Abstract:
This invention discloses an apparatus and method to affect brainwave entrainment by Very Low Frequency eXclusive-OR (XOR) modulation of a Very High Frequency carrier over a premise&#39;s power-line Alternating Current (AC) wiring. A microcontroller with stored program memory space is used to store and produce the waveforms that lead to brainwave entrainment by controlling an H-Bridge capable of generating bipolar square waves, which output is capacitive coupled to a premises AC power-line and a light sensing device is used by the microcontroller to determine whether to produce daytime or nighttime entrainment frequencies.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 61/298,851, filed Jan. 27, 2010. The foregoing application is herein incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to the field of using a microcontroller with stored program memory space to produce waveforms to control an H-Bridge, which is capacitive coupled to a premise&#39;s AC power-line wiring to emit a non-sensory electromagnetic signal to affect brainwave entrainment by Very Low Frequency eXclusive-OR (XOR) modulation of a Very High Frequency carrier signal. 
     BACKGROUND OF THE INVENTION 
     Brainwave entrainment occurs when observable and measureable brainwave activity follows the repetitious patterns of external stimulus. Sensory forms of entrainment, including visual stimulation as from a flickering candle or auditory stimulation as from a dripping faucet, can lead a person into a trancelike state. This state can often occur during highway driving, causing the common phenomena of “highway hypnoses.” Such trancelike states can be confirmed with electroencephalography (EEG) which monitors a subject&#39;s brainwave activity, where the brainwave activity mimics that of sleeping brainwaves. 
     It has been shown that human brainwaves have standardized patterns which are consistent from day to day. These patterns, or rhythms, are referred to as circadian rhythms when the patterns have a period of twenty-four hours before repeating. Periods or cycles with approximately ninety-minutes are referred to as ultradian rhythms. While the specific brain activity of any given ultradian rhythm can vary, the general patterns are consistent within the larger circadian rhythm. These ultradian rhythms have been widely studied for night cycles and have common names such as ‘Stage 1’, ‘Stage 2’, and ‘REM’ sleep. Similarly, there exist ultradian cycles for daytime cycles. Daytime ultradian rhythms are typically identified by measuring the core body temperature of a mammal, as ambulatory EEG monitoring is both expensive and invasive. Such daytime ultradian rhythms may be recognized intuitively as most people experience the typical mid-morning and mid-afternoon slumps in energy, as well as accompanying peaks in activity.  FIG. 1  shows a complete circadian rhythm with both day and night ultradian cycles. 
     Over time, however, the ultradian rhythms observed during sleep cycles tend to flatten out, resulting in poorer sleep. Furthermore, one can lose the natural rhythms of sleeping, waking, and living