Lab 8

Approximate Time: 3 hours

“This material is adapted from iWorx Systems Inc with permission.” 

Equipment Required

IXTA, and power supply for IXTA

ROAM ECG

Alcohol swabs

Disposable ECG electrodes

Setup

Note: The student should make sure that all jewelry from their body has been removed. Please move all electronic devices away from the equipment as this may interfere with the signal (unplugged laptops, tablets, phones, smart watches, etc.)

Note: Disconnect the subject from the IXTA prior to powering off the device.

1. Use an alcohol swab to clean the areas where the electrodes will be attached. Make sure these areas are dry before attaching the electrodes.
2. Remove the plastic covering from the five disposable electrodes and apply an electrode to the scrubbed areas as shown in the picture below.
3. Remove the Wireless ROAM from the iWorx unit and place the electrodes so that:

Red lead (cable) is attached under the left clavicle (top left).

Black cable is attached under the right clavicle (top right) .

White cable is attached to the bottom left.

Brown cable is attached to the bottom right.

Snap the wireless ROAM on the fifth electrode  Note: females can position the fifth electrode in between the red and black lead – making a horizontal line.

Students are encouraged to go the restroom to put the electrodes on themselves.

4. Instruct the subject to sit quietly with their hands in their lap. If the subject moves, the ECG trace will move off the top or bottom of the screen. If the subject moves any muscles in the arms or upper body, electromyograms (EMGs) from the muscles will appear on the ECG recording as noise.

Start the Software

1. Turn onthe iWorx TA-ROAM box.
2. Clickthe Labscribe23 icon on the computer screen.
3. A default mode box will appear, clickOK. A pop-up box should appear indication that the iWorx IX-TA ROAM (hardware) has been found, click
4. When the program opens, Clickon Settings on the toolbar on top. Select Human Heart and then SixLeadECG-ROAM.
5. LabScribe will appear on the computer screen as configured by the SixLeadECG settings.
6. Your screen will have graphs specific to your recording. You will notice that each graph is color coded.  Anything with a blue background bar represents data being recorded on those channels are live, meaning that the data is coming directly from the subject.  A light green background bar that the data being recorded on that channel is data being calculatedfrom the subject’s data from the other channels.
7. Adding a channel– Click the Fx button on the first ECG channel – Click Periodic, then Rate and OK. This will create a new channel that will measure HR.
8. Name this channel by clickingthe title on the left. Label this channel, Heart Rate.
9. ChangeV2-V1 (on the right of the new graph) to Mean on the Heart Rate channel.

Procedure

1. Changethe Display Time to 15 seconds.
2. LabelResting Subject 1 on the Mark box. Click the Mark button to attach the comment to the data.
3. Clickon the Record button. Continue to record for at least 2 minutes.
4. Clickon the AutoScale All button. Your recording should like the figure below.

• If the signal on the Lead I and Lead II channels is upside down when compared to trace click on the downward arrow to the left of the channel title and select the Invert function. The trace should now look similar to the one in the figure.

5. ClickStopto halt recording.
6. You are now ready to analyze the data, scroll through the recording and find a section of data with five good ECG cycles in succession.
7. Use the Display Time icons to adjust the Display Time of the Main Window to show the complete ECG cycles on the Main window (this is done by clickingthe half displaytime button – it looks like one volcano).
8. The mathematical functions, V2-V1 and T2-T1 should appear on the right of each graph.
9. Once the cursors (vertical red lines going through all channels) are placed in the correct positions for determining the time interval of each wave in an ECG cycle. The values of the time interval can be recorded in Tables.
10. Use the mouse to click on and drag the cursors to specific points on the ECG recording to measure the following (measure at least 3 ECG cycles):

• PR Interval:To measure this interval, place one cursor at the beginning of the P wave and the second cursor at the beginning of the QRS complex. The value for T2-T1 on the ECG channel is the PR interval. Measure this interval for two additional ECG cycles.

• QT Interval:To measure this time interval, place one cursor at the beginning of the QRS complex and the second cursor at the end of the T wave. The value for T2-T1 on the ECG channel is the QT interval.  Measure this time interval for two additional ECG cycles.

