Thermal clearance blood flow sensor--sensitivity, linearity and flow depth discrimination

Area of Science:

• Biomedical Engineering
• Physiological Measurement
• Sensor Technology

Background:

• Accurate measurement of skin blood flow is crucial for understanding physiological processes and diagnosing conditions.
• Existing methods may lack the ability to differentiate blood flow at various depths within the skin.
• Thermal clearance techniques offer a non-invasive approach to assess blood flow.

Purpose of the Study:

• To design and evaluate a novel thermal clearance sensor capable of measuring blood flow at multiple depths.
• To assess the sensor's static and dynamic performance characteristics.
• To investigate the factors influencing the sensor's depth sensitivity.

Main Methods:

• Development of a thermal clearance sensor with four distinct sensing elements.
• Conducting static and dynamic laboratory tests to evaluate sensor response.
• Analyzing the relationship between sensor geometry, material properties, and depth sensitivity.

Main Results:

• The designed sensor successfully measured blood flow changes at four different depths.
• Laboratory tests demonstrated a linear response to blood flow within the physiological range.
• Sensor geometry significantly impacts depth response, with conventional materials limiting sensitivity to 0.2 mm.

Conclusions:

• The developed multi-depth thermal clearance sensor shows promise for physiological skin blood flow assessment.
• The study highlights the importance of sensor geometry in achieving depth-specific measurements.
• Material limitations currently restrict the achievable depth sensitivity of this sensor technology.