“… Development of different methods over the years. Invasive blood pressure waveform study [ 17 , 18 , 19 , 20 , 21 , 22 , 23 ]; Arterial tonometry study [ 33 , 65 , 67 , 68 , 86 , 89 , 90 , 91 ]; Volume clamp method study [ 32 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 92 , 93 , 94 , 95 , 96 , 97 ]; Ultrasound-based method study [ 34 , 35 , 36 ]; Deep learning with biosignals related study [ 25 , 37 , 38 , 39 , 40 , 70 , 72 , 73 , 74 , 75 ]. …”