MRI Gradient Waveform Modulation for Peripheral Nerve Stimulation Avoidance
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Solution Overview
Problem
MRI procedures induce peripheral nerve stimulation (PNS) in patients due to changing magnetic fields, causing discomfort or pain, and current solutions like analgesic drugs or acupuncture have drawbacks such as side effects or invasive procedures.
Innovation Solution
Modulating magnetic resonance gradient waveforms to stimulate peripheral nerves and induce a nerve conduction block, allowing for localized and reversible analgesia during MRI scans without the need for precise stimulation point detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fast gradient switching is used in MRI to improve imaging speed, then productivity is improved, but peripheral nerve stimulation occurs causing patient discomfort
Solution Approach 1:
The patent converts the harmful peripheral nerve stimulation into a beneficial analgesic effect by applying electrical stimulation through modified gradient waveforms to activate endogenous painkilling mechanisms. The harmful induced currents are redirected to stimulate A-delta and C fibers to trigger release of endorphins, enkephalins, and other analgesic substances, thereby converting PNS from a harmful side effect into a therapeutic tool for pain management during MRI procedures.
Solution Approach 2:
The patent modifies gradient waveform parameters including amplitude, duration, rise time, and repetition rate to optimize the balance between achieving sufficient signal encoding and inducing analgesic effects. By carefully controlling these parameters, the system can induce peripheral nerve stimulation at levels that provide pain relief without causing uncomfortable or painful sensations, thus resolving the contradiction between imaging speed and patient comfort.
2Object-affected harmful factors
If systemic analgesic drugs are administered to reduce PNS discomfort, then patient comfort is improved, but side effects occur
Solution Approach 1:
The patent employs the body's own endogenous analgesic systems to provide pain relief during MRI procedures. By stimulating specific nerve fibers through modified gradient waveforms, the patient's body naturally releases endorphins, enkephalins, and other painkilling substances, eliminating the need for external pharmaceutical interventions and their associated side effects. This self-service approach allows the patient's physiological systems to self-regulate pain perception during the scan.
3Object-affected harmful factors
If acupuncture is used to induce analgesia, then patient comfort is improved, but the procedure becomes invasive
Solution Approach 1:
The patent replaces mechanical acupuncture procedures with electromagnetic field-based gradient waveform modifications. Instead of physically inserting needles into acupuncture points, the system uses time-varying magnetic fields to induce electrical currents that stimulate the same neural pathways and trigger endogenous analgesic mechanisms, achieving comparable pain relief without invasive procedures or physical contact with the patient's body.
4Manufacturing precision
If gradient amplitude is increased to improve imaging quality, then manufacturing precision is improved, but peripheral nerve stimulation threshold is exceeded causing discomfort
Solution Approach 1:
The patent employs dynamic gradient waveform design where parameters such as amplitude, duration, and rise time are continuously adjusted during the MRI sequence. The gradient amplitudes are modulated to remain below PNS thresholds while maintaining sufficient encoding strength for image quality. This dynamic adjustment allows the system to optimize the balance between imaging precision and patient comfort on a per-encoding-step basis, rather than using fixed conservative limits throughout the entire scan.
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 approach effectively reduces PNS-induced discomfort and pain by providing temporal and spatial control of analgesic effects, avoiding the limitations of existing methods like systemic analgesics and invasive stimulation techniques.
Implementation Method 1
Faraday's Law of Induction states that changing magnetic fields induce electrical currents in any conducting medium. Thus, in accordance with Faraday's Law, exposure of conductive tissue to time-varying magnetic fields used in MRI scanners induces an electric field and currents into a patient's body.
Implementation Method 2
Modulating magnetic resonance gradient waveforms to stimulate peripheral nerves and induce a nerve conduction block
Data Source
AI summary
Techniques are disclosed related to increasing prior limits imposed on MR gradient switching speed (dB/dt) without causing significant discomfort or severe pain perception to patients. The technique disclosed herein do so by modifying the pulsing gradient fields that are ordinarily available for MR imaging protocols. Doing so stimulates the peripheral nerves and thus enables a quick, reversible, and complete inhibition of action potential propagation through the stimulated region of tissue, referred to as a nerve conduction block.