Patent Publication Number: US-2017360360-A1

Title: Sleep monitoring cap

Description:
BACKGROUND 
     Grant of Non-Exclusive Right 
     This application was prepared with financial support from the Saudi Arabian Cultural Mission, and in consideration therefore the present inventor(s) has granted The Kingdom of Saudi Arabia a non-exclusive right to practice the present invention. 
     Description of the Related Art 
     A large number of people have difficulties with falling asleep and maintaining sleep. Many people may experience frequent awakenings or they do not use their sleep time efficiently. The effects of even small amounts of sleep loss accumulate over time, which can result in a “sleep debt,” which manifests itself in the form of increasing impairment of alertness, memory, and decision-making. Vigilance, memory, decision-making, and other neurocognitive processes are all impacted by poor sleep quality, sleep deprivation, and accumulating sleep debt with potentially detrimental consequences. 
     Many people do not realize they are not sleeping well but nonetheless, suffer the consequences of inefficient sleep. Other people attempt to overcome sleep-related problems by taking sleep-inducing or sleep-assisting drugs, such as stimulants or using relaxation techniques prior to sleeping. While temporary amelioration of the effects of sleep deprivation can be achieved using some of these techniques, an adequate amount of sleep that is commensurate with a person&#39;s accumulated sleep debt is indispensable for complete recuperation in the long run. 
     Many situations do not allow for a regular bout of nocturnal sleep. In such situations, brief naps, taken at various times throughout the day, have been advocated as an effective and natural means of countering fatigue and improving performance. Unfortunately, it is not easy to devise an optimal schedule for napping. In addition, the effects of a nap on dexterity and cognition depend, not only upon its duration, but also upon the sleep quality, the timing or period on the circadian cycle (i.e., the human&#39;s genetic preference to perform certain physiological functions only at certain times of the day or night) at which the nap occurred, and the depth of sleep from which the subject is awakened. 
     Sleep occurs in various stages, and each stage has its attendant purpose and advantages. Adequate balance among the sleep stages over long periods of time is important. For example, a persistent lack of Rapid Eye Movement (REM) sleep can result in a decline in performance, even if the total sleep time per day appears adequate. Therefore, a sleep paradigm that only prescribes durations and/or frequencies for sleeping will not necessarily result in a consistent and effective mitigation of performance deficits. 
     Sleep occupies approximately one-third of our lives. It has been established that sleep or the lack thereof is associated with heart disease, diabetes, immune deficiency, and memory deficit. Current practices for assessing sleep disorders can be time consuming and financially intensive. Sleep disorder research is usually conducted in a sleep laboratory managed by practitioners where sleep disorders, such as narcolepsy and sleep apnea, can be diagnosed. Home sleep testing kits are available. However, many sleep disorders cannot be detected by home sleep testing kits. 
     Drowsiness also negatively impacts a large number of people. Deaths due to falling asleep while driving in the United States are estimated at 5600 per year. In addition, drowsiness can negatively impact other areas of life, such as work activities. 
     The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     SUMMARY 
     In one embodiment, a sleep-monitoring cap includes a plurality of interconnected electrodes embedded within a body of the sleep-monitoring cap. The plurality of interconnected electrodes is located at positions across a central transverse region, below and along a side of each eye, and on a rear mid-region of a person&#39;s head when the person is wearing the sleep-monitoring cap. The sleep-monitoring cap also includes a vibratory device embedded within the body of the sleep-monitoring cap, wherein the vibratory device is connected to the plurality of interconnected electrodes. The sleep-monitoring cap also includes first processing circuitry embedded within the body of the sleep-monitoring cap. The first processing circuitry is configured to monitor, convert, process, and store a first set of brain wave activity retrieved by the plurality of interconnected electrodes from the person wearing the sleep-monitoring cap; determine whether a sleep state exists from the monitored first set of brain wave activity; when the sleep state exists, determine whether a first sleep stage is a REM sleep stage; when the first sleep stage is a REM sleep stage, record the sleep state as a sleep onset REM period; and activate the vibratory device after a pre-determined time period when the sleep onset REM period has been recorded. The sleep-monitoring cap also includes second processing circuitry embedded within the body of the sleep-monitoring cap. The second processing circuitry is configured to monitor, convert, process, and store a second set of brain wave activity retrieved by the plurality of interconnected electrodes from the person wearing the sleep-monitoring cap; determine whether the monitored second set of brain wave activity includes low amplitude mixed-frequency waves; when the monitored second set of brain wave activity includes the low amplitude mixed-frequency waves, activate the vibratory device; determine whether the monitored second set of brain wave activity includes theta waves followed by vertex sharp waves; and when the monitored second set of brain wave activity includes the theta waves followed by the vertex sharp waves, activate the vibratory device. 
