Full-Duplex EPG System with Optical Folding Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing external pulse generator (EPG) systems for spinal cord stimulation face challenges in maintaining optimal electrode current due to patient position and activity changes, leading to inadequate or excessive stimulation, power consumption issues, and difficulties in initial lead alignment and optical signal interpretation.
Innovation Solution
The EPG system incorporates an optical folding assembly with VCSELs and photodiodes for dynamic modulation of stimulation current based on spinal cord distance, using parabolic redirectors for efficient optical signal alignment and processing, and a header assembly with lead retainer holes for precise lead positioning, optimizing fiber coupling and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dynamic adjustment of electrode current is implemented to maintain optimal stimulation, then therapeutic efficacy is improved, but device complexity increases
Solution Approach 1:
The system uses optical reflectometry to continuously measure the distance between the electrode array and spinal cord, providing feedback that drives dynamic adjustment of electrode current. This feedback mechanism maintains optimal stimulation by compensating for changes in spinal cord position, thereby improving therapeutic efficacy while managing device complexity through automated control.
Solution Approach 2:
The patent replaces direct mechanical measurement of spinal cord position with optical measurement using light reflectometry. This substitution allows non-contact, continuous monitoring of the electrode-spinal cord distance, enabling dynamic current adjustment without complex mechanical sensing systems, thus improving reliability while controlling device complexity.
2Measurement precision
If optical reflectometry is used to measure spinal cord distance, then measurement precision is improved, but use of energy increases
Solution Approach 1:
The optical reflectometry system performs distance measurements periodically rather than continuously, reducing energy consumption while maintaining sufficient measurement precision for effective stimulation control. The system can adjust the measurement frequency based on operational requirements, balancing accuracy with power usage.
Solution Approach 2:
The system uses optical signals to create a reflective copy of the spinal cord's position information, allowing indirect measurement of distance without direct contact. This optical copying method provides precise distance data while consuming less energy compared to direct mechanical sensing or continuous high-power optical monitoring.
3Measurement precision
If multiple surgical leads are precisely placed to interpret optical signals, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The lead assembly integrates both electrical stimulation function and optical signal transmission function into a single multi-functional component. This eliminates the need for separate surgical leads for optical measurement, simplifying the surgical procedure while maintaining precise optical signal interpretation through the combined lead structure.
Solution Approach 2:
The patent merges the electrical and optical functions into a single lead assembly, where the same lead that delivers electrical stimulation also carries optical fibers for distance measurement. This integration reduces the number of separate components that need to be precisely placed during surgery, improving ease of operation while preserving measurement precision through the unified lead design.
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 ensures consistent and non-noxious spinal cord stimulation by dynamically adjusting current density, minimizing power usage, and simplifying lead alignment, thereby enhancing therapeutic efficacy and battery life while maintaining effective pain relief.
Implementation Method 1
A full-duplex optical system is provided that includes a transceiver, an optical fiber, a vertical cavity surface emitting laser (VCSEL), and a photodetector. The transceiver causes the optical fiber to transmit an optical signal from the VCSEL to a spinal cord.
Implementation Method 2
The transceiver causes the optical fiber to transmit the optical signal from the VCSEL to the spinal cord and causes the photodetector to detect the reflected optical signal from the spinal cord.
Implementation Method 3
The transceiver causes the optical fiber to transmit an optical signal from the VCSEL to the spinal cord and causes the photodetector to detect the reflected optical signal from the spinal cord.
Data Source
AI summary
The invention provides an EPG system and lead configuration which boasts both a novel optical folding assembly and compact package size. The percutaneous leads provided offer additional advantages over the prior art including integral formation of optical and electrical components in a compact size.