Infant security system - Patent Review 4853692

Claims

We claim:

1. An infant security system for thwarting the kidnapping of infants from a children's ward or maternity ward of a hospital or the like having at least one exit through which an infant may be transported, said infant security system comprising:

at least one transmitting means for transmitting infant security indicating signals,

said at least one transmitting means being securably attached to an infant to be monitored, and including tamper signal generator means for generating at least a first unique coded tamper signal indicative of tampering with said at least one transmitting means, and including means for periodically generating a second unique coded signal;

at least one receiving means associated with said at least one transmitting means for detecting said unique signals and for generating alarm condition signals in response to the detection of the first unique signal and the failure to detect the second unique signal;

said means for periodically generating including maintenance signal generator means for periodically generating said second unique coded signal indicative of the infant being within a predetermined distance of said at least one said receiving means and not being shielded from said at least one receiving means; and

alarm means, responsive to said alarm condition signals, for providing an indication of said alarm condition.

2. An infant security system according to claim 1, wherein said at least one transmitting means includes antenna means coupled to said means for generating for transmitting signals input thereto.

3. An infant security system according to claim 2, wherein said transmitting means is a radio frequency (RF) transmitter and wherein said antenna means emits a substantially omni-directional radiation pattern.

4. An infant security system according to claim 1, further including switch means, coupled to said tamper signal generator means, for initiating the generation of said coded tamper signal upon detecting a tampering indicating condition.

5. An infant security system according to claim 4, wherein said switch means coupled to said tamper signal generator means includes first switch means for normally preventing energizing signals from initiating the operation of said tamper signal generator means, and second means operatively coupled to said first switch means for controlling said first switch means to pass energizing signals to said tamper signal generating means upon detection of a tampering indicating condition.

6. An infant security system according to claim 5, wherein said first switch means and said second means coact such that when said second means is in a closed circuit condition said first switch means is in an open circuit condition, and when said second means is in an open circuit condition, the first switch means is in a short circuit, signal passing condition.

7. An infant security system according to claim 5, wherein said second means includes two terminals, a voltage source connected to one of said terminals and a coil operatively coupled to said first switch means, and wherein one end of a metallic wire is connected to each of said terminals to place a short circuit across said terminals to permit current flow through said coil.

8. An infant security system according to claim 4, wherein said switch means includes first switch means for normally preventing said tamper signal generator means from being energized, and tamper loop means for detecting a tampering condition and for controlling said first switch means to energize said tamper signal generator means.

9. An infant security system according to claim 1, wherein said at least one transmitting means further includes energizable means for generating a signal which may be detected when said at least one transmitting means is disposed within a predetermined distance from an associated detector means.

10. An infant security system according to claim 9, further including at least one detector means disposed at said at least one exit for detecting signals generated by said energizable means, and exit alarm means associated with said at least one detector means for providing an indication of an alarm condition.

11. An infant security system according to claim 1, wherein said at least one receiving means includes

first channel means for detecting the presence of a first of said at least two unique signals and for generating an alarm triggering signal in response to detecting said first of said at least two unique signals, and

second channel means for detecting a second of said at least two unique signals and for generating an alarm triggering signal in response to detecting the absence of said second one of said at least two unique signals for a predetermined period of time;

said at least one receiving means including means responsive to said alarm triggering signals for providing an indication of an alarm condition.

12. An infant security system according to claim 1, wherein said at least one receiving means is mounted on or adjacent to the crib of the infant attached to the transmitting means associated with said at least one receiving means.

13. An infant security system according to claim 1, wherein said at least two unique signals are coded with binary frequency modulated coding.

14. An infant security system according to claim 1, wherein said at least one transmitting means is encapsulated in rugged plastic and is attached to the infant by a plastic leg strap.

15. An infant security system according to claim 1, wherein said at least one receiving means includes means for retransmitting said detected unique signals.

