Guardian Technologies

Cincinnati Microwave, Inc.

Jim A McCurdy

Frank C Pennypacker

Michael McLaughlin

Michael Doyle

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.

Tamper-proof bracelet for home arrest system

A tamper-indicating transmitter is disclosed that indicates a subsequent tamper event during a tamper alert period, T, which is initiated by a first tamper event. In a preferred embodiment, the transmitter includes a transmitter housing having a conductive strap attached thereto for securing the transmitter about a confinee's limb, the confinee typically participating in a home arrest program. Within the housing, a clock source generates pulses having a period t that are input to a counter whose reset line is connected to the conductive strap. When the conductive strap is opened, the counter is held reset and its output is a predetermined multiple bit maximum. Upon the closing of the strap, the counter counts the clock pulses and decrements the counter output from the initial predetermined maximum count down to a predetermined minimum count which remains on the counter output if no subsequent opening of the strap occurs. The counter output is combined with an identification code and is serially provided to a digital/RF converter which transmits a data message containing the counter output and an identification code to a monitoring unit that relays the status of the transmitter to supervisory personnel at a central monitoring station. The counter output is used by the monitoring unit to compute a time a strap closure so a tamper by the confinee during the tamper alert period following securement of the transmitter to the confinee can be distinguished from the strap opening and closing at the transmitter installation.

Tamper indicating transmitter

A transmitter secured to the body of the confinee is provided with tamper detection means such as a conductive mounting strap, which if broken, sets a resettable electronic latch whose output determines the status of a tamper signal receivable by a remote station located within the confinement area. The latch is connected to a timer which serves to automatically reset the latch a first interval of time after it is initially set thereby eliminating the need for external reset equipment to carry out the reset operation. In order to avoid subterfuge, said first time interval is selected to be longer than any continuous interval of time the confinee is permitted to be absent from the confinement area. Information relating to the status of the tamper signal may also be relayed to a central monitoring station. To prevent transmission of a false tamper indication to the central station, the invention further contemplates inhibiting transmission of tamper indications to the central station in the event that less than a second interval of time, which is greater than said first interval, has elapsed since the occurrence of one or more predetermined events associated with normal operation of the system.

Growing community of inventors

Middletown, OH, United States of America

Jim A McCurdy