Read a Biopac AcqKnowledge file


Updated 20 Dec 2010

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[INFO, DATA] = ACQREAD(FILENAME) reads the content of the AcqKnowledge file specified in the string FILENAME. INFO is a structure containing the metadata (header, markers, etc.). DATA is a cell array, indexed by the channel number, containing the acquired physiological signals.

[INFO, DATA] = ACQREAD displays a dialog box that is used to retrieve the desired file.

ACQREAD supports all files created with Windows/PC versions of AcqKnowledge (3.9.1 or below), BSL (3.7.0 or below), and BSL PRO (3.7.0 or below).

ACQREAD supports channels that were acquired using different sampling rates, therefore having a different number of samples.

Details of the AcqKnowledge file format are presented in Biopac's Application Note #156 (last updated on June 29, 2007), and available at : "".

ACQREAD, version 3.0 (2010-12-20)


1) ACQREAD is faster than other similar functions available to date on the Matlab Central File Exchange, especially for files with multiple channels acquired at different sampling rates.

2) No scaling is done by ACQREAD. It reads the raw data as stored in the ACQ file, and returns it in the DATA structure without any processing. However, the scaling information of each channel is available in the INFO structure.

Cite As

Sebastien Authier (2023). ACQREAD (, MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2006a
Compatible with any release
Platform Compatibility
Windows macOS Linux

Inspired by: Load BIOPAC ACQ (AcqKnowledge for PC) data

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Version Published Release Notes

License updated as requested by MathWorks.

An error in the function definition line (generating a warning message) was corrected.