     In one embodiment, a sleep-monitoring cap includes a plurality of interconnected electrodes embedded within a body of the sleep-monitoring cap. The plurality of interconnected electrodes is located at positions across a central transverse region, below and along a side of each eye, and on a rear mid-region of a person&#39;s head when the person is wearing the sleep-monitoring cap. The sleep-monitoring cap also includes a vibratory device embedded within the body of the sleep-monitoring cap, wherein the vibratory device is connected to the plurality of interconnected electrodes. The sleep-monitoring cap also includes processing circuitry embedded within the body of the sleep-monitoring cap. The processing circuitry is configured to monitor, convert, process, and store brain wave activity retrieved by the plurality of interconnected electrodes from the person wearing the sleep-monitoring cap; determine whether a sleep state exists from the monitored brain wave activity; when the sleep state exists, determine whether a first sleep stage is a REM sleep stage; when the first sleep stage is a REM sleep stage, record the sleep state as a sleep onset REM period; and activate the vibratory device after a pre-determined time period when the sleep onset REM period has been recorded. 
     In one embodiment, a sleep-monitoring cap includes a plurality of interconnected electrodes embedded within a body of the sleep-monitoring cap. The plurality of interconnected electrodes is located at positions across a central transverse region, below and along a side of each eye, and on a rear mid-region of a person&#39;s head when the person is wearing the sleep-monitoring cap. The sleep-monitoring cap also includes a vibratory device embedded within the body of the sleep-monitoring cap, wherein the vibratory device is connected to the plurality of interconnected electrodes. The sleep-monitoring cap also includes processing circuitry embedded within the body of the sleep-monitoring cap. The processing circuitry is configured to monitor, convert, process, and store brain wave activity retrieved by the plurality of interconnected electrodes from the person wearing the sleep-monitoring cap; determine whether the monitored brain wave activity includes low amplitude mixed-frequency waves; when the monitored brain wave activity includes the low amplitude mixed-frequency waves, activate the vibratory device; determine whether the monitored brain wave activity includes theta waves followed by vertex sharp waves; and when the monitored brain wave activity includes the theta waves followed by the vertex sharp waves, activate the vibratory device. 
     The foregoing paragraphs have been provided by way of general introduction, and are not intended to limit the scope of the following claims. The described embodiments will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: 
         FIG. 1  illustrates an overhead view of electrode positioning of a sleep-monitoring cap on a person&#39;s head according to one embodiment; 
         FIG. 2  illustrates a back view of electrode positioning of a sleep-monitoring cap on a person&#39;s head according to one embodiment; 
         FIG. 3  illustrates a side view of electrode positioning and a sleeping cap positioning on a person&#39;s head according to one embodiment; 
         FIG. 4  illustrates a front view of electrode positioning and a sleeping cap positioning on a person&#39;s head according to one embodiment; 
         FIG. 5  is an exemplary algorithm for monitoring and determining brain wave activity according to one embodiment; 
         FIG. 6  is an exemplary algorithm for monitoring drowsiness according to one embodiment; 
         FIG. 7  illustrates an exemplary sleep-monitoring cap with an embedded transistor according to one embodiment; 
         FIG. 8  illustrates a hardware description of an exemplary computing device according to one embodiment; 
         FIG. 9  is a schematic diagram of an exemplary data processing system according to one embodiment; and 
         FIG. 10  is a schematic diagram of an exemplary central processing unit (CPU) according to one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The science of sleep distinguishes five stages of sleep, including wakefulness as a pre-sleep stage. There are three stages of non-rapid eye movement (NREM), which are stage 1, stage 2, and stage 3. There is also a rapid eye movement (REM) stage. The different stages of sleep can be identified using various techniques to monitor brain wave patterns, such as using an electroencephalogram (EEG) technique, monitoring eye movements using an electro-oculogram (EOG) technique, and monitoring the movements of the chin using electromyogram (EMG) techniques. 
     A rested wakeful stage is characterized by low amplitude alpha waves (8-12 Hz) present in an EEG of a person whose brain waves are being monitored. Alpha waves are brain waves typically exhibited while a person is in a wakeful and relaxed state with the person&#39;s eyes being closed. The alpha waves typically decrease in amplitude while the person&#39;s eyes are opening or the subject is in a drowsy or sleeping state. 
