Tamper-proof bracelet for home arrest system

• US 5,471,197 A
• Filed: 02/19/1993
• Issued: 11/28/1995
• Est. Priority Date: 02/19/1993
• Status: Expired due to Fees

• Current Assignee: Cincinnati Microwave, Inc (Bel Tronics Ltd.)
• Original Assignee: Cincinnati Microwave, Inc (Bel Tronics Ltd.)
• Inventors: Doyle, Michael, McLaughlin, Michael, McCurdy, Jim
• Primary Examiner(s): SWANN III, GLEN R
• Application Number:
  US08/020,207
• Time in Patent Office: 1,012 Days
• Field of Search: 340/573, 340/568, 340/693, 340/539, 340/555, 379/38
• US Class Current: 340/573.4
• CPC Class Codes: G08B 21/22 responsive to presence or absence of persons

Abstract

A personnel monitoring apparatus has a transmitter for transmitting a data encoded signal. A strap is provided for coupling the transmitter to a person to be monitored. An emitter is attached to the transmitter for emitting an optical signal. A detector is attached to the transmitter for detecting the optical signal. An optical fiber is incorporated with the strap for optically coupling the emitter and the detector. A comparator compares the optical signal and a reference signal, and the result of the comparison sets the value of a preselected data bit in the data encoded signal.

Claims

1. A personnel monitoring apparatus, comprising:

a housing having a pair of slots each having a clear window therein;

a strap having two ends each for coupling to a respective slot;

an optical fiber incorporated with the strap and having two ends each adapted to be optically aligned with respective windows upon coupling of the strap; and

a circuit board mounted inside the housing and comprising;

first means for transmitting a data encoded signal comprised of a plurality of data bits;

second means adjacent one of said windows for emitting an optical signal;

third means adjacent the other of said windows for detecting an optical signal;

fourth means for comparing the detected optical signal to a reference signal, wherein a preselected one of said data bits has a value that is dependent on the result of said comparison.

2. A personnel monitoring apparatus according to claim 1, wherein said housing further comprises a pair of clips adjacent each slot, each of said clips having pins thereon which are adapted to insert through the slot, and wherein the strap is fitted with a plurality of holes such that said strap may be secured within said slots by engaging the clips such that the pins are inserted through the holes.

3. A personnel monitoring apparatus, comprising:

a housing having a first slot and a second slot formed therein;

a first window centered in the first slot;

a second window centered in the second slot;

a transmitter affixed inside the housing for generating and transmitting a plurality of data bits;

an optical emitter affixed inside the housing and directed such that an optical signal is emitted through the first window;

an optical detector affixed inside the housing and directed such that the optical signal is detected through the second window;

a strap adapted to be secured inside the first slot and the second slot; and

an optical fiber incorporated with the strap for optically coupling the optical emitter to the optical detector;

a comparator coupled to the optical detector and to the transmitter for comparing the optical signal to a reference signal, wherein a preselected one of said data bits has a value that is dependent on the result of said comparison.

4. The personnel monitoring apparatus of claim 3, wherein the housing includes a controller which periodically drives the emitter and samples the detector.