,1. 4
2. 2
3. 3
4. 4
5. 3
6. 2
7. 2
8. 1
9. 5
10. 4
11. 4
12. 3
13. 3
14. 5
15. 4
16. 5
17. 5
18. 4
,40 Biopotential Measurements and Electrodes
7 Solutions
1. Block diagram for a cochlear implant
Tx Coil
Power
Recovery
Transmitter
Audio DSP + N-channel
ADC Neuro- Cochlea
AFE Filter Bank
stimulator
Microphone Data Flexible
Demodulator Electrode
Battery and External Power Management Array
Skin
Rx Coil
(a) Microphone: transduces audio signals to electrical impulses.
(b) Audio AFE: a set of amplifiers that take the small amplitude microphone
signal and amplify it to the full range of ADC filtering signals outside
audio range.
(c) ADC: digitizes signals
(d) DSP: Further filtering in digital domain plus channelization to determine
which cochlear electrode to stimulate.
(e) Transmitter: Power amplifier for the appropriate frequency and supply
required to drive the external coil.
(f) Tx and Rx coils: provide inductive coupling for power and data trans-
mission.
(g) Power Recovery: Rectifier and Regulators, doing AC/DC power conver-
sion.
(h) Data demodulator: recover the data signals in the transmitted carrier
wave. Amplifiers and Comparator or ADC.
(i) N-channel Neurostimulator: N-programmable pulse current sources to
stimulate hair cells on the cochlea.
(j) Flexible Electrode array: insertable into the cochlea reaching areas of
hair cells corresponding to different frequencies.
, Biopotential Measurements and Electrodes 41
2. EMG Dipole Traveling Wave
2. 2
3. 3
4. 4
5. 3
6. 2
7. 2
8. 1
9. 5
10. 4
11. 4
12. 3
13. 3
14. 5
15. 4
16. 5
17. 5
18. 4
,40 Biopotential Measurements and Electrodes
7 Solutions
1. Block diagram for a cochlear implant
Tx Coil
Power
Recovery
Transmitter
Audio DSP + N-channel
ADC Neuro- Cochlea
AFE Filter Bank
stimulator
Microphone Data Flexible
Demodulator Electrode
Battery and External Power Management Array
Skin
Rx Coil
(a) Microphone: transduces audio signals to electrical impulses.
(b) Audio AFE: a set of amplifiers that take the small amplitude microphone
signal and amplify it to the full range of ADC filtering signals outside
audio range.
(c) ADC: digitizes signals
(d) DSP: Further filtering in digital domain plus channelization to determine
which cochlear electrode to stimulate.
(e) Transmitter: Power amplifier for the appropriate frequency and supply
required to drive the external coil.
(f) Tx and Rx coils: provide inductive coupling for power and data trans-
mission.
(g) Power Recovery: Rectifier and Regulators, doing AC/DC power conver-
sion.
(h) Data demodulator: recover the data signals in the transmitted carrier
wave. Amplifiers and Comparator or ADC.
(i) N-channel Neurostimulator: N-programmable pulse current sources to
stimulate hair cells on the cochlea.
(j) Flexible Electrode array: insertable into the cochlea reaching areas of
hair cells corresponding to different frequencies.
, Biopotential Measurements and Electrodes 41
2. EMG Dipole Traveling Wave
