Efficacy of a hands-free vascular ultrasound probe holder in active and inactive limbs during cycling exercise

Measurement of blood flow during exercise is crucial for understanding physiological responses and performance outcomes. However, traditional methods are often invasive, costly, or require substantial training, limiting widespread research in this area. This study introduces the innovative use of limb-affixed ultrasound probe holders for vascular imaging during exercise to overcome these challenges. We investigated a commercially available probe holder, the Usono ProbeFix dynamic (PFD), in capturing artery diameter and blood velocity during dynamic exercise compared with a trained sonographer. Twenty healthy adults (11 females) underwent simultaneous imaging of the brachial artery and superficial femoral artery (SFA) using both manual and PFD imaging on separate days. Data were collected for 60 s at rest on a cycle ergometer and after 4 min of cycling at 50, 100, and 150 W. The PFD was comparable with a trained sonographer at rest (both 99 ± 2%) but demonstrated superiority in capturing blood velocity in the inactive limb (main effect of scanning condition P < 0.01; e.g., 150 W exercise: 85 ± 21% vs. 74 ± 25%). There was no effect of scanning condition on velocity capture success in the SFA (main effect: 69 ± 21% vs. 65 ± 16%; P = 0.42). A systematic constriction of brachial artery diameter (∼0.02 cm) was noted in the PFD condition (P < 0.01), likely due to the compression of the shallow artery. The findings suggest that ultrasound probe holders offer a promising solution for increasing accessibility to exercising blood flow in vascular physiology research, though require considerations for data cleaning and diameter assessment. Further investigation is warranted to optimize the application of these devices in dynamic exercise scenarios.NEW & NOTEWORTHY This study explores an ultrasound probe holder (PFD) for measuring blood flow during exercise, addressing the limitations of traditional methods. We compared PFD imaging with manual scanning in capturing artery diameter and blood velocity during cycling exercise. Results showed that the PFD matched trained sonographer accuracy at rest and outperformed them in capturing blood velocity during exercise in the inactive limb but not active limb. We highlight the PFD's potential impact in vascular physiology research.