Abstract:
The present invention relates to a sleep alert device ( 11 ) that mounts on the steering wheel of a vehicle that acts by pressure by the ringers or hand of the driver. The invention includes a multiplicity of sensors ( 12 ) as well as an instant alarm system which prevents accidental problems with previous delay alarm systems and repositioning of the hands without pausing or turning the device off. Sensors ( 12 ) are mounted circumferentially around the steering wheel and trigger and alarm with no delay of any kind and are connected directly or wirelessly to a control panel for control of the pressure sensors ( 12 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of and priority to U.S. Provisional Application No. 60/678,881, filed May 6, 2005 and is hereby incorporated in its entirety by reference herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to sleep detection warning devices and more particularly it pertains to a novel steering wheel sleep alert warning system for waking a dozing driver.  
         [0004]     2. Description of the Prior Art  
         [0005]     Drivers of motor vehicles, especially truck drivers, often put in long grueling hours at the wheel of their vehicle. Because of the need or desire to reach a given destination at a given time it is not infrequent that drivers spend more time at the wheel than is reasonably prudent and safe or spend time driving fatigued long past when they should be asleep. It is not surprising then that motor vehicle accidents occur where the driver has dozed off at the wheel and where the vehicle has veered off the road. Accidents result not only in vehicle damage, property damage and severe injury or death of the driver, it can also result in the death or injury of other drivers or pedestrians in the area of the accident. According to the National Highway Traffic Safety Administration, there are about 100,000 police-reported crashes that are the direct result of driver fatigue each year. Accidents that occur when the driver falls asleep at the wheel often have a high percentage of fatality. NHTSA conservatively estimates fatigue-related crashes results in an estimated 1,550 deaths, 71,000 injuries and $12.5 billion in monetary losses each year. In Europe too the situation is very similar. The German Insurance Association—GDV (Gesamtverband der Deutschen Versicherungswirtschaft e.V.)—estimates that about 25 percent of all fatal accidents on German motorways are caused by tiredness.  
         [0006]     A number of systems have been developed to attempt to alert the driver who is falling asleep. Volvo is introducing a complex system of cameras, sensors, processors and computer controls for their consumer based automobiles to alert when a driver has become fatigued by measuring the movement of the car. It apparently only works when the vehicle is traveling 60 KPH or more. The device works independent of the driver and depends on complex calculations without actually knowing the condition of the driver.  
         [0007]     Eye and head movements have been associated with fatigue and some solutions have revolved around devices that utilize this information. In U.S. Pat. No. 6,107,922 to Bryuzgin issued Aug. 22, 2000 a self contained headset is described. The device monitors the position of a driver&#39;s lower jaw as an indicator of the driver&#39;s condition. The device is triggered when the drivers jaw moves downward triggering an alarm condition. The device relies on motion that could also occur during talking or head movement and isn&#39;t necessarily the first motion indicator of a tired driver. In U.S. Pat. No. 6,559,779 to Zoerb, a safety apparatus utilizing an eyeglass mounted light beam emitter and detector which will sound an alarm when a drowsy driver&#39;s eye closes and his eyelashes interrupt a focused light beam is described. The device requires accurate alignment and calibration and is affected by both exterior light sources and well as head movements and blink pattern.  
         [0008]     It is known that as a driver fatigues, his grip on the steering wheel relaxes. Measurement of grip has been measured by devises which mount on the steering wheel and those that mount on the hand. In U.S. Pat. No. 6,218,947 to Sutherland issued Apr. 17, 2001 describes a sleep alarm mounted on the steering wheel comprising a pair of conductive elements that measure conductive capacitance between the two hands on the steering wheel. The difference is used to establish a baseline which when changed initiates an alarm.  
