(a) CRI values for HUVECs as a function of stimulated acoustic pressures at the indicated input voltages [0 MPa (n=21), 1.8 MPa (input voltage: 9.48 Vpp) (n=21), 2.4 MPa (input voltage: 12.64 Vpp) (n=21), 3.0 MPa (input voltage: 15.80 Vpp) (n=21), and 3.6 MPa (input voltage: 18.96 Vpp) (n=19)] (PRF: 1 kHz and duty cycle: 1 %). CRI values were normalized by the CRI value at 3.6 MPa (b) CRI values for HUVECs as function of duty cycles [0.1 (n=10), 0.25 (n=10), 0.50 (n=10), and 0.75 % (n=8)] [PRF: 1 kHz and simulated acoustic pressure (input voltage: 18.96 Vpp): 3.6 MPa (p-value: 0.25 < 0.05)]. CRI values were normalized by the CRI value at 0.75 %.