• QRS Complex Interval:to measure this interval, place one cursor at the beginning of Q and the second cursor at the end of S. Measure this time interval for two additional ECG cycles.

11. Record the calculated Heart Rate showed in the Heart Rate channel (green bar). Note: Subject needs to be completely RELAX for this value to be within the normal range.

12. Complete the chart below with the values obtained:

*note: As there are many varying answers to these, you will be automatically marked “incorrect” by Canvas when you first submit your values, but as long as you followed directions, your instructor will mark them all correct.

To determine blood pressure:

Place a pressure cuff around the upper arm 1 inch above the junction of the elbow. Inflate the cuff to approximately 160 mmHg to completely occlude the brachial artery. While listening with the stethoscope’s diaphragm over the brachial artery distal to the occlusion, slowly release, at approximately 3 mm Hg/second, the pressure until an intermittent sound is heard. This first sound indicates systolic pressure. Continue to release the pressure until the sound disappears. The point at which the sound disappears indicates the diastolic pressure.

Warning:  This procedure involves stopping blood flow to the arm, which is potentially dangerous. If there are enough students in the lab with experience in this procedure, they may assist inexperienced students. Please take the following precautions:

1. Know what you are doing ahead of time.
2. Do not leave the cuff inflated for any prolonged period of time (>30 seconds).
3. The volunteer should flex and extend their fingers between experiments to maintain blood flow.
4. This experiment should be performed on healthy individuals who do not have a personal or family history of cardiovascular or respiratory disease

To determine pulse:

We will determine pulse rates manually and with the pulse oximeter. To take a manual pulse, place your fingers (not your thumb) on the thumb side of your partner’s wrist at the radial artery. Place the pulse oximeter on a finger on that hand. Count the pulse for 15 seconds and multiply this number by 4 to obtain the beats per minute. The pulse can also be monitored on the neck (carotid artery).

Caution: great pressure is not required to monitor the pulse, and, in fact, too much pressure may produce a change in the pulse rate. Never monitor a subject’s pulse with your thumb, because you may feel YOUR OWN pulse, from the artery in the thumb.

Measure you and your partner’s pulse and blood pressure in three different conditions:

supine (after 10 minutes), standing (immediate), and standing (after 5 minutes). Determine your pulse both manually and with the pulse oximeter, while your lab partner determines your blood pressure and records data on your datasheet. For each of the pulse rate determinations, obtain an average of 3 separate recordings (for each), and record it in the spaces provided. Then switch and take readings on your lab partner.

1. Record the normal resting (standing) pulse rate (using the pulse oximeter) and blood pressure of a volunteer in the group (Use your standing 5-minute values from Activity 1) under ‘Normal’ on the data sheet.
2. With the deflated pressure cuff in place, have the group’s volunteer perform a standard exercise for one minute using a step-up test, squats, running in place, jumping jacks, or whatever other exercise you want to do that will increase your heart rate.

**IF YOU FEEL THAT YOU SHOULD NOT DO THIS EXERCISE ACTIVITY, PLEASE FEEL FREE TO OPT OUT OF IT.

3. After exercise, the volunteer will monitor his or her own pulse rate (using the pulse oximeter) while you monitor his or her blood pressure. After one minute of exercise the subject stops and the pulse rate and blood pressure are monitored immediately.
4. Continue to determine the pulse rate every 15 seconds for two minutes or until the recovery heart rate reaches the pre-exercise value. Determine the blood pressure at one minute and two minutes following exercise.

Record your results:

Continue taking readings until normal values are reached:

Health and Safety Training for Biology 2425-Physiology Labs involving human blood

• It is required for Lab Instructors to teach students the importance of handling blood in a safe manner. Students who fail to follow the rules will be expelled from class.
• Human blood can potentially contain blood borne viruses, such as HIV and hepatitis.  Working with blood therefore carries a risk of infection if blood is not handled with care.
• Do not touch or come into contact with another student’s blood. Students should handle only their own blood!
• Students that do not feel comfortable with obtaining a small sample of their own blood can complete the lab activity by using the alternate sheep blood instead.
• The Lab Instructor and students are required to wear laboratory coat, gloves, and safety goggles at all times through the entire lab.
• Lab Instructor will introduce the equipment being used and demonstrate how to use the equipment.

