Improved radiometric performance attained by an elliptical microwave antenna with suction

Area of Science:

• Biomedical Engineering
• Medical Physics
• Radiometry

Background:

• Accurate in vivo temperature measurement is crucial for medical applications.
• Conventional microwave antenna fixation methods can lead to inconsistent contact and measurement variability.
• Anatomical curvature and body movement pose challenges for stable antenna placement.

Purpose of the Study:

• To develop and evaluate a new method for securely mounting medical microwave antennas on the human body.
• To improve the repeatability and accuracy of in vivo temperature measurements using microwave radiometry.
• To assess the effectiveness of a vacuum pressure system for antenna fixation.

Main Methods:

• A low-cost vacuum pressure source was utilized to create suction for mounting an elliptical microwave antenna with a vacuum chamber cavity.
• The vacuum-mounted antenna was experimentally evaluated for measurement repeatability by repeated mounting on specific anatomical locations.
• Four anatomical sites (hand, belly, hip, chest) were used to test the system's performance against variations in curvature and load.

Main Results:

• The vacuum suction method significantly decreased the standard deviation of radiometric temperature measurements compared to manual fixation.
• Repeated measurements demonstrated reduced uncertainty and improved estimation of true temperature with the vacuum antenna.
• The antenna showed greatest potential for improved performance when mounted on bone-filled areas, even during body movement.

Conclusions:

• Vacuum-assisted antenna mounting offers a more reliable and repeatable approach for in vivo microwave radiometry.
• This technique enhances electromechanical coupling between the antenna and skin, leading to more accurate temperature readings.
• The proposed solution is particularly beneficial for measurements on curved or mobile anatomical regions.