         [0009]     In U.S. Pat. No. 6,016,103 to Leavitt issued Jan. 18, 2000 there are at least one pressure sensor on each of two gloves. The sensors can be positioned on any of the fingers (shown on the finger tips) or the palm of the hand. There is a remote communication means between the two gloves and an alarm is activated when grip pressure of both hands falls below a threshold level. The device requires the drivers grip to be relaxed on both hands to be triggered and the device has a preferred embodiment where grip pressure has to fall below a threshold for a given period of time. In U.S. Pat. No. 6,172,610 to Prus issued Jan. 9, 2001, there is described a contact means where there is a sensor mounted on a glove and a contact mounted on the steering wheel. As long as the glove and wheel sensors are in contact the alarm does not sound. Contact is measured by the drivers&#39; skin resistance rather than pressure and has been considered unreliable since the ambient temperature differences effect perspiration and thus alter skin resistance readings. In U.S. Pat. No. 6,590,499 to D&#39;Agosto, describes a steering wheel mounted alert system. It requires either a custom manufactured steering wheel or custom installation.  
         [0010]     While it is clear that each of these devices fulfill a particular objective or requirement it is clear that each has particular limitations and in general are either extraordinarily complex or do not activate an alarm until the driver has already started to dose off. It would be useful if there was a sensor arrangement which sounded an alarm instantly when the driver starts to doze and not when he is asleep. It would be useful if the system were simple and operated with a minimum of complicated interactions.  
       SUMMARY OF THE INVENTION  
       [0011]     It is an object of the present invention to provide a novel device that has addressed the above problems along with other benefits to the user which will become evident from the disclosure and examples described herein. The present invention is relatively simple to use, activates immediately if a driver starts to nod off, can easily be turned off for repositioning or other activity and is cost effective compared to other systems. Accordingly, the invention provides in a broad embodiment a steering wheel sleep alert device for use while driving a vehicle comprising:  
         [0012]     A sleep alert device for use while driving a vehicle comprising: 
        a) a plurality of pressure sensors mounted on a tube adapted for mounting on a motor vehicle steering wheel, the pressure sensors mounted to give a multiplicity of positions where hand grip pressure on a steering wheel can be measured;     b) an alarm which is activated immediately when the grip pressure on all of the sensors are below a predetermined value;     c) a means for turning the sensors on or off; and     d) a pause means for temporarily deactivating the sensors while the device is in use.        
 
         [0017]     It is another object of this invention to provide a sleep alarm that is effective by placement on the hands in a desirable location on a steering wheel that is more likely to be a true measure of pressure. It is yet a further object of the invention to take automation out of the process of putting a sleep detector on hold or during other activities which eliminate errors or dependence on the automated part of the system to be accurate.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  shows a perspective of the invention with multiple sensors mounted on a tube.  
         [0019]      FIG. 2  is a flow chart showing the operation of the circuit of the invention.  
         [0020]      FIG. 3  shows a perspective of the invention with multiple sensors mounted on a tube wherein the tube is covered with fabric. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     The present invention consists of a tube fitted with a plurality of pressure sensors that fits over the steering wheel of a motor vehicle. These sensors are connected to a microprocessor for determining pressure of the fingers or hand on the steering wheel while driving. It is powered by a battery or other power source and controlled by an on off switch and a pause means. The on of and pause means may be the same means or switch. An alarm which can activate upon reaching a minimum pressure value is connected to the processor and in one embodiment the threshold level is adjustable. In one embodiment the tube is covered with a fabric or other material for comfort or to protect the sensors from damage.  
         [0022]     As used herein “sleep alert device” refers to a device designed to alert the user when they are falling asleep in order to prevent the user from falling asleep while driving a vehicle. This is most useful while driving a car or truck where if the driver even begins to nod off, the sleep alert device can activate an alarm and prevent the driver from falling asleep.  
         [0023]     By “tube” herein is meant a tubular structure that is shaped to fit a steering wheel. The inner diameter of the tube is sized such that it will conveniently fit over the outer diameter of a steering wheel. While normally this means a round shape as showing in the embodiments depicted in the figures, other shapes could be manufactured to correspond to other shapes of steering wheels. The tube will have a slit which is described as an opening allowing mounting of the tube to the steering wheel. The material the tube is made from is such that it will remain in place on the steering wheel. Such materials as plastics, elastomers, polymers, natural and artificial fibers all can be adapted to use in the present invention. Other materials will become obvious based on the disclosed invention herein.  
