Implantable Stimulation Control via Evoked Potential Sensing
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Solution Overview
Problem
Existing electrical stimulation therapies often evoke unwanted action potentials in patient tissues, leading to side effects such as paresthesia, due to changes in impedance, lead movement, or patient posture, which existing manual adjustments fail to address effectively.
Innovation Solution
A medical device system that automatically adjusts electrical stimulation parameters to prevent action potentials by sensing evoked compound action potentials and incrementally reducing stimulation amplitude to maintain therapy efficacy without evoking action potentials, using sensors and processors to titrate parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical stimulation therapy is delivered at high intensity to maintain therapeutic efficacy, then treatment effectiveness is improved, but unwanted action potentials are evoked causing side effects such as paresthesia
Solution Approach 1:
The system continuously monitors for evoked compound action potentials (ECAPs) in real-time during stimulation delivery. When an ECAP is detected, the system automatically adjusts stimulation parameters (amplitude, pulse width, or frequency) to eliminate the unwanted action potential while maintaining therapeutic efficacy. This closed-loop feedback mechanism allows dynamic optimization of stimulation parameters based on actual tissue response.
Solution Approach 2:
The system dynamically adjusts stimulation parameters in real-time based on detected tissue responses. Rather than using fixed parameters, the system modifies amplitude, pulse width, or frequency on-the-fly to maintain stimulation below the threshold that evokes unwanted action potentials. This dynamic adaptation enables the system to respond to changing impedance, lead movement, or patient posture conditions.
2Object-affected harmful factors
If manual parameter adjustments are made to prevent action potentials, then side effects are reduced, but the complexity of operation increases and real-time adaptation is limited
Solution Approach 1:
The system performs automatic parameter optimization without requiring manual intervention. The clinician or patient simply initiates therapy, and the system autonomously monitors for ECAPs and adjusts stimulation parameters to prevent unwanted action potentials. This self-adjusting capability eliminates the need for complex manual titration procedures while maintaining side effect reduction.
Solution Approach 2:
The system uses real-time feedback from ECAP detection to automatically control stimulation parameters. This closed-loop system continuously monitors tissue response and self-corrects parameter settings, replacing manual adjustment processes with automated feedback-driven control that simplifies operation while maintaining effectiveness.
3Ease of operation
If fixed stimulation parameters are used, then device operation is simple, but the system cannot adapt to changes in impedance, lead movement, or patient posture
Solution Approach 1:
The system transitions from fixed parameters to dynamic parameter adjustment. Stimulation settings are continuously adapted based on real-time detection of ECAPs and changes in tissue response. This dynamic approach allows the system to automatically compensate for impedance changes, lead movement, or posture variations while maintaining simplicity of operation through automation.
Solution Approach 2:
The system implements real-time feedback monitoring of tissue response during stimulation. When changes in impedance or tissue characteristics cause unwanted action potentials, the feedback mechanism detects these changes and automatically adjusts parameters to maintain optimal therapy. This feedback-driven adaptability allows the system to respond to changing conditions without requiring manual reprogramming.
4Object-affected harmful factors
If stimulation amplitude is reduced to prevent action potentials, then side effects are eliminated, but therapeutic efficacy may be compromised
Solution Approach 1:
The system delivers stimulation at amplitudes that are sufficient to provide therapeutic benefit but deliberately kept below the threshold that evokes unwanted action potentials. By operating in this partial action regime - using just enough stimulation to achieve therapy without exceeding the harmful threshold - the system maintains efficacy while preventing side effects. The real-time ECAP monitoring ensures the stimulation remains in this optimal range.
Solution Approach 2:
The system dynamically changes stimulation parameters (amplitude, pulse width, frequency) to optimize the balance between therapeutic efficacy and action potential prevention. Rather than using a fixed amplitude, the system adjusts multiple parameters in combination to maintain stimulation effectiveness while staying below the threshold for unwanted neural activation. This multi-parameter optimization allows flexible adjustment to maintain both efficacy and safety.
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 effectively maintains therapeutic efficacy while preventing action potentials, reducing side effects like paresthesia, and allowing for automatic titration of parameters without patient feedback, even in changing conditions.
Implementation Method 1
sensing the evoked compound action potentials in tissue of the patient via one or more sensors
Implementation Method 2
the medical device system may deliver a series of electrical pulses in which the amplitude of the respective pulses is increased
Data Source
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AI summary
The techniques described herein are example medical devices, systems, and methods for sensing evoked potentials in a tissue of the patient, and, based on the sensed evoked potentials, adjusting one or more parameters defining the electrical stimulation therapy delivered to the patient. In one example, a system controls delivery of an electrical stimulation therapy from an implantable medical device to a patient according to at least one therapy program, wherein the electrical stimulation therapy is configured to provide pain relief to the patient without substantially resulting in paresthesia perceived by the patient. The system periodically adjusts the electrical stimulation therapy delivered to the patient in response to detected compound action potentials, wherein the adjustment to the electrical stimulation therapy is configured to eliminate action potentials in tissue of the patient evoked by the delivered electrical stimulation, and wherein the controlling and the adjusting are performed via one or more processors.