Smartphone-Based Mobile Thermal Imaging Technology to Assess Limb Perfusion and Tourniquet Effectiveness Under Normal and Blackout Conditions

SLR - November 2018 - Shawniece Boss

Reference: Barron MR, Kuckelman JP, McClellan JM, Derickson MJ, Phillips CJ, Marko ST, Smith JP, Eckert MJ, Martin MJ. Smartphone-Based Mobile Thermal Imaging Technology to Assess Limb Perfusion and Tourniquet Effectiveness Under Normal and Blackout Conditions. Journal of Trauma and Acute Care Surgery. 2017 Dec; 83 (6), 1129–1135.

Scientific Literature Review

Reviewed By: Shawniece Boss, DPM
Residency Program: New York Presbyterian Queens, Flushing, NY

Podiatric Relevance: The podiatric surgeon commonly encounters traumatic amputations of the lower extremity. Most of these amputations stem from military and motor vehicle settings. During the transport of these patients to higher level of care, focus and efforts should aim for maximal limb salvage. Applying an adequate field tourniquet will result in better prognosis for limb salvage. Having a tool to assess the adequacy of tourniquet placement and utilizing a smartphone mobile thermal imaging device will help consistently and rapidly achieve this goal.

Methods: Three separate experiments were conducted on 10 swine. Experiment 1 simulated proper tourniquet applications, experiment 2 simulated a tourniquet inadequately tightened and experiment 3 simulated an inadequately tightened tourniquet during “blackout-combat conditions.” Static images were taken of all three subject groups utilizing the FLIR ONE smartphone-based thermal. All images were then presented to blind evaluators.

Results: The thermal imaging temperature decreased significantly once the varying tourniquet pressures were applied. The thermal image showed clearly visible perfusion differences between baseline and the experimental groups. Ninety-eight percent of the blinded evaluators correctly identified adequate and inadequate tourniquet placement.

Conclusions: The smartphone-based mobile study was designed to determine if thermal imaging could accurately assess lower-extremity perfusion after tourniquet placement. The results of this study show that this modality could have a significant impact on our ability to assess this treatment protocol. If distributed to local EMS dispatchers, this tool could be very valuable in our management of lower-extremity hemorrhaging and nonhemorrhaging injuries. I found it valuable that the blinded volunteers had little to no knowledge of thermal imaging technology before this study. Evaluators ranged from students to attending level, which greater proves that these results will be reproducible.