     NREM Stage 1 is characterized by irregular theta waves of low amplitude present in the EEG of a person. Slow rolling eye movements are also present in an EOG of the subject. 
     NREM Stage 2 is characterized by high frequency (12-16 Hz) bursts of brain activity called sleep spindles riding on top of slower brain waves of higher amplitude. During NREM Stage 2, a gradual decline in heart rate, respiration, and core body temperature occurs as the body prepares to enter deep sleep. 
     NREM Stage 3 is characterized by delta waves (1-3 Hz) of large amplitude that dominate for more than 20% of the time. 
     REM sleep presents a marked drop in muscle tone and bursts of rapid eye movements that can be seen in the EOG. The EEG in REM is not specific and resembles that of wakefulness or NREM Stage 1 sleep. Other physiological signals (e.g. breathing, heart rate) during REM sleep also exhibit a pattern similar to that occurring in an awakened individual. 
     Sleep stages come in cycles that repeat on the average of four to six times a night, with each cycle lasting approximately ninety to one hundred twenty minutes. The order of the stages of a sleep cycle and the length of the sleep stages may vary from person to person and from sleep cycle to sleep cycle. For example, NREM Stage 3 may be more prevalent during sleep cycles that occur early in the night, while NREM Stage 2 and REM sleep stages may be more prevalent in sleep cycles that occur later in the night. The sequence and/or length of sleep stages during an overnight sleep or nap is sometimes interrupted with brief periods of wakefulness. This makes up a person&#39;s sleep architecture. 
     A balanced sleep architecture is important, especially during a nap or shortened period of sleep because the various stages of sleep contribute differently to recuperation. A sleep period composed only of light sleep (NREM Stage 1) does not improve performance, whereas even a few minutes of solid sleep (NREM Stage 2) can boost alertness, attention, and motor performance. Deep sleep (NREM Stage 3) is desirable because it reduces stress and improves skill acquisition. However, interruptions during NREM Stage 3 sleep can lead to decrements in performance. A persistent lack of REM sleep can result in a decline in performance, even if the total sleep time per day appears to be adequate. 
     One of the common sleep disorders is narcolepsy, which is a result of abnormal REM sleep. Narcoleptics generally experience the REM stage of sleep within five minutes of falling asleep, while a non-narcoleptic does not experience REM in the first hour or so of a sleep cycle until after a period of slow-wave sleep. Narcoleptics commonly experience frequent excessive daytime sleepiness, comparable to how non-narcoleptics feel after 24 to 48 hours of sleep deprivation. The disturbed nocturnal sleep is often confused with insomnia. Narcoleptics can also experience cataplexy, which is a sudden and transient episode of muscle weakness or total loss of muscle tone accompanied by full conscious awareness, typically triggered by emotions such as laughing, crying, tenor, etc. 
     Embodiments herein describe methods and systems for monitoring sleep and sleep disorders. An embodiment describes a method of monitoring REM sleep patterns, which includes applying electrodes to a person&#39;s head, wherein the electrodes are configured to measure a plurality of sleep stages of the person during a sleep state. The method also includes determining how long after falling asleep the person enters REM sleep. When the person enters REM sleep as a first sleep stage, the method includes waking the person up approximately 20 minutes later using a vibrator, which is electronically attached to the electrodes. If the sleep did not occur, the test will end after approximately 20 minutes. The method also includes receiving data results of the plurality of sleep stages, via a memory device. 
     Another embodiment describes an electrode cap, which is configured to determine narcolepsy in a person. The cap is configured to fit over a person&#39;s head during sleep, and includes a plurality of electrodes in the cap configured to measure different stages of sleep of the person. The cap also includes a vibrator, which is configured to wake the person up after approximately 20 minutes when REM sleep is entered as a first sleep stage. The cap also includes a memory device to record the different stages of sleep activity of the person. 
     Another embodiment describes an electrode cap, which is configured to measure a drowsiness stale. The cap is configured to fit over a person&#39;s head, and includes a plurality of electrodes in the cap configured to measure brain wave activity of a person wearing the cap. The cap also includes a vibrator, which is configured to vibrate when slow eye movement followed by theta EEG waves are measured by the cap. The vibrator is also configured to vibrate when the cap measures theta waves followed by vertex sharp waves. 
