Non-invasive Nerve Stimulator for Overactive Bladder
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Solution Overview
Problem
Current non-invasive electrical stimulation methods struggle to selectively stimulate deep nerves without causing pain or unintended muscle contractions, particularly in treating conditions like overactive bladder and urinary incontinence, due to limitations in depth of penetration and selectivity.
Innovation Solution
The development of novel electrode-based and magnetic stimulation devices that use specific waveform parameters and architectures to deliver electrical or magnetic fields non-invasively to the posterior tibial nerve, allowing for deeper penetration without pain, using capacitive or ohmic coupling with dielectric materials and toroidal windings to shape the electric field effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional electrical stimulation methods are used to stimulate deep nerves, then the depth of penetration is insufficient, but increasing the stimulation intensity causes pain and unintended muscle contractions
Solution Approach 1:
The stimulation is divided into multiple phases within a single pulse cycle: a high-voltage prepulse phase that selectively activates deep nerve fibers, followed by a main pulse phase. This segmentation allows the high voltage to be applied briefly without causing sustained pain or muscle contraction, as the nerve is already depolarized and refractory during the main pulse.
Solution Approach 2:
A high-voltage prepulse is applied before the main stimulation pulse to pre-depolarize the nerve membrane. This preliminary action brings the nerve close to the activation threshold, allowing the subsequent main pulse (at lower voltage) to effectively stimulate the deep nerve without requiring high intensity that would cause pain.
Solution Approach 3:
The stimulation uses periodic pulsed waveforms with specific duty cycles, where high-voltage stimulation is applied in brief bursts followed by longer low-voltage or zero-voltage intervals. This periodic modulation allows deep nerve stimulation while providing sufficient rest periods to prevent sustained muscle contraction and reduce pain perception.
2Length of stationary object
If higher stimulation intensity is applied to achieve deeper nerve penetration, then the depth of penetration increases, but selectivity decreases causing unintended muscle contractions
Solution Approach 1:
The electrode design creates localized high electric field regions through specific geometric configurations (e.g., needle electrodes, focused arrays) that concentrate the electric field precisely at the target nerve location. This allows high intensity stimulation to be applied locally without affecting surrounding muscles, maintaining selectivity even at higher intensities.
Solution Approach 2:
The high-voltage prepulse selectively brings deep nerve fibers to threshold before the main pulse is applied. Since the nerve is already depolarized and in a refractory state during the main pulse, the main pulse can be applied at lower intensity without causing unintended muscle contractions, thus maintaining selectivity while achieving deep penetration.
3Object-affected harmful factors
If non-invasive electrical stimulation is used to treat overactive bladder, then patient comfort improves, but the effectiveness of treatment decreases due to insufficient nerve stimulation
Solution Approach 1:
The high-voltage prepulse non-invasively pre-depolarizes the posterior tibial nerve, bringing it close to the activation threshold. This allows the subsequent main pulse to effectively stimulate the sacral nerve roots and treat overactive bladder without requiring high intensity that would cause pain, thus maintaining both comfort and effectiveness.
Solution Approach 2:
The stimulation protocol segments the pulse into a high-voltage prepulse phase for deep nerve activation and a main pulse phase for therapeutic effect. This segmentation allows the high voltage to be applied briefly without causing sustained discomfort, while still achieving effective non-invasive treatment of overactive bladder.
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
These devices enable selective stimulation of the target nerve, reducing pain and muscle contractions, thereby effectively treating conditions like overactive bladder and urinary incontinence with improved depth of penetration and therapeutic outcomes.
Implementation Method 1
a magnetic stimulator comprising two toroidal windings
Implementation Method 2
deliver electrical or magnetic fields non-invasively to the posterior tibial nerve
Implementation Method 3
using capacitive or ohmic coupling with dielectric materials
Implementation Method 4
capacitive or ohmic coupling with dielectric materials to shape the electric field effectively
Implementation Method 5
transcutaneous electrical nerve stimulation and magnetic nerve stimulation
Implementation Method 6
using capacitive or ohmic coupling with dielectric materials
Data Source
AI summary
Transcutaneous electrical and magnetic nerve stimulation devices and methods of treating lower urinary tract disorders deliver energy noninvasively to nerves within a patient. The disorders comprise overactive bladder, urge incontinence, stress incontinence, urge frequency, non-obstructive urinary retention and interstitial cystitis/painful bladder syndrome. For example, a posterior tibial nerve of a patient is stimulated non-invasively. Protocol parameters are selected for a nerve stimulation session for treating each individual patient, where modules of the bladder of the patient are represented as coupled non-linear oscillators.