Cochlear Limited

About: Cochlear Limited is a company organization based out in Sydney, New South Wales, Australia. It is known for research contribution in the topics: Cochlear implant & Hearing loss. The organization has 1290 authors who have published 1479 publications receiving 33109 citations. The organization is also known as: кохлеарные Americas & COCHLEAR LIMITED.

Planar cell polarity in the inner ear.

Abstract: The inner ears of vertebrates represent one of the most striking examples of planar cell polarity (PCP). Populations of directionally sensitive mechanosensory hair cells develop actin-based stereociliary bundles that are uniformly oriented. Analysis of perturbations in bundle polarity in mice with mutations in Vangl2 formed the basis for the initial demonstration of conservation of the PCP signaling pathway in vertebrates. Subsequent studies have demonstrated roles for other "core" PCP genes, such as Frizzled, Disheveled, and Celsr, and for identifying novel PCP molecules such as Scribble and Ptk7. In addition, the demonstration of hearing deficits in humans with mutations in cilia genes combined with analysis of PCP defects in mice with ciliary deletion has implicated the cilia as an important modulator of hair cell polarization. Finally, the presence of shortened cochleae in many PCP mouse mutants has revealed an additional role for the PCP pathway in the development of the auditory system.

Optimizing cochlear implant electrode selection

Abstract: A method is described to allow for better selection of electrodes for neural stimulation, for example in a cochlear implant. A series of stimuli, at different stimulation levels, are provided at each electrode to be tested, and the neural response to each stimulus is measured, using an implanted electrode. A value is then calculated relating stimulus level to response, to allow the relative responsiveness of electrodes to be determined. This can then be used as the basis for a stimulation map used to select which electrodes are stimulated and at what level.

Speech prosody perception in cochlear implant users with and without residual hearing

Abstract: OBJECTIVES The detection of fundamental frequency (F0) variations plays a prominent role in the perception of intonation. Cochlear implant (CI) users with residual hearing might have access to these F0 cues. The objective was to study if and how residual hearing facilitates speech prosody perception in CI users. DESIGN The authors compared F0 difference limen (F0DL) and question/statement discrimination performance for 15 normal-hearing subjects (NHS) and two distinct groups of CI subjects, according to the presence or absence of acoustic residual hearing: one "combined group" (n = 11) with residual hearing and one CI-only group (n = 10) without any residual hearing. To assess the relative contribution of the different acoustic cues for intonation perception, the sensitivity index d' was calculated for three distinct auditory conditions: one condition with original recordings, one condition with a constant F0, and one with equalized duration and amplitude. RESULTS In the original condition, combined subjects showed better question/statement discrimination than CI-only subjects, d' 2.44 (SE 0.3) and 0.91 (SE 0.25), respectively. Mean d' score of NHS was 3.3 (SE 0.06). When F0 variations were removed, the scores decreased significantly for combined subjects (d' = 0.66, SE 0.51) and NHS (d' = 0.4, SE 0.09). Duration and amplitude equalization affected the scores of CI-only subjects (mean d' = 0.34, SE 0.28) but did not influence the scores of combined subjects (d' = 2.7, SE 0.02) or NHS (d' = 3.3, SE 0.33). Mean F0DL was poorer in CI-only subjects (34%, SE 15) compared with combined subjects (8.8%, SE 1.4) and NHS (2.4%, SE 0.05). In CI subjects with residual hearing, intonation d' score was correlated with mean residual hearing level (r = -0.86, n = 11, p < 0.001) and mean F0DL (r = 0.84, n = 11, p < 0.001). CONCLUSION Where CI subjects with residual hearing had thresholds better than 60 dB HL in the low frequencies, they displayed near-normal question/statement discrimination abilities. Normal listeners mainly relied on F0 variations which were the most effective prosodic cue. In comparison, CI subjects without any residual hearing had poorer F0 discrimination and showed a strong deficit in speech prosody perception. However, this CI-only group appeared to be able to make some use of amplitude and duration cues for statement/question discrimination.

Process and device for supply of an at least partially implanted active device with electric power

Abstract: An improved implantable thermoelectric energy converter for converting thermal energy generated by an implant wearer into electrical power for supplying electric power to an at least partially implanted active device, the implantable thermoelectric energy converter including a hot pole, a cold pole, and a plurality of individual modules electrically coupled to one another disposed between the hot pole and the cold pole. In particular, the hot pole thermally couples one end of the plurality of individual modules to an implantation site having a temperature substantially that of a core body temperature and the cold pole thermally couples another end of the plurality of individual modules to an implantation site closer to an outer skin surface of the implant wearer. In another embodiment, the implantable thermoelectric energy converter may also include an implantable energy storage for collecting and temporarily storing the electric power generated. In accordance with still another embodiment of the present invention, the cold pole of the implantable thermoelectric energy converter may form a cooling body having an enlarged surface area which is adapted to be positioned directly under a skin surface of the implant wearer. In yet another embodiment, the implantable thermoelectric energy converter may be implanted in the skull or neck area of the implant wearer's body.

Virtual wire assembly having hermetic feedthroughs

Abstract: A virtual wire assembly is disclosed. The assembly comprises a substantially electrically-nonconductive substrate; and a plurality of hermetic feedthroughs each comprising a conductive region extending transversely through the substrate to form a conductive pathway with accessible surfaces at opposing ends thereof, wherein each conductive pathway is electrically isolated from other conductive pathways. In certain embodiments of this aspect of the invention, the substantially electrically-nonconductive substrate is a semiconductor device, and the conductive regions each are comprised of an n-type or a p-type doped semiconductor material. Also disclosed are implanted medical devices requiring electronic or other components to be retained in a hermetic enclosure, such as cochlear and other sensory or neural prosthetic devices.