degree

19
Q

How to perform ESRT

A
  1. Place probe in contralateral ear
  2. continuously record acoustic admittance w/ 226 Hz probe tone within Decay screen
  3. Present programming stim used for upper limit of DR (C/M level)
  4. Change in admittance occurs time locked with stimulus when presentation level is the ideal intsenity for the upper limit of the DR

Medel is the only one with ESRT screen

Must consider hx. of middle ear disorder

20
Q

Stimulation Mode

A

location of the reference electrode re: active electrode

Monopolar (ground is outside of the cochlea)
Bipolar (stim occurs w/in cochlea)

Cochlear and AB: either
Medel: monopoglar only

21
Q

DR

A
For speech (single)- 30 dB
multiple speakers >60 dB

NH: 100 dB
CI: 3-20 dB

distance between Ts and C

Input DR (IDR): CI select the range of intensities o output to code

22
Q

Threshold trouble shooting

A

T’s are too loud
-person hears motor noise of processor. Turn mics off and no longer hear, turn T’s down

Child w/ 5 dB to NBN: adjust T levels
Bring Ts up for better thresholds and lower Ts for poorer thresholds

23
Q

Threshold

A

Cochlear Nucleus: ser at a level at or just above threshold
“just barely detecting

Medel CIS: highest stim where no sound is perceived

T tail: audible over a given range–> set at upper limit of their range.

24
Q

T levels in Ped

A

May use with objective offset programming method

At least one behavioral and at least one electrode measurement
–Behaviorally: VRA (booth, puppets)
CPA

25
Q

Comfort levels/Most comfortable levels

A

Upper limit of DR
Cochlear (Cs): set below max. comfort (right below UCL) due to summation across electrode

Medel: highest stim level at which sound is loud, but comfortable

AB: most comfortable level-daily listening level. Speech burst are used for setting M-levels (groups of 4 using broadband stim)

26
Q

C/M level measurements

A

ascending technique
-switching from older map: decrease globally by 10 cus and then ascend.

-steep loudness growth in some
loundness charts are helpful

27
Q

Influences on levels

A

Speech processing strategy
Bipolar vs monopolar
stim rate (increase in rate, level decreases)
Proximity of electrode array to modiolus (further= more current level, modiolus hugging (lower level)

28
Q

Loudness balancing

A

Ensure equal loudness on all electrodes

  • Two methods
  • -balancing (low to high)
  • -sweeping (pulse on each channel)
29
Q

Compliance levels

A
  • amount of voltage allowed for each electrode
  • “out of compliance” = max voltage available from implant is not sufficient to generate the desired current level
  • going to sound soft.
  • -cant increase stim units.
    solution: increase the pulse width.
30
Q

Consequences of being out of compliance

A

-Insufficent loudness growth, variable loudness, lack and loudness growth
distorted sound
poor battery life
decreased performance

31
Q

Power optimization

A
  • can better type provide enough voltage to deliver the requested amount of current
  • as required voltage increases, battery life decreases
  • ->pot. solution: decrease pulse rate
  • want to use automatic power as much as possible.

This is measured when the coil is on the pt.’s head

Calculated for each map by determining how much power is needed in the worst case condition to ensure all electrodes
are w/in compliance

32
Q

Live voice modifications

A
Tilting
Increase/decrease levels on all channels
-echoy/boomy= upper limits, bring down C/Ms
-low level humming= Ts (bring them down)
Gain- too loud, bring down on the processor programming
Freq. adjustments
-Tinny-HF
-Hallow -MF
-boomy-LF
33
Q

Noise reduction

A

AGC autosensitivity
Adaptive DR Organization (ADRO)- gain adjsutmet at each freq. band
BEAM- multi mic
-cochlear and AB

34
Q

Patient conrtols

A

Programs
Volume (Cs/Ms)
Sensitivity (distance of hearing and perception in noise)

35
Q

Processing strategey

A

set of rules to convert acoustic input into electrical output

sequential or paired
Captures following parameters of sound
-Time (well)
-Intensity
-Spectral (poorly)
36
Q

Temporal domain

A

-temporal envelope is important (and is perceived), but so is fine structure.

37
Q

Intensity domanin

A
  • directional mics
  • mic placement (hear level, head piece, t mic)
  • automatic gain control (AGC)
  • input DR compression –> takes IDR and puts into electrical DR
38
Q

Spectral domain

A

NH: 20-20, 000 Hz
CI: ~250-8000 (AB and M =60dB at 250)
-not much resolution needed for speech as with music. Music of diff, but close freq will be passed through the same filter (perceived as the same sound)

39
Q

Processing strategies

A
  • Continuous interleaved sampling (CIS) -simplest
  • HiResolution AB
  • Advanced combination encoder (ACE) Cochlear
  • Spectral peak (SPEAK)
  • Fine structure processing (FSP) Medel
40
Q

Continuous interleaved sampling

A

sequential
slowest (1000 stim rate)
simpliest - 8 channels
bandpass filters

AB’s version= Multiple pulsatile sampler (MPS) double the stim rate, increases the “temporal” resolution

Medel uses CIS+ and HDCIS- wider freq range and use of virtual channels for improved “spectral” resolution.