Related Experiment Video
Updated: Jan 25, 2026

Tumor Hypoxia Assessment: In Vivo 3D Oxygen Imaging Through Electron Paramagnetic Resonance
Published on: February 14, 2025
Measuring Flap Oxygen Using Electron Paramagnetic Resonance Oximetry
Marc A Polacco1, Huagang Hou2, Periannan Kuppusamy3
1Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
Objectives/Hypothesis:
To determine if electron paramagnetic resonance (EPR) oximetry is a viable technology to aid in flap monitoring.
Study Design:
Prospective cohort.
Methods:
This was a cohort study assessing accuracy and speed of EPR oximetry in detecting ischemia of a saphenous artery-based flap in a rat model, using transcutaneous oximetry as a control. Measurements were obtained under both resting and ischemic conditions for nine Sprague Dawley rats (18 flaps), for 3 postoperative days following flap elevation.
Results:
The mean partial pressure of oxygen prior to tourniquet application was 66.9 ± 8.9 mm Hg with EPR oximetry and 64.7 ± 5.2 mm Hg with transcutaneous oximetry (P = .45). Mean partial pressures of oxygen during tourniquet application were 8.9 ± 3.2 mm Hg and 8.5 ± 2.9 mm Hg for EPR oximetry and transcutaneous oximetry, respectively (P = .48), and 67.2 ± 6.9 mm Hg and 65.3 ± 6.1 mm Hg after tourniquet release for EPR oximetry and transcutaneous oximetry, respectively (P = .44). The mean ischemia detection time of EPR oximetry was 49 ± 21 seconds.
Conclusions:
Offering timely, accurate, and noninvasive tissue oxygen measurements, EPR oximetry is a promising adjunct in flap monitoring.
Level Of Evidence:
NA Laryngoscope, 129:E415-E419, 2019.
More Related Videos
Related Concept Videos
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
Resonance
Paramagnetism
Pulse Oximetry
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...
Special considerations while measuring oxygen saturation
Ensuring accuracy in vital sign recordings while prioritizing patient comfort and minimizing anxiety is...
Electronic Distance Measuring Instruments

