Mathematical derivation, circuits design and clinical experiments of measuring blood flow volume (BFV) at arteriovenous fistula (AVF) of hemodialysis (HD) patients using a newly-developed photoplethysmography (PPG) sensor

Mathematical derivation of calculating blood flow volume (BFV) at arteriovenous fistula (AVF) using a newly-developed photoplethysmography (PPG) sensor is presented in this work. Also, the readout circuit of the PPG sensor intended to increase the signal-noise ratio (S/NR) is designed and presented in this work. The designed PPG sensor equipped with derived mathematical equations shows high correlation (R
²
= 0.7563) and low error (RMSE = 212 ml/min) as compared to the gold standard.