Method for locating an implanted fluid access port
View Patent ↗An implanted fluid access port locator system for adjustable gastric bands. The system may include an access port having an RFID tag with its antenna adjacent to the receiving portion of the port. An external locator with radio frequency transmitter/receiver circuitry sends read or interrogation signals to the RFID tag and may send write signals to the tag to write treatment data to memory of the RFID tag. The locator may include 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. A method of locating implanted fluid access port includes providing radio frequency transmitter/receiver circuitry on the access port and manipulating a handheld locator outside the body to pinpoint the position and orientation of the access port. A mark may be made with a handheld locator to direct insertion of a needle for adding or removing fluid from an implanted system through the access port.
1. A method of adding or removing fluid from an implanted gastric band system through an access port, comprising:
providing an external locator comprising a radio frequency transmitter/receiver for sending an interrogation signal and receiving a response;
maneuvering the external locator outside a patient within whom has been implanted a fluid-actuated gastric band system having a fluid access port, the fluid access port including a radio frequency receiver/transmitter;
sending an interrogation signal from the external locator to stimulate the access port receiver/transmitter to generate a response signal;
adjusting the position of the external locator until the response signal indicates that a reference point on the external locator is positioned over an entrance point on the patient's body directly over the access port;
passing a hypodermic needle through the entrance point and into the access port; and
introducing fluid to or removing fluid from the access port using the needle,
wherein the external locator includes an antenna array with an array face having four or more antennae mounted on a planar mounting element in a diamond pattern with each of the antenna being a predetermined distance from the center of the diamond pattern, the array operable by the radio frequency transmitter for transmitting the interrogation signal and receiving the response signal, and wherein the antenna array generates a difference signal for each opposing pair of the antennae based on the response signal.
2. The method of claim 1 , further including marking the entrance point.
3. The method of claim 2 , further including actuating a plunger on the external locator to mark the entrance point.
4. The method of claim 1 , wherein the fluid access port further includes a radio frequency identification (RFID) tag and the external locator includes circuitry, and the method further includes reading information from the RFID tag using the external locator circuitry.
5. The method of claim 4 , further including writing information to the RFID tag using the external locator circuitry.
6. The system of claim 1 , wherein the external locator comprises a display operable to display the location information and comprises a receptacle for receiving a syringe with a hypodermic needle, and wherein the location of the needle is the reference point.
7. A method of adding or removing fluid from an implanted gastric band system through an access port, comprising:
providing an implanted fluid-actuated gastric band system having a fluid access port with a radio frequency identification (RFID) tag;
providing an external locator comprising a radio frequency transmitter for sending an interrogation signal and receiving a response, and circuitry for reading information received from the RFID tag;
locating an entrance point over the implanted fluid access port by maneuvering the external locator over the general area where the access port is located;
sending an interrogation signal from the external locator to stimulate the access port RFID tag to generate a response signal;
passing a hypodermic needle through the entrance point and into the access port; and
introducing fluid to or removing fluid from the access port using the needle based on the information received from the RFID tag,
wherein the external locator includes an antenna array with an array face having four or more antennae mounted on a planar mounting element in a diamond pattern with each of the antenna being a predetermined distance from the center of the diamond pattern, the array operable by the radio frequency transmitter for transmitting the interrogation signal and receiving the response signal, and wherein the antenna array generates a difference signal for each opposing pair of the antennae based on the response signal.
8. The method of claim 7 , wherein the RFID tag includes memory and the external locator includes circuitry for writing information to the RFID tag memory.
9. The method of claim 8 , wherein the memory further stores data pertaining to the patient that can be modified by write signals from the external locator and wherein the response signal further comprises the stored patient data.
10. The method of claim 7 , wherein the antenna array senses location information comprising a signal strength value and direction information relative to the array face.
11. The method of claim 7 , wherein the external locator comprises a receptacle for receiving a syringe with a hypodermic needle, and wherein the method includes positioning the external locator so that the hypodermic needle is over the entrance point.
12. The method of claim 7 , wherein the access port further comprises a body with a surface for receiving a needle, wherein the RFID tag is mounted on or within the body proximate to the needle receiving surface.
13. A method of adding or removing fluid from an implanted gastric band system through an access port, comprising:
providing a fluid-actuated gastric band system having a fluid access port, the fluid access port comprising a body with a surface for receiving a needle and an antenna mounted on or within the body proximate to the needle receiving surface;
providing an external locator comprising a transmitter/receiver for sending an interrogation signal to and receiving a response from the access port antenna;
maneuvering the external locator over the implanted fluid access port;
sending an interrogation signal from the external locator to stimulate the access port antenna to generate a response signal;
adjusting the position of the external locator until the response signal indicates that a reference point on the external locator is positioned over an entrance point on the patient's body directly over the access port;
passing a hypodermic needle through the entrance point and into the access port; and
introducing fluid to or removing fluid from the gastric band system via the access port using the needle,
wherein the external locator includes an antenna array with an array face having four or more antennae mounted on a planar mounting element in a diamond pattern with each of the antenna being a predetermined distance from the center of the diamond pattern, the array operable by the transmitter/receiver for transmitting the interrogation signal and receiving the response signal, and wherein the antenna array generates a difference signal for each opposing pair of the antennae based on the response signal.
14. The method of claim 13 , wherein the fluid access port further includes a radio frequency identification (RFID) tag, and the external locator includes circuitry for reading information from the RFID tag.
15. The method of claim 13 , wherein the external locator includes, circuitry, and the method further includes reading information from the RFID tag using the external locator circuitry.
16. The method of claim 13 , wherein the external locator includes circuitry, and the method further includes writing information to the RFID tag using the external locator circuitry.
17. The method of claim 13 , further including introducing to or removing fluid from the access port using the needle based on the information received from the RFID tag.