RESUMO
OBJECTIVE: Implementation of clinical guidelines for diagnosing peripheral artery disease will demand screening many millions of patients who are considered at-risk. This will require faster, easier screening technologies to identify patients with compromised blood flow to the extremities. APPROACH: The feasibility of using surface temperature response to Ka band (26.5-40 GHz) near-field irradiation to assess skin blood flow was explored using an animal model. Ears of domestic rabbits were subjected to low-power continuous wave radio frequency heating from an open-ended waveguide (WR-28) at f = 35 GHz. Three flow conditions were evaluated: (1) a baseline flow condition, (2) occluded flow and (3) reactive hyperemia. Surface temperatures were monitored continuously by means of an infrared thermography camera during each 2 min exposure. MAIN RESULTS: Ensemble average results showed significant differences (p < .05) at exposure times 30, 60, 90 and 120 s between baseline and occluded conditions, and between baseline and reactive hyperemia conditions. The occluded condition (N = 12) resulted in an average temperature increase of 21.4 °C ± 3.9 after 2 min, compared with an average increase of 12.1 °C ± 1.6 for baseline conditions (N = 9) and 4.7 °C ± 3.6 for post-occlusion/hyperemic conditions (N = 8). SIGNIFICANCE: Results are compared with the results of a simple two parameter mathematical model. These results suggest a method for non-invasive skin blood flow assessment to screen for peripheral artery disease and associated risk of cardiovascular events.