Design and characterization of a fiber optic respiratory plethysmograph (FORP)

Invasive techniques used in the measurement of respiration are often regarded as cumbersome, distressing to the subject and in some cases impractical for prolonged use. A current non- invasive alternative is the respiratory inductive plethysmograph (RIP), widely used in the clinical environment. The RIP, however, is expensive and prone to electromagnetic interference (EMI) and is therefore unsuitable in such environments as the interior of a magnetic resonance imaging (MRI) scanner. This research focuses on the development and construction of an all-optical analogue of the RIP, the fiber optic respiratory plethysmograph (FORP). A number of calibration techniques, both linear and non-linear, have been investigated to determine the relationship between the ribcage and abdomen during breathing. An evaluation of these techniques has provided an efficient method of respiratory volume monitoring. The results of testing the device using the various calibration methods are presented.