History

Question 1

Alessandro Volta (1970’s)

Answer 1

first described sensation of a “boom within the head” followed by a sound of “thick, boiling soup” after inserting two rods connected to a 50V electrical source into his ears

Question 2

Guillaume-Benjamin- Amand Duchenne (1855)

Answer 2

French neurologist, experimented with alternating current in his ear and described sensation of “fly’s wings beating between a pane of glass and a curtain”

Question 3

Brenner (1868)

Answer 3

used bipolar stimulation (one electrode in ear canal in saline and another in different location on body) in one subject and reported on effects of polarity, rate and intensity of stimulus and placement of electrodes.

gave the idea we use today for reference electrode

Question 4

Military medical academy in Leningrad in the 1930s

Answer 4

stimulating electrodes into middle ear in patients with and without ME structures.

Pitch was no different for pts w/ or w/o ME structures ! ME was r/o as site of electrical stim

Question 5

Mechanical response of Organ of Corti vs. direct stimulation of nVIII

NOT ELECTROPHONIC HEARING

Answer 5

electrophonic hearing: electrical stim of the Organ of Corti causes mechanical response = release of NTs from HCs onto nVIII (Stevens & Jones, 1939)
◦ Tectoral membrane converts electrical signal into the acoustic resulting in tonal pitch but at double the signal frequency
◦ Direct electric activation of nVIII w/ steep loudness growth and occasional activation of nVII

Question 6

The cochlear microphonic (described by E.G. Wever and C.W. Bray, 1930)

Answer 6

electrical potentials measured primarily from OHCs in cochlear in response to stimulus closely mirrored the stimulus.

DISMISSED THE TELEPHONE EFFECT OF HEARING

Question 7

The vocoder (by Homer Dudley in 1939)

Answer 7

served as the basis for early speech processing strategies for multi-channel implants.

pull out the envelope information!!!!!

Question 8

1940-1950 large amounts of research in telephonic hearing

Answer 8

Conclusion = deafness could not be completely corrected with wide-field electrical stimulation
◦ Instead, more localized stimulation of auditory nerve fibers would be necessary

Question 9

Lundberg 1950s

Answer 9

Directly stimulated auditory nerve in patient during neurosurgery.
Used sinusoidal current and patient reported hearing only noise.

Question 10

Eyries and Djourno

Answer 10

Implant subsequently malfunctioned (twice!) and they stopped working together.
Credited with first CI. However, later investigation of patient’s anatomy raised question of site of stimulation (cochlear nerve or cochlear nucleus in brainstem?)

Question 11

January 1961

Answer 11

Dentist-turned-otologist
Patient brought in a French article about the work of
Eyries and Djourno

House had previously experimented with electrical hearing in patients during stapes surgery by placing electrodes on or near the oval window

Collaborated with Doyle brothers (a neurosurgeon and an electrical engineer) to create CI

All three attempts yielded patient perception of square-wave stimulus, but all three had to be removed secondary to biocompatibility concerns.

House stopped working with Doyles over disagreements about publicity of findings.
! Doyles continued work but lost research funding in 1968.

Question 12

F Blair Simmons

Answer 12

Stanford researcher and otolaryngologist, F. Blair Simmons, intraoperative study in an 18 y/o pt indicated bipolar stimulation of nVIII yielded auditory sensations and discrimination of different stimulus frequencies
Two years later (1964), he implanted an electrical hearing device into the modiolus of a 60-year-old man

Follow-up psychophysical testing of the patient was difficult and Simmons was pessimistic about future electrical stimulation of nVIII yielding useful speech information.

Use of electrical hearing for communication was “less than 5%” likely and Stanford put off human experimentation until animal testing could be done.

Question 13

house and urban

implant only worked when connected to the comp.

Answer 13

develop single-channel device and implant in patients.

House concerned with safety and efficacy of device.

One patient, Charles Graser, became long-term experimental subject.

From research on Graser, House and Urban abandoned idea of multiple- electrode system and instead, went for single-wire electrode.

Question 14

Nucleus multi-channel CI came out in 1985

for children two years of age and older, 1990

Answer 14

1st FDA approval

Question 15

2000

2002

Answer 15

What year did FDA lower age of CI candidacy to 12 months of age for one implant, and all CI manufacturers?