OmniPlex v1.10 with Digital Referencing and Channel Mapping
August 22, 2013

DALLAS, TX — (August 22, 2013) – Plexon Inc, the leader in advanced hardware and software solutions for neuroscience and behavioral research, announces the newest software release for its flagship OmniPlex® Neural Data Acquisition System – OmniPlex Software v1.10. This release contains the significant addition of sophisticated digital referencing and electrode channel mapping functionality among other improvements.

Referencing is a technique for removing undesired signal artifacts which occur across multiple acquisition channels, including transients such as those generated by animal movement, and sustained interference such as 50/60Hz power line noise. Typically, a reference signal channel is selected, possibly from a designated reference electrode, which contains only the artifact signal. This artifact signal is then subtracted from the other channels, thereby removing the artifacts while leaving only the signals of interest.

Referencing can be performed in the analog or digital domains. Analog referencing is imperfect, and performing the subtraction before digitization makes it difficult to perform referencing on only a filtered subset of the signal. It also entails certain practical limitations on the number of references and the number of channels which can use the same reference.

OmniPlex Software v1.10’s new digital referencing feature avoids many of the limitations of analog referencing. In digital referencing, the subtraction is performed by subtracting corresponding sample values in software, and there are no inherent limitations on the number of references or the number of channels that use them. Also, spike channels can be referenced independently of field potential channels without any reduction in channel count. Moreover, performing the referencing in software is a more flexible and extensible approach that allows more advanced methods to be implemented without incurring the cost and complexity of the equivalent analog circuitry.

Not only is standard digital referencing now available, but OmniPlex Software 1.10 further supports two advanced methods: common average referencing (CAR) and common median referencing (CMR). Both methods combine multiple channels to form a composite reference signal which is then subtracted to remove or reduce unwanted components. The basic idea of both CAR and CMR is that if many signal channels are averaged together, the averaged signal being the result of averaging corresponding sample values across channels, then artifact signals that are the same across all channels (such as AC power line noise) will “survive the averaging” in the reference signal. Conversely, components unique to each channel, such as spikes, will tend to “cancel out” and have a mean near zero. The digital referencing is performed at the full 40kHz wideband sampling rate for maximum precision.

Plexon’s earlier OmniPlex System incorporating an analog amplifier offered only analog referencing; however, both the OmniPlex System using an analog amplifier and the OmniPlex System with DigiAmp™ digitizing amplifier will perform digital referencing if running OmniPlex Software 1.10.

The second most significant addition to the OmniPlex Software is channel mapping. Channel mapping allows users of electrodes with nonstandard or inconvenient physical channel numbering, such as with silicon probes, to map (renumber) the channels without the use of custom adaptors or cables which were previously required. Researchers utilizing electrodes with complex geometries such as stereotrodes or tetrodes will appreciate the convenience. The addition of channel mapping support greatly simplifies the integration of various electrodes with the OmniPlex System.

OmniPlex Software v1.10 is an important release offering researchers the ability to improve the quality of neural signals as well as simplify the interface with uniquely configured electrodes. This latest download is available for Windows 7 and XP platforms, and can be found on the OmniPlex System webpage, and at For more information regarding these or other improvements, please read the Release Notes contained within the install package.

About Plexon Inc
Plexon is a pioneer and leading innovator of custom, high performance data acquisition, behavior and analysis solutions specifically designed for scientific research. We collaborate with and supply thousands of customers including the most prestigious neuroscience laboratories around the globe driving new frontiers in areas including basic science, brain-machine interfaces (BMI), neurodegenerative diseases, addictive behaviors and neuroprosthetics. Plexon offers integrated solutions for in vivo neurophysiology, optogenetics, and behavioral research — backed by its industry-leading commitment to quality and customer support.