Abstract:
A system used to protect the occupants of a stationary motor vehicle, particularly unattended children and pets, from dangerous conditions occurring within the vehicle. The system comprises a sensor which senses dangerous environmental conditions such as high temperatures within the vehicle. In the preferred embodiment, the sensor is used with a transmitter to continuously transmit sound detected within the vehicle passenger compartment as well as transmitting information about any dangerous conditions which occur to a remotely located person. In a second embodiment, dangerous conditions trigger an alarm attached to the vehicle. The alarm amplifies the sound detected within the vehicle, such as a crying child, or a barking dog, and also produces a standard alarm sound alternated with an amplified voice declaring the dangerous condition. In a third embodiment, a sensor module attached to a wireless telephone informs a remotely located person of the dangerous condition through another wireless telephone or a pager.

Description:
BACKGROUND OF THE INVENTION 
     A person will frequently leave an infant, toddler, or pet within a car with the expectation that his or her time away from the car is not long enough to allow any hazard to the individual or animal within; however, the person may be delayed in his or her business. Furthermore, it can often be difficult for an individual to know where the line is between safe and unsafe conditions within the passenger compartment while he or she is not there. Unfortunately, too many times, the child or pet comes to harm because the environment within the car becomes unsafe. High temperatures are usually the culprit of the hazardous environment; however, other potential dangers exist such as freezing temperatures, high levels of carbon monoxide (CO) when the engine is left running, or people who pose a threat to the child or pet. 
     Although car alarms are available for burglar entry sensing, theft deterrence, or theft protection, these alarms are only capable of sensing automobile motion, shock, motion in the interior passenger compartment, or forced entry. They do not sense passenger compartment temperature or other conditions relating to an occupant&#39;s environment. Furthermore, the type of sound emitted by such car alarms is non-descriptive, so the sound produced by such alarms would provide little measure of safety for an infant caught inside a hot vehicle. 
     Inside a home, infants and toddlers are often monitored using baby monitors. FIG. 1 illustrates a typical baby monitor in block diagram form. It comprises two sections. The first section  100  comprises a microphone  110 , a pre-amplifier  120 , a transmitter  140 , and a power supply  180 . The second section comprises a receiver  200 , and a loudspeaker or headphones  210 . The power supply  180  is designed for use with small batteries and/or household voltage  300 . It is not designed to operate from a 12 V car battery, or to plug into a cigarette lighter. Such baby monitors are designed primarily for use inside a home, and they are only designed to detect sound. The adult at the receiving end of the monitor  200  can thus often tell when a child has awakened or possibly when a child has been injured, but the adult is unaware of temperature or other environmental factors at the transmitter end. While such baby monitors are often adequate for the controlled environment of a typical home, the environment inside a motor vehicle is much less controlled, and a pet or sleeping child would be unable to report dangerous conditions to an adult listening at the other end of a standard baby monitor. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to overcome the shortcomings of the prior art by providing a system which can sense dangerous conditions within a vehicle, and appropriately warn someone to come to the aid of a helpless passenger. To fulfill the object, the system is equipped with one or more sensing devices such as temperature sensors, CO sensors, microphones, or equipment for detecting motion near the exterior of the vehicle. The system is also equipped with apparatus that will appropriately warn someone of the dangerous condition in such a way as to instigate action. 
     The first and preferred embodiment of the invention comprises an enhanced baby monitor system, designed especially for use in vehicles, in which the transmitter comprises a temperature sensor, a CO sensor, and a means for conveying information about temperature and CO content along with the sound detected by its microphone. This embodiment also allows for an array of external motion detectors to be plugged into it in order to detect a person trying to break into the vehicle and thus pose a threat to the vehicle occupant. 
     Another embodiment comprises an enhanced car alarm system which comprises temperature sensors and CO sensors located inside the vehicle, as well as sensors to detect motion in the vicinity of the vehicle. The alarm also comprises means to convey information about a dangerous condition in the form of simulated voice, so that in the event of a dangerous condition, the alarm broadcasts a standard alarm sound alternated with the simulated voice as well as amplifying the sound inside the vehicle, such as a crying child. 
     A third embodiment of the invention comprises an environmental warning module which can attach to a wireless telephone. When a dangerous condition is sensed, the module uses the wireless telephone to report a message to a remotely located person. The message is reported through another telephone or through a pager. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a conventional baby monitor. 
     FIG. 2 is a block diagram of the preferred embodiment of the environmental warning system. 
     FIG. 3 is a block diagram of the environmental warning module of the embodiment of FIG.  2 . 
     FIG. 4 shows the placement of the components of the embodiment of FIG. 2 into a vehicle and on a remotely located person. 
     FIG. 5 is a block diagram of a second embodiment of the environmental warning system. 
     FIG. 6 is a block diagram of the environmental warning module of the embodiment of FIG.  5 . 
     FIG. 7 shows the placement of the components of the embodiment of FIG. 5 into a vehicle. 
     FIG. 8 is a block diagram of a third embodiment of the environmental warning system. 
     FIG. 9 shows the placement of the components of the embodiment of FIG. 8 into a vehicle and on a remotely located person. 