**DO NOT PERFORM THE BLOOD LAB ACTIVITIES IF YOU HAVE ANY OF THE FOLLOWING CONDITIONS:

1. Bleeding disorders such as hemophilia or thrombocytopenia
2. A blood-borne infectious disease such as HIV or Hepatitis.
3. Individuals with a history of thrombosis, stroke, or liver disease.
4. Individuals taking anticoagulant medication.

Salt Lake Community College has a Bloodborne Pathogen Policy that can be found at

http://i.slcc.edu/facilities/docs/BLOODBORNE_PATHOGEN_POLICY_Oct_2011_RW.pdfLinks to an external site.

Procedure: Please read and follow all instructions enclosed in your blood typing kit.  Your kit is only meant for your use, do NOT share your kit with another.

Safety Procedures:

1. Clean the table with a disinfectant solution and wipe it down with paper towels both before and after lab.
2. Wear gloves at all times during the entire lab. Replace damaged gloves immediately.
3. Wear safety goggles during the entire lab.
4. Work alone at your “assigned area”.
5. Wipe your thumb or finger with a sterile alcohol swab and allow the skin to dry.
6. The alcohol swab wrappers and band-aids wrappers need to be disposed in the biohazard bag.
7. Uncover the sterile lancet. Once used, dispose of the lancet into the sharps container immediately. DO NOT REUSE LANCETS!!
8. Gloves and paper towels need to be disposed in the biohazard bag.
9. Capillary tubes need to be disposed into the sharps container
10. Notify your instructor if sharps container or biohazard bag is getting full.
11. Notify your instructor if you accidentally discard something in the wrong container.
12. Keep your work area clean and uncluttered.
13. Wash your hands immediately before leaving the lab.

This chart will be posted in the “assigned area”

SPECIFIC DISPOSAL

***STUDENTS WHO DID NOT SIGN THE CONSENT FORM MAY FOLLOW THE ALTERNATIVE BLOOD PROCEDURE AVAILABLE IN THE LAB

Imagine you worked with blood transfusions and had patients with the blood types listed below. Please select the answer which includes ALL blood types each patient COULD receive. (make sure you read all possible answers before selecting)

***In this activity, you will determine the hematocrit using capillary tubes and a centrifuge.  ONLY one member of each group will be doing this activity. To avoid contamination, your instructor will be running the centrifuge. 

Hematocrit Determination

1. Place the blood samples in the heparinized capillary tubes into a numbered radial slot position of a centrifuge fitted with a capillary tube head. Position the capillary tube with the clay seal away from the center of the capillary tube head. Remember the number of the position of your capillary tube. When the head is filled with capillary tubes carefully screw down the cover of the centrifuge and spin the samples for 3 minutes (this will be run by your instructor).

2. When the centrifuge has stopped spinning (Caution: allow the head to stop of its own momentum and do not try to stop it sooner, or you might re-mix the solution), take your (check your number) capillary tube and hold it vertically with the clay-sealed end down. Observe the upper clear plasma, the lower portion of packed red blood cells (RBCs), and the thin boundary of white blood cells (WBCs) that separates the RBCs from the plasma. Another precaution: after you remove the capillary tube from the centrifuge read the hematocrit as soon as possible. If that is not possible, store the capillary tube in a vertical position.

3. To determine the Hct of your sample use a small plastic ruler to measure to the closest estimated fraction of a millimeter: A) Measure the height of the whole blood column of from the clay/blood junction at the bottom of the tube to the meniscus of the plasma at the top of the blood column. Record the total height of the whole blood column on the data sheet. B) Next measure the height of the column of packed RBCs from the clay/blood junction at the bottom of the tube to the top of the RBCs at the WBC/RBC junction. Record the height of the RBC column on the data sheet.

From these values calculate the Hct by the formula:

Hct  =  (height of RBC column / height of whole blood column) X 100

Hematocrit Determination