Segmented Tip Electrodes for Directional Deep Brain Stimulation
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Solution Overview
Problem
Conventional deep brain stimulation leads with ring-shaped electrodes lack the ability to precisely direct electrical stimulus current to specific positions, often resulting in unwanted stimulation of neighboring neural tissue and undesired side effects due to undirected current distribution.
Innovation Solution
The development of implantable electrical stimulation leads featuring segmented tip electrodes that are electrically isolated from each other, allowing for precise current steering and directional targeting of neural tissue stimulation by distributing the electrodes circumferentially around the lead, enabling radial positioning and three-dimensional current delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If ring-shaped electrodes are used for stimulation, then the electrode structure is simple and easy to manufacture, but the stimulus current cannot be directed to specific positions and undirected stimulation occurs
Solution Approach 1:
The ring-shaped electrode is divided into multiple segmented electrodes arranged circumferentially around the lead body. Each segmented electrode can be independently controlled to deliver current, enabling directional stimulation while maintaining the overall circular configuration. This segmentation allows selective activation of specific arc segments to target precise neural locations.
Solution Approach 2:
Different segments of the electrode ring are activated selectively based on the target location. By controlling which segments are active, the current distribution is optimized for specific directional targeting while other segments remain inactive. This local quality control enables precise spatial modulation of the stimulation field.
2Area of stationary object
If ring-shaped electrodes are used, then the electrode coverage is comprehensive, but unwanted stimulation of neighboring neural tissue occurs
Solution Approach 1:
The continuous ring electrode is segmented into multiple independent arc-shaped electrodes. By activating only the segments that face the target neural tissue and keeping other segments inactive, the current is confined to the desired direction. This prevents current spread to neighboring tissues that do not require stimulation, reducing side effects while maintaining comprehensive coverage capability.
Solution Approach 2:
The electrode system transitions from a static all-or-nothing activation mode to a dynamic selective activation mode. Different segment combinations can be activated based on the specific target location and clinical requirements, allowing real-time optimization of current distribution to maximize therapeutic effect while minimizing off-target stimulation.
3Measurement precision
If segmented tip electrodes are used for precise current steering, then the directional targeting precision is improved, but the device complexity increases
Solution Approach 1:
The electrode is segmented into a limited number of arc-shaped elements (typically 4-8 segments) distributed circumferentially. This segmentation provides sufficient directional resolution for clinical applications while avoiding excessive complexity. Each segment is independently addressable through standard lead wiring configurations, balancing precision with manufacturability.
Solution Approach 2:
Multiple segmented electrodes are electrically connected through the lead body to a single or few contact points on the lead shaft. This merging of multiple electrode elements into a unified electrical structure simplifies the external wiring and programming while maintaining the functional independence of each segment for directional control.
Data Source
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AI summary
An implantable electrical stimulation lead includes a lead body having a proximal end portion, a distal end portion, a distal tip, a longitudinal length, and a longitudinal surface. Segmented tip electrodes are disposed circumferentially about the distal tip of the lead body and are electrically-isolated from each other. Each segmented tip electrode has an inner surface and an opposing outer stimulating surface exposed along the longitudinal surface of the lead body. A portion of the lead body is disposed against the inner surfaces of each of the segmented tip electrodes and circumferentially between each of the segmented tip electrodes. A non-tip electrode is disposed along the distal end portion of the lead body proximal to the segmented tip electrodes. Terminals are disposed along the proximal end portion of the lead body. Conductors electrically couple the terminals to the segmented tip electrodes and to the non-tip electrode.