title: Effects of biphasic current pulse frequency, amplitude, duration, and interphase gap on eye movement responses to prosthetic electrical stimulation of the vestibular nerve.
abstract: An implantable prosthesis that stimulates vestibular nerve branches to restore sensation of head rotation and vision-stabilizing reflexes could benefit individuals disabled by bilateral loss of vestibular (inner ear balance) function. We developed a prosthesis that partly restores normal function in animals by delivering pulse frequency modulated (PFM) biphasic current pulses via electrodes implanted in semicircular canals. Because the optimal stimulus encoding strategy is not yet known, we investigated effects of varying biphasic current pulse frequency, amplitude, duration, and interphase gap on vestibulo-ocular reflex (VOR) eye movements in chinchillas. Increasing pulse frequency increased response amplitude while maintaining a relatively constant axis of rotation. Increasing pulse amplitude (range 0- 325 μA) also increased response amplitude but spuriously shifted eye movement axis, probably due to current spread beyond the target nerve. Shorter pulse durations (range 28- 340 μs) required less charge to elicit a given response amplitude and caused less axis shift than longer durations. Varying interphase gap (range 25- 175 μs) had no significant effect. While specific values reported herein depend on microanatomy and electrode location in each case, we conclude that PFM with short duration biphasic pulses should form the foundation for further optimization of stimulus encoding strategies for vestibular prostheses intended to restore sensation of head rotation.
authors.affiliation: Departments of Otolaryngology/Head and Neck Surgery and Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA. natan@jhu.edu
authors.forename: Natan S
authors.initials: NS
authors.lastname: Davidovics
authors.forename: Gene Y
authors.initials: GY
authors.lastname: Fridman
authors.forename: Bryce
authors.initials: B
authors.lastname: Chiang
authors.forename: Charles C
authors.initials: CC
authors.lastname: Della Santina
mesh_terms: D000818:Animals; D002682:Chinchilla; D004599:Electric Stimulation Therapy / Q000379:methods*; D005133:Eye Movements; D012027:Reflex, Vestibulo-Ocular; D015837:Vestibular Diseases / Q000503:physiopathology* / Q000534:rehabilitation*; D014725:Vestibular Nerve / Q000503:physiopathology*
references.citation: J Neurosci Methods. 2005 Feb 15;141(2):171-98
references.pmid: 15661300
references.citation: Hear Res. 1999 Apr;130(1-2):171-88
references.pmid: 10320107
references.citation: J Neurophysiol. 2008 Jul;100(1):140-53
references.pmid: 18417632
references.citation: J Neurophysiol. 1988 Jul;60(1):167-81
references.pmid: 3404215
references.citation: Hear Res. 2006 Mar;213(1-2):17-24
references.pmid: 16439079
references.citation: Acta Otolaryngol. 2001 Jan;121(2):216-9
references.pmid: 11349782
references.citation: J Neurophysiol. 1984 Jun;51(6):1236-56
references.pmid: 6737029
references.citation: IEEE Trans Biomed Eng. 2008 Jun;55(6):1744-53
references.pmid: 18714839
references.citation: Exp Brain Res. 1988;70(3):470-6
references.pmid: 3384048
references.citation: J Neurophysiol. 1988 Jul;60(1):182-203
references.pmid: 3404216
references.citation: IEEE Trans Biomed Eng. 1996 Feb;43(2):161-6
references.pmid: 8682527
references.citation: JAMA. 1998 Feb 18;279(7):541-4
references.pmid: 9480366
references.citation: Hear Res. 2006 Oct;220(1-2):49-60
references.pmid: 16904278
references.citation: Exp Brain Res. 2008 Dec;191(4):435-46
references.pmid: 18712370