       FIG. 1  illustrates an overhead view of electrodes positioned on a head  100  of a person. A front end  110  of head  100  includes two eyes  120 , and each side of head  100  includes an ear  130 . A back end  140  of head  100  is also illustrated. Head  100  illustrates the placement of electrodes for purposes of measuring sleep states of the person via an electro-encephalogram (EEG). The illustrated electrode notations use the standard naming and positioning scheme in the 10-20 international system for EEG applications. However, other naming conventions are contemplated by embodiments described herein. Even though several other electrodes have been established for use in an EEG for various purposes, embodiments described herein for measuring different sleep stages utilize the electrodes illustrated in  FIG. 1 . All electrodes at the notated positions in  FIG. 1  are interconnected, such that electrical signals from the electrodes can be transmitted and recorded, via interconnecting electrical transmission times and a memory transistor chip, respectively. 
     An EEG measures brain waves by applying multiple electrodes to various positions on the head, as illustrated in  FIG. 1 . An EEG amplifier measures voltage differences between points on the scalp against reference points, M 1  or M 2 , depending on the place of the active electrode, thereby creating a channel between two connected electrodes. EEG electrodes are small metal plates that are attached to the scalp. This can be accomplished by using a conducting electrode gel. In other embodiments, an elasticized cap fitted to a person&#39;s head can be used to hold the electrodes next to the scalp. The electrodes can be made from various materials, such as tin and silver/silver-chloride electrodes. Gold and platinum electrodes can also be used, as well as other conducting materials. 
       FIG. 2  illustrates a back view of electrodes positioned on a person&#39;s head  200 .  FIG. 2  illustrates electrodes from the crown of the head  200  towards the lower backside of the head  200 . Ears  210  are illustrated on either side of the head  200  to better illustrate positioning of the electrodes. The illustrated electrodes are interconnected, along with electrodes on the front side of the head, as illustrated in  FIG. 1 .  FIG. 2  also illustrates a vibrator  220 , which is connected to the circuitry of the interconnected electrodes, via vibrator connectors  230 . 
       FIG. 3  illustrates a side view of electrodes positioned on a person&#39;s head  300  as viewed from a side perspective. An ear  310  and an eye  320  are also illustrated.  FIG. 3  also illustrates a vibrator  330  on the lower back side of the head  300 , which is connected by circuitry to the interconnected electrodes. Vibrator  330  is also held flush against the back side of the person&#39;s head  300 . Vibrator  330  could be positioned just below the hairline of the person&#39;s head  300 , although this is not a requirement. 
       FIG. 3  also illustrates a cap  340  that contains the electrodes illustrated in  FIG. 1 . The electrodes are embedded in the material of the cap  340 , such that each electrode maintains its intended position flush against the person&#39;s head  300  with respect to all surrounding electrodes. The vibrator  330  is contained within the lower back region of the cap  340 , such that the vibrator  330  is held against the person&#39;s head below or near to the hairline of the person&#39;s head  300 . Edges  340   a  of the cap  340  are illustrated to run below the eye  320 , behind the ear  310 , and down and around the neck. Eye holes can be provided within the cap  340  to allow the person to see while wearing the cap  340 . 
     Cap  340  also contains a processor  350  for recording and storing data from the electrical signals of the electrodes and for processing and analyzing the signals from the electrodes. The processor  350  could be located on the top side of the cap  340  as illustrated in  FIG. 3  or another position, such that it would not provide any discomfort to the person from lying directly on the processor  350  while sleeping. A rechargeable battery-operated power source could also be included in the cap  340 . 
       FIG. 4  illustrates a front view of electrodes and a cap  400  positioned on a person&#39;s head, wherein an edge  400   a  of the cap  400  runs below the eyes and above the nose and ears. Cap  400  properly places associated eye electrodes near the lower edges of the eyes while the person sleeps. Eye holes in the cap  400  would allow the person to see while wearing the cap  400 . However, cap  400  could also be configured without eye holes to aid the person in sleeping by providing a dark environment. 
       FIG. 5  is an exemplary algorithm  500  for monitoring and determining brain wave activity of a person, using at least in part, embodiments described above for a sleep-monitoring cap. In an embodiment, the algorithm  500  monitors and determines narcolepsy in a person wearing the sleep-monitoring cap. Exemplary algorithm  500  is implemented, via a sleep-monitoring cap configured with circuitry to perform the following algorithmic steps. 
