Fig. 7: Clinical validation of the thrill sensor in hemodialysis patients.

a Photo and digital subtraction angiography (DSA) or Doppler ultrasound images of well-functioning arteriovenous grafts (AVGs) in three patients (Patient A, B, and C). The monitoring points (P1āP10) are distributed along the graft from the arterial anastomosis (P1) to the venous anastomosis (P10), with P6 at the U-turn. b Thrill intensity histogram and time-domain thrill signals at key monitoring points (P1, P6, P10) for three patients of well-functioning AVGs. The thrill intensity is highest at P1 and decreases towards P6, reaching a minimum, and then increases towards P10. Data are presented as mean valuesā±āāSD from nā=ā9 individual cardiac cycles in each monitoring point. c Photo and DSA images of abnormal AVGs with residual stenosis at venous anastomosis in three patients (Patient D, E, and F). d Thrill intensity histogram and time-domain thrill signals at key monitoring points for three patients of abnormal AVGs with residual stenosis. The thrill intensity is reduced overall, with a notable increase singularity at P10. Data are presented as mean valuesā±āāSD from nā=ā9 individual cardiac cycles in each monitoring point. e Photo and DSA images of abnormal AVGs with irregular lesions in three patients (Patient G, H, and I). Patient Gās AVG exhibits a morphological 90° turn, Patient Hās AVG has graft ectasia, and Patient Iās AVG has a non-drug-eluting stent implanted near the venous anastomosis. f Thrill intensity histogram and time-domain thrill signals at key monitoring points for three patients of abnormal AVGs with irregular lesions. The thrill intensity is reduced overall, with a notable increase singularity at the lesion point. Data are presented as mean valuesā±āāSD from nā=ā9 individual cardiac cycles in each monitoring point. g Correspondence between the thrill intensity and blood flow rate in the AVGs of 9 patients. The thrill intensity exhibits a positive correlation with the blood flow rate in well-functioning AVGs (Patient AāC) and a significant thrill intensity reduction in abnormal AVGs (Patient DāI). h Diagram of the thrill intensity distribution along the AVGs of 9 patients.