16. An infant security system according to claim 15, further including a plurality of auxiliary receiving means for receiving said retransmitted unique signals;

a central control panel for receiving signals transmitted from said at least one receiving means; and

means for coupling said auxiliary receiving means to said central control panel.

17. A valuable object security system for thwarting the kidnapping or unauthorized taking of said object from a predetermined area having at least one exit, said valuable object security system comprising:

transmitting means securably attached to said valuable object for transmitting security indicating signals;

said transmitting means including:

tamper signal generating means for generating a unique coded tamper signal indicative of unauthorized tampering with said transmitting means,

maintenance signal generating means for periodically generating a unique coded maintenance signal indicative of the valuable object being within said predetermined area;

receiving means associated with said transmitting means and including

first channel means for detecting said tamper signal and for generating an alarm triggering signal in response thereto,

second channel means for detecting said periodically generated maintenance signal and for generating an alarm triggering signal in response to detecting the absence of a maintenance signal for a predetermined period of time; and

alarm means responsive to said alarm triggering signals for providing an indication thereof.

18. A valuable object security system according to claim 17, wherein said valuable object is an infant and said predetermined area is a maternity ward or children's ward in a hospital.

19. A valuable object security system according to claim 17, wherein said transmitting means further includes energizable means for generating a signal which may be detected when said at least one transmitting means is disposed within a predetermined distance from an associated detector means.

20. A valuable object security system according to claim 19, further including at least one detector means disposed at said at least one exit for detecting signals generated by said energizable means, and exit alarm means associated with said detector means for providing an indicating of an alarm condition.

21. A valuable object security system according to claim 17, wherein said transmitting means includes antenna means coupled to receive signals from said tamper signal generating means and said maintenance signal generating means for transmitting signals input thereto.

22. A valuable object security system according to claim 21, wherein said transmitting means is a radio frequency (RF) transmitted and wherein said antenna means emits a substantially omni-directional radiation pattern.

23. A valuable object security system according to claim 17, further including switch means, coupled to said tamper signal generator means, for initiating the generation of said coded tamper signal upon detecting a tampering indicating condition.

24. A valuable object security system according to claim 23, wherein said switch means coupled to said tamper signal generating means includes first switch means for normally preventing energizing signals from initiating the operation of said tamper signal generating means, and second means operatively coupled to said first switch means for controlling said first switch means to pass energizing signals to said tamper signal generating means upon detection of a tampering indicating condition.

25. A valuable object security system according to claim 24, wherein said first switch means and second means coact such that when said second means is in a closed circuit condition, said first means is in an open circuit condition and when said second means in an open circuit condition, the first switch means is in a short circuit, signal passing condition.

26. A valuable object security system according to claim 24, wherein said second means includes two terminals and wherein one end of a metallic wire is connected to each terminal to place a short circuit across said terminals to thereby maintain said first switch means in an open circuit condition.

27. A valuable object security system according to claim 23, wherein said switch means includes a first switch means for normally preventing said tamper signal generating means from being energized and tamper loop means for detecting a tampering condition and for controlling said first switch means to energize said tamper signal generating means.

28. A valuable object security system according to claim 17, wherein said receiving means includes means for retransmitting said detected unique coded signals.

29. A valuable object security system according to claim 28, further including a plurality of auxiliary receiving means for receiving said retransmitted unique coded signals;

a central control panel for receiving signals transmitted from said receiving means; and

means for coupling said auxiliary receiving means to said central control panel.

30. For use in a valuable object security system for thwarting the kidnapping or unauthorized taking of said valuable object from a predetermined area having at least one exit, a security signal transmitting device to be securably attached to said valuable object comprising;

tamper signal generating means for generating a unique coded tamper signal indicative of unauthorized tampering with said transmitting means; and

maintenance signal generating means for periodically generating coded maintenance signals indicative of the valuable object being within said predetermined area, whereby the reception of the tamper signal by an associated receiving device indicates an unauthorized tampering with the transmitting means and the failure to detect the maintenance signal by said associated receiving device indicates the breach of a security condition.

