Vessel Attribute Estimation for More Accurate Virtual Flow Reserve
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Solution Overview
Problem
Intravascular imaging methods like OCT often provide incomplete data for blood vessel length, leading to inaccurate Virtual Flow Reserve (VFR) calculations due to assumptions about unimaged vessel regions, which can affect diagnostic accuracy.
Innovation Solution
Utilizing extravascular images to estimate the size and structure of unimaged blood vessel regions, incorporating them into a resistance model with intravascular data to improve VFR computation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If intravascular ultrasound (IVUS) imaging is used to obtain accurate vessel attributes, then measurement precision is improved, but device complexity and procedure time increase due to the need for additional catheters and equipment
Solution Approach 1:
The optical coherence tomography (OCT) catheter is designed to perform multiple functions: it can image vessel attributes, deliver thermal energy for ablation, and potentially deliver other therapeutic agents. This multi-functionality eliminates the need for separate IVUS catheters and ablation devices, reducing overall device complexity while maintaining measurement precision through OCT imaging capabilities
Solution Approach 2:
The patent combines the imaging function (OCT catheter) and the therapeutic function (radiofrequency ablation catheter) into a single integrated device. This merging allows simultaneous or sequential performance of imaging and treatment without requiring multiple separate catheters, thereby reducing device complexity and procedural steps while maintaining accurate vessel attribute measurement
2Measurement precision
If intravascular ultrasound (IVUS) imaging is used to obtain accurate vessel attributes, then measurement precision is improved, but the procedure time increases due to additional setup and imaging steps
Solution Approach 1:
The OCT imaging is performed during the same catheter positioning and insertion procedure that is required for the subsequent ablation treatment. The vessel attributes are measured preliminarily during the necessary diagnostic phase, eliminating the need for separate imaging procedures and reducing overall procedure time while maintaining measurement precision
Solution Approach 2:
The multi-functional catheter allows the same device to perform both imaging and treatment, meaning the procedure time for imaging does not add to the treatment time. The catheter is already in position for therapy when imaging is performed, so no additional setup or positioning time is required compared to using separate devices
3Device complexity
If optical coherence tomography (OCT) is used to image vessel attributes, then device complexity is reduced by using a single catheter, but the accuracy of vessel attribute measurement may be compromised compared to IVUS
Solution Approach 1:
The patent utilizes the specific optical properties of vascular tissue and adjusts OCT imaging parameters (wavelength, resolution, penetration depth) to optimize measurement accuracy for vessel attributes. By changing and optimizing these parameters, OCT achieves measurement precision comparable to IVUS while maintaining the advantage of reduced device complexity through single-catheter design
4Reliability
If radiofrequency ablation is performed to treat cardiac arrhythmias, then treatment effectiveness is improved, but the risk of damaging surrounding healthy tissue increases
Solution Approach 1:
The integrated catheter system provides real-time OCT imaging feedback during the ablation procedure, allowing continuous monitoring of tissue characteristics and ablation lesion formation. This feedback enables the operator to adjust ablation parameters dynamically, ensuring effective arrhythmia treatment while stopping before damaging surrounding healthy tissue, thus improving reliability while reducing harmful effects
Solution Approach 2:
The OCT imaging system acts as an intermediary between the ablation energy delivery and the surrounding tissue. It provides real-time information about tissue properties and ablation progression, serving as a mediator that guides the ablation process to achieve effective treatment while preventing damage to healthy tissue through informed parameter adjustment
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
Enhances the accuracy of VFR calculations by providing precise measurements of unimaged vessel segments, reducing errors and improving diagnostic precision.
Implementation Method 1
delivering a radiofrequency energy to the tissue
Implementation Method 2
an optical coherence tomography (OCT)
Data Source
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AI summary
Systems and methods are disclosed for identifying features of a blood vessel using extravascular and intravascular images in order to estimate a virtual flow reserve (VFR) of the imaged blood vessel. Aspects of the disclosure include using extravascular images to estimate the size of the blood vessel in regions that have not been intravascularly imaged. The VFR estimation may be based on a resistance model that incorporates both the intravascular image data and the estimated blood vessel size. In other aspects, multiangled extravascular images are captured and analyzed in order to identify the size and orientation of branch vessels.