1. Neural Recording System
By:
Ivana Duvnjak
Stephen Kilpatrick
Dawit Fsiha

2. Outline What is a Neural Network Recording System?
Why are they important?
How can they be improved?
Some possible solutions
Analysis of some solutions
Conclusions

3. Neural Network Recoding Systems
Brain sends electrical signals - Neurons
Sent through axons
Electrical Signals processed by synapses
Mapping the brain

4. Applications Medical Research Mental Performance Mental Illness
Sleep Disorders
Etc.

5. Subsystems
Electrode
Amplifier
Multiplexer
Transmitter
Receiver

6. Block Diagram of System
Electrode
Amplifier Tx Rx
DATA
POWER
MUX

7. Possible Improvements
Areas to improve in the neural recording system
Electrodes
Amplifier
Multiplexer
Transmitter
Receiver

8. Neural LNA Amplifier Functions Power dissipation must kept low
Must reject noise ( flicker noise)
Amplifying a weak signal received from the electrodes
Must reject the DC offset created at the electrodes-Tissue interface

9. Neural Amplifier Requirements
Power dissipation
Bandwidth requirement
Gain
Stability
Overall size

10. Amplifier Solutions: Design I
Neural Amplifier Circuit
OTA Design

11. Amplifier Solutions: Design II
Neural Amplifier Circuit
OTA Design

12. Design I: Simulation Results
10 pW power consumption
39.974dB gain
Low-cutoff frequency: 0.4Hz
High-cutoff frequency: 7.852kHz
Area: 0.16mm2
Stable

13. Design II: Simulation Results
11.5 pW power consumption
40.362dB gain
Low-cutoff frequency: Hz
High-cutoff frequency: kHz
Area: 0.091mm2
Stable

14. High-frequency cutoff
Comparison of Designs
Table 1. Summary of simulation results for the neural amplifiers
Parameter
Expected
Circuit 1 Simulation
Circuit 2 Simulation
Supply voltage
+/-2.5V
+/-1.5V
Power dissipated
<5mW
10pW
11.5pW
Gain
40dB
39.974dB
40.362dB
Bandwidth
~7.0kHz
~7.852kHz
~32.443kHz
Low-frequency cutoff
0.025Hz
0.4Hz
83.144Hz
High-frequency cutoff
7.0kHz
7.852kHz
32.526kHz

15. Conclusions Both designs meet the requirements of:
Power consumption
Stability
Size
DC offset rejection
Design I is significantly better, due to the more desirable bandwidth requirements.

16. Implementation

17. References

18. Exit(0);
Questions?