31. A transmitting device according to claim 30, further including switch means, coupled to said tamper signal generating means, for initiating the generation of said coded tamper signal upon detecting a tampering indicating condition.

32. A transmitting device according to claim 31, wherein said switch means coupled to said tamper signal generating means includes first switch means for normally preventing energizing signals from initiating the operation of said tamper signal generating means, and second means operatively coupled to said first switch means for controlling said first switch means to pass energizing signals to said tamper signal generating means upon detection of a tampering indicating condition.

33. A transmitting device according to claim 32, wherein said first and second means coact such that when said second means is in a closed circuit condition, said first switch means is in an open circuit condition and when said second means is in an open circuit condition the first switch means is in a short circuit, signal passing condition.

34. A transmitting device according to claim 32. wherein said second means includes two terminals and wherein one end of a metallic wire is connected to each terminal to place a short circuit across said terminals to thereby maintain said first switch means in an open circuit condition.

35. A transmitting device according to claim 31, wherein said switch means includes first switch means for normally preventing said tamper signal generating means from being energized and tamper loop means for detecting a tampering condition and for controlling said first switch means to energize said tamper signal generator.

36. A transmitting device according to claim 34, wherein said first switch means comprises relay means for preventing when energized said tamper signal generating means from generating a coded tamper signal, said second means including a voltage source for energizing said relay means as long as said short circuit remains intact.

37. A transmitting device according to claim 30, further including energizable means for generating a signal which may be detected when said at least one transmitting means is disposed within a predetermined distance from an associated detector means.

38. A transmitting device according to claim 30, further including antenna means coupled to said tamper signal and maintenance signal generating means for transmitting signals input thereto.

39. A transmitting device according to claim 38, wherein said transmitting device is a radio frequency (RF) transmitter and wherein said antenna means emits a substantially omni-directional radiation pattern.

40. A transmitting device according to claim 30, wherein said at least two unique signals are coded with binary frequency modulated coding.

41. A transmitting device according to claim 30, wherein said transmitting device is encapsulated in a rugged plastic and includes plastic leg strap means for attaching said transmitting device to the leg of an infant.

42. For use in a valuable object security system for thwarting the kidnapping or unauthorized taking of said valuable object from a predetermined area having at least one exit, said security system having at least one transmitting means for transmitting coded security signals, a security signal receiving device comprising:

first channel means for detecting a uniquely coded tamper signal indicative of unauthorized tampering with said transmitting means for generating an alarm triggering signal in response thereto;

second channel means for detecting a periodically generated maintenance signal indicative of the valuable object being within said predetermined area and for generating an alarm triggering signal in response to the absence of a detected maintenance signal for a predetermined period of time; and

alarm means responsive to said alarm triggering signals for providing an alarm condition indicating signal.

43. A receiving device according to claim 42, wherein said first channel means and said second channel means includes means for detecting binary coded frequency modulated signals.

44. A receiving device according to claim 42. wherein the valuable object is an infant and wherein said receiving device is mounted on or adjacent to the crib of an infant attached to a transmitting means associated with said receiving device.

45. A receiving device according to claim 42, including means for retransmitting said detected unique signals, whereby said signals may be transmitted to a central control panel.

46. A method of thwarting the kidnapping of infants from the maternity ward of a hospital or the like having at least one exit through which an infant may be transported, said method comprising the steps of:

securably attaching a transmitting means to each of a plurality of infants;

generating and transmitting coded signals from each transmitting means indicative of predetermined infant security conditions;

detecting with a receiver means associated with said transmitting means said transmitted coded signals;

said step of generating and transmitting coded signals including the step of periodically generating coded signals from each of said transmitting means indicative of the infant being within a predetermined distance of an associated receiver means and not being shielded form said associated receiver means; and

selectively energizing an alarm upon the detection of an infant security condition which may be indicative of the abduction of an infant.

47. A method according to claim 46, including the step of generating a uniquely coded tamper signal indicative of tampering with said transmitting means.

