Spinal Cord Stimulation Device with Respiration-Synchronized ANS Feedback
Solution Overview
Problem
Spinal cord stimulation devices experience decreased efficacy over time due to habituation from monotonically pulsed electrical fields, and existing variations in stimulation patterns, such as pseudo-random pulse frequency and burst stimulation, yield sub-optimal therapeutic effects.
Innovation Solution
An implantable spinal cord stimulation device with a control unit that adjusts stimulation intensity based on autonomic nervous system (ANS) signals, synchronizing with respiration phases to deliver higher intensity pulses during inspiration and lower intensity pulses during expiration, using an ANS sensing unit to detect respiration phases and modulate stimulation parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If monotonically pulsed electrical fields are used for spinal cord stimulation, then the device structure is simple, but the therapeutic efficacy decreases over time due to habituation
Solution Approach 1:
The patent implements dynamic stimulation patterns where pulse frequency and amplitude are continuously varied based on real-time detection of autonomic nervous system activity. The stimulation device transitions from static monotonous pulses to dynamic adaptive patterns that change with physiological states, thereby preventing habituation while maintaining therapeutic efficacy.
Solution Approach 2:
The patent employs a feedback mechanism where the stimulation device monitors autonomic nervous system responses (such as respiratory rate, heart rate variability) and adjusts stimulation parameters accordingly. This closed-loop control ensures the stimulation remains effective by adapting to the patient's physiological state, preventing the habituation that occurs with fixed patterns.
2Reliability
If stimulation intensity is continuously high to maintain efficacy, then pain relief is improved, but power consumption increases
Solution Approach 1:
The patent utilizes periodic modulation of stimulation intensity synchronized with the patient's respiratory cycle. Stimulation is delivered in bursts correlated with respiratory phases rather than continuously, maintaining therapeutic efficacy during critical phases while reducing overall power consumption during less critical phases.
Solution Approach 2:
The patent dynamically changes stimulation parameters (frequency, amplitude, pulse width) based on detected autonomic nervous system activity. When pain relief is most needed (detected through physiological markers), parameters are adjusted to maximize efficacy; when less critical, parameters are reduced to conserve battery power, optimizing the balance between efficacy and energy consumption.
Data Source
AI summary
A spinal cord stimulation device having a stimulation unit for generation and delivery of stimulation pulses, a control unit for controlling the stimulation unit with respect to stimulation intensity and an autonomic nervous system (“ANS”) sensing unit that is configured to generate ANS indicating signals that represent an increased sympathetic tone or an increased parasympathetic tone, respectively. The control unit is configured to control the intensity of respective stimulation pulses depending on a respective ANS indicating signal as generated by said ANS sensing unit.