ECAP-Based Electrical Stimulation Control for Electrode-Movement Compensation
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Solution Overview
Problem
Existing electrical stimulation therapies face challenges in maintaining consistent neural activation due to changes in electrode-tissue distance caused by patient movement, leading to varying therapy efficacy and potential discomfort.
Innovation Solution
A system that delivers interleaved informed and control pulses, where control pulses elicit evoked compound action potentials (ECAPs) to adjust stimulation parameters, ensuring consistent neural activation by monitoring ECAP characteristics and adjusting pulse intensity accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical stimulation therapy is delivered via leads with electrodes, then neural activation can be achieved to treat various conditions, but electrode-tissue distance changes due to patient movement cause varying therapy efficacy and discomfort
Solution Approach 1:
The system senses evoked compound action potentials (ECAPs) in response to stimulation pulses and uses this feedback information to adjust stimulation parameters. The ECAP sensing provides real-time information about neural activation levels, allowing the system to compensate for electrode-tissue distance changes and maintain consistent therapy efficacy despite patient movement.
Solution Approach 2:
The system dynamically adjusts stimulation parameters (amplitude, pulse width, frequency) based on sensed ECAP characteristics. When ECAP amplitude decreases indicating increased electrode-tissue distance, the system increases stimulation amplitude or adjusts pulse width to maintain the same level of neural activation, thereby compensating for positional changes.
2Measurement precision
If control pulses are delivered to elicit detectable ECAP signals, then stimulation parameters can be adjusted for consistent neural activation, but additional non-therapeutic pulses increase overall stimulation load
Solution Approach 1:
The system delivers control pulses at reduced amplitude or shorter duration compared to full therapeutic pulses, sufficient to elicit detectable ECAP signals but consuming less energy. This partial action approach allows ECAP monitoring without proportionally increasing overall energy consumption, as the control pulses serve only for measurement and parameter adjustment.
Solution Approach 2:
Control pulses for ECAP sensing are delivered periodically interspersed with therapeutic pulses rather than continuously. This periodic sampling approach provides sufficient ECAP data for parameter adjustment while minimizing the number of additional control pulses, thereby reducing overall energy consumption while maintaining measurement precision.
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
Maintains consistent therapy efficacy by dynamically adjusting stimulation parameters based on ECAP signals, reducing discomfort and ensuring effective neural activation despite electrode movement.
Implementation Method 1
sensing, after one or more control pulses of the plurality of control pulses and prior to an immediately subsequent informed pulse of the plurality of informed pulses, a respective evoked compound action potential (ECAP)
Data Source
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AI summary
Devices, systems, and techniques for controlling electrical stimulation therapy are described. In one example, a system may be configured to deliver electrical stimulation therapy to a patient, the electrical stimulation therapy comprising a plurality of therapy pulses at a predetermined pulse frequency over a period of time and deliver, over the period of time, a plurality of control pulses interleaved with at least some therapy pulses of the plurality of therapy pulses. The system may also be configured to sense, after one or more control pulses and prior to an immediately subsequent therapy pulse of the plurality of therapy pulses, a respective evoked compound action potential (ECAP), adjust, based on at least one respective ECAP, one or more parameter values that at least partially defines the plurality of therapy pulses, and deliver the electrical stimulation therapy to the patient according to the adjusted one or more parameter values.