An EKG, or electrocardiogram, is a graphical recording of the beating of the heart.  Doctors can look at an EKG and see evidence for heart disorders/defects, such as abnormal patterns.  There is a pacemaker located in the right atrium which initiates an electrical sequence and controls the beating of the heart through electric impulses.  A single beat is made up of five components: P, Q, R, S, and T.  The image below shows the five components that make up a single beat:

5 components of a single beat Photo found on this
5 components of a single beat
Photo found on this

The purpose of this lab was to obtain graphs of electrical activity of the heart over a period of time, to recognize the different wave forms seen in an EKG and associate these wave forms with activity of the heart, to determine an individual’s heart rate by determining the rate of wave forms in the EKG, and to compare a normal wave form to abnormal ones.

Prior to starting the lab, my group members and I opened up the LabQuest app and connected the EKG Sensor to it.  Then, one of my group members wiped her arms with rubbing alcohol in order for the electrode tabs to stick and to obtain the best results.   Three electrode tabs are placed on the inside of her right wrist, right upper forearm, and left upper forearm.  Then we connected the EKG clips to the electrode tabs: black on the right wrist, green on the right upper forearm, and red on the left upper forearm.  She sat in a relaxed position with her arms resting on the table and we collected the data on the LabQuest app.

Collecting data
Collecting data

After we collected the data, we switched the red and green EKG clips so that the green clip is now attached to the tab on the left arm and the red clip is attached on the right arm.  This will mimic the electrical activity of someone having a heart attack.  Then, the data was collected.

The data that we collected for the normal heart rate is shown in the graph/table below:

Normal heart beat
Normal heart rate graph
Data results
Data results

This graph shows a normal heart beat because all the 5 components are present and normal.  We were able to collect our data by identifying the 5 components in a heart beat.  We also calculated the beats per minute by dividing 60 over 0.82, which equals to 73 BPM.

The data that we collected for mimicking a heart attack is shown in the graph below:

Heart attack graph
Heart attack graph

Based on this graph, the P wave is present but abnormal, the QRS complex is inverted and is abnormal, as well as the T wave.

In conclusion, my groupmate’s heart rate was normal.  We compared our graphs to the graph below of a normal heart rate to make observations and conclusions:

Normal heart rate
Normal heart rate Photo from here

The P-R interval of my groupmate’s heart rate is 0.12s and the standard heart rate is about 0.15s.  The QRS is 0.05s compared to less than 0.1s on the standard heart rate graph.  The Q-T interval is 0.32s and the standard time is about 0.35s.  As you can see, her heart rate is normal and healthy.


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