Week 1 History of CI Flashcards
1
Q
Andre Djourno
A
(1904-1996)
- French physiologist
- interested in neuroprosthesis and transcutaneous stimulation (across skin)
- –used induction coils to stimulate the rabbit’s sciatic nerve
- –best signal for muscle contraction=400-500 Hz within speech range
- —-high freq failed to create contraction and low freq were painful
- –so attempted to trigger muscle contraction using his voice
- no tissue damage after 2 yrs repetitive stimulation for the rabbit
- he suggested using induction coils as an option for treating deafness in a paper he published in 1954
2
Q
Charles Eyries
A
(1908-1996)
- French surgeon
- neuroanatomy and embryology of the VII nerve was his interest
- did VII nerve repair
- had a lab in the medical school associated with the hospital at which Djourno was working for
3
Q
Djourno and Eyries Collaboration
A
- Eyries had a 57 yr old pt with large bilat cholesteatomas
- –temporal; bone resection had been performed, causing ablation of the labyrinth and facial nerve and total loss of hearing on both sides
- Eyries wanted to find a graft for the VII nerve from cadavers in the med school, where he met Djourno. Then Djourno convinced him of the additional procedure to stimulate hearing
- –surgery on this pt on 2/25/1957
- —-right side facial nerve was grafted and proximal cochlear nerve stump was shredded so the electrode was seated in the remaining stump and the induction coil into the temporalis muscle
- –intraoperative monitoring: pt can detect 100 Hz tone
- –after surgery: good intensity recognition, poor frequency recognition, no speech recognition
4
Q
what happened with the 1st Djourno and Eyries Pt?
A
- after therapy, pt could differentiate high freq from low freq
- could appreciate environmental sounds and some words, but not speech
- several months later the implant quit working. A solder joint connecting the wires to the ground electrode broke
- –surgery was repeated with a new device which ended the same way, the Eyries refused to do it a third time
- Djourno has another implant done with another otologist but pt lost to follow up
- Djourno then lost funding
5
Q
What happened when Eyries and Djourno’s work got to the US?
A
- didnt get to the US until a year later
- –the New York Times published a translation (in 1958) of the original article that was published in a French Journal in March 1957
- in 1959 a pt showed William F. House a summary of the work
6
Q
William House and The Doyles–Los Angeles
A
- House is an otologist who worked with John Doyle, a neurosurgeon, and his brother James Doyle, an electrical engineer
- while doing stapes surgery, House and Doyle placed a needle electrode on the promontory or into the open oval window to try to induce hearing
- –square wave stimuli wee used and pts reported hearing them with no discomfort
- –this inspired the use of a hard wired system
7
Q
House and Doyles: 1st pt
A
- in 1961 a 40 yr old pt with severe otosclerosis and deafness volunteered
- –on 1/5/1961, pt had consistent responses to promontory stimulation
- –so on 1/9/1961 a gold wire was implanted in the round window
- —-poor loudness tolerance which resulted in wire removal
- re-implanted on February 1st 1961 with a 5 wire electrode array and induction system under the skin
- –pt heard square wave stimulation, and needed higher current/intensity over time
- –after several weeks, device had to be removed due to swelling and possible infection
- —-which raised possible bio-compatibility problem
8
Q
House and Doyles: 2nd pt
A
- 2nd pt was implanted in the same period (around 1961)
- –pt heard square wave stimulation, with time a higher current was needed to induce a response
- –for fear of infection, wire was removed
9
Q
Doyle patent for multielectrode device
A
- James Doyle and Earle Ballentyne submitted a patent in 1961 for a multi-electrode device. Patent was not granted until 1969
- after the 2 implants, the press reported about “artificial ear” to restore hearing
10
Q
House and Doyle disagreement
A
- House and the Doyles disagreed an how aggressively to market the device, and House was concerned about bio-incompatibility
- the Doyle bros kept implanting pts until 1968 when they couldn’t gt any more funding
11
Q
pacemaker technology in the late 1960s
A
- in 1967 william house became interested in CIs again after the improvements in medical prosthesis and collaborated with Jack Urban (electrical engineer)
- in 1969 House implanted several pts with Urban
12
Q
House and Urban’s 3 pts
A
1: implant removed due to tissue rejection
1: lost to follow up
1= Charles Grazer who became a longitudinal study
13
Q
Charles Grazer
A
- stimulus levels and results were found to be stable over many years in Grazer’s implant
- Grazer was an excellent subject and many improvements in signal processing came as a result of his cooperativeness
- House focused on the single electrode device, later became House/3M
14
Q
Single Channel Device and FDA
A
- House continued with the single channel device developed by him and Jack Urban. House/3M single channel device gained FDA approval in 1984 and was the 1st approved CI
- 1981 House implanted 1st preschooler who was age 3 and deafened from meningitis
15
Q
F. Blair Simmons–Stanford University
A
- 1962: Simmons stimulated the auditory nerve intraoperatively at Stanford
- –18 yr old pt with cerebellar tumor
- –During surgery (awake) pt discriminated sounds up to 1k Hz
- 1964 Simmons implanted 60 yr old man with multiple disabilities with a 6 electrode array ( inserted about 3-4mm)
- –different pitches were detected with different electrodes
- –outcome was poor, further human implantation at Stanford was discontinues pending animal studies
