System and method of determining respiratory status from oscillometric data

Abstract

A system and method for determining the respiratory and other physiological status of a patient. Here, an oscillometric device is mounted on a patient's limb, and oscillometric pulse waveforms are obtained as the device's cuff deflates, thus obtaining pulse wave signals and artifact signals over multiple patient breaths. A computer processor analyzes these signals, and removes artifacts according to various algorithms. The resulting signal can be viewed as containing both an amplitude modulated envelope of pulse waves (AM signals) and a frequency modulated sequence of pulses at various time intervals (FM signals). The main harmonics of the AM and FM signals contain respiratory status data, and the system analyzes both signals. Breathing depth and even pain data may also be obtained by this method. Artifacts caused by aberrant breathing can be distinguished using non-contact microphones and suitable algorithms. The final respiratory status data is output or stored in memory.