Time Series and Batch Analysis Using ICM+ Philip M. Lewis Scientific Research Officer Dept of Neurosurgery Alfred Hospital, Melbourne Victoria, Australia

Typical Applications of ICM+ Continuous calculations of time-domain indices of autoregulation Mx, PRx Frequency-domain parameters ABP/CBFV LF/HF cross spectral gain, phase ICP fundamental amplitude Time/Frequency domain combinations RAP index

Example - FundFrq Labels (Aliases) Raw signals

A Word About Frequency-Domain Calculations Efficient FFT calculation requires the input data of length N to conform to the rule N = 2x, where x = 1,2,3,4 etc. In other words, the amount of data fed into the FFT algorithm needs to be a power-of-2 long! E.g.: 1 sample = 20 2 samples = 21 4 samples = 22 . . 16384 samples = 214 If the input data length does not conform to this rule, ICM+ will ‘pad out’ the data with zeroes to make it fit the required length E.g. 3 samples will be increased to 4 500 samples will become 512 This is fine, but BUT… 16385 samples will become 32768!! If you’re processing lots of large files, you may need extra cups of coffee… Now we resume normal programming…

Example – ABP/CBFV respiratory phase shift

Example – ABP/CBFV respiratory phase shift `

Output

Signal Labels

All “renamed” or “aliased” to FV when analysing

Lots of Files…

Summary Spreadsheet

Batch Analysis

Batch Analysis Options

ICM+ Tools Written to ease the pain of summarising large volumes of ICM+ batch analysis data Allows for outputting summary measures of column data Mean, Median, Std Dev, Max, Min, etc etc Tabulates results by filename More sophisticated summaries being developed

ICM+ Tools Demonstration