Today I was able to acquire a number of my own real time ECG samples, filter the 60 Hz power line noise out of the signals by means of the digital Notch Filter C code, launched to OMAP-L138 LCDK, and record the result into MATlab work space using MATlab DAQ Toolbox.
(Please, click on the picture below to see the enlarged image)
Being able to record real time ECG signals into MATlab allows us to further process data using MATlab programming tools. Thus, at this point it has been decided to replace the WinDSK8 software, initially used in the project, with MATlab. The Tutorial about “how to get started with WInDSK8” will still be placed on this website.
Now we have a working digital Notch filter, needed to eliminate the 60Hz Power line interference from an ECG signal. The filter was implemented by writing a C/C++ code and inserting it into a Code Composer Studio Project. As it has already been mentioned, Code Composer Studio is compatible with TI OMAP-L138 LCDK, so we were able to load the code to the board and run it. The video, linked below, shows that the filter attenuates the amplitude of the 60Hz input signal while keeping the amplitudes of other frequencies inputs unchanged.
Using the analog amplifier circuit, built for Experiment 2, we have been able to record an ECG signal on a digital oscilloscope screen.
After having connected the analog amplifier’s output (pin 6 of the U4 op-amp) to the analog Line In input of the OMAP-L138 LCDK board, we were able to obtain a digital signal of approximately 1 Hz frequency with clearly distinguishable QRS peaks on a PC screen, using the Oscope/Analizer function of the winDSK8 software. The signal, however, was distorted by a 60Hz noise, which is to be removed by means of a digital Notch filter. The results for filtered ECG signal, as well as the lab guide for Experiment 3 will be posted soon.
This evening, we received the news that our Draft Paper submitted on January 7th, was accepted into the 2014 ASEE Annual Conference! This is an admirable milestone achieved by our research group as we are one step closer to a Final Paper acceptance!
We are now working on the revision for the Final Paper that shall be submitted on the 16th of February. Our research group is working harder than ever before to submit a state-of-the-art paper. We appreciate the support, and will provide project updates on a weekly basis.
A timeline of our paper’s journey:
October 20, 2013: Abstract submitted
November 5, 2013: Abstract accepted/Call for Draft Paper
January 7, 2014: Draft Paper submitted
February 4, 2014: Draft Paper accepted/Call for Final Paper
February 16, 2014: Deadline for Final Paper submission
It is December 25th, but this is not an excuse for us to stop working on this project! We made available three new tutorials that will walk you through the basic steps to set up your OMAP board, and to implement and run your first piece of code into the board.
Please check it out on the Tutorials Menu, located under the Biomedical Signal Processing page.
Last month an important milestone in this project was achieved! The final ECG circuit was finally assembled, specified, and tested! That was the first time we achieved a real-time ECG signal on the screen of our laboratory’s oscilloscope.
You can check out the video of our first ECG signal here (I apologize for the quality of the video, we did not have a good camera to register this moment).
The tutorial for this accomplishment and the steps to reproduce it are listed here. Please feel free to check it out. Any comments and suggestions are welcomed!