Bone-Anchored Hearing Aid Antenna Parasitic Coupling
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Solution Overview
Problem
In bone-anchored hearing aids, the parasitic effects caused by the vibrator housing interfere with the performance of the antenna, leading to resonant behavior and variations in antenna performance.
Innovation Solution
The implementation of a capacitance between the vibrator leads and the vibrator housing eliminates or reduces parasitic capacitance and inductance, thereby improving the antenna's performance by minimizing interference from the vibrator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vibrator housing is electrically connected to the electronics of the bone anchored hearing aid, then the vibrator can be powered and controlled, but parasitic capacitance and inductance cause resonant behavior that damages antenna performance
Solution Approach 1:
A capacitor is introduced as an intermediary component between the vibrator housing and the antenna feed line. This capacitor blocks the parasitic capacitance and inductance from coupling into the antenna system while still allowing the vibrator to be electrically connected to the electronics for power and control signals.
Solution Approach 2:
The harmful parasitic effects are extracted and isolated from the antenna system by placing the capacitor at the interface between the vibrator housing and the antenna feed line, effectively removing the resonant behavior that was damaging antenna performance.
2Reliability
If lead wires with parasitic inductance are used to connect the coil and piezoelectric component to the vibrator housing, then the vibrator components can be electrically connected, but the parasitic inductance contributes to resonant behavior at radio frequencies
Solution Approach 1:
The capacitor serves as an intermediary that blocks the parasitic inductance from the lead wires from affecting the antenna system. By placing the capacitor between the vibrator housing and the antenna feed line, the resonant behavior caused by the inductive lead wires is prevented from coupling into the antenna.
3Strength
If the vibrator housing is made as a large electrically significant component, then it can accommodate the vibrator and provide structural support, but it creates significant parasitic capacitance that interferes with antenna operation
Solution Approach 1:
The capacitor is placed at the interface between the large vibrator housing and the antenna feed line, acting as an intermediary that blocks the parasitic capacitance generated by the housing from interfering with antenna operation, while allowing the housing to maintain its structural support function.
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 application of capacitance between the vibrator leads and the housing effectively reduces parasitic coupling, enhancing the antenna's performance and maintaining consistent communication between the bone-anchored hearing aid and external devices.
Implementation Method 1
each of the one or more vibrator leads being connected to the vibrator and to the vibrator housing via a capacitance, and where the capacitance is configured to eliminate at least a parasitic capacitance
Data Source
AI summary
A bone-anchored hearing aid is disclosed. A bone-anchored hearing aid for a recipient may comprise an antenna configured to transmit and/or receive a wireless signal, an electronic circuit configured to receive the wireless signal, one or more vibrator leads, a vibrator configured for receiving an electrical signal from the electronic circuit via the one or more vibrator leads, and the vibrator may be configured to provide a vibrational stimulation to the recipient patient based on the electrical signal. Furthermore, the hearing aid includes a vibrator housing configured to accommodate at least the vibrator, and wherein each of the one or more vibrator leads may be connected to the vibrator and to the vibrator housing via a capacitance, and where the capacitance is configured to eliminate at least a parasitic coupling between the vibrator and the vibrator housing for improving the performance of the antenna.