MULTICHANNEL DATA ACQUISITION
State-of-the-art recording system: captures multi-channel data sets from Awake,
behaving or anesthetized rats, primates, or tissue culture plates. Data can be obtained from awake, behaving rats or primates, anesthetized rats or primates.
Spike Sorting: Continuous voltage signals are amplified and filtered from arrays of neuron-recording microprobes, and other signal generating devices. Multiple signals are digitized continuously at 50 KHZ by individual 24-bit AD converters. Signal processing is conducted through a combination of FPGAs (Field Programmable Gate Arrays and Digital Signal Processors). Pairs of channels are selected for digital subtraction to provide superior noise rejection.
Candidate spike waveforms that exceed a threshold are captured from each channel and transferred to the host computer for sorting and storage. Real-time or off-line sorting is achieved by a basic method involving multiple time/voltage threshold boxes. The user grabs, positions, and sizes one or more boxes on top of a specific shape within a group of ‘valid’ or noise generated waveforms. Boxes can be shared between waveforms or designated specific to a waveform. One to four separate waveforms are sorted from noise and each other. Pre-set sorting parameters are stored to minimize sorting times between sessions.
Semi automation assists the sorting process.
Data stored consist of sets of time stamped events labeled according to recording probe and neuron number. ‘Fast ‘voltage signals, up to 50,000 points per second can be stored continuously on a subset of channels.
‘Slow’ voltage signal sources, up to 1000 points per second, are recorded continuously on selected channels.
This process results in datasets of accurate event times which are available for viewing from within the database or for exporting to Matlab or other standard file formats. Data output is possible at the end of a session or of accumulated data at any time during a recording session. Continuous recording can be achieved in sessions 48 hours or more.
Data sets are integrated with event times and intervals generated by the Real Time Experimental Control Software that operates in parallel with the Spike Sorter and Continuous data acquisition.
The image located above shows ‘box-sorting’ of two similar test waveforms with duration of one msec.
The array of smaller windows at right shows thirty two windows sorted at 20/sec for each channel.
Continuous sorting is possible of 128 channels.
Electronics Hardware: A single long form PCI board is mounted within a high performance PC with dual core processor and dual monitor capability. Daughter boards provide groups of 32 preamplifiers and ADs, one for each channel. Signal processing is achieved through integration of an FPGA and DSP for each group of 16 channels. Cables lead to a groups of sixteen channel PA-01 or PA-02 Preamplifier filter modules located near to the experimental preparation.
This newly designed compact configuration eliminates the need for a separate chassis and power supply. Costs are reduced substantially to the customer for large systems.
Contact for Quotation: Neuroplex will compete in cost and features with any other commercially available system.