Coronary Sinus Lead Electrode Orientation to Limit Phrenic Stimulation
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Solution Overview
Problem
Existing medical electrical leads for cardiac pacing in the coronary vasculature often cause unintended phrenic nerve stimulation due to the radial distribution of electrodes, leading to inefficient energy use and reduced device longevity.
Innovation Solution
The design of an intravenous medical electrical lead with electrodes configured to rotate back to face myocardial tissue while the insulated portion faces neural tissue, minimizing unwanted neural stimulation by limiting the sweep of electrical stimuli, thereby reducing energy consumption and increasing pacing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrodes are radially spaced around the circumference of the lead, then the lead can deliver electrical stimulation to cardiac tissue, but unintended phrenic nerve stimulation occurs
Solution Approach 1:
The patent applies local quality by creating asymmetric electrode configurations where specific angular portions of the electrode circumference are made electrically active while other portions are insulated or inactive. This allows the lead to deliver stimulation selectively to cardiac tissue while avoiding adjacent neural tissue, resolving the contradiction between reliable cardiac stimulation and harmful nerve stimulation.
Solution Approach 2:
The patent employs asymmetry by positioning electrically active electrode portions at specific angular orientations that face cardiac tissue, while insulating opposite portions that would face the phrenic nerve. This asymmetric configuration ensures that electrical energy is directed only where needed (cardiac tissue) and not where it would cause harm (phrenic nerve), simultaneously achieving reliable cardiac capture and avoiding nerve stimulation.
2Reliability
If electrical stimuli are directed 360 degrees around each electrode, then cardiac tissue capture is maximized, but energy consumption increases and device longevity decreases
Solution Approach 1:
The patent applies local quality by making only specific angular portions of the electrode circumference electrically active, rather than the entire circumference. This localized electrical activity concentrates energy delivery precisely where cardiac tissue is present, maximizing capture efficiency while minimizing unnecessary energy dissipation in other directions, thereby extending device longevity.
Solution Approach 2:
The patent applies partial action by activating only the necessary angular portion of the electrode that faces cardiac tissue, rather than using the full 360-degree electrode circumference. This partial activation suffices to achieve reliable cardiac capture while significantly reducing overall energy consumption, as energy is not wasted stimulating areas without cardiac tissue.
Data Source
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AI summary
One embodiment of the invention comprises an intravenous medical electrical lead that includes an elongated lead body. The elongated lead body comprises a length between a proximal end and a shaped distal end, The lead body includes a longitudinal axis extending between the proximal end and the shaped distal end. The lead body has an outer circumference with a set of electrodes circumferentially spaced apart. Each electrode includes an electrically active portion and an insulated portion at an outer circumference of the electrode. If the lead body rotates within the delivery catheter, the lead body is configured to rotate back into a position such that the electrically active portion of a set of electrodes faces myocardial tissue when exiting the guide catheter while the insulated portion of electrode are diametrically opposed to neural tissue such as the phrenic nerve.