Locator system for implanted access port with RFID tag

• US 7,727,143 B2
• Filed: 05/31/2006
• Issued: 06/01/2010
• Est. Priority Date: 05/31/2006
• Status: Expired due to Fees

• Current Assignee: Apollo Endosurgery US, Inc. (Boston Scientific Corporation), Enomatic Asia Pacific Limited
• Original Assignee: Allergan, Inc. (Canada) (Abbvie Incorporated)
• Inventors: Weihrich, Donald, Birk, Janel
• Primary Examiner(s): Lacyk; John P
• Application Number:
  US11/444,702
• Publication Number:
  US 20070282196A1
• Time in Patent Office: 1,462 Days
• Field of Search: 600 29- 32, 600/37, 128/DIG.25, 128897-899, 606151-158
• US Class Current: 600/37
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61F 5/0003 Apparatus for the treatment of obesity; Anti-eating devices surgical instruments or methods for treatment of obesity, devices specially adapted therefor A61B17/00; hollow or tubular parts of organs A61F2/04
• CPC Class Codes: A61M 2039/0238 having means for locating the implanted device to insure proper injection, e.g. radio-emitter, protuberances, radio-opaque markers
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 39/0208 Subcutaneous access sites for injecting or removing fluids transcutaneous access sites A61M39/0247; implantable infusion devices A61M5/14276

Abstract

An access port locator system for adjustable gastric bands. The system includes an access port with an RFID tag with its antenna adjacent to the receiving portion of the port. The system includes a locator with radio frequency transmitter/receiver circuitry for sending read or interrogation signals to the RFID tag and for sending write signals to the tag to write treatment data to memory of the RFID tag. The locator also includes an antenna array with four patch antenna arranged in pairs to model two monopulse radar antenna systems. The locator also includes processor(s) and logic modules/circuitry for processing the tag response signals received by the antenna array to determine location information for the RFID tag and associated port, i.e., to identify the center of the port relative to the antennae array or array face such as with strength and direction information relative to the array face.

Claims

1. A gastric band system adapted for locating an access port, comprising:

a gastric band with a fill line having an access port for receiving a needle, wherein the access port comprises a radio frequency identification (RFID) tag; and

a locator comprising;

a radio frequency transmitter generating an interrogation signal, wherein the RFID tag operates in response to the transmitted interrogation signal to generate a tag response signal;

an antenna array with an array face having a minimum of two pairs of antennae positioned an equal distance apart from each other, each of the antennae being spaced an equal distance from a central axis of the antenna array, the array operable by the radio frequency transmitter for transmitting the interrogation signal and receiving the tag response signal; and

a location processing module processing the tag response signal to determine location information for the access port, wherein the location processing module processes a difference signal for each pair of antennae to determine the location information for the access port, the difference signals being generated based on the tag response signal received by each of the antennae.

2. The system of claim 1, wherein the access port comprises a surface for receiving the needle and the RFID tag comprises an antenna positioned at least partially about the periphery of the receiving surface of the port and wherein the location information is indicative of substantially being in the center of the receiving surface.

3. The system of claim 1, wherein the location information comprises a signal strength value and direction information relative to the array face from the locator.

4. The system of claim 3, wherein the locator further comprises a receiver processing module operating prior to the location processing module to generate an in-phase tag response signal and a quadrature tag response signal from each of the difference signals.

5. The system of claim 1, wherein the locator further comprises a tag data processing module processing a sum signal generated by the antenna array based on the tag response signal to obtain tag data stored in memory associated with the RFID tag.

6. The system of claim 1, wherein the radio frequency transmitter generates a write signal comprising patient treatment data for transmittal to the RFID tag and wherein the RFID tag comprises memory and is operable in response to receiving the write signal to store the patient treatment data in the memory.

7. The system of claim 1, wherein the locator comprises a display operable to display the location information and comprises a receptacle for receiving a syringe with a needle, the receptacle being configured to position the needle perpendicular to the array face and about at the center of the antenna array.

8. A locator apparatus for locating an implantable medical devices such as access ports of gastric bands, comprising:

a transmitter generating a read signal;

an antenna array receiving a response signal from an identification tag mounted on an implantable medical device in response to the read signal, wherein the antenna array comprises four antennae mounted on a planar mounting element in a diamond pattern with each of the antennae being a predetermined distance from the center of the diamond pattern and wherein the antenna array generates a difference signal for each opposing pair of the antennae based on the received response signal; and

a location processing module processing the difference signals to determine location information for the implantable medical device relative to the antenna array.