         [0024]     As used herein “pressure sensors” refers to electronic pressure sensor pads known in the art which can be used to measure pressure. In the present invention the sensors will measure the pressure between the steering wheel and the user&#39;s fingers when a tube fitted with the pressure sensors is mounted on a steering wheel. The pressure sensors are mounted around the tube such that when the tube is mounted on the steering wheel, the user can grab any portion of the steering wheel and be essentially assured of grabbing at least one pressure sensor. In this manner the driver can reposition their hands at any time and be assured of always being in contact with a pressure sensor as long as there is at least one hand grabbing the steering wheel. While this can be done with just a few sensors strategically placed, in one embodiment there are at least 4 sensors. In another embodiment, there are at least 8. In another embodiment there are at least 12 sensors. In another embodiment at least 15. In a series of other embodiments the minimum number of sensors is at least 18, 20, 25, 30, 35, 40, 45 and 50. It is clear from this disclosure that the number of sensors will be dictated in part by both the size of the steering wheel and the size of the users hand when determining an optimum number of sensors. As described above however, one embodiment has the number and position of the sensors such that a sensor is grabbed no matter where the driver grabs on the steering wheel. This is referred to herein also as a multiplicity of positions.  
         [0025]     Pressure sensors are normally connected to a microprocessor or the like and this can be done as in the figures which follow by a direct wire connection but with today&#39;s miniaturization of components could be done by RF, Bluetooth or other wireless means. The pressure sensor could be a simple on off switch mechanism or could be, in one embodiment, a timer which turns the unit on or off after a given period of driving or after starting the vehicle. The pressure sensor could be connected directly to the alarm via wired or wireless means. The tube is designed to easily fit over the steering wheel by an opening or slit in the back of the tube such that the tube can easily be placed on the steering wheel and just as easily removed. The ideal mounting position for the tube is such that the pressure sensors are positioned such that they are below the normal hand position of the driver holding the steering wheel. In one embodiment the sensor is placed at a position on the tube such that when mounted on a steering wheel, it is where it will most likely comes in contact with the hand which would be on the palm side of the finger between the distal interphalangeal joint and the metacarpophalangeal joint of the finger.  
         [0026]     There are several controls which can be mounted on the hand, on the steering wheel, on the dash or any convenient place in the vehicle. Attachment to the pressure sensors can be by wired or wireless means. The controls can be mounted together or any of the controls can be separated from the rest and mounted as desired.  
         [0027]     As used herein “alarm” refers to a means for shaking a dozing driver from his about to be sleeping state. This could be an audio alarm, a vibratory means, or the like which would startle the driver just enough to bring him back from the brink of sleep. In one embodiment this may be a buzzer or other audio device. The alarm would be connected to the microprocessor or the pressure sensor directly and be triggered when, after gripping the steering wheel and engaging the sensor, there are no sensors that remain above a predetermined level. Thus as long as the driver keeps a given grip on the steering wheel with one hand the alarm will not sound. This allows repositioning of the hands as previously described. In one embodiment there could be an adjustment means for adjusting the level at which the alarm is triggered. It is an embodiment of this invention that there not be a delay in activation of the alarm built into the mechanism, as for example as taught in U.S. Pat. No. 6,016,103. A delay would mean that the driver could have already driven off the road, crashed and been killed before the alarm would be triggered.  
         [0028]     With the plurality of sensors around the steering wheel, as long as there is one hand on the steering wheel there is always pressure on at least one sensor that will remain above a predetermined grip pressure. Thus, the driver can reposition hands one at a time and as long as the driver does not let go with both hands the alarm would not be triggered. This gives the advantage of being able to move the hands about the steering wheel to prevent fatigue without having to pause or turn off the alarm system. The alarm would then be triggered at a point when there is no sensor above a predetermined pressure as would happen when letting go with both hands or the reduced grip on both hands when beginning to dose.  