    
    
     DESCRIPTION OF EMBODIMENTS 
     The inventors propose a method of protecting a person or animal which has been left within a vehicle. The protection method combines several devices and technologies which are commonly available but heretofore have not been used in combination to create an environmental warning system for a person or animal left within a vehicle. This section describes in detail three embodiments of the environmental warning system. 
     Refer to the accompanying figures. FIG. 2 is a block diagram of the first and preferred embodiment of the environmental warning system. The first embodiment of the environmental warning system comprises sensor-transmitter module  501 , external motion sensors  413 , receiver  200 , and speaker or headphones  210 . Sensor-transmitter module  501  further comprises environmental warning module  401 , power supply  601 , microphone  110 , preamplifier  120 , summer module  510 , and transmitter  140 . FIG. 3 shows more detail on environmental warning module  401  which comprises a sensor array  410 , a voice synthesizer  420 , an alarm synthesizer  430 , and a timer  440 . The sensor array  410  comprises temperature sensor  411 , CO sensor  412 , A/D converter  418 , and comparators  414 - 417 . 
     FIG. 4 shows the placement of the components within a vehicle  1 , and on a remotely located person  2 . During normal operation, the remotely located person  2  hears the sound inside the passenger compartment of the vehicle  1 , as well as being informed of the temperature inside the passenger compartment at predetermined intervals. When the environmental warning module  401  senses a dangerous condition, the remotely located person will continue to hear the sound inside the passenger compartment of the vehicle  1 , as well as hearing an alarm sound alternated with a voice indicating the type of danger which exists. 
     This embodiment comprises apparatus which is similar to apparatus found in a conventional baby monitor system such as a microphone  110 , a pre-amplifier  120 , a transmitter  140 , a receiver  200 , and a loudspeaker or set of headphones  210 . The power supply  601  in the preferred embodiment of the environmental warning system is designed to operate from any of the following power sources  301 : a 12 V car battery (connected with a cigarette lighter plug  3 ), small portable batteries such as a transistor 9 V battery, and household voltage. It can thus be used in any application in which a standard baby monitor could be used, as well as being used inside a vehicle. Whereas a conventional baby monitor transmits the sound coming into the microphone  110 , the first embodiment of the environmental warning system uses a summer module  510  to combine this sound with other signals coming from the environmental warning module  401  prior to transmission through transmitter  140 . 
     As shown in FIG. 3, the sensor array  410  comprises sensors such as a temperature sensor  411 , a CO sensor  412  and an array of comparators  414 - 417 . It also receives signals from a remote array of external motion detectors  413 . Comparator  414  compares the signal from the temperature signal with a preset temperature value representing an upper limit in tolerable temperature, such as 90° F. Similarly, comparator  415  compares the temperature with a lower limit such as 45° F. The values can be preset in the factory or adjusted by the user of the equipment. Comparator  416  compares the CO level against a preset limit. Comparator  417  compares the amount of motion in the vicinity of the vehicle against a limit which can be preset in the factory or adjusted by the user. When any of the sensors  411 - 413  sense a condition which is dangerous, then the corresponding comparator produces a logical 1. When any of the comparators  414 - 417  produce a logical 1, the alarm synthesizer  430  produces a signal which sounds to the remotely located person  2  like a typical alarm. When any of the comparators produce a logical 1, then the voice synthesizer  420  produces a voice signal which corresponds to the comparator which produced a logical 1. For example, if comparator  414  produces a logical 1, then the voice synthesizer would produce a signal which would cause the remotely located person  2  to hear words such as “the temperature in the car has reached dangerously high levels”. Furthermore, the alarm sound and the voice sound would be alternated. 
     The temperature sensor signal is converted into a digital signal by analog-to-digital converter  418  and sent to inputs on the voice synthesizer  420 . The signal comparison and processing can also be accomplished with other combinations of analog and digital signal processing such as is common to the art. Timer  440  causes the voice synthesizer to output temperature information at predetermined intervals, such as once per minute. The information would be spoken by simulating a voice saying, for example, “77 degrees Fahrenheit”, or whatever the actual temperature is. Thus, while no dangerous signals are being sensed by sensors  411 - 413 , the temperature is being verbally transmitted to the remotely located person so that he or she will be aware of temperature trends within the vehicle even before they reach dangerous levels. 
     FIG. 5 is a block diagram of a second embodiment of the environmental warning system. The second embodiment of the environmental warning system comprises environmental warning module  402 , alarm system  502 , microphone  110 , external motion sensors  413 , and loudspeaker  620 . Environmental warning module  402  comprises a sensor array  410 ′, a voice synthesizer  420 ′, and an alarm synthesizer  430 ′. Alarm system  502  comprises multiplexor  520 , summer module  511 , preamplifier  120 , switch  530 , amplifier  600 , car alarm unit  610 , and power supply  602 . FIG. 6 shows more detail on sensor array  410 ′. Sensor array  410 ′ comprises temperature sensor  411 , CO sensor  412 , and comparators  414 - 417 . FIG. 7 shows the placement of the components within a vehicle  1 . 
