Authors:
A. Bonfanti
1
;
T. Borghi
2
;
R. Gusmeroli
2
;
G. Zambra
2
;
A. S. Spinelli
2
;
A. Oliynyk
3
;
L. Fadiga
1
and
G. Baranauskas
4
Affiliations:
1
The Italian Institute of Technology, Italy
;
2
Politecnico di Milano - IU.NET, Italy
;
3
Universitá di Ferrara, Italy
;
4
Italian Institute of Technology, Italy
Keyword(s):
Prosthetic device, action potential (AP), multichannel recording system, spike detection, spike sorting.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Engineering
;
Biomedical Instrumentation
;
Biomedical Instruments and Devices
;
Implantable Electronics
;
Low-Power Design
;
Microelectronics
Abstract:
Since the proof that prosthetic devices directly controlled by neurons are viable, there is a huge increase in the interest in integrated multichannel recording systems that register neural signals with implanted chronic electrodes. One of the bottlenecks in such compact systems is the limited rate of data transmission in the wireless link, requiring some sort of data compression/reduction. To solve such a problem, we propose an analog low power integrated system for action potential (AP) detection and sorting. In this system, AP detection is performed by a double threshold method that reduces the probability of false detections while AP sorting is based on the measurement of peak and trough amplitudes and spike width. The circuit has been implemented in 0.35−μm CMOS technology with power consumption of 70 μW per channel including the pre-amplifier. The system was tested with real traces. Compared to standard AP sorting techniques, the proposed simple AP
sorter was able to correctly
assign to single units over 90% of detected APs. Thus, our system preserves most information encoded by APs and we estimate that for a typical trace the required bandwidth per channel will be less than 4 kbps or 400 kbps for 100 channel.
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