Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Ear or nose prosthesis
Reexamination Certificate
1999-06-28
2002-03-12
Isabella, David J. (Department: 3738)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Ear or nose prosthesis
C607S057000
Reexamination Certificate
active
06355064
ABSTRACT:
The invention relates to an auditive prosthesis, comprising a cochlear implantable electrode-set applied on a carrier, which electrode-set is provided for applying electrical currents for stimulating auditory nerves in the modiolus, wherein the electrode-set comprises a first series of electrode-poles arranged beside each other and at a distance of each other along a first longitudinal side of the carrier, each of the electrode-poles of said first set are individually connected with a signal-generator, which electrode-set comprises a second electrode-pole connected with the signal-generator, which second electrode-pole is arranged along a second longitudinal side of the carrier.
Such an auditive prosthesis is known from the German patent application 28 23 798. The known prosthesis is implanted in the cochlear of a patient having auditory problems in order to improve his auditory perception. By means of the electrodes, currents are applied, under control of received sound-signals, which currents stimulate the auditory nerves in the modiolus, in order to induce action-potentials in those nerves, which action-potentials will thereafter be transported to the brains for interpretation of the audio-signals. With the known prosthesis the electrode-set is formed of the first and second point-shaped electrode-poles, wherein each electrode-pole is each time connected via a wire with the signal-generator. The second electrode-poles form the earth.
A problem of the known auditive prosthesis is that each electrode-pole has each time to be connected with an individual wire with the signal-generator. In order to obtain an increased spacious resolution of the stimulation-pattern, it is necessary to have a plurality of first poles. In view of the limited space available in the scala tympani, the requirement of each time a wire for each pole leads to a limitation in the number of poles and thus to a limited spacious resolution. By using moreover for the first as well as for the second electrode-poles each time point-shaped electrodes, the geometry of the field-lines to be applied is limited.
It is an object of the invention to realise an auditive prosthesis wherein stimulation with a higher spacious resolution is possible.
An auditive prosthesis according to the invention is therefore characterised in that, the second electrode-pole extends over substantially the same distance as the one over which the first electrode-poles extend and which signal-generator is provided for generating signals which generate between electrode-poles to be selected, electrical field-lines with radial and/or longitudinal components. Due to this the second electrode-pole forms a collective pole and thus only a single wire is necessary for connection with the signal-generator. When the first pole comprises n electrodes only n+1 wires are required, due to which a plurality of first electrode-poles is possible, without having the limited space available in the scala tympani forming too quickly a problem. The combination of the first electrode-poles and the second collective pole offers moreover the possibility to generate by means of the signal-generator signals enabling to generate radial as well as longitudinal field-lines. Using those two kinds of field-lines enables to increase the spacious resolution.
It is favourable that said second pole is longitudinally configured. The configuration of the second electrode-pole thus allies to the one of the carrier.
A first preferred embodiment of an auditive prosthesis according to the invention is characterised in that said signal-generator is provided for generating bi-phase-stimulation-pulses of which a first and second phase have substantially a same time-duration but are opposite to each other. The use of the collective second pole with bi-phase-stimulation enables a better control of the field-lines.
A second preferred embodiment of an auditive prosthesis according to the invention is characterised in that said electrode-set comprises at least one selectable reference-electrode and wherein a feedback-element is applied between the selected reference-electrode and the generator, which feedback-element is provided for reducing to zero the net current measured over a current pulse-period. This enables to avoid direct currents over the electrode-contacts which could be unfavourable for the modiolus.
REFERENCES:
patent: 4522209 (1985-06-01), Patrick et al.
patent: 5649970 (1997-07-01), Loeb et al.
patent: 5876443 (1999-03-01), Hochmair et al.
patent: 5922017 (1999-07-01), Bredberg et al.
patent: 2823798 (1979-09-01), None
patent: WO9306698 (1993-04-01), None
Offeciers Erwin
Peeters Stefaan
Van Ruiten Nick
Gottlieb Rackman & Reisman P.C.
Isabella David J.
LandOfFree
Implanted hearing prosthesis does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Implanted hearing prosthesis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Implanted hearing prosthesis will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2855901