     This second embodiment is capable of functioning as a standard car alarm, in addition to an environmental warning system. Switch  530  allows the user to choose between standard alarm operation, and environmental warning system operation. When the switch is in position B, car alarm unit  610  is connected to amplifier  600 . Car alarm unit  610  when taken together with amplifier  600 , loudspeaker  620 , and power supply  602  can function as a standard car alarm. Car alarm unit  610  comprises the appropriate sensors and logic required of standard car alarms. The power supply  602  is designed to operate from a car battery power source  302 . 
     When switch  530  is in position A, the system functions as an environmental warning system. When a dangerous condition is sensed by sensor array  410 ′ or external motion detectors  413 , then sensor array  410 ′ sends signals to voice synthesizer  420 ′ and alarm synthesizer  430 ′. Alarm synthesizer  430 ′ synthesizes a standard alarm sound, and voice synthesizer  420 ′ synthesizes a voice calling for help. Information about the type of danger is incorporated into the call for help. For example, if the temperature in the passenger compartment reaches dangerously high levels, the voice synthesizer  420 ′ would produce a voice signal such as “Please help! Helpless vehicle occupant exposed to dangerously high temperatures”. Multiplexor  520  alternates the voice signal with the standard alarm signal. Microphone  110  monitors the sound within the passenger compartment of the vehicle. Summer  511  adds the signal from microphone  110  to the signal from multiplexor  520 . The signal from summer  511  is amplified by amplifier  600  and sent to the loudspeaker  620 . The output at the loudspeaker would therefore be a standard alarm alternated with a voice calling for help; furthermore, the sound inside the passenger compartment, such as a crying child, would be superimposed on the alarm signal. 
     FIG. 8 is a block diagram of a third embodiment of the environmental warning system. The third embodiment of the environmental warning system comprises environmental warning module  700 , external motion detectors  413 , wireless telephone  720 , and a telephone or pager  900 . Environmental warning module  700  comprises microphone  110 , preamplifier  120 , sensor array  410 ′, voice synthesizer  420 ′, summer module  511 , dialer module  710 , 3-way switch  711 , phone number setting  712 , and power supply  603 . 
     FIG. 9 shows the placement of the components within a vehicle  1  and on remotely located person  2 . The power supply  603  is capable from running off of a rechargeable battery pack or a car battery  303  via cigarette lighter plug  3 . The operation of sensor array  410 ′, external motion detectors  413 , microphone  110 , pre-amplifier  120 , voice synthesizer  420 ′, and summer  511  is the same as in the second embodiment. When sensor array  410 ′ senses a dangerous condition, rather than triggering an alarm, it sends a signal to dialer module  710  which dials a prearranged telephone number  712  to inform a remotely located person  2  of the dangerous condition. The environmental warning module  700  allows the user to select from three different receiver types using 3-way switch  711 . The three receiver types are (1) telephone, (2) numeric pager, and (3) alpha-numeric pager. 
     If option  1  (telephone) is chosen, and a dangerous condition occurs, the dialer sends sound signals from summer  511  to the wireless telephone. As in the second embodiment, the output from summer  511  comprises a voice calling for help superimposed on the sound within the passenger compartment, such as a crying child. 
     If option  2  (numeric pager) is chosen, and a dangerous condition occurs, the dialer sends a numeric code to the wireless telephone  720 . The numeric code corresponds to a dangerous condition which can be understood by the remotely located person with the pager, based on prior arrangement. For example, the numeric message could be “505001” for a dangerously high temperature, “505002” for a dangerously low temperature, etc. 
     If option  3  (alpha-numeric pager) is chosen, and a dangerous condition occurs, the dialer sends an alpha-numeric code to the wireless telephone  720 . This causes an alpha-numeric message to appear on the pager  900  of the remotely located person  2 . The alpha-numeric message let&#39;s the person  2  know that a dangerous condition has occurred, and what that dangerous condition is. 
     The present invention is thus a warning system which detects dangerous environmental conditions in a parked automobile with trapped passengers, such as infants, toddlers, pet animals, or handicapped passengers, which could potentially save such passengers from harm or death. 
     While the above descriptions include many specificities, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of embodiments thereof. Many other variations are possible. For example: 
     The system does not need to include all of the previously cited sensors in order to function as an environmental warning system; 
     The high/low temperatures could be used in conjunction with other sensors for motion or noise (cries for help); 
     Once a dangerous situation is signaled, not only could alarms be triggered, but signals could be sent to the owner, police, or other emergency services. 
     Environmental warning systems offered to consumers could have all detection/alarm features offered, with the option of activating certain selected features. 
     Multiple temperature sensors could be placed in the automobile to improve reliability of detecting dangerous temperature conditions. 
     The temperature information could be transmitted to the receiver at time intervals which vary with temperature so, for example, the information could be transmitted at shorter time intervals for more dangerous temperatures. 
     Signal processing and comparison of sensed conditions to predetermined conditions can be accomplished through many different methods, employing various combinations of analog and digital signal processing such as is common to the art. 
     The power supplies can be located external to the environmental warning modules (such as with ac adapters or battery packs) or internal to the modules. 
     The phone in the third embodiment can be either an external phone, or a phone circuit incorporated into the environmental warning system.