Catheter Oxygen Sensor With Permeable Wall
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Solution Overview
Problem
Acute kidney injury (AKI) is a complication following surgeries like cardiac procedures, caused by hypoxia leading to ischemia reperfusion injury, which complicates renal function monitoring due to inaccessibility of kidneys, and existing monitoring methods lack accuracy and specificity.
Innovation Solution
A catheter assembly with a separate lumen for an oxygen sensing element that senses dissolved oxygen in urine without direct contact, maintaining the integrity of the sensor and allowing the catheter to remain flexible, enabling accurate monitoring of kidney oxygenation status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the oxygen sensing element is placed in direct contact with urine to measure dissolved oxygen, then measurement precision is improved, but reliability deteriorates due to sensor degradation from exposure to harsh urinary environment
Solution Approach 1:
The patent employs the catheter wall as an intermediary membrane that allows oxygen to pass through while blocking urine contact with the sensor. The sensing element is positioned in a sealed lumen, and the catheter wall material (such as silicone rubber) serves as a selective barrier that permits oxygen diffusion but prevents urine and other harsh substances from reaching the sensor, thus maintaining both measurement accuracy and sensor reliability
Solution Approach 2:
The oxygen sensing element is nested within a sealed lumen of the catheter structure. This nested configuration allows the sensor to be positioned close to the urine flow path for accurate measurement while being physically protected by the catheter wall and sealed lumen structure, enabling indirect measurement without direct exposure
2Measurement precision
If the catheter structure is made rigid to house sensors, then measurement precision is improved, but ease of operation deteriorates due to difficulty in insertion and patient comfort
Solution Approach 1:
The patent utilizes the flexible catheter wall (typically made of materials like silicone rubber or latex) as both a protective barrier and an oxygen-permeable membrane. This flexible shell maintains the structural integrity needed to house the sensing element while allowing the catheter to remain soft and flexible for easy insertion and patient comfort. The thin film nature of the catheter wall also facilitates oxygen diffusion to the sensor
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 a non-invasive, accurate method to assess kidney oxygenation and function, reducing the risk of AKI by allowing clinicians to intervene early, thereby minimizing hospital stays and complications.
Implementation Method 1
senses the amount of dissolved oxygen in a fluid external to the lumen without contacting the fluid
Data Source
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AI summary
Example devices and techniques for sensing a parameter of a substance of interest are disclosed. An example catheter includes an elongated body defining a lumen. The lumen is configured to receive or house an oxygen sensing element. When the oxygen sensing element is located in a proximal portion of the lumen, the oxygen sensing element is configured to sense an amount of dissolved oxygen in a fluid external to the lumen. The catheter is configured to block ingress of the fluid into the lumen while the oxygen sensing element senses the amount of dissolved oxygen.