Respiratory Physiology Part 1:
Spirometry: Respiratory Volumes and Capacities
Student Learning Objectives:
• Record and ID lung volumes from a spirogram.
• Define all lung volumes /capacities listed in lab exercise.
• Distinguish between a lung capacity and a lung volume.
• Calculate lung capacities from lung volumes.
• Compare values obtained with values in text.
Reading: Fox pp.535-539.
Spirometry is a technique used clinically to assess lung function. Patients breathe into a machine that measures volumes of air moved in and out of the lungs under different conditions. Abnormal results can indicate disease in the lungs and/or cardiovascular system.
Read pages 567-568 in Silverthorn before proceeding. Make sure you can define and ID any volumes and or capacities. You will use Biopac physiological recording equipment to record and measure lung volumes, capacities and forced expiratory volumes and make calculations on the data. A lung volume is an amount of air moved in or out of the lungs. A lung capacity is obtained by summing known volumes. Forced expiratory volume is an amount of air that can expired per unit time, with maximum effort. It is measured during the vital capacity maneuver. (See Part II). Each lab group will need a data acquisition box (MP35) connected to a computer, an airflow transducer, a bacteriological filter, a disposable mouthpiece, a nose clip, a calibration syringe and a set of illustrations showing you how to connect the equipment. Make sure the data acquisition box is on before starting software. Connect the docking station to the Ethernet for printing before starting up the computer. Ask the instructor to supervise before printing your records. Make a note of the computer number you are using so that you can use the same one for part II of respiratory physiology.
1. With the MP35 turned off, plug the airflow transducer into Channel 1. Switch on the MP35 then start up the laptop.
2. Open Lesson 12 Pulmonary function 1 in Biopac Software.
3. Place a filter into the end of the calibration syringe.
4. Insert the calibration syringe/filter assembly into the INLET (marked) of the airflow transducer.
Make sure there is a tight seal. Support the apparatus by holding the calibration syringe, not the airflow transducer.
5. Type in the subject's filename, then click OK.
6. Make sure that the airflow transducer is held upright. Pull the calibration syringe plunger all the way out then remove your hand from the plunger. Hold the apparatus steady during the calibration.
7. Click Calibrate and hold the apparatus for the entire calibration procedure of 8 seconds. Do not push the plunger yet.
8. Calibration will automatically stop, and ask if you have read the next set of instructions. Do not click
"Yes" until you have completely read and understood the instructions.
9. Support the apparatus by holding the calibration syringe. During this stage of calibration, take one second to push the plunger in, wait 2 seconds, take one second to pull the plunger out, wait 2 seconds, and repeat 4 times. That is, you will cycle the plunger in and out completely 5 times). When you are done, click "End Calibration".
10. If your data shows 5 upward and 5 downward deflections, you are done with this section. If not, click
Redo Calibration and repeat steps above. Note: the tracing should go up when you pull the plunger out
(inspiration) and down when you push the plunger in (expiration). If it is reversed, you have the syringe in the wrong end of the transducer! Turn it around and place in the inlet.
10. Remove the calibration syringe and set it aside. Keep the filter attached to the airflow transducer.
Data Recording, Part 1.
Tidal Volume, Vital Capacity, Inspiratory Reserve Volume, Expiratory Reserve Volume.
1. Remove a mouthpiece from the plastic bag and insert