Alarm for security tag

• US 8,410,926 B1
• Filed: 05/07/2010
• Issued: 04/02/2013
• Est. Priority Date: 05/07/2010
• Status: Active Grant

• Current Assignee: RF Technologies, Inc. (Microwave Techniques LLC)
• Original Assignee: RF Technologies, Inc. (Microwave Techniques LLC)
• Inventors: Gary, Wyndham F. Jr., LaBorde, John, Krueger, Jeff
• Primary Examiner(s): CROSLAND, DONNIE L
• Application Number:
  US12/776,275
• Time in Patent Office: 1,061 Days
• Field of Search: 340/539.12, 340/539.31
• US Class Current: 340/539.12
• CPC Class Codes: A61B 2562/0214 Capacitive electrodes
• CPC Class Codes: A61B 2562/0271 Thermal or temperature sensors
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: G08B 21/0211 Combination with medical sensor, e.g. for measuring heart rate, temperature
• CPC Class Codes: G08B 21/0261 System arrangements wherein the object is to detect trespassing over a fixed physical boundary, e.g. the end of a garden
• CPC Class Codes: G08B 21/0286 Tampering or removal detection of the child unit from child or article

Abstract

A security system can include a tag unit adapted to be secured to an infant via band. The first tag unit can include a temperature sensor, and a capacitance sensor. A temperature alarm can be provided in response to a negative slope of a temperature curve associated with temperature data from the temperature sensor. A capacitance alarm can be provided in response to a comparison to capacitance data from the capacitance sensor to a baseline when the tag unit is not secured to the infant. A resistance alarm can be provided in response to resistance data indicating a spike in resistance followed by a relatively flat line response.

Claims

1. An infant security system, comprising:

a tag unit adapted to be secured to an infant via a band, the tag unit including a temperature sensor, and a capacitance sensor,

wherein a temperature alarm is provided in response to a negative slope of a temperature curve associated with temperature data from the temperature sensor, a capacitance alarm is provided in response to a comparison of capacitance data from the capacitance sensor to a baseline when the tag unit is not secured to the infant, and a resistance alarm is provided in response to resistance data indicating a spike in resistance followed by a relatively flat line response.

2. The infant security system of claim 1, wherein the temperature sensor is located entirely within the tag unit and does not sense temperature at a skin portion of the infant.

3. The infant security system of claim 1, wherein the resistance alarm, the temperature alarm, and the capacitance alarm are determined by a control circuit within the tag unit.

4. The infant security system of claim 1, wherein the resistance alarm is provided when the resistance data indicates an open circuit.

5. The infant security system of claim 4, wherein the capacitance sensor includes two plates located on an inside surface of a plastic enclosure of the tag unit closest to the infant'"'"'s skin.

6. The infant security system of claim 1, wherein the negative slope is a relatively consistent slope for at least 30 seconds.

7. The infant security system of claim 1, wherein the negative slope includes an at least 8 degree temperature decline.

8. The infant security system of claim 1, wherein the resistance alarm, the temperature alarm, and the capacitance alarm are determined by a central computer communicating with the tag unit via an RF link.

9. The infant security system of claim 1, wherein the tag unit performs initialization when secured to the infant, the initialization comprising of initialization of capacitance, temperature, and battery state machines.

10. A tag for securing to a person via a band, the tag comprising:

control circuitry receiving a temperature signal from a temperature sensitive component, a capacitance signal from a capacitive element and a resistance signal associated with the band,

wherein the control circuitry provides at least one of a temperature alarm in response to a negative slope of a temperature curve associated with the temperature signal, a capacitance alarm in response to a comparison of the capacitance signal associated with the capacitive element to a baseline, and a resistance alarm in response to the resistance signal having a spike followed by a relatively flat line response.

11. The tag of claim 10 further comprising:

an RF transmitter for providing a message including at least one of the resistance alarm, the temperature alarm, and the capacitance alarm to a central computer.

12. A method of determining a security alarm indication that a tag has been removed form a person, the tag being secured to the person using a band, the method comprising:

providing a temperature signal associated with a temperature of the tag;

providing a capacitance signal associated with a capacitive element of the tag;

providing a resistance signal associated with a resistance across the band; and

providing the security alarm in response to at least one of a negative slope of a temperature curve associated with the temperature signal, in response to a comparison of the capacitance signal to a baseline when the tag unit is not secured to the person, and in response to the resistance signal indicating a spike in resistance followed by a relatively flat line response.

13. The method of claim 12, wherein the person is an infant.

14. The method of claim 12, wherein the band has a variable resistance when stretched.

15. The method of claim 12, further comprising:

providing an RF message to a central station in response to the security alarm.

16. The method of claim 15, wherein the band has width of approximately 0.56 inches and a thickness of 0.06 inches.

17. A tag unit in a security system, the tag unit being secured to a human, the tag unit comprising:

a strip of band material having a width of approximately 0.56 inches and a thickness of approximately 0.06 inches, the band material being woven material and being able to withstand a static force of at least 30 pounds without tearing, the band material having a resistance of 110 ohms per quarter inch of stretch;

a temperature sensor,

a capacitance sensor; and

wherein a temperature alarm is provided in response to a negative slope of a temperature curve associated with temperature data from the temperature sensor, a capacitance alarm is provided in response to a comparison of capacitance data from the capacitance sensor to a baseline when the tag unit is not secured to the human, and a resistance alarm is provided in response to resistance data indicating a spike in the resistance of the band material followed by a relatively flat line response.

18. The tag unit of claim 17, wherein the band material does not include latex.

19. The tag unit of claim 17, wherein the strip has a length of approximately 6 inches.

20. The tag unit of claim 17, wherein the strip has a first end having a first side at a 30 degree angle with respect to parallel sides of the strip and a second end having a second side at a 0 degree angle with respect to the parallel sides of the strip.