48. A method according to claim 46, further including the steps of generating a signal by an energizable means in each of said transmitting means which may be detected when any one of said transmitted means is disposed within a predetermined distance from an associated detector detector means.

49. A method according to claim 48, further including the step of disposing at least one detector means at predetermined exit areas for detecting signals generated by said energizable means, and providing an indication of an alarm condition in response to detecting signals from said energizable means.

50. A method according to claim 46, further including the step of mounting said receiving means on or adjacent to the crib of the infant wearing the transmitting means associated with said receiving means.

51. A method according to claim 46, including retransmitting said detected unique signals to a central control station.

52. A method according to claim 51, further including receiving said retransmitted unique coded signals by a plurality of auxiliary receiving means and coupling said signals received by said auxiliary receiving means to said central control station.

53. A method for thwarting the kidnapping of infants from the maternity ward of a hospital or the like having at least one exit through which an infant may be transported, said method comprising the steps of:

securably attaching a transmitting means to each of a plurality of infants in the maternity ward;

periodically generating and transmitting a first uniquely coded "I'm Okay" signal from each of said transmitting means;

generating and transmitting from a transmitting means a second uniquely coded tamper signal if said transmitting means is tampered with;

detecting with a receiver means associated with said transmitting means a tamper signal and generating an alarm triggering signal in response thereto;

detecting with said receiver means associated with said transmitting means said "I'm Okay" signal and generating an alarm triggering signal in response to the absence of detecting said I'm Okay signal for a predetermined period of time; and

providing an alarm in response to said alarm triggering signals.

54. A method according to claim 53, further including the step of disposing an energizable means on each of said transmitting means for generating a signal which may be detected when one of said transmitting means is disposed within a predetermined distance of from an associated detector mounted at an exit.

55. A method according to claim 52, further including the step of mounting said receiver means on or adjacent to the crib of the infant wearing the transmitting means associated with said receiving means.

56. A method according to claim 53, including retransmitting said detected unique signals to a central control station.

57. A method according to claim 56, further including receiving said retransmitted unique coded signals by a plurality of auxiliary receiving means and coupling said signals received by said auxiliary receiving means to said central control station.

FIELD OF THE INVENTION

This invention generally relates to an electronic security system designed to thwart burglars and kidnappers and to insure that valuable objects remain within a prescribed area. More particularly, the invention relates to a hospital-based infant security system designed to prevent an infant from being kidnapped from a hospital maternity or children's ward.

BACKGROUND AND SUMMARY OF THE INVENTION

Child abduction is a major problem in this country and throughout the world, with the number of children abducted increasing from year to year. While the number of abducted children has increased so too has the brazenness of the abductors. In this regard, there has been far too many highly publicized kidnappings of newborn infants from closely monitored hospital maternity wards. Such infants have become attractive targets for kidnappers due to the high price paid in black market transactions for newborn infants and the absence of any risk of identification by the kidnapping victim.

The present invention provides hospital maternity wards with the maximum practical degree of security while avoiding the police state environment which would be created by posting uniformed security guards at every maternity ward exit. Rather than creating a police state environment, the present invention provides a passive security system requiring no human intervention except when it is turned on, turned off, or when an alarm is detected. At the same time, the system provides the hospital maternity ward with multiple levels of security thereby dramatically reducing the likelihood of an infant being successfully kidnapped from the hospital.

In an exemplary embodiment of the present invention, infants in a hospital maternity ward are supplied with a very small radio frequency (RF) transmitter capable of transmitting a plurality of coded signals. A corresponding remote RF receiver tuned to receive the transmitted coded signals is associated with each transmitter. The main functions of the RF transmitter and receiver are to insure that (1) the RF transmitter remains attached to the infant and (2) the infant and the attached RF transmitter remain in the proximity of the corresponding receiver.

Each of the transmitters in the system includes a magnetic strip which generates a low frequency electromagnetic field when activated. The exit points of the hospital maternity ward (such as doors, elevators, stairways, etc.) are provided with a magnetic receiver which detects an activated magnetic strip passing through that exit point. Upon detecting the alternating electromagnetic field generated by the magnetic strip an associated audible alarm is sounded.