references.citation: J Acoust Soc Am. 1999 Aug;106(2):998-1009
references.pmid: 10462805
references.citation: Hear Res. 2006 May;215(1-2):47-55
references.pmid: 16644157
references.citation: IEEE Trans Biomed Eng. 1983 Jul;30(7):407-14
references.pmid: 6604691
references.citation: Exp Neurol. 1964 Nov;10:393-405
references.pmid: 14228399
references.citation: Ann Otol Rhinol Laryngol. 1964 Mar;73:153-69
references.pmid: 14128701
references.citation: Hear Res. 2008 Aug;242(1-2):154-63
references.pmid: 18468821
references.citation: Exp Brain Res. 2000 Feb;130(3):277-97
references.pmid: 10706428
references.citation: J Neurophysiol. 2007 Feb;97(2):1503-14
references.pmid: 17122313
references.citation: IEEE Trans Biomed Eng. 2008 Nov;55(11):2608-19
references.pmid: 18990631
references.citation: IEEE Trans Biomed Eng. 1992 Dec;39(12):1244-54
references.pmid: 1487287
references.citation: J Neurophysiol. 2005 Feb;93(2):643-55
references.pmid: 15456806
references.citation: IEEE Trans Biomed Eng. 2006 Nov;53(11):2362-72
references.pmid: 17073343
references.citation: Conf Proc IEEE Eng Med Biol Soc. 2005;2005:7380-5
references.pmid: 17281986
references.citation: Hear Res. 2008 Aug;242(1-2):141-53
references.pmid: 18501539
references.citation: Hear Res. 2003 Jul;181(1-2):94-9
references.pmid: 12855367
references.citation: Acta Otolaryngol. 2002 Jul;122(5):495-500
references.pmid: 12206257
references.citation: Ann Biomed Eng. 1979;7(2):117-25
references.pmid: 533020
references.citation: IEEE Trans Biomed Eng. 2007 Jun;54(6 Pt 1):1016-30
references.pmid: 17554821
references.citation: Hear Res. 2005 Jul;205(1-2):210-24
references.pmid: 15953530
references.citation: Nature. 1991 Jul 18;352(6332):236-8
references.pmid: 1857418
references.citation: IEEE Trans Biomed Eng. 2002 Feb;49(2):175-81
references.pmid: 12066886
references.citation: Hear Res. 1984 Jun;14(3):225-43
references.pmid: 6480511
references.citation: Biol Cybern. 2007 Dec;97(5-6):341-9
references.pmid: 18046573
references.citation: Acta Otolaryngol. 2009 May;129(5):481-6
references.pmid: 18615331
references.citation: Exp Neurol. 1964 Feb;9:137-60
references.pmid: 14126123
references.citation: Ann Biomed Eng. 2000 May;28(5):572-81
references.pmid: 10925955
references.citation: J Vestib Res. 2008;18(2-3):147-57
references.pmid: 19126985
references.citation: Hear Res. 2008 Aug;242(1-2):3-21
references.pmid: 18616994
references.citation: J Neurophysiol. 2005 May;93(5):2777-86
references.pmid: 15601735
references.citation: J Neurosci Methods. 2005 Apr 30;143(2):141-50
references.pmid: 15814146
references.citation: J Biomed Mater Res. 2000 May;50(2):215-26
references.pmid: 10679687
references.citation: J Assoc Res Otolaryngol. 2005 Sep;6(3):191-206
references.pmid: 16088383
references.citation: Otol Neurotol. 2001 Sep;22(5):662-71
references.pmid: 11568676
references.citation: Ann N Y Acad Sci. 1992 May 22;656:732-8
references.pmid: 1599178
references.citation: J Assoc Res Otolaryngol. 2007 Jun;8(2):258-79
references.pmid: 17265124
references.citation: J Neurol. 1998 Jun-Jul;245(6-7):314-21
references.pmid: 9669481
references.citation: J Vestib Res. 2002-2003;12(2-3):87-94
references.pmid: 12867667
references.citation: J Neurophysiol. 1989 Jul;62(1):264-72
references.pmid: 2754477
references.citation: Otol Neurotol. 2004 Jul;25(4):559-69
references.pmid: 15241236
references.citation: J Neurophysiol. 1999 Oct;82(4):2000-5
references.pmid: 10515990
references.citation: Ann Otol Rhinol Laryngol. 1969 Aug;78(4):815-26
references.pmid: 4979119
references.citation: IEEE Trans Biomed Eng. 2007 Jun;54(6 Pt 1):1005-15
references.pmid: 17554820