         [0029]     As used herein “pause means” refers to a switch or other means for deactivating the device while in use for repositioning both the hands or the like. It can consist of an on off switch in fact be the power switch but in one embodiment it a separate switch which allows the device to remain powered while momentarily deactivating the ability of the alarm to sound. The switch can be a momentary or spring loaded switch, can be a gravity activated switch or the like.  
         [0030]     As mentioned above wireless connections are contemplated within the scope of several embodiments of the invention. Such wireless means are now well know in the art as described above and one skilled in the art would be able to adapt the invention for such use.  
         [0031]     Timers within the scope of the invention are well known and would consist of an electronic clock timer which could be programmed to turn the device on or off at a predetermined time or perhaps used as an alarm clock to remind the driver for a particular activity or to automatically give the driver an opportunity to reposition the sensor hand without pressing the pause button. This last embodiment would be an automatic pause timer.  
         [0032]     It is known within the art that each driver has his or her own driver grip pressure. In one embodiment then the grip pressure can be adjusted on the device by addition of a means of variably adjusting resistance or other standard means for setting pressure on a sensing device.  
         [0033]     In an embodiment shown in the drawing,  FIG. 1  is a perspective of the invention  11  with sensors  12  positioned around tube  13 . Tube  13  is positioned around a steering wheel (not shown) by opening back slit  50 . In  FIG. 1  slit  50  is positioned on the back side of the tube and extends circumferentially around the entire tube such that the tube can be positioned on the steering wheel with the slit  50  to the back of the steering wheel. It is clear that the tube could be attaché by other means other than the pressure of the closing tube. For example the tube could be sewn in place use snaps or Velcro closures or any other convenient method of attachment. The drawing only depicts the slit, in see through fashion. A small portion of the back slit  50  is shown, but the slit continues around the entire tube  11 . The driver places tube  13  on his steering wheel by opening the slit and placing the tube around the steering wheel. Where the tube is made of elastic type materials it will e self closing. Other methods of closing are described above. On/off button  16  as shown activates the device. Additional switch  15  depicted on the tube  13  can be a pause means the on off switch or both. Control panel  20  for mounting controls is shown in this embodiment. The Control panel  20  can be mounted in any convenient location. Also on control panel  20  is pressure control switch  25  for controlling the amount of pressure which activates the invention. Lastly shown is adjustable volume switch  26  for adjusting the volume of the alarm  30 . Alarm  30  in this embodiment is shown as a hashed area, indicating that alarm has a speaker means for some kind to sound. A battery can be inserted if necessary into the control panel  20  or anywhere according to the art. Lastly, connecting wires  40  and  41  represent the electrical connection between the sensors  12  and pause button  15  respectively.  
         [0034]      FIG. 2  represents a flow diagram of the workings of the present invention. The flow diagram indicates the instantaneous nature of the sensor of the invention as well as the ultimate simplicity.  
         [0035]      FIG. 3  represents yet another embodiment of the invention wherein the tube has fabric covering  60 . The covering  60  is designed for comfort and can further be padded or otherwise treated as a cushioning means for the grip of a hand. As in  FIG. 1 , the connecting wires  40  and  41  are shown connecting to control panel  20 . Also shown are on/off button  16  as well as pressure control switch  25  and alarm volume control  26 . Pause button  15  in this embodiment is positioned on the tube  13 .  
         [0036]     It is understood that wired connection  40  could also represent a wireless connection within the skill in the art. According, the pause mechanism connection  41  could also be wireless.  
         [0037]     Accordingly, a novel approach to producing a driver sleep alert device is now disclosed which over comes many of the problems and faults of previous devices. One skilled in the art will be able to produce variations and other embodiments within the scope of the invention in view of the above disclosure. The disclosure is thus not intended to be limiting or all inclusive and the broadest possible interpretation is intended in the claims which follow.