Stellate provides unique solutions for research applications that complement the Harmonie line of products and simplify data collection, management and analysis. Our products can be found at the most prestigious universities and research laboratories around the world, where they are used for a number of applications:
- Animal Research (e.g. seizure modeling in rats or sheep)
- Spike generation, morphology
- Seizure prediction
- REM sleep
Stellate’s Pro-Amp amplifier can be conveniently configured to facilitate simultaneous recording of 8 channels each from 4 animals, using independent references for each animal. The data is originally recorded as a 32-channel file (with optional synchronized Digital Video of all 4 animals in the same picture) which can then be subsequently split into 4 independent 8-channel files, with a separate software utility.
The Pro-Amp ensures outstanding signal quality, with programmable filters from 0.1 to 500 Hz and sampling rates of up to 2000Hz.”
The Secondary File Writer is a module that works only in real-time (during EEG recording) and allows the creation of a secondary or parallel EEG file. Its purpose is to provide the researcher access to the ongoing EEG recording data in a format that is easily accessible by external third party programs without interfering with the ongoing clinical EEG. This tool provides a means for researchers to develop EEG analysis methods for real-time external applications. This access is provided by means of creating a parallel EDF file during recording.
The EDF format was chosen as it allowed us to fulfill the following goals:
• Keep file format simple – an EDF file reader can easily be created (coded) in a few days or freeware readers can be downloaded from the internet
• Keep file size small. That is, the data is stored in 2 byte binary format (EDF specifications)
This tool is used like other processors so little time is required for setup and use.
The Multi Rate Signal Extractor is a Windows standalone application that works with Stellate’s signal file to allow the creation of new EEG files from a subset of channels in the original file. In addition to extracting a subset of channels, this tool allows the data to be resample (up/down) in the new file generated. Additionally, the new file retains relevant patient information and all associated montages and events.
This tool is designed with a number of applications in mind, most notably in recording EEG of animals. Researchers conducting small animal studies often would like to record many animals simultaneously using one data acquisition system. By using this tool it is possible to separate the data for each animal in a individual file. In other applications, it may be possible to resample the data at different rates (for example, higher resolution in Heart Rate Variability studies.) It may be desirable to extract a particular channel for archiving for use in a particular study.
MATLAB®Signal File Interface toolbox is a library of MATLAB® functions that allows access to the data that is stored in the Harmonie Signal Files. These functions allow the importation of recorded data, detected events and various other types of recording information into the MATLAB® environment. For example, it may be possible to read into the MATLAB® environment a segment of multichannel recorded data that is formatted in a specific montage. One may want to have access to events marked in the file or their properties for further statistical analysis. This data access functionality is particularly useful for researchers who would like to do further analysis of the EEG data or those who would like to develop additional processing tools relevant to their own research. This tool allows access to the raw EEG data. It is also possible to create simulated signal files in the Harmonie format using this tool which can be later reviewed using Stellate's Harmonie EEG Review software.
This toolbox works in conjunction with the Harmonie library and is Harmonie version specific. That is, the library version must match the correct Harmonie version. It is also necessary to have the correct version of HARMONIE Reviewers installed on your computer.
This is a Harmonie processor that can create contiguous spectral events in the file for user specified epoch lengths and allows the possibility of studying the spectral character of the recorder data (both real-time and in offline review). The properties of the events are created by the user as spectral features. These can be, for example, band power in a particular channel, band power ratios, spectral edge, and relative power in specific bands. The band definition can be configured as needed. The resulting events can be configured as needed, and their properties can be used in a variety of ways – trended in the unique Stellate’s PolyTrend™ software, imported into Matlab using the Matlab-Signal File Interface Toolbox or in customized reports in the Harmonie Database.
Digital PSG techniques provide a flexible way of recording, reviewing and storing the PSG data. The desire for quantitative EEG and Sleep event analysis/trending is ever increasing – for example for studying Sleep Microstructure. Over the years, various qualitative descriptors have been proposed to aid in the PSG/EEG interpretation process. Numerous researchers have shown this to be particularly useful for long-term EEG/PSG analysis (i.e. trending).
To address this need Stellate has developed a highly flexible PolyTrends™ Program that allows the trending of various kinds of data in a compressed format. PolyTrends™ is a module of Stellate’s Harmonie Program that allows the trending of detected events and quantitative measures derived from the recorded data in a manner specified by the user. The easy-to-use, yet highly configurable trend is a powerful feature that will allow the researcher to investigate various possibilities. PolyTrends™ allows the researchers to specify which data to trend, what methods to use to derive the quantitative measures and the format of the display graphs. The possibility of exporting the trending data in Excel format will allow the researcher to conduct further statistical analysis.
