Piezoelectric Polymer Needle Sensors for Ultrasound Tracking
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Solution Overview
Problem
Current ultrasound imaging systems face challenges in visualizing needle tips due to the specular nature of needle surfaces, which reflect beams away from the imaging probe, limiting visibility and requiring additional solutions like echogenic coatings or ultrasound receivers to improve positional accuracy, especially when the needle is inserted perpendicular to the imaging plane or has a small offset.
Innovation Solution
The integration of small ultrasound receivers formed from piezoelectric polymers, such as PVDF or P(VDF-TrFE), on the needle or device, which generate or receive ultrasonic energy, and are configured with dielectric layers and conductive shields to enhance visibility and positional accuracy without interfering with the device's functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultrasound receivers are added near the tip of the needle, then positional accuracy is improved (exceeding 0.5 mm), but device complexity increases due to additional components
Solution Approach 1:
The patent combines multiple functional layers (piezoelectric polymer, dielectric layers, conductive shields, electrodes) into a single integrated sensor assembly that is conformally formed on the needle surface. This merging approach maintains high positional accuracy while reducing the number of separate components and simplifying the overall device structure.
Solution Approach 2:
The patent uses thin film structures including piezoelectric polymer films, dielectric layers, and conductive shield films that are conformally deposited on the needle surface. These thin films provide the necessary sensing and shielding functions without adding significant bulk or complexity to the device.
2Measurement precision
If sensors are added to the needle, then visibility and tracking accuracy are improved, but the sensor may interfere with device functionality by blocking the lumen or interfering with mechanics
Solution Approach 1:
The patent places sensors only at specific locations on the needle surface where they are most needed for tracking accuracy, rather than covering the entire needle. The conformal formation allows sensors to be positioned locally at the tip and along specific segments, minimizing interference with the lumen and mechanical functions while maintaining tracking performance.
Solution Approach 2:
The sensor assembly is segmented into distinct functional layers (piezoelectric polymer, dielectric layers, conductive shields, electrodes) that are conformally formed on the needle surface. This segmentation allows each layer to perform its specific function independently while collectively providing accurate tracking without blocking the lumen or interfering with mechanics.
3Illumination intensity
If multiple imaging beams from varied angles are used, then visualization improvement is achieved, but the strategy is limited primarily to linear arrays and does not help when needle is inserted perpendicular to imaging plane
Solution Approach 1:
The patent introduces ultrasound receivers (sensors) as intermediary elements on the needle that actively receive and detect ultrasound beams. These sensors serve as mediators between the imaging system and the needle, providing direct feedback about beam-sensor interactions that enable accurate positional calculation regardless of needle orientation or imaging plane configuration.
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
This solution provides high sensitivity and accuracy in tracking the needle tip under ultrasound guidance, allowing for precise localization even when the needle is not visible in the ultrasound image, while maintaining a low profile and scalability for mass production at a low cost.
Implementation Method 1
A sensor is conformally formed on the surface and includes a piezoelectric polymer formed about a portion of the surface
Implementation Method 2
The piezoelectric polymer is configured to generate or receive ultrasonic energy
Data Source
AI summary
A medical device includes a conductive body having a surface and a sensor conformally formed on the surface and including a piezoelectric polymer formed about a portion of the surface and following a contour of the surface. The piezoelectric polymer is configured to generate or receive ultrasonic energy. Electrical connections conform to the surface and are connected to an electrode in contact with the piezoelectric polymer. The electrical connections provide connections to the piezo electric polymer and are electrically isolated from the conductive body over a portion of the surface.