Optical Pressure Sensor Guidewire for Intravascular Measurement
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Solution Overview
Problem
Current medical devices for intracorporeal use, such as guidewires, lack effective solutions for accurately measuring and monitoring blood pressure within blood vessels, particularly in determining fractional flow reserve, which is crucial for diagnosing vascular conditions.
Innovation Solution
A pressure sensing guidewire with a tubular member housing an optical pressure sensor featuring a deflectable polymer membrane and a pressure equalization channel, integrated with an optical fiber, allowing for precise pressure measurement and minimization of fluid permeability through coatings, enabling accurate blood pressure monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an optical pressure sensor with deflectable membrane is used to measure blood pressure accurately, then measurement precision is improved, but device complexity increases due to integration of optical fiber and sensor components within the guidewire
Solution Approach 1:
The optical pressure sensor is integrated within the guidewire structure by nesting the deflectable membrane and optical fiber components inside the tubular member. The sensor body is positioned within the tubular member, and the optical fiber is routed through the guidewire, allowing the measurement function to be embedded within the existing device architecture rather than adding external complexity
Solution Approach 2:
The patent combines multiple functions into a single integrated sensor assembly: the deflectable membrane serves as both the pressure-sensing element and the interface with blood pressure, while the optical fiber integrates light transmission and pressure measurement capabilities. The sensor body merges the membrane attachment, optical coupling, and pressure equalization functions into one compact unit within the guidewire
2Measurement precision
If a polymer deflectable membrane is used for pressure sensing, then sensitivity to pressure changes is improved, but fluid permeability increases allowing blood products to penetrate the membrane
Solution Approach 1:
The patent applies different properties to different regions of the membrane system: the deflectable membrane itself is made from polymer material optimized for pressure sensitivity and deflectability, while separate coating layers are applied to specific surfaces of the membrane to provide fluid impermeability. This allows the membrane to maintain its pressure-sensing quality while the coating provides the protective barrier against fluid penetration
Solution Approach 2:
The pressure sensing system uses a composite structure combining polymer membrane material with additional coating materials. The polymer provides the necessary mechanical properties for pressure sensing, while the coating material provides fluid impermeability. This composite approach allows both requirements to be satisfied simultaneously without compromising either pressure sensitivity or fluid barrier properties
3Reliability
If pressure equalization channel is formed in the optical fiber or sensor body, then pressure measurement reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The pressure equalization channel acts as an intermediary pathway that connects the external blood pressure environment to the internal sensor cavity. Rather than requiring the membrane itself to be perfectly impermeable or the optical fiber to have complex internal structures, the channel provides a controlled fluid communication path that equalizes pressure across the sensor assembly, simplifying the requirements for other components while ensuring reliable pressure transmission
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 solution enables accurate measurement and calculation of fractional flow reserve, enhancing diagnostic capabilities by providing reliable and sensitive pressure readings within blood vessels, improving clinical assessments.
Implementation Method 1
a deflectable membrane coupled to the sensor body; wherein the deflectable membrane includes a polymer
Implementation Method 2
an optical fiber coupled to the sensor body and extending proximally therefrom
Implementation Method 3
a pressure equalization channel is formed in the optical fiber, the sensor body, or both
Data Source
AI summary
Pressure sensing guidewires and methods for making and using pressure sensing guidewires are disclosed. An example pressure sensing guidewire may include a tubular member having a proximal region and a housing region. An optical pressure sensor may be disposed within the housing region. The optical pressure sensor may include a sensor body and a deflectable membrane coupled to the sensor body. The deflectable membrane may include a polymer. An optical fiber may be coupled to the sensor body and may extend proximally therefrom. A pressure equalization channel is formed in the optical fiber, the sensor body, or both.