Cochlear implant and simplified method of fitting same
View Patent ↗A bionic ear cochlear stimulation system has the capability to stimulate fast enough to induce stochastic neural firing, thereby acting to restore “spontaneous” neural activity. Such neurostimulation involves the use of a high rate pulsitile stimulation signal that is amplitude modulated with sound information. Advantageously, by using such neurostimulation, a fitting system may be utilized that does not normally require T-level threshold measurements. T-level threshold measurements are not required in most instances because the high-rate pulsitile stimulation, even though at levels that would normally be a sub-threshold electrical stimulus, is able to modulate neural firing patterns in a perceptible way.
1. A method of fitting a bionic ear implant having an electrode array with multiple electrode contacts through which electrical stimulation may be applied to the patient's cochlea; the method comprising:
measuring M-levels associated with a stimulus applied to selected ones of the multiple electrode contacts, where an M-level comprises a comfortable stimulation intensity;
globally determining a T-level for all of the electrode contacts, where a T-level comprises a minimally perceptable stimulation intensity; and
using the M- and T-levels to help set the intensity of stimuli applied to the electrode contacts after fitting, wherein globally determining a T-level comprises setting the T-level to zero as the determined T-level.
2. A method of fitting a bionic ear implant having an electrode array with multiple electrode contacts through which electrical stimulation may be applied to the patient's cochlea; the method comprising:
measuring M-levels associated with a stimulus applied to selected ones of the multiple electrode contacts, where an M-level comprises a comfortable stimulation intensity;
globally determining a T-level for all of the electrode contacts, where a T-level comprises a minimally perceptable stimulation intensity; and
using the M- and T-levels to help set the intensity of stimuli applied to the electrode contacts after fitting, wherein globally determining a T-level comprises setting the T-level to a value that is a prescribed fraction of the measured M-level.
3. A method of fitting a bionic ear implant having an electrode array with multiple electrode contacts through which electrical stimulation may be applied to the patient's cochlea; the method comprising:
measuring M-levels associated with a stimulus applied to selected ones of the multiple electrode contacts, where an M-level comprises a comfortable stimulation intensity;
globally determining a T-level for all of the electrode contacts, where a T-level comprises a minimally perceptable stimulation intensity; and
using the M- and T-levels to help set the intensity of stimuli applied to the electrode contacts after fitting,
wherein globally determining a T-level comprises setting the T-level to a value that is a prescribed fraction of the measured M-level; and
wherein setting the T-level to a prescribed fraction of the measured M-level comprises setting the T-level to be 1/10 of the measured M-level.
4. A method of fitting a multichannel bionic ear implant, the bionic ear implant having multiple channels coupled to multiple electrode contacts of an electrode array, the bionic ear implant having means for applying electrical stimulation to the patient's cochlea through the electrode contacts of the electrode array; the method comprising:
measuring M-levels associated with a stimulus applied to selected ones of the multiple electrode contacts, where an M-level comprises a comfortable stimulation intensity;
determining a T-level for each channel using live speech, where a T-level comprises a minimally perceptable stimulation intensity; and
using the M- and T-levels of each channel to help set the intensity of stimuli applied to the electrode contacts after fitting,
wherein determining a T-level using live speech comprises:
sweeping tones at a center frequency of each channel while the bionic ear implant is set to a comfortable volume in live speech mode; and
assessing whether the tones are detected in each channel without a T setting, and if so not using a T-setting on that channel, and if not increasing a T-setting on that channel during live speech to give desired detectability.