View Full Version : SUMMARY for Reading Biopac Acqknowledge files in Matlab

04-29-2008, 11:21 AM
Dear Biomech-L subscribers,

Thank you to everyone who responded to my request for help in opening
acq files in Matlab. I have included the original posting below and
provided a summary of replies. The first item in the summary of
responses is a link to an m-file which was specifically designed to open
acq files in Matlab, and worked perfectly for my purpose.

Best regards,
Danny Russell


We are trying to import Acqknowledge output files from the BIOPAC Data
Acquisition System into Matlab. Currently we need to open and save each
individual acq file in text format before we can process the data using
Matlab. This is very time consuming for over 2000 data files. If you
know a way of speeding this process up please let me know.

I'm happy to provide a summary of replies.

Best regards,
Danny Russell


Use the following script:
The script is not written by BIOPAC systems and thus the functionality
is not guaranteed. It should be tested before using. We recommend
exporting your graph in PC format if on the MAC(when using on the
Macintosh, go to File->Save as and export to the PC graph format).
Alex Dimov

Version 3.7.2 of Biopac Student Lab has the capability to export
directly to .mat files.
Check also this site: http://www.biopac.com/FAQ-Details.asp?ID=88
Alternatively, there are functions on the matlab file exchange website
that can import acq files
(http://www.mathworks.com/matlabcentral/fileexchange/loadFileList.do). I
tried some of these, but none did the job quite well.
Martijn Muller

If you send a few data set to www.thebiocat.com
), BioCAT may help you (coding simple m
file to do this job).
Dongchul Lee

What do you want to do?? Do you want to read the acq files in one matlab
Or directly to import (process) the measure via matlab?
If former, I recommend the matlab function, 'dir'.
The function finds same file extension in current folder. More detail,
please refer the help of Matlab. Ex)
ACQ_File = dir('*.txt');
for k=1:length(ACQ_File)
fid = fopen(ACQ_File(k).name,'rt');
temp = fscanf(fid,'%f %f %f %f',[4 inf]);
If later, it needs some programming skills. More detail, please refer
below site. http://www.biopac.com/FAQ-Details.asp?ID=115

I am aware of the following m files available from matlab central that
may be of use to you (although I have not yet got round to trying
either of them):


Omar Mian

Matlab can read many different file types. So if the file format is
known, Matlab should be able to read it.
Check the Matlab file Exchange site
http://www.mathworks.com/matlabcentral/ to see if others have made code
for this issue.
Nitin Moholkar

I used to have exactly the same problem as you do. I wrote a small
program to solve this problem. Please check my website:
If your data file is in uncompressed binary format (16bit signed
integer in binary form: 0000-FFFF), then I believe you may try this
Click open you can see a standard Open File dialog, which allows you to
select MULTIPUL files. Then choose Customize setting in Preset box, specify
the start address of the data section (start from zero is fine, you can
figure out the data section easily from the output file) and the number of
the channels. After click Convert this program will process all the files
you selected and convert them into tab separated text files.
I will be glad to provide source code. If you can give me some
examples of your data file (two raw data files and two processed text files
from them with different number of channels). I can check them quickly and
tell you if my program will work.
Have a nice day.
Yu Shu, Phd


Daniel M. Russell, Ph.D.
Associate Professor of Kinesiology
Penn State Berks
Tulpehocken Road
P.O. Box 7009
Reading, PA 19610-6009
(610) 396-6009 (Voicemail)
(610) 396-6155 (Fax)