EE 1105/1305 – Intro to Electrical and Computer Engineering Module 5 – EKG Week of March 30 th , 2020 Name:________________________________ Group:_____________ IMPORTANT - READ CAREFULLY: Lab questions are now broken into PRE-LAB, LAB, and POST-LAB components. Please go to the EE1305 website and read the lab procedure, and complete all of the PRE- LAB sections, BEFORE coming to the lab. Pre-Lab - Question 1 : What is electrocardiogram (EKG)? Plot EKG signal with at least 3 cycles (you can search online to see how EKG signal looks like). Example of possible solution: This is an example of EKG signal. Please find a different figure for your report. Explain your EKG plot in terms of the frequency of the signal (number of cycles per second) Example of possible solution: In the figure above, there are 3 cycles and time period is 2.75 second. The frequency of EKG signal will be: f= Number of cycles time = 3 2.75 = 1.09 1 s =1.09 Hz
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EE 1105/1305 – Intro to Electrical and Computer EngineeringModule 5 – EKG
IMPORTANT - READ CAREFULLY: Lab questions are now broken into PRE-LAB, LAB, and POST-LAB components. Please go to the EE1305 website and read the lab procedure, and complete all of the PRE-LAB sections, BEFORE coming to the lab.
Pre-Lab - Question 1: What is electrocardiogram (EKG)?
Plot EKG signal with at least 3 cycles (you can search online to see how EKG signal looks like).
Example of possible solution: This is an example of EKG signal. Please find a different figure for your report.
Explain your EKG plot in terms of the frequency of the signal (number of cycles per second)
Example of possible solution: In the figure above, there are 3 cycles and time period is 2.75 second. The frequency of EKG signal will be:
f= Number of cyclestime
= 32.75
=1.09 1s=1.09Hz
Please calculate the frequency of your EKG signal.
Pre-Lab - Question 2: What are lab safety recommendations regulated by the Association for Advancement of
Medical Instrumentation (AAMI)?
EE 1105/1305 – Intro to Electrical and Computer EngineeringModule 5 – EKG
Answer: Please pay attention to items below:1. Unplug the power brick from your laptop, and run the laptop on its batteries during the EKG
experiment. This converts the connection to a Type BF (fully floating) connection.2. Do not connect yourself to any other AC-powered instrumentation while you are doing this
experiment. Do not connect yourself to ground by holding onto an earth connection such as a water fixture.
3. If you are using one of the computers in the lab in E340, connect your power supply to one of your neighbor's PC. There should be plenty of PCs in the lab to enable you to do this.
NOTE: For this week’s lab, you are individually work for all procedures and everything should be completed by yourself. But, do not worry since we made everything easier for you and give you all instructions and help you need. For most questions, you are provided with sample of solutions and hints.
Lab – Procedure 1: A series of RC filters and the AD623 instrumentation amplifier will be used to construct the EKG circuit. Please follow procedure 1 to check AD623 amplifier connection diagram and AD623 amplifier gain (G).
Include the equations for gain (G) of the amplifier (AD623).
Answer: RG=100,000G−1
What is RG? Where is it placed?
RG is a resistor with two terminals of –RG and +RG. Please Look at Figure 1 and say where RG is placed?
Solve for gain (G) assuming that RG=499 Ω (Please show calculation step by step)? What is the value of gain (G) if RG=499 Ω?
If you solve for G, you should end up with G=201.4
EE 1105/1305 – Intro to Electrical and Computer EngineeringModule 5 – EKG
Lab – Procedure 2: Follow the procedure 2 on the website to build three types of RC filters shown in Figure 2.
Include the calculations for the characteristic frequency (fc) of each filter (see figure 2 in procedure 2).
Solution for low pass filter (circuit 1):
f c=1
2πRC= 12×π × (1K Ω ) (0.1uF )
= 12×π × (1000Ω ) (0.1×10−6F )
f c=159.15HzPlease solve f c for circuit 2 and 3.
Circuit 2:
f c=1
2πRC=??
Circuit 3:For circuit 3, you have 3 pairs of resistors and capacitors. So, you have 3 characteristic frequency (f c1 , f c2∧f c 3). Solve f c for each pair.
f c1=1
2 πRC=??
f c2=1
2 πRC=??
f c3=1
2 πRC=??
Include 3 screen shots for each filter (see step 6 in procedure 2)
Picture for circuit 1: (you do not need to cut legs of components since you need them for the rest of the semester)
EE 1105/1305 – Intro to Electrical and Computer EngineeringModule 5 – EKG
Adjust the frequency of the waveform to be (a) lower than fc (for example 10 Hz), (b) equal to fc (For circuit 1, fc=159.15 Hz), and (c) higher than fc (for example 10 KHz).
Here is the link of video instructions for this part:
Picture for circuit 2:Adjust the frequency of the waveform to be (a) lower than fc (for example 10 Hz), (b) equal to fc, and (c) higher than fc (for example 10 KHz).
Picture for circuit 3:Adjust the frequency of the waveform to be (a) lower than fc1 (for example 10 Hz), (b) equal to fc1, and (c) higher than fc3 (for example 10 KHz).
Include the Bode Plot (MATLAB Plot) with the fc value identified on the graph (1 for each filter, see step 7 in procedure 2)
At end of the video (the link is provided above), you can find instruction for creating Bode Plot.For all circuits, adjust the frequency range, setting the range to a low of 10 Hz, and a maximum of 100 kHz.
Lab – Procedure 3: Follow the procedure 3 on the website to construct the EKG circuit shown in Figure 3.
Calculate the value of fc for each of the filters in your circuit (see Figure 3 in procedure 3)I solve for first one please solve for f c2 and f c3f c1=
12 πRC
= 12×π× (1K Ω ) (10uF )
= 12×π × (1000Ω) (10×10−6F )
=15.9Hz
f c2=1
2 πRC=??
EE 1105/1305 – Intro to Electrical and Computer EngineeringModule 5 – EKG
Build the EKG circuit (Figure 3) on your breadboard. Put your UTEP ID across your breadboard and take a picture of your UTEP ID and final circuit on your breadboard, and include it in your report.
EE 1105/1305 – Intro to Electrical and Computer EngineeringModule 5 – EKG
Post- Lab – Step 1 Organize all of your Figures and tables neatly in your Word document. Figure caption is placed at the bottom while table caption should be placed on top of the table. For any figure you copy from website, please include reference number at the end of figure caption. Then cite to the website in Reference section of your report.
Post- Lab – Step 2 In a few sentences, answer the following sentences. You can also answer them in your Word doc if you want to type/need more room.
What was the goal of this module? What did you learn?
Post- Lab – Step 3 In a few sentences, answer the following sentences. You can also answer them in your Word doc if you want to type/need more room.
Explain how you know if your filter is a low pass, high pass or band pass filter based on your Bode Plot.
Post- Lab – Step 4
Imagine you are going to design a band pass filter to select heart rate signal (desired signal) and reject noises (undesired signal). The band pass filter has two cut of frequency, fc1 and fc2. Select one of the following as an optimal choice for the cut off frequency of the band pass filter:
