Phrenic Nerve Stimulation via Bipolar Intravascular and Extracorporeal Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current phrenic nerve stimulation techniques during cardiac cryoablation procedures are inefficient due to challenges in positioning and maintaining the stimulation catheter, leading to unstable electrical stimulation and potential misinterpretation of diaphragmatic contraction responses, which can result in phrenic nerve injury.
Innovation Solution
A system comprising a stimulation catheter with intravascular electrodes and an extracorporeal electrode patch, configured to be affixed to the patient opposite the phrenic nerve, allowing for stable and robust phrenic nerve stimulation through a bipolar mode operation, with the extracorporeal patch creating a large electric field that tolerates slight movements of the catheter and maintains effective stimulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stimulation catheter with intravascular electrodes is used for phrenic nerve stimulation, then the stimulation can be performed during cardiac cryoablation procedures, but the positioning and maintenance of the catheter is difficult, leading to unstable electrical stimulation
Solution Approach 1:
The patent introduces an extracorporeal electrode patch as an intermediary element that works in conjunction with the intravascular electrodes. This patch is positioned on the patient's skin overlying the phrenic nerve, creating a bipolar stimulation configuration. The intermediary patch helps stabilize the electrical field and provides a reference point that compensates for minor catheter movements, thereby resolving the instability issue while maintaining ease of operation.
Solution Approach 2:
The patent transitions from a purely intravascular single-point stimulation approach to a bipolar configuration that extends into the extracorporeal space. By adding the extracorporeal electrode patch dimension, the system creates a more robust electrical field that is less sensitive to catheter position variations, effectively using spatial extension to improve stimulation reliability.
2Reliability
If the stimulation catheter is repositioned to correct unstable stimulation, then the phrenic nerve can be adequately stimulated, but time is lost to relocate the catheter and restart stimulation
Solution Approach 1:
The extracorporeal electrode patch serves as a stable intermediary that remains fixed on the patient's skin while the intravascular catheter can be repositioned. This fixed reference point allows for quicker adjustments since the patch provides a consistent electrical field anchor, reducing the time needed to restore effective stimulation after catheter movement.
Solution Approach 2:
The extracorporeal electrode patch is positioned in advance on the patient's skin overlying the phrenic nerve pathway. This preliminary placement creates a pre-established electrical field configuration that remains stable during the procedure, allowing for faster correction of stimulation issues without requiring complete repositioning of the entire stimulation system.
3Measurement precision
If diaphragmatic monitoring is used to assess phrenic nerve injury, then injury can be detected, but unstable stimulation may cause false interpretation of contraction response
Solution Approach 1:
The extracorporeal electrode patch acts as a stabilizing intermediary that creates a more consistent bipolar electrical field. This stability translates to more reliable diaphragmatic contraction responses, reducing false positives or negatives in phrenic nerve injury assessment. The patch provides a fixed reference that enhances the precision of monitoring by eliminating stimulation variability as a confounding factor.
4Power
If the stimulation catheter is positioned close to the phrenic nerve for effective stimulation, then the risk of phrenic nerve injury increases due to close proximity during cryoablation
Solution Approach 1:
The extracorporeal electrode patch serves as a safety intermediary that enables effective phrenic nerve stimulation without requiring the intravascular catheter to be positioned extremely close to the nerve. The bipolar configuration distributes the electrical field more evenly, providing adequate stimulation power while maintaining a safer distance between the catheter and the phrenic nerve during cryoablation 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 provides stable and robust phrenic nerve stimulation, reducing the risk of injury and improving the reliability of diaphragmatic contraction monitoring, allowing for more secure and efficient cardiac cryoablation procedures.
Implementation Method 1
The system comprises a stimulation catheter including one or more intravascular electrodes arranged on a distal portion of the catheter... The extracorporeal electrode patch is operable in a bipolar mode with the one or more intravascular electrodes
Data Source
AI summary
The disclosure notably relates to a system for phrenic nerve stimulation. The stimulation system comprises a catheter (200) including one or more intravascular electrodes each arranged on a distal portion (240) of the catheter. The catheter is configured to be introduced in the superior vena cava (VC) of a human patient. The stimulation system also comprises an extracorporeal electrode patch (260) configured to be affixed to the patient opposite to the distal portion relative to the phrenic nerve. The extracorporeal electrode patch is operable in a bipolar mode with the one or more intravascular electrodes. Such a system forms an improved solution for phrenic nerve stimulation, in particular during a cryoablation procedure.