# US 8,786,431 B2 · Tunable loop-dipole RFID tag antenna for dentures

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- Number: US 8,786,431 B2
- Document ID: US8786431B2
- Status: Granted
- Kind: B2
- Application number: 13/341,900
- Filed: 2011-12-30
- Published: 2012-07-12
- Granted: 2014-07-22
- Earliest claimed: 2011-01-03
- Applicants: Akshay Athalye; Branko Mrdakovic; Branko Kolundzija
- Inventors: Akshay Athalye; Branko Mrdakovic; Branko Kolundzija
- Web page: https://patentgrep.com/patent/US8786431B2

## CPC

- G08B 21/24: Reminder alarms, e.g. anti-loss alarms
- H01Q 1/44: using equipment having another main function to serve additionally as an antenna {, e.g. means for giving an antenna an aesthetic aspect}(H01Q1/27 - H01Q1/34 take precedence)
- H01Q 5/385: Two or more parasitic elements
- H01Q 7/00: Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
- H01Q 9/26: with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength (resonant loop antennas H01Q7/00)
- H01Q 21/30: Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
- G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

A radio frequency identification (RFID) transponder for use in dentures is provided. The RFID transponder includes a passive RFID microchip configured for storing information related to a denture and a loop dipole antenna configured for sending the information in response to receiving a signal from an RFID reader. The loop dipole antenna in turn includes a wire forming a loop structure and a set of dipole arms going out from the loop structure. Each end of the set of dipole arms is folded at least once to form at least one meander and the dipole arms follow a shape of the denture. The RFID transponder also includes at least one tuning patch configured for tuning input impedance of the loop dipole antenna. The RFID transponder is embedded in the denture and the passive RFID microchip is electrically coupled to the loop structure.

## Claims

### Claim 1

A radio frequency identification (RFID) transponder for use in dentures, comprising:
a passive RFID microchip configured for storing information related to a denture;
a loop dipole antenna configured for sending the information in response to receiving a signal from an RFID reader, the loop dipole antenna including:
a wire forming a loop structure; and
a set of dipole arms going out from the loop structure, wherein each end of the set of dipole arms is folded at least once to form at least one meander and wherein the dipole arms follow a shape of the denture; and
at least one tuning patch configured for tuning input impedance of the loop dipole antenna,
wherein the RFID transponder is embedded in the denture, and
wherein the passive RFID microchip is electrically coupled to the loop structure.

### Claim 2 (depends on 1)

The RFID transponder of claim 1, wherein the information related to the denture includes an identification of the denture owner and at least one of (1) the denture owner's medical records and (2) data pertinent to the denture's lost and found history including date and time when the denture was lost and place where it was found.

### Claim 3 (depends on 1)

The RFID transponder of claim 1, wherein the wire forming the loop structure and the dipole arms are made of different materials.

### Claim 4 (depends on 1)

The RFID transponder of claim 1, wherein a material used to make the loop-dipole antenna includes copper, silver, gold, platinum, aluminum, or a combination thereof.

### Claim 5 (depends on 1)

The RFID transponder of claim 1, wherein the loop dipole antenna has a non-planar shape that is determined by the shape of the denture.

### Claim 6 (depends on 1)

The RFID transponder of claim 1, wherein the loop dipole antenna gives the denture-embedded RFID transponder a reading distance of at least 20 feet.

### Claim 7 (depends on 1)

The RFID transponder of claim 1, wherein the at least one tuning patch includes a couple of tuning patches that are positioned symmetrically with respect to the loop-dipole antenna.

### Claim 8 (depends on 1)

The RFID transponder of claim 1, wherein a material used to make the tuning patch includes copper, silver, gold, platinum, and aluminum.

### Claim 9

A radio frequency identification (RFID) system for detecting and identifying lost dentures in a facility, comprising:
at least one reader deployed in fixed locations in a facility and configured for transmitting a first signal and detecting from a distance of at least one feet a second signal transmitted from an RFID transponder embedded in a denture in response to receiving the first signal;
a first server located within the facility and configured for communicating with the at least one reader over a network in the facility and for controlling operations of the at least one reader, wherein the at least one reader sends an alert to the first server when it detects the second signal from the RFID transponder and wherein the first server is further configured for sending a message when it receives the alert from the at least one reader; and
a second server located outside of the facility and configured for receiving the message and for relaying the message by converting the message to at least one of an email, a text message, a pager message, and a voice message.

### Claim 10 (depends on 9)

The RFID system of claim 9, further comprising at least one of an audible alarm and a visual alarm that are coupled to the at least one reader and wherein the at least one reader is further configured for setting off the alarms.

### Claim 11 (depends on 9)

The RFID system of claim 9, wherein the network in the facility includes a wireless network.

### Claim 12 (depends on 11)

The RFID system of claim 11, further comprising at least one portable reader configured for scanning areas outside a maximum reading distance of the at least one fixed reader by transmitting a third signal, for detecting a fourth signal transmitted from the RFID transponder in response to receiving the third signal, and for sending an alert to the first server over the wireless network in the facility when it detects the fourth signal from the RFID transponder.

### Claim 13 (depends on 12)

The RFID system of claim 12, wherein the second signal and the fourth signal include information related to the denture including an identification of the denture owner and at least one of (1) the denture owner's medical records and (2) data pertinent to the denture's lost and found history including date and time when the denture was lost and place where it was found.

### Claim 14 (depends on 13)

The RFID system of claim 13, wherein at least one of the first server and the second server are further configured for processing the information related to the denture, for generating a record using the processed information, and for storing the generated record.

### Claim 15

A method of detecting and identifying lost denture in a facility, comprising:
transmitting a first signal at a reader deployed in a fixed location in a facility;
detecting from a distance of at least one feet a second signal transmitted from an RFID transponder embedded in a denture in response to the first signal; and
sending over a network in the facility an alert to a first server located within the facility in response to detecting the second signal from the RFID transponder,
wherein the second signal includes information related to the denture including an identification of the denture owner and at least one of (1) the denture owner's medical records and (2) data pertinent to the denture owner's lost and found history including data and time when the denture was lost and place where it was found.

### Claim 16 (depends on 15)

The method of claim 15, further comprising setting at least one of an audible alarm and a visual alarm when the second signal is detected.

### Claim 17 (depends on 15)

The method of claim 15, further comprising processing the information related to the denture and generating at least one of an email, a text message, a pager message, and a voice message based at least in part on the information related to the denture.