If you are found to be eligible and you agree to take part in this study, you will have a lung function test with the VRI system immediately before or after the standard lung function test. To perform the VRI test, you will be asked to remove your shirt and put on a garment to cover the front of your body. You will also be asked to remove your jewelry and other body accessories. You will then be asked to sit on a backless chair, and you will be instructed how to sit with the proper posture and breathe correctly for this test.