title: Examination of a mechanical amplifier in the incudostapedial joint gap: FEM simulation and physical model.
abstract: Implantable assembly components that are biocompatible and highly miniaturized are an important objective for hearing aid development. We introduce a mechanical transducer, which could be suitable as part of a prospective fully-implantable hearing aid. The transducer comprises a sensor and an actuator unit in one housing, located in the joint gap between the middle ear ossicles, the incus and stapes. The setup offers the advantage of a minimally invasive and reversible surgical solution. However, feedback between actuator and sensor due to mechanical coupling limits the available stable gain. We show that the system can be stabilized by digital control algorithms. The transducer is tested both in a finite elements method simulation of the middle ear and a physical model of a human middle ear. First, we characterize the sensor and actuator elements separately. Then, the maximum stable gain (MSG) of the whole transducer is experimentally determined in the middle ear model. With digital feedback control (using a least mean squares algorithm) in place, the total signal gain is greater than 30 dB for frequencies of 1 kHz and above. This shows the potential of the transducer as a high frequency hearing aid.
authors.affiliation: Clinic of Otorhinolaryngology, Department of Medicine, Technische Universität Dresden, Universitätsklinik Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany. martin.koch@uniklinikum-dresden.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Koch
authors.affiliation: Clinic of Otorhinolaryngology, Department of Medicine, Technische Universität Dresden, Universitätsklinik Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany. tillmoritz.essinger@uniklinikum-dresden.de.
authors.forename: Till Moritz
authors.initials: TM
authors.lastname: Eßinger
authors.affiliation: Clinic of Otorhinolaryngology, Department of Medicine, Technische Universität Dresden, Universitätsklinik Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany. Matthias.Bornitz@uniklinikum-dresden.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Bornitz
authors.affiliation: Clinic of Otorhinolaryngology, Department of Medicine, Technische Universität Dresden, Universitätsklinik Carl Gustav Carus, Fetscherstraße 74, 01307 Dresden, Germany. Thomas.Zahnert@uniklinikum-dresden.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Zahnert
mesh_terms: D000161:Acoustic Stimulation / Q000295:instrumentation*; D000669:Amplifiers, Electronic; D003054:Cochlear Implants; D004429:Ear Ossicles / Q000502:physiology; D020342:Finite Element Analysis; D006310:Hearing Aids; D006801:Humans; D055585:Physical Phenomena; D011446:Prospective Studies; D011474:Prosthesis Design / Q000295:instrumentation*; D014159:Transducers
references.citation: Audiol Neurootol. 1999 May-Aug;4(3-4):156-62
references.pmid: 10187924
references.citation: Hear Res. 2000 Dec;150(1-2):43-69
references.pmid: 11077192
references.citation: Audiol Neurootol. 2007;12(4):265-76
references.pmid: 17406105
references.citation: Expert Rev Med Devices. 2011 Jul;8(4):441-7
references.pmid: 21728730
references.citation: Audiol Neurootol. 2003 May-Jun;8(3):140-52
references.pmid: 12679625
references.citation: HNO. 2009 Mar;57(3):199-207
references.pmid: 19247624
references.citation: J Speech Hear Disord. 1986 Aug;51(3):272-81
references.pmid: 3736027
references.citation: Ann Otol Rhinol Laryngol. 1995 Apr;104(4 Pt 1):311-6
references.pmid: 7717624
references.citation: J Acoust Soc Am. 2010 Sep;128(3):1245-61
references.pmid: 20815460
references.citation: Hear Res. 2013 Jul;301:35-43
references.pmid: 23246425
references.citation: HNO. 2004 Apr;52(4):321-8
references.pmid: 15143763
references.citation: Otol Neurotol. 2004 May;25(3):323-32
references.pmid: 15129113
references.citation: Trends Amplif. 2009 Sep;13(3):206-14
references.pmid: 19762429
references.citation: Hear Res. 2012 Feb;284(1-2):82-92
references.pmid: 22155337
references.citation: Hear Res. 2010 May;263(1-2):145-51
references.pmid: 20156543
references.citation: Laryngorhinootologie. 2007 Jun;86(6):431-5
references.pmid: 17226436