At the heart of the infant security system is the transmitting device which generates at least two uniquely coded signals and which is preferably snugly disposed around the leg or ankle of each of the infants. The associated receiver is placed, for example, on the cart containing the infant's crib or bassinet which will typically be close enough to the infant so that it is well enough within the range of the transmitter.

Every few seconds the RF transmitter will transmit, for example, a coded RF pulse. If an infant with an attached RF transmitter is removed by some predetermined minimum distance from its associated RF receiver, then the RF receiver will not receive the transmitted coded signal which will trigger an alarm. If the infant is placed in a metal container thereby preventing the transmitted signal from being received by the RF receiver, an alarm is likewise triggered.

If a kidnapper attempts to detach the RF transmitter from the infant, a switch is opened (or closed) which in turn causes the RF transmitter to emit a second coded signal. Upon detection of the second coded signal, an alarm in the RF receiver is triggered. In order to legitimately remove the infant from the maternity ward area, the magnetic strip associated with the transmitting device must be deactivated and the RF receiver deactivated with, for example, a security key.

While being primarily directed to a hospital-based infant security system, the present invention likewise contemplates that the security system may be used to secure a wide range of other valuable objects. For example, the system may be used to prevent a valuable art object from being improperly removed or stolen from its assigned room. Likewise, the present invention may be utilized to prevent a dangerous chemical from being improperly removed from its storage area. Alternatively, the security system of the present invention may be utilized to prevent an individual from leaving a designated area in any workplace, hospital, or institutional setting.

BRIEF DESCRIPTION OF THE DRAWINGS

These as well as other features of this invention will be better appreciated by reading the following detailed description of the presently preferred embodiment taken in conjunction with the accompanying drawings of which:

FIG. 1 is a block diagram of an exemplary embodiment of the security system of the present invention;

FIG. 2 is an exemplary block diagram of the timing circuit 8 shown in FIG. 1;

FIG. 3 is a schematic diagram of a RF transmitter and the plastic leg strap which may be used in the infant security system shown in FIG. 1;

FIG. 4 is an RF transmitter and leg strap incorporating a monitored tamper loop;

FIG. 5 is an exemplary block diagram of timing circuit 16 shown in FIG. 1;

FIG. 6 is a block diagram of a RF transceiver that may be used in another embodiment of the present invention; and

FIG. 7 is a block diagram of a communications system of an infant security system incorporating a central control panel.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows a portion of a hospital maternity ward 1. Such a maternity ward typically consists of one or more hallways off of which are various rooms for the nursery, mothers' beds, doctors' examinations, infant bathing, etc. Exit points from the maternity ward typically are through an exit door 3 or an elevator 5.

At the heart of the infant security system of the preferred embodiment of the present invention is RF transmitting module 7. As generally represented in FIG. 1, each infant in the maternity ward is provided with its own transmitting module 7A through 7Z. The RF transmitting module 7 is preferably attached to the infant by a plastic leg or ankle band as will be described in more detail in FIG. 3 below.

The RF transmitter module 7 contains two coded RF signal generators Ta and M, switching module Sw (which is only generally represented in FIG. 1), and a transmitting antenna 9. As will be appreciated by those skilled in the art, the transmitting antenna 9 should be impedance matched to the RF generators Ta and M. Additionally, the transmitting antenna 9 should have an omni-directional radiation pattern so that its position with respect to an associated RF receiver 13 is not critical (which is particularly important where infants are likely to be moved within the maternity ward).

If the security system is being utilized to protect stationary art objects as opposed to providing infant security, then the RF transmitter 7 can be energized from the available building service power. However, if the object to be secured is movable, e.g., an infant, then the RF transmitter 7 must be powered by an internal battery. In any event, battery power is highly desirable as a back up to insure that the security system will function in the event of a power failure.

