Signal Acquisition System

Week 7

The next step in our project was to put all of the physical pieces together. The connection of the computer, data acquisition board, circuit boards and the person using the device was first on our agenda, and was readily placed on the table. For the DAQ to be able to work with both the computer and the circuit boards, a driver needed to be installed on the computer being used to accommodate the signals and MATLAB code.

Figure 1: Data Acquisition Board input diagram.

The next connection was the DAQ to the circuit board. Because the ports on our DAQ were not labeled, we used the diagram, found in Figure 1. We used ports 1, 2 and 3. For every analog input, there is a matching ground input. Additionally, there are two sets of inputs for the EOG signal circuit board (ports 2 and 3), and a single set of inputs for the EMG signal circuit board (port 1). Each of the wires then connected to the corresponding port on each circuit board.

Figure 2: The entire configuration of the system.

Finally, the wires from the circuit boards to the electrodes were connected, and then the electrodes were stuck to the face of the user. The entire setup is shown in Figure 2.  Unfortunately, the adhesive on the electrodes were very weak, and fell off of the face under the weight of the alligator clips. To solve this, we will either use additional adhesive, or find electrodes that will stick better to the face.