9. The apparatus of claim 8, wherein the identification tag is an RFID tag and the transmitter is a radio frequency transmitter and the apparatus further comprising a receiver processing module operating to mix the difference signals with a sample of the transmitted read signal and to filter background noise from the mixed signals to generate in-phase tag response signals and quadrature tag response signals and wherein the location processing module processes the in-phase tag response signals and the quadrature tag response signals to determine the location information.

10. The apparatus of claim 9, wherein the determined location information comprises strength information for the response signal and direction information relative to the center of diamond pattern of the antenna array.

11. The apparatus of claim 8, further comprising a housing within which the planar mounting element is mounted, wherein the housing comprises a recessed surface for receiving a syringe, the recessed surface including a needle guide passing through the housing adapted for receiving a needle attached to the syringe, and wherein the needle guide passes through the center of the diamond pattern of the antenna array.

12. The apparatus of claim 8, wherein the antenna array further is configured to output a sum signal for each of the opposing pairs of the antennae and further comprising a tag data processing module processing the sum signals to identify data stored in memory of the identification tag provided in the tag response signal.

13. A system adapted for locating a port, comprising:

an implantable medical device with a fill line having a port for receiving a needle, wherein the port comprises a radio frequency identification (RFID) tag; and

a locator comprising;

a radio frequency transmitter generating an interrogation signal, wherein the RFID tag operates in response to the transmitted interrogation signal to generate a tag response signal;

an antenna array operable by the radio frequency transmitter for transmitting the interrogation signal and receiving the tag response signal, wherein the antenna array comprises a minimum of two pairs of antennae positioned an equal distance apart from each other, each of the antennae being spaced an equal distance from a central axis of the antenna array; and

a location processing module processing the tag response signal to determine location information for the access port, wherein the location processing module processes a difference signal for each pair of antennae to determine the location information for the access port, the difference signals being generated based on the tag response signal received by each of the antennae.

14. The system of claim 13, wherein the antenna array the location information comprises a signal strength value and direction information relative to the array face.

15. The system of claim 14, wherein the locator further comprises a receiver processing module operating prior to the location processing module to generate an in-phase tag response signal and a quadrature tag response signal from each of the difference signals.

16. The system of claim 13, wherein the locator further comprises a tag data processing module processing a sum signal generated by the antenna array based on the tag response signal to obtain tag data stored in memory associated with the RFID tag.

17. The system of claim 13, wherein the radio frequency transmitter generates a write signal comprising patient treatment data for transmittal to the RFID tag and wherein the RFID tag comprises memory and is operable in response to receiving the write signal to store the patient treatment data in the memory.

18. An access port for positioning beneath the skin of a patient to provide access to a medical device, comprising:

an antenna for receiving an interrogation signal from a locator;

memory storing port information; and

circuitry for responding to the received interrogation signal to generate a response signal comprising at least a portion of the stored port information, whereby the locator functions to determine location information for the access port, wherein the locator comprises an antenna array with an array face having a minimum of two pairs of antennae used to transmit the interrogation signal and receive the response signal, the antennae positioned an equal distance apart from each other, each of the antennae being spaced an equal distance from a central axis of the antenna array, and further wherein the locator comprises a location processing module, wherein the location processing module processes a difference signal for each pair of antennae to determine the location information for the access port, the difference signals being generated based on the response signal received by each of the antennae.

19. The access port of claim 18, wherein the access port further comprises a body with a surface for receiving a needle, wherein the antenna, memory, and circuitry are provided in a radio frequency identification (RFID) tag mounted on or within the body proximate to the needle receiving surface, and the interrogation signal is a radio frequency signal.

20. The access port of claim 18, wherein the access port comprises a surface for receiving a needle and the antenna is positioned at least partially about the periphery of the receiving surface of the port and wherein the location information is indicative of the locator being proximate to the receiving surface of the port.

21. The access port of claim 18, wherein the memory further stores data pertaining to the patient that can be modified by write signals from the locator and wherein the response signal further comprises the stored patient data.

22. The access port of claim 18, wherein the location information comprises a signal strength value and direction information relative to the array face from the locator.