Signal generator M is driven by a timing circuit 8 so as to generate a coded RF pulse, which will be referred to hereinafter as the maintenance signal m. Pulse m is emitted every T.sub.m seconds, where m is chosen to be sufficiently small so it is not possible for the infant to be removed too great a distance from an associated receiver 13 during the time period that it takes for several maintenance pulses m to be generated. On the other hand, T.sub.m should be selected such that pulse generation does not occur at a frequency that would create an excessive power drain on the transmitter battery. The maintenance signal generator M is directly connected to the transmitting antenna 9 so that all pulses generated are radiated.

FIG. 2 schematically discloses an exemplary timing circuit 8 for driving maintenance signal generator M. Timing circuit 8 includes a source (not shown) of clock pulses having a period Tc. The clock pulses drive a counter 40 having a clock input C, an output O, and a reset input R.

The counter 40 generates at output O a transition from logical "0" to logical "1" after N clock pulses have been received. Monostable multivibrator (one shot) 42 generates an output pulse upon receiving a logical "0" to "1" transition from counter 40. By setting counter 40 such that N=Tm/Tc, then the output of one shot 42 will be a pulse every Tm seconds, thereby enabling the maintenance signal generator M to be appropriately driven as described above. The counter is designed so that after it has counted N clock pulses it automatically resets to begin another count.

Turning back to FIG. 1, the RF transmitting module 7 also includes a tamper signal generator Ta, which is an RF signal generator that generates a coded signal, hereafter denoted A. Since the tamper signal generator Ta is directly connected to the transmitting antenna 9 all generated coded signals A will be radiated.

Tamper signal generator Ta is connected to a switching module SW as generally shown in FIG. 1. The tamper generator Ta is turned on (or off) by placing switch S1 in the closed (or opened) position. Switch S1 works in conjunction with switch S2 so that when switch S2 is open, switch S1 is closed. Conversely, when switch S2 is closed, switch S1 is opened, as is schematically represented in FIG. 1.

FIG. 3 shows an exemplary circuit for achieving such coaction between switching elements S1 and S2 using a simple DC relay 44. If no current passes through the coil 46 of relay 44, then the relay's normally closed contacts (i.e., switch S1) will be in the closed position. However, if current flows through coil 46, then switch S1 will be in the open position as shown in FIG. 3.

In the infant security system exemplary embodiment of the present invention, under normal operating conditions, a short circuit is placed across the terminal of S2 by metallic wire 50 which is implanted in plastic leg strap 52. Thus, under normal conditions, battery 48 will be coupled to coil 46 and current will flow through the relay coil 46. This current flow holds switch S1 in the open position maintaining tamper signal generator Ta in a de-energized state. However, if a kidnapper cuts plastic leg strap 52 (and metallic wire 50), then the current flow to coil 46 will be interrupted, thereby causing switch S1 to close and tamper signal generator Ta to be energized.

The RF transmitter module 7 shown in FIG. 3 is small and lightweight so that it may comfortably wrap around an infant's leg without interfering with the movement of the infant. The RF transmitting module 7 and associated band 52 somewhat resemble a watch with the RF circuitry encapsulated in a rugged plastic enclosure at the head of the watch.

When the present invention is utilized to protect, for example, valuable art objects, it is contemplated that the switching module SW and switches S1 and S2 will be implemented by a conventional mechanical switching module having two switches which are coupled such that when one switching contact is closed, the other is opened and vice versa.

When, for example, the present invention is used for protecting a valuable art object, the method of mounting the RF transmitter 7 to the valuable object must served to close or otherwise place a short circuit across switch S2. If the switch S2 shown in FIG. 1 was, prior to mounting, spring biased to be in the normally opened position then the transmitter would be mounted to the valuable object such that switch S2 is forced to the closed position shown in FIG. 1.

Thus, if an attempt is made to physically separate the RF transmitter 7 from the valuable object, switch S2 will return to its normally open position. Thus, as long as the RF transmitter 7 remains attached to the valuable object, switch S2 is closed, switch S