nirs

A trick to detect bad channel in NIRS data…

Some noise is easy to detect – simply plotting the time courses of NIRS signal, you will find the noise so out of range and you will discard the data. However, I find in some instances the noise level seems to be in the normal range but the dat
Xu Cui
35 sec read

Near Infrared Spectroscopy (NIRS): List of manufactures

This post is under updating … The information is not complete Table can be found here: https://spreadsheets.google.com/spreadsheet/ccc?key=0AmI1wIXzRozHdFQzWHNQajI5eTlOeWRFd0tCT0hwYmc&hl=en_US Artinis OctaMon The m
Xu Cui
2 min read

What does a wavelet transform plot tell you?

Let’s say you collected some brain data (time series) using NIRS while the participants were performing a task (say finger tapping), and you use the wt function in the “Cross Wavelet and Wavelet Coherence Toolbox” (link dead. Please
Xu Cui
1 min read

Handy programs to visualize NIRS data (5): plot2

Let’s say you have two correlated variables, x and y. You may have more then one data points with x=10 and y=5. But if you do a scatter plot all these data points of the same value will become a single dot. You may want to use circles with size
Xu Cui
31 sec read

Handy programs to visualize NIRS data (4): wt

In case you need to visualize your time series in both time and frequency domain (or just frequency domain), you can use the wt (wavelet transform) function in the Cross Wavelet and Wavelet Coherence toolbox by Grinsted et al. I often find the color
Xu Cui
33 sec read

Handy programs to visualize NIRS data (3): plotFFT

Sometimes you wish to know the spectrum of a time series. plotFFT is a handy function for this purpose. You instantly know the power of the signal at each frequency. Here is an example on how to use this function: figure; plotFFT(randn(1,1000)); Sour
Xu Cui
11 sec read

Handy programs to visualize NIRS data (2): plotTopoMap

Often you need to view the spatial pattern of activation as in the example below. plotTopoMap allows you to do that. It probably only works for Hitachi devices where the spatial relationship between channels are known. In the above example, the activ
Xu Cui
37 sec read

Handy programs to visualize NIRS data (1): plotTraces

You often need to plot the time series of NIRS signal from all channels with event indicators (See the example below). plotTraces can do that easily. In the above example, time series of all 24 channels are plotted. The number on the y-axis indicates
Xu Cui
26 sec read

How to control ETG-4000 and receive realtime feedback simultaneously?

If you want to control ETG-4000 with your program through the serial port, and at the same time your experiment requires realtime feedback from the ETG4000, you can either merge the RealtimeOT script and your presentation script (which will be very c
Xu Cui
19 sec read