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Biomedical subjects

J A Donaldson

Publications and source records attributed to J A Donaldson.

At least 55 records · Page 3Linked to original sources
PubMedDate not supplied

Psychophysical evaluation of cochlear prostheses in a monkey model.

Functional aspects of cochlear prostheses implanted in the scala tympani were tested in monkeys trained to perform a simple reaction-time task. Thresholds for detection of electrical stimulation and dynamic ranges were tested for a wide range of frequencies of sinusoidal stimulation and for biphasic rectangular pulses of various durations and repetition rates. The results are comparable with available data from implanted human patients and extend these findings, exploring various aspects of electrical stimulation in greater detail.

Acoustic Stimulation↗
PubMedDate not supplied

Electronystagmographic and audiologic findings in patients with Meniere's disease.

Electronystagmographic (ENG) and audiologic findings were reviewed for 206 patients treated for Meniere's disease (MD) at the University of Washington Hospital over a 10-year period (1971-80). The most frequently seen ENG findings were unilateral caloric weakness (UW) in 49%, directional preponderance (DP) in 36%, and spontaneous and/or positional nystagmus (SN, PN) in 32%. ENG was normal in 25%. Bilateral caloric weakness (BW) occurred in 36% of patients with bilateral hearing loss. UW was reliably correlated with the side of audiometric involvement; after exclusion of bilateral cases, only 3% of patients showed UW contralateral to the ear with hearing los. Neither DP nor direction of SN or PN correlated at all with side of hearing loss. There was no significant correlation of severity of hearing loss (by pure-tone thresholds or speech discrimination score) with ENG abnormality (UW or DP). Glycerol-positive patients had significantly poorer hearing than glycerol-negative patients, but ENG findings were similar in the two groups.

Audiometry↗