![](bg6.png)
to have the better rejection of parasitic signals, the
wrapped hexagonal patch has a sensitivity decreasing
slowly along this Oy axis. In fact, the bent hexago-
nal patch only begins to have larger sensitivity than
the tripolar cuff for action potentials placed at more
than fifty times the radius of the cuff, corresponding
to approximately 7cm. At this distance, the parasitic
signal could be neglected in comparison to ENG sig-
nal.
6 CONCLUSIONS AND
PERSPECTIVES
We have presented here a method to build multipo-
lar cuff electrodes and how to extract useful informa-
tions from the multiple channels. Although numeri-
cal investigations are still necessary to an exhaustive
comparison of multipolar structures, the comparison
between the classical tripolar cuff electrode for ENG
recording and a multipolar electrode has shown that
this new type of the design is very promising. In ev-
ery simulation, multipolar electrodes prove to be more
sensitive to sources located inside the nerve, and in al-
most every case they show better far source rejection.
We hope the improvement of the recorded signal
given by this new design will allow the use of sig-
nal processing techniques such as source separation.
Then, multipolar configurations could make it possi-
ble to estimate more precise parameters like the speed
and the direction of propagation of the AP (Taylor
et al., 2004; Rieger et al., 2006).
Future works include the complete test of the
seven-channel amplifier. It requires special attention
to electromagnetic interferences due to the high gain
it can reach. Then, we will be able to process the in
vivo qualification of the whole system.
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CONSIDERATIONS ON IMPROVING THE DESIGN OF CUFF ELECTRODE FOR ENG RECORDING - Geometrical
Approach, Dedicated IC, Sensitivity and Noise Rejection
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