Coherence Gated Doppler Motion Sensor for Blood Vessel Localization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current motion sensors used in medical applications, such as laser Doppler flowmetry and Doppler optical coherence tomography, face challenges with low signal-to-noise ratio and low spatial resolution when detecting and localizing blood vessels, making them unsuitable for precise medical procedures.
Innovation Solution
A coherence gated Doppler motion sensor system utilizing a selected bandwidth light source and optical fibers to create a coherence gated target volume, allowing for real-time detection and localization of blood vessels with improved signal-to-noise ratio and spatial resolution, using a handheld probe with no moving parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laser Doppler flowmetry is used for medical applications, then microcirculatory function can be assessed, but signal-to-noise ratio and spatial resolution are low
Solution Approach 1:
The patent divides the detection process into two separate optical paths: a reference path that carries unmodulated light and a measurement path that carries Doppler-shifted light from moving scatterers. This segmentation allows independent optimization of each path, improving the signal-to-noise ratio by separating the weak Doppler signal from the strong reference signal, thereby resolving the contradiction between measurement precision and reliability
Solution Approach 2:
The patent introduces a photomixer as an intermediary device that combines the reference light and measurement light to generate a beat signal. This intermediary mechanism converts the optical Doppler shift into an electrical signal that can be processed with high signal-to-noise ratio, simultaneously improving both measurement precision and reliability
2Measurement precision
If Doppler optical coherence tomography is used, then 3D imaging with Doppler shift detection is achieved, but the device is expensive, complicated and difficult to use
Solution Approach 1:
The patent extracts only the essential Doppler detection function from the complex DOCT system, eliminating the need for full 3D imaging capabilities, scanning mechanisms, and complex optical coherence processing. This extraction maintains high spatial resolution for blood vessel detection while dramatically reducing device complexity, making it suitable for practical medical use
Solution Approach 2:
The patent employs simpler, more cost-effective optical components and a streamlined optical design compared to commercial DOCT systems. By using affordable light sources, basic optical elements, and a compact probe design, the system achieves comparable measurement precision at a fraction of the cost and complexity
3Reliability
If conventional motion sensors are used, then blood flow detection is possible, but the probe size and complexity are not compatible with minimally invasive tools
Solution Approach 1:
The patent combines the light delivery function and light collection function into a single integrated probe tip, eliminating the need for separate large-scale optical components. This merging allows the entire Doppler detection system to be miniaturized into a handheld probe that maintains full detection capability while being compatible with minimally invasive surgical procedures
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 enables effective detection and localization of blood vessels with improved sensitivity and specificity, suitable for real-time guidance during medical procedures, reducing costs and complexity compared to existing technologies.
Implementation Method 1
Doppler shift between the light from the light source and the scattered light received at the detector
Implementation Method 2
an optical detector...configured to direct onto the optical detector scattered light returning from the single probe tip through a return optical path
Implementation Method 3
coherence gated Doppler motion sensor...based on a Doppler shift between the light from the light source and the scattered light received at the detector
Data Source
AI summary
A motion sensor applicable to medical procedures includes a source of light with a wavelength bandwidth and an optical detector. A first optical coupler terminates in a first probe tip and couples the light into the first probe tip. A second optical coupler terminates in a second probe tip and directs onto the detector scattered light returning through the second probe tip. A presentation device outputs a signal that indicates motion in a target volume of a sample in a vicinity of the probe tips based on a Doppler shift of the scattered light. The volume depends on coherence distance determined by the bandwidth. In variations, the first and second tips are the same tip, a multimode fiber is included, the bandwidth is between 0.1% and 5% of a center wavelength, or the presentation device is a speaker, or some combination.