In this work, an algorithm was developed to measure respiration rate for an embedded\ndevice that can be used by a field robot for relief operations. With this algorithm, the rate measurement\nwas calculated based on direct influences of respiratory-induced intensity variation (RIIV) on\nblood flow in cardiovascular pathways. For this, a photoplethysmogram (PPG) sensor was used\nto determine changes in heartbeat frequencies. The PPG sensor readings were filtered using an\nInformation Filter and a fast Fourier transform (FFT) to determine the state of RIIV. With a relatively\nlight initialization, the information filter can estimate unknown variables based on a series of\nmeasurements containing noise and other inaccuracies. Therefore, this filter is suitable for application\nin an embedded device. For faster calculation time in the implementation, the FFT analysis was\ncalculated only for a major peak in frequency domain. Test and measurement of respiration rate\nwas conducted based on the device algorithm and spirometer. Heartbeat measurements were also\nevaluated by comparing the heartbeat data of the PPG sensor and pulse-oximeter. Based on the\ntest, the implemented algorithm can measure the respiration rate with approximately 80% accuracy\ncompared with the spirometer.
Loading....