Tank filters placed in series with the lead wires or circuits of active medical devices to enhance MRI compatibility

• US 7,945,322 B2
• Filed: 11/09/2006
• Issued: 05/17/2011
• Est. Priority Date: 11/11/2005
• Status: Expired due to Fees

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Frysz, Christine A., Dabney, Warren S., Brendel, Richard L., Stevenson, Robert A.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US11/558,349
• Publication Number:
  US 20070112398A1
• Time in Patent Office: 1,650 Days
• Field of Search: 607/2, 607/9
• US Class Current: 607/2
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01F 2017/065 Core mounted around conductor to absorb noise, e.g. EMI filter
• CPC Class Codes: H01G 4/35 Feed-through capacitors or anti-noise capacitors
• CPC Class Codes: H01G 4/40 Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations
• CPC Class Codes: H03H 1/0007 of radio frequency interference filters
• CPC Class Codes: H03H 2001/0042 Wound, ring or feed-through type capacitor
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part

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.

Claims

1. A medical therapeutic device, comprising:

an active medical device including electronic circuitry for therapy delivery or detection of biological signals, an electrode, and an electrical conductor for connecting the electrode to the electronic circuitry;

a tank filter placed in series with the conductor and having electrical inductance in parallel with capacitance, whereby the tank filter attenuates current flow over a range of frequencies; and

an RFID chip associated with the active medical device or the electrical conductor or the electrode for identifying the presence of the tank filter in the active medical device or the electrical conductor or the electrode.

2. The device of claim 1, wherein the RFID chip is incorporated into the active medical device having the tank filter associated therewith.

3. The device of claim 1, wherein the conductor comprises a lead wire, and wherein the RFID chip is incorporated into the lead wire.

4. The device of claim 1, wherein the RFID chip is implanted into a patient operably connected to the active medical device or a lead wire system thereof that includes the tank filter.

5. The device of claim 1, wherein the RFID tag identifies the range of frequencies.