US 12,170,013 B2
Electronic tag
Aled Hughes, Worksop (GB)
Assigned to Allied Universal Electronic Monitoring Limited, Worksop (GB)
Appl. No. 17/764,243
Filed by G4S Monitoring Technologies Limited
PCT Filed Sep. 23, 2020, PCT No. PCT/GB2020/052306
§ 371(c)(1), (2) Date Mar. 28, 2022,
PCT Pub. No. WO2021/064354, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 1914109 (GB), filed on Sep. 30, 2019.
Prior Publication US 2022/0351602 A1, Nov. 3, 2022
Int. Cl. G08B 21/22 (2006.01); G08B 21/18 (2006.01); H04W 4/02 (2018.01); H04W 4/021 (2018.01); H04W 4/029 (2018.01)
CPC G08B 21/22 (2013.01) [G08B 21/182 (2013.01); H04W 4/021 (2013.01); H04W 4/023 (2013.01); H04W 4/029 (2018.02)] 11 Claims
OG exemplary drawing
 
1. An electronic tag configured to be secured to a body of a person, the electronic tag comprising:
an antenna configured to transmit or receive an electromagnetic signal; and
an inductive proximity sensor configured to:
determine a proximity of a metallic object to the electronic tag, based on electromagnetic coupling between the inductive proximity sensor and the metallic object; and
determine, based on the proximity being below a proximity threshold, that a metallic object is attenuating the electromagnetic signal transmitted or received by the antenna;
a counter configured to have a value that is changed towards a blocked threshold in response to a proximity determination being below the proximity threshold and changed towards an unblocked threshold in response to a proximity determination being above the proximity threshold; and
a computer-readable storage medium configured to store a blocked state, wherein the blocked state is set to blocked in response to the value of the counter reaching the blocked threshold to indicate the electronic tag is blocked and the blocked state is set to unblocked in response to the value of the counter reaching the unblocked threshold to indicate the electronic tag is unblocked.