In-Ear Caloric Stimulation Device Using Thermoelectric Waveforms
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Solution Overview
Problem
Current caloric vestibular stimulation methods are limited by slow thermal changes in the ear canal, which can lead to ineffective diagnosis and treatment of medical conditions, as they fail to induce sustained physiological responses due to adaptation of the vestibular system to constant thermal stimuli.
Innovation Solution
An in-ear stimulation device with first and second earpieces, thermoelectric devices, heat sinks, and a controller that generates actively controlled time-varying waveforms to maintain thermal stimulus intensity, minimizing drift and ensuring effective delivery of caloric outputs through temperature sensors and impedance monitoring for optimal patient compliance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional water caloric tests are used, then the procedure is simple to perform, but the thermal changes in the ear canal are slow and fail to induce sustained physiological responses
Solution Approach 1:
The patent replaces the mechanical water irrigation system with thermoelectric devices (Peltier elements) that use electrical energy to generate rapid thermal changes. This substitution enables fast heating and cooling cycles without the complexity of water delivery mechanisms, achieving rapid thermal stimulation while maintaining relative device simplicity.
Solution Approach 2:
The patent implements periodic thermal stimulation through oscillating waveforms that continuously alternate between heating and cooling phases. This periodic action prevents vestibular adaptation by constantly varying the thermal stimulus, thereby sustaining physiological responses such as nystagmus throughout the treatment session.
2Duration of action of moving object
If constant thermal stimulus is applied, then the initial physiological response is strong, but the response diminishes over time due to vestibular system adaptation
Solution Approach 1:
The system employs periodic thermal waveforms that oscillate between heating and cooling phases, preventing the vestibular system from adapting to a constant stimulus. This continuous variation in thermal stimulus maintains sustained physiological responses including nystagmus throughout the treatment session.
Solution Approach 2:
The patent incorporates feedback mechanisms through temperature sensors and impedance monitoring that track the physiological response in real-time. The controller adjusts the thermal waveform parameters based on this feedback to maintain optimal stimulation intensity and prevent adaptation, thereby ensuring consistent physiological responses throughout treatment.
3Speed
If rapid temperature changes are implemented, then sustained physiological responses are achieved, but thermal drift due to patient contact becomes significant
Solution Approach 1:
The patent uses temperature sensors in thermal contact with the earpiece to monitor the actual thermal stimulus delivered. The controller continuously compares the measured temperature with the desired waveform and adjusts the thermoelectric device output in real-time to compensate for thermal drift caused by patient contact and environmental factors.
Solution Approach 2:
The patent replaces passive thermal delivery with an actively controlled electrical system that uses feedback to maintain precise temperature control. This electrical control system can rapidly adjust power delivery to compensate for thermal losses, maintaining stimulus stability despite rapid temperature changes and patient contact.
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 device achieves sustained vestibular stimulation, inducing nystagmus detectable by videonystagmography and electronystagmography, effectively treating conditions like migraines and diabetes by maintaining phasic firing rates beyond the adaptation period of constant thermal stimuli.
Implementation Method 1
at least first and second thermoelectric devices thermally coupled to respective ones of the first and second earpieces
Implementation Method 2
a first heat sink thermally coupled to the first thermoelectric device opposite the first earpiece and a second heat sink thermally coupled to the second thermoelectric device opposite the second earpiece
Data Source
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AI summary
An in-ear stimulation device for administering caloric stimulation to the ear canal of a subject includes (a) first and second earpieces configured to be insertable into the ear canals of the subject; (b) at least first and second thermoelectric devices thermally coupled to respective ones of the first and second earpieces; (c) a first heat sink thermally coupled to the first thermoelectric device opposite the first earpiece and a second heat sink thermally coupled to the second thermoelectric device opposite the second earpiece; and (d) a controller comprising a waveform generator in communication with the first and second thermoelectric devices, the waveform generator configured to generate a first control signal to control a first caloric output to the first thermoelectric device and a second control signal to control a second caloric output to the second caloric device.