Hybrid diffuse optical techniques for continuous hemodynamic measurement in gastrocnemius during plantar flexion
Brad Henry1, Mingjun Zhao1, Yu Shang1
1University of Kentucky, College of Engineering, Department of Biomedical Engineering, 143 Graham Avenue, Lexington, Kentucky 40506-0108, United States.
Journal of Biomedical Optics
|January 1, 2016
Summary
This study adapted optical techniques to measure lower limb muscle blood flow and oxygen use during exercise. Results show comparable hemodynamic data and correlate with other methods, paving the way for disease diagnosis.
Area of Science:
- Physiology
- Biomedical Engineering
- Medical Diagnostics
Background:
- Diffuse optical techniques are established for forearm muscle hemodynamics.
- Translating these methods to lower limb muscles is crucial due to disease prevalence.
- Existing methods lack continuous, absolute hemodynamic measurements in lower limbs.
Purpose of the Study:
- To adapt and validate a hybrid near-infrared spectroscopy and diffuse correlation spectroscopy system for lower limb muscle measurements.
- To continuously quantify hemodynamic responses in the medial gastrocnemius during plantar flexion.
- To calibrate optical measurements with absolute blood flow and oxygen consumption values.
Main Methods:
- Utilized a hybrid near-infrared spectroscopy and diffuse correlation spectroscopy system with a gating algorithm.
- Performed plantar flexion exercises in 10 healthy subjects.
- Calibrated relative blood flow (rBF) and oxygen consumption rate (rV̇O2) using venous and arterial occlusions.
Main Results:
- Successfully quantified oxy-, deoxy-, and total hemoglobin, blood oxygen saturation, rBF, and rV̇O2.
- Achieved comparable results to similar studies.
- Demonstrated significant correlation between optical muscle BF and strain gauge venous plethysmography whole limb BF.
Conclusions:
- The adapted hybrid optical system reliably measures lower limb muscle hemodynamics.
- The calibration method provides absolute baseline values for BF and V̇O2.
- This technology holds potential for diagnosing diseases affecting lower limb muscles.
