Telemetry Coil Placement in Implantable Device Case
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reduced header volume in implantable pulse generators (IPGs) due to advancing technology and the need for more electrodes creates space constraints, making it challenging to accommodate an adequate telemetry coil, which affects data telemetry reliability and compatibility with Magnetic Resonance Imaging (MRI) techniques.
Innovation Solution
The telemetry coil is placed inside the device case, and improved telemetry circuitry is implemented, including resonant tanks and decoupling circuitry, to enhance data transfer reliability by minimizing mutual inductance with the charging coil, using LSK communication and discrete logic gates to control coil interactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the header volume is reduced to accommodate more electrodes, then the electrode count increases, but the space for telemetry coil decreases
Solution Approach 1:
The patent relocates the telemetry coil from the traditional header location to the device case, utilizing three-dimensional space distribution. By separating the telemetry coil placement from the header constraint and positioning it within the device case alongside the charging coil, the design resolves the spatial conflict between accommodating more electrodes in the header and maintaining adequate telemetry coil space.
2Quantity of substance
If the telemetry coil is placed inside the device case, then space in the header is freed for more electrodes, but mutual inductance with the charging coil increases
Solution Approach 1:
The patent introduces a magnetic shield as an intermediary element between the telemetry coil and the charging coil. This magnetic shield acts as a mediator that blocks magnetic field interference between the two coils, enabling the telemetry coil to be positioned inside the device case near the charging coil without suffering from harmful mutual inductance effects. The shield allows both coils to coexist in close proximity while maintaining signal integrity.
Solution Approach 2:
The patent applies different magnetic shielding characteristics to different regions of the device case. The magnetic shield is strategically positioned to provide localized protection specifically in the area where the telemetry coil operates, while allowing other regions to maintain their magnetic field characteristics. This localized approach enables the telemetry coil to be positioned close to the charging coil without creating unwanted interference throughout the entire device.
3Volume of moving object
If the telemetry coil is placed inside the device case, then device size can be reduced for patient comfort, but MRI compatibility may be affected
Solution Approach 1:
The magnetic shield serves as an intermediary that protects the telemetry coil from MRI interference while allowing the coil to be positioned inside the device case. The shield blocks external magnetic fields from the MRI scanner from directly coupling with the telemetry coil, thereby maintaining MRI compatibility. This enables the device to maintain a compact size with the telemetry coil positioned within the case without compromising MRI safety or image quality.
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 configuration increases the reliability of data transfer and power receipt while maintaining compatibility with MRI, reducing unwanted energy sinks and improving patient comfort by allowing for smaller device sizes with increased electrode counts.
Implementation Method 1
Wireless data telemetry and power transfer between the external devices 12 and 50 and the IPG 100 takes place via inductive coupling, and specifically magnetic inductive coupling
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
An implantable medical device is disclosed comprising a conductive case; a charging coil within the case for receiving power from an external charger, the charging coil wound around an area having a first extent; and a telemetry coil within the case for receiving data from an external controller, or for transmitting data to the external controller, or for receiving and transmitting data from and to the external controller, the telemetry coil would around an area having a second extent, in which the second extent of the telemetry coil at least overlaps the first extent of the charging coil. The charging coil can be proximate to one side of a circuit board, with the telemetry coil is proximate to the other side. The implantable medical device further comprises a non-conductive header comprising at least one lead connector for coupling to an electrode lead.