     In step S 510 , a person&#39;s brain-wave activity is monitored, via a sleep-monitoring cap, such as the cap described above with reference to  FIGS. 1-4 . In step S 520 , it is determined whether the person is asleep. If the person is still not asleep after approximately 20 minutes, a vibrator contained within the cap vibrates in optional step S 525 , using the vibrator described above with reference to  FIGS. 2-3 . In an embodiment, it may be desirable for the person to rise up and move about before resuming the sleep monitoring. 
     If the person is asleep (a “yes” decision in step S 520 ), the process continues to step S 530 . In step S 530 , it is determined whether the first stage of sleep entered from a waking state is REM. If the first stage is not REM (a “no” decision in step S 530 ), the process ends. If the first stage is REM (a “yes” decision in step S 530 ), the process continues to step S 540  where a Sleep Onset REM Period (SOREMP) is recorded. 
     The process continues to step S 550 , where a vibration occurs approximately  20  minutes after SOREMP is detected, using the vibratory device embedded in the cap. In an embodiment, a wake-up period approximately 20 minutes after entering SOREMP is conducted in narcolepsy testing. However, other waiting periods after entering SOREMP are contemplated by embodiments described herein. 
     In step S 560 , data capture is discontinued after the vibratory device is activated, i.e. the person has been awakened. Brain activity continues to be monitored as long as the sleep-monitoring cap is activated in order to capture any additional SOREMP activity during a single sleep session. Therefore, the process begins again at step S 510 . 
     The vibrator, such as vibrator  220  or  330  can be programmed, via cap processor  350  with various options. For example, the vibrator can continue to vibrate until motion is detected or until a waking state is monitored by processor  350 . If the person does not move or a waking state is not detected by processor  350  after a pre-determined amount of time, a different type of vibration and/or a different intensity of vibration could commence to awaken the person. 
     Measuring EEG waves is an objective way to distinguish between a sleep state and a wakefulness state. The different sleep stages, as well as a wakefulness state are associated with specific EEG wave activity. 
     A wakefulness state is associated with beta activity in the range of 12-40 Hertz. 
     Stage 1 sleep is associated with slow eye movement (SEM) and theta waves in the range of 4-7 Hertz. Stage 1 sleep can also be associated with vertex sharp waves coming from the central lobe (illustrated as Cz in  FIG. 1 ) with an amplitude of 50-150 microVolts. Stage 1 sleep is also associated with alpha attenuation, where alpha waves become slower and less prominent. This stage is sometimes called a drowsiness stage or a transition stage from wakefulness to sleep. Stage 1 usually lasts for 2-5 minutes before stage 2 begins. 
     Stage 2 sleep is associated with K complex and sleep spindle. This stage is the most prominent stage in a normal sleeper. 
     Stage 3 sleep is associated with delta activity. Delta activity is very slow and is usually in the range of 0-4 Hertz. This stage is associated with memory consolidation. 
     Stage REM sleep is associated with high frequency low amplitude waves in which the brain becomes very active. REM stage sleep frequently exhibits alpha activity. REM stage sleep can he distinguished by rapid eye movement and a drop in muscle activity. 
       FIG. 6  is an exemplary algorithm  600  for monitoring the drowsiness of a person, using at least in part, embodiments described above for a sleep-monitoring cap. In an embodiment, the algorithm  600  monitors and determines a state of drowsiness by monitoring Stage 1 sleep. Exemplary algorithm  600  is implemented, via a sleep-monitoring cap configured with circuitry to perform the following algorithmic steps. 
     In step S 610 , brain wave activity is monitored by a sleep-monitoring cap, such as the sleep-monitoring cap described with reference to  FIGS. 1-4 . In step S 620 , it is determined whether low amplitude mixed-frequency waves are detected by the sleep-monitoring cap. This can be determined by detecting SEM followed by theta EEG waves in the frequency range of 4-7 Hertz. If low amplitude mixed-frequency waves are detected (a “yes” decision in step S 620 ), a vibratory device, such as vibrator  220  or  330  is activated in step S 630  to awaken the person wearing the sleep-monitoring cap. 
     If low amplitude mixed-frequency waves are not detected (a “no” decision in step S 620 ), it is determined whether theta waves followed by vertex sharp waves are detected in step S 640 . If theta waves followed by vertex sharp waves are detected (a “yes” decision in step S 640 ), a vibratory device, such as vibrator  220  or  330  is activated in step S 630  to awaken the person wearing the sleep-monitoring cap. If theta waves followed by vertex sharp waves are not detected (a “no” decision in step S 640 ), the process resumes at step S 610  where brain wave activity continues to be monitored as long as the sleep-monitoring cap is activated. 
