Tank filters placed in series with the lead wires or circuits of active medical devices to enhance MRI compatibility
First Claim
1. An electrode assembly for an implantable active medical device, comprising:
- an active fixation distal tip electrode including a helix coil insertable into biological tissue; and
a tank filter electrically connected in series with the helix coil and to a lead of the active medical device, the tank filter having inductance in parallel with capacitance and an overall circuit Q such that the tank filter attenuates current flow over a range of selected frequencies.
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Accused Products
Abstract
A TANK filter is provided for a lead wire of an active medical device (AMD). The TANK filter includes a capacitor in parallel with an inductor. The parallel capacitor and inductor are placed in series with the lead wire of the AMD, wherein values of capacitance and inductance are selected such that the TANK filter is resonant at a selected frequency. The Q of the inductor may be relatively maximized and the Q of the capacitor may be relatively minimized to reduce the overall Q of the TANK filter to attenuate current flow through the lead wire along a range of selected frequencies. In a preferred form, the TANK filter is integrated into a TIP and/or RING electrode for an active implantable medical device.
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Citations
20 Claims
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1. An electrode assembly for an implantable active medical device, comprising:
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an active fixation distal tip electrode including a helix coil insertable into biological tissue; and a tank filter electrically connected in series with the helix coil and to a lead of the active medical device, the tank filter having inductance in parallel with capacitance and an overall circuit Q such that the tank filter attenuates current flow over a range of selected frequencies. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A medical therapeutic or diagnostic device, comprising:
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an implantable active medical device including electronic circuitry for therapy delivery or detection of biological signals; a lead in electrical communication with the active medical device electronic circuitry; and an electrode assembly electrically connected to the lead, the electrode assembly comprising; an active fixation distal tip electrode including a helix coil insertable into biological tissue and; a tank filter electrically connected in series with the helix coil and to the lead, the tank filter having inductance in parallel with capacitance and an overall circuit Q resulting in an 3 dB bandwidth on the order of MHz such that the tank filter attenuates current flow at a selected range of MRI RF pulsed frequencies. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification