RFID DETECTION AND IDENTIFICATION SYSTEM FOR IMPLANTABLE MEDICAL DEVICES

• US 20110063088A1
• Filed: 06/17/2010
• Published: 03/17/2011
• Est. Priority Date: 09/16/2009
• Status: Active Grant

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Kelley, Scott W., Spaulding, Joseph, Muffoletto, Barry C., Truex, Buehl E., Tyers, Geddes Frank, Stevenson, Robert A.
• Granted Patent: US 8,093,991 B2
• Time in Patent Office: Days
• US Class Current: 340/10.4
• CPC Class Codes: G06K 19/07758 arrangements for adhering the record carrier to further objects or living beings, functioning as an identification tag

Abstract

An RFID tag is disposed within a hermetically sealed housing of an IMD. Low frequency RFID interrogators and tags are used, and the housing walls are made of materials, and/or are reduced in thickness, to facilitate RF communication between the RFID tag and an RFID reader/interrogator programmer. An RFID reader/interrogator may be used which has a limited transmit time and time-out period to avoid interference with the operation of the IMD.

Claims

1. An RFID detection and identification system, comprising:

an active implantable medical device (IMD) having a hermetically sealed housing for preventing entry of body fluids into the IMD;

an RFID tag disposed within the IMD housing; and

a radio frequency (RF) transmissive window or wall of the IMD housing adjacent to the RFID tag, for facilitating RF communication between the RFID tag and an RF interrogator.

2. The system of claim 1, wherein the IMD housing forms an electromagnetic shield having a first wall thickness, and the RF transmissive window comprises a portion of the electromagnetic shield but has a reduced second wall thickness.

3. The system of claim 2, wherein the second wall thickness is one-half or less of the first wall thickness.

4. The system of claim 3, wherein the second wall thickness is 0.005 inches or less.

5. The system of claim 2, wherein the IMD housing is filled with a non-conductive material.

6. The system of claim 5, wherein the nonconductive material comprises a fluid or a gel material.

7. The system of claim 1, including a recess in the IMD housing adjacent to the RF transmissive window, in which at least a portion of the RFID tag is disposed.

8. The system of claim 7, wherein an exterior wall of the IMD housing comprises a flush and uniform surface over and adjacent to the recess.

9. The system of claim 7, wherein an exterior wall of the IMD housing comprises a protrusion adjacent to the recess.

10. The system of claim 7, wherein the recess and the RF transmissive window are formed by punching a portion of the wall of the IMD housing to form the inner recess, and then reducing the thickness of the punched-out portion of the wall to form the RF transmissive window.

11. The system of claim 10, wherein the thickness of the punched-out portion of the wall is reduced by grinding or pressing.

12. The system of claim 11, wherein an exterior surface of the punched-out portion of the wall is flush with the remaining portion of the wall.

13. The system of claim 1, wherein the RF transmissive window comprises a Grade 5 or a Grade 23 titanium.

14. The system of claim 1, wherein the RF transmissive window comprises alloys of stainless steel 316 or Haynes 25.

15. The system of claim 1, wherein the RF transmissive window or wall comprises a hermetic ceramic or related non-metallic material.

16. The system of claim 1, wherein the RF transmissive window comprises a window plug inserted into an aperture in the IMD housing wall.

17. The system of claim 16, wherein the window plug comprises thinner metallic material or a more RF transmissive material compared with the remainder of the IMD housing.

18. The system of claim 17, wherein the window plug comprises a hermetic ceramic or related non-metallic material.

19. The system of claim 16, including a ferrule disposed between the window plug and the IMD housing wall.

20. The system of claim 1, wherein the RFID tag comprises an RFID chip having an antenna wrapped around an elongated ferrite metal core.

21. The system of claim 20, wherein an end of the ferrite metal core is disposed adjacent to the RF transmissive window.

22. The system of claim 1, wherein the RFID tag comprises an RFID chip having dual antennas.

23. The system of claim 1, wherein the RF interrogator has a limited transmit time and an associated time-out period.