     In an additional embodiment, when the vibrator has been activated in step S 630 , a wireless signal can be transmitted, via an electronic transmitter embedded in the sleep-monitoring cap, to a light-emitting device in step S 650 . The light-emitting device can be worn on the sleep-monitoring cap, such as the back side or the front side. When the light-emitting device is activated, it would inform individuals surrounding the person wearing the sleep-monitoring cap that the person is entering into a drowsy state. This would inform surrounding individuals of an impending problem, and allow the surrounding individuals to possibly offer assistance. The light-emitting device can be a steady light or a flashing light. 
     The light-emitting device can also be affixed to a rear side of a vehicle in which the person is driving. When the light-emitting device becomes activated, it would inform other surrounding drivers of a possible impending problem. This would allow other drivers to provide more distance between the vehicle with the light-emitting device and other drivers&#39; vehicles. The light-emitting device can be a single device or interconnected multiple devices. The light-emitting device(s) can be similar to emergency flashers of a vehicle. 
     In an additional embodiment, one or more registered numbers can be contacted in step S 660 , subsequent to steps S 630  and S 650 . One of the registered numbers could be a mobile phone number of the person wearing the sleep-monitoring cap. In essence, this would provide a “wake-up call” to the person wearing the sleep-monitoring cap when a drowsy state has been detected. In addition, other landline or mobile numbers could be registered to inform other individuals of the person&#39;s drowsy state, such as a spouse, a supervisor, a medical practitioner or medical personnel, or a local law enforcement agency. 
       FIG. 7  illustrates an exemplary sleep-monitoring cap in which a transmitter  700  is embedded in the sleep-monitoring cap. The transmitter  700  could be located adjacent to the processor  350  or included within the same electronic device as the processor  350 . In another embodiment, the transmitter  700  could be located in other areas of the sleep-monitoring cap, such as near or adjacent to the vibrator  330 . The transmitter  700  is used in conjunction with a receiving light-emitting device located on the sleep-monitoring cap or located at another location, such as the rear side of a vehicle. 
     The structure of the sleep-monitoring cap in which the electrodes, the processor  350 , the vibrator  330 , and the transmitter  700  are embedded includes a material or fabric configured to firmly hold the electrodes close to the scalp of the person wearing the sleep-monitoring cap. The material or fabric would be stretchable, so as to provide a snug fit and maintain the position of each electrode close to the scalp without moving. In addition, a stretchable material or fabric would allow an adequate fit for multiple sizes and shapes of heads. The material or fabric could include nylon or polyester, designed to stretch when a force is applied to it, and return to its original shape and size when the force is removed. Embodiments also include a mesh material in which multiple open spaces or pores exist within the sleep-monitoring cap. 
     One or more straps affixed to the sleep-monitoring cap could also be configured to help maintain the snug fit. In an embodiment, a pair of straps could extend from the frontal lobe area of the head and snap or tie under the chin. In another embodiment, a pair of straps could extend from a rear area of the head behind the ears and snap or tie under the chin. 
     The sleep-monitoring cap can also be designed to be thin and fit under a hat. This would be advantageous for monitoring drowsiness when the person is amongst other individuals and does not wish for the sleep-monitoring cap to be viewed by others. 
     A hardware description is given with reference to  FIG. 8  of a computing device, such as processor  350  and transmitter  700 , which is used in conjunction with associated circuitry for embodiments described herein. The circuitry represents hardware and software components whereby the “configured by circuitry,” “configured by programming and circuitry,” and/or “configured to” elements of the disclosures noted herein are programmed. The programming in hardware and software constitutes algorithmic instructions to execute the various functions and acts noted and described herein. The computing device described herein can include one or more types of wireless and/or portable computing devices. The computing device described herein can also include physically separated devices that operate within a network. 
     In  FIG. 8 , the computing device includes a CPU  800  which performs the processes described above. The process data and instructions may be stored in memory  802 . These processes and instructions may also be stored on a storage medium disk  804  such as a hard disc drive (HDD) or portable storage medium, or may be stored remotely. Further, the claimed embodiments are not limited by the form of the computer-readable media on which the instructions of the inventive process are stored. For example, the instructions may be stored on CDs, DVDs, in FLASH memory, RAM, ROM, PROM, EPROM, EEPROM, hard disk or any other information processing device with which the computing device communicates. 
     Further, the claimed embodiments may be provided as a utility application, background daemon, or component of an operating system, or combination thereof, executing in conjunction with CPU  800  and an operating system such as Microsoft Windows 7, UNIX, Solaris, LINUX, Apple MAC-OS and other systems known to those skilled in the art. 
     CPU  800  may be a Xenon or Core processor from Intel of America or an Opteron processor from AMD of America, or may be other processor types that would be recognized by one of ordinary skill in the art. Alternatively, the CPU  800  may be implemented on a Field Programmable Grid-Array (FPGA), Application-Specific Integrated Circuit (ASIC), Programmable Logic Device (PLD), or using discrete logic circuits, as one of ordinary skill in the art would recognize. Further, CPU  800  may be implemented as multiple processors cooperatively working in parallel to perform the instructions of the inventive processes described above. 
     The computing device in  FIG. 8  also includes a network controller  806 , such as an Intel Ethernet PRO network interface card from Intel Corporation of America, for interfacing with network  88 . As can be appreciated, the network  88  can be a public network, such as the Internet, or a private network such as an LAN or WAN network, or any combination thereof and can also include PSTN or ISDN sub-networks. The network  88  can also be wired, such as an Ethernet network, or can be wireless such as a cellular network including EDGE, 3G and 4G wireless cellular systems. The wireless network can also be WiFi, Bluetooth, or any other wireless form of communication that is known. 
     The computing device further includes a display controller  808 , such as a NVIDIA GeForce GTX or Quadro graphics adaptor from NVIDIA Corporation of America for interfacing with display  810 , such as a Hewlett Packard HPL2445w LCD monitor. A general purpose I/O interface  812  interfaces with a keyboard and/or mouse  814  as well as a touch screen panel  816  on or separate from display  810 . General purpose I/O interface  812  also connects to a variety of peripherals  818  including printers and scanners, such as an OfficeJet or DeskJet from Hewlett Packard. 
     A sound controller  820  is also provided in the computing device, such as Sound Blaster X-Fi Titanium from Creative, to interface with speakers/microphone  822  thereby providing sounds and/or music. The general purpose storage controller  824  connects the storage medium disk  804  with communication bus  826 , which may he an ISA, EISA, VESA, PCI, or similar, for interconnecting all of the components of the computing device. A description of the general features and functionality of the display  810 , keyboard and/or mouse  814 , as well as the display controller  808 , storage controller  824 , network controller  806 , sound controller  820 , and general purpose I/O interface  812  is omitted herein for brevity as these features are known. 
     The computing devices used with embodiments described herein may not include all features described in  FIG. 8 . In addition, other features used with embodiments described herein may not be described with reference to  FIG. 8 . 
       FIG. 9  is a schematic diagram of an exemplary data processing system, according to certain embodiments described herein. The data processing system is an example of a computer in which code or instructions implementing the processes of the illustrative embodiments can be executed. 
     In  FIG. 9 , data processing system  900  employs an application architecture including a north bridge and memory controller application (NB/MCH)  925  and a south bridge and input/output (I/O) controller application (SB/ICH)  920 . The central processing unit (CPU)  930  is connected to NB/MCH  925 . The NB/MCH  925  also connects to the memory  945  via a memory bus, and connects to the graphics processor  950  via an accelerated graphics port (AGP). The NB/MCH  925  also connects to the SB/ICH  920  via an internal bus (e.g., a unified media interface or a direct media interface). The CPU  930  can include one or more processors and/or can be implemented using one or more heterogeneous processor systems. 
     For example,  FIG. 10  shows one implementation of CPU  930 . In one implementation, an instruction register  1038  retrieves instructions from a fast memory  1040 . At least part of these instructions are fetched from an instruction register  1038  by a control logic  1036  and interpreted according to the instruction set architecture of the CPU  930 , Part of the instructions can also be directed to a register  1032 . In one implementation the instructions are decoded according to a hardwired method, and in another implementation the instructions are decoded according to a microprogram that translates instructions into sets of CPU configuration signals that are applied sequentially over multiple clock pulses. 
     After fetching and decoding the instructions, the instructions are executed using an arithmetic logic unit (ALU)  1034  that loads values from the register  1032  and performs logical and mathematical operations on the loaded values according to the instructions. The results from these operations can be fed back into the register  1032  and/or stored in a fast memory  1040 . According to certain implementations, the instruction set architecture of the CPU  930  can use a reduced instruction set architecture, a complex instruction set architecture, a vector processor architecture, or a very large instruction word architecture. Furthermore, the CPU  930  can be based on the Von Neuman model or the Harvard model. The CPU  930  can be a digital signal processor, an FPGA, an ASIC, a PLA, a PLD, or a CPLD. Further, the CPU  930  can be an x86 processor by Intel or by AMD; an ARM processor; a Power architecture processor by, e.g., IBM; a SPARC architecture processor by Sun Microsystems or by Oracle; or other known CPU architectures. 
     Referring again to  FIG. 9 , the data processing system  900  can include the SB/ICH  920  being coupled through a system bus to an I/O bus, a read only memory (ROM)  956 , universal serial bus (USB) port  964 , a flash binary input/output system (BIOS)  968 , and a graphics controller  958 . PCI/PCIe devices can also be coupled to SB/ICH  920  through a PCI bus  962 . 
     The PCI devices can include, for example, Ethernet adapters, add-in cards, and PC cards for notebook computers. The Hard disk drive  960  and CD-ROM  966  can use, for example, an integrated drive electronics (IDE) or serial advanced technology attachment (SATA) interface. In one implementation the I/O bus can include a super I/O (SIO) device. 
     Further, the hard disk drive (HDD)  960  and optical drive  966  can also be coupled to the SB/ICH  920  through a system bus. In one implementation, a keyboard  970 , a mouse  972 , a parallel port  978 , and a serial port  976  can be connected to the system bus through the I/O bus. Other peripherals and devices can be connected to the SB/ICH  920  using a mass storage controller such as SATA or PATA, an Ethernet port, an ISA bus, a LPC bridge, SMBus, a DMA controller, and an. Audio Codec. In an embodiment, peripheral devices can be connected to processor  350  for downloading of stored data retrieved by the sleep-monitoring cap. 
     Moreover, the present disclosure is not limited to the specific circuit elements described herein, nor is the present disclosure limited to the specific sizing and classification of these elements. For example, the skilled artisan will appreciate that the circuitry described herein may be adapted based on changes on battery sizing and chemistry, or based on the requirements of the intended back-up load to be powered. 
     The functions and features described herein may also be executed by various distributed components of a system. For example, one or more processors may execute these system functions, wherein the processors are distributed across multiple components communicating in a network. For example, distributed performance of the processing functions can be realized using grid computing or cloud computing. Many modalities of remote and distributed computing can be referred to under the umbrella of cloud computing, including: software as a service, platform as a service, data as a service, and infrastructure as a service. Cloud computing generally refers to processing performed at centralized locations and accessible to multiple users who interact with the centralized processing locations through individual terminals. 
     Many advantages are provided by the sleep-monitoring cap having circuitry configured to monitor and detect a sleeping disorder, such as narcolepsy. An accurate detection of narcolepsy usually requires one or more days and nights at a sleep disorder facility, which can be expensive and time consuming. Embodiments described herein provide a portable inexpensive alternative outside of the sleep disorder facility. Sleep activity can be monitored in the home of the person, instead of a medical facility. Data retrieved by the processor  350  can be examined by medical personnel to determine a possible sleep disorder of the person using the sleep-monitoring cap. In particular, embodiments described herein can monitor and detect narcolepsy of the person using the sleep-monitoring cap. 
     Many advantages are also provided by the sleep-monitoring cap having circuitry configured to monitor and detect drowsiness of a user wearing the sleep-monitoring cap. Drowsiness affects many people in many different environments, such as while driving or operating equipment, while working at a task, and while listening to a speaker. Embodiments described herein can help keep the person wearing the sleep-monitoring cap away from danger, keep the person alert to perform a given task, and save the person embarrassment from falling asleep at a meeting or lecture, respectively. 
     Embodiments described herein for a sleep-monitoring cap transmit signals to a light-emitting device when brain wave activity, indicative of drowsiness is detected. This provides an indicator to others near to the person wearing the sleep-monitoring cap of his/her drowsiness. Embodiments also provide a sleep-monitoring cap to detect drowsiness in which the feedback is provided only to the person wearing the sleep-monitoring cap. The sleep-monitoring cap can be thin, so as to fit underneath a regular hat. This would conceal most or all of the sleep-monitoring cap from view by others. 
     The foregoing discussion discloses and describes merely exemplary embodiments of the present disclosure. As will be understood by those skilled in the art, the present disclosure may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the present disclosure is intended to be illustrative and not limiting thereof. The disclosure, including any readily discernible variants of the teachings herein, defines in part, the scope of the foregoing claim terminology.