Dual-Mode Microwave Antenna for Non-Invasive Blood Perfusion Measurement
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Solution Overview
Problem
Conventional methods for measuring blood perfusion are invasive, unreliable, and prone to errors due to imperfect contact with the skin, and they fail to provide non-invasive, rapid, and repeatable results.
Innovation Solution
A dual-mode microwave system combining microwave heating and radiometry using a novel dual-mode antenna with separate input ports for heating and radiometry, along with identical low noise amplifiers to reduce interference and enhance sensitivity, allowing for non-invasive characterization of blood perfusion rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional contact-based methods are used to measure blood perfusion, then measurement can be performed, but the methods are invasive, unreliable, and prone to errors due to imperfect contact with the skin
Solution Approach 1:
The patent replaces mechanical contact-based measurement systems with a microwave-based electromagnetic system. The dual-mode antenna emits microwave energy that penetrates the skin to measure blood perfusion rates without physical contact, eliminating the reliability issues associated with imperfect skin contact while being completely non-invasive
Solution Approach 2:
The patent introduces microwave radiation as an intermediary between the measurement system and the biological tissue. The microwave energy acts as a mediator that can penetrate the skin and interact with blood perfusion without requiring direct mechanical contact, thereby improving reliability while eliminating invasiveness
2Measurement precision
If separate heating and radiometry systems are used, then temperature measurement can be performed, but the system complexity increases and interference between heating signal and radiometer input occurs
Solution Approach 1:
The patent combines the heating antenna and radiometry antenna into a single dual-mode antenna structure. This unified antenna performs both heating and temperature measurement functions, reducing system complexity while maintaining measurement precision through careful mode separation
Solution Approach 2:
The patent employs periodic switching between heating mode and radiometry mode in the dual-mode antenna. By alternating between these two operational states, the system achieves both heating and temperature measurement functions while preventing signal interference through time-division multiplexing
3Measurement precision
If microwave heating is applied to characterize tissue, then temperature decay analysis can be performed, but the heating signal may leak to the radiometer input causing measurement errors
Solution Approach 1:
The patent uses periodic switching between heating mode and radiometry mode to prevent signal leakage. The dual-mode antenna is activated in heating mode during heating periods and switched to radiometry mode during measurement periods, ensuring that the strong heating signal does not interfere with the sensitive radiometer input
Solution Approach 2:
The patent segments the operational timeline into distinct heating phases and measurement phases. By separating these functions in time rather than space, the system eliminates cross-interference between the heating signal and radiometer detection while maintaining both functions' effectiveness
4Productivity
If conventional methods are used for blood perfusion measurement, then measurement can be obtained, but the results are not rapid or repeatable
Solution Approach 1:
The patent replaces slow, invasive mechanical measurement methods with rapid microwave-based measurement. The microwave system can quickly penetrate the skin and obtain temperature decay data for perfusion rate calculation, providing both rapid results and high repeatability through non-contact, consistent measurements
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides a reliable, rapid, and repeatable method for measuring blood perfusion rates without invasive procedures, offering accurate temperature decay analysis and perfusion rate determination, suitable for clinical and diagnostic applications.
Implementation Method 1
directing microwave energy into a biological tissue using a first slot antenna during a first time period
Implementation Method 2
detecting microwave radiation emitted by the biological tissue using a second slot antenna during a second time period subsequent to the first time period
Data Source
AI summary
Systems and methods are provided for characterizing biological tissues through their thermal signatures that include directing microwave energy into a biological tissue using a first slot antenna, detecting microwave radiation emitted by the biological tissue using a second slot antenna, generating output signals corresponding to the microwave radiation, processing the output signals to characterize a temperature of the biological tissue as a function of time to yield temperature characteristics, and characterizing a biological function of the biological tissue based on the temperature characteristics. The first and second slot antennas can be defined using a dual mode antenna and the generating can include alternatively collecting signals from the second slot antenna through a first low noise amplifier (LNA) and a reference load through a second LNA that the two LNAs are substantially identical.