Week 17 (03/07/2021)

Following the Spring Break, the analog circuit (Figure 1) was finalized and completely built. With the circuit complete, testing was done with the electrodes to prove that brainwaves were indeed being recorded by the system.

Figure 1: Final Circuit Diagram

The team performed testing inside the Faraday cage. The purpose of the Faraday cage testing was to verify that the electrodes were not just acting as a radio, amplifying weaker electromagnetic interference in the room that would corrupt the original signal.

After confirming that the signal data is similar, the team tested whether any of the data being collected was due to movement. Tyler was placed in a comfortable, laying down position with his eyes closes, and the electrodes cables placed in a stable position to verify that none of the data being collected was due to the cables swinging or body movement.

Following the Faraday cage and couch testing, four sets of data were collected to compare the datasets to ensure that the electrodes are actually collecting brain signals. The datasets collected were six minutes of laying down with the eyes open, six minutes laying down with the eyes closed, six minutes of the electrodes attached to the hand, and six minutes of the electrodes attached to an inanimate object. The four datasets collected will be analyzed by next week.

In terms of research, the team clustered datasets from four different patients that experience the same psychiatric problems. Figure 2 illustrates the 3-D plot comparing the signal's time-domain peak-to-peak voltage, frequency-domain peak-to-peak voltage, and the index of those peak-to-peak frequencies. It is clearly seen that all the data points of Patient 1, 2, and 4 are clustered within a specific region, where one set of data may have a large amplitude than the others, but it is noticeable that Patient 3 has a much less frequency amplitude with some of their frequencies in the 25 Hz area.

Figure 2: 3-D Plot of Four Patients

THIS WEEK

Tyler

• Finalized circuit diagram (Figure 1)

• Tested the circuit under various conditions to verify its functionality

Mark

• Performed clustering and signal analysis on datasets involving the four patients
  

NEXT WEEK

Tyler

• Continue to test EEG circuit, data collection, and perform any necessary circuit debugging

• Present current progress to Loyola Marymount University's Electrical Engineering faculty

Mark

• Perform clustering and signal analysis on the four collected datasets

• Continue to edit MATLAB code for improvements

• Present current progress to Loyola Marymount University's Electrical Engineering faculty