Neurostimulation Electrode Current Distribution Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implantable neurostimulation systems face challenges in maintaining effective current distribution across electrodes due to impedance variations, leading to reduced therapeutic efficacy and patient comfort, especially when using voltage-regulated output pulses.
Innovation Solution
A method and system that estimate current-to-voltage relationships across active electrodes and adjust voltages to achieve a desired current distribution, using electrical energy perturbations and network resistance computations to maintain consistent current delivery despite impedance changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage-regulated output pulses are used for neural stimulation, then the system can deliver electrical energy to electrodes, but impedance variations cause current distribution to become inconsistent, reducing therapeutic efficacy
Solution Approach 1:
The system measures actual current distribution across electrodes and uses this feedback to dynamically adjust voltage outputs. The controller continuously monitors impedance variations and modifies voltage-regulated output pulses in real-time to maintain desired current distribution, resolving the contradiction between reliability and adaptability to impedance changes.
Solution Approach 2:
The system changes voltage parameters dynamically based on measured impedance conditions. By adjusting voltage magnitude and distribution across electrodes in response to impedance variations, the system maintains consistent current delivery despite changing tissue conditions, effectively resolving the contradiction between reliable current distribution and tolerance to impedance changes.
2Manufacturing precision
If independently controlled current sources are used for each electrode, then current distribution can be precisely controlled, but device complexity increases significantly
Solution Approach 1:
The patent uses a single voltage source that serves multiple electrodes simultaneously through dynamic voltage distribution. This universal approach achieves precise current control across all electrodes without requiring separate independent sources for each electrode, thereby maintaining manufacturing precision while reducing device complexity.
Solution Approach 2:
The controller acts as an intermediary between the single voltage source and multiple electrodes. It processes impedance measurements and calculates appropriate voltage distributions, enabling precise current control through software-based management rather than hardware multiplication, thus achieving high precision with lower complexity.
3Reliability
If the number of electrodes is increased to improve stimulation coverage, then therapeutic effectiveness improves, but the number of possible stimulation parameter sets increases exponentially, making programming difficult
Solution Approach 1:
The system automatically determines optimal stimulation parameter sets by measuring impedance across electrodes and calculating configurations that achieve desired current distribution. This self-service capability reduces programming burden by eliminating the need for manual exploration of exponential parameter combinations, maintaining therapeutic effectiveness while improving ease of operation.
Solution Approach 2:
The system uses feedback from impedance measurements to automatically select and adjust stimulation parameter sets. By continuously monitoring electrode conditions and adapting parameters accordingly, the system simplifies programming while maintaining effective stimulation across multiple electrodes, resolving the contradiction between therapeutic effectiveness and programming simplicity.
Data Source
AI summary
In one technique, a desired electrical current distribution on at least three active electrodes is selected. An electrical energy perturbation is generated on at least one electrode. A current-to-voltage relationship at each active electrode is estimated based on the energy perturbation. The current-to-voltage relationship for each active electrode takes into account current flow through other active electrodes. The voltage distribution necessary to achieve the desired current distribution is determined based on the estimated current-to-voltage relationship. Voltage-regulated energy is conveyed between the electrodes and tissue in accordance with the determined electrical voltage distribution. In another technique, an electrical energy perturbation on at least one of the electrodes is generated. Network resistances for each of at least three active electrodes are computed in response to the energy perturbation. The network resistances represent the resistances between the electrodes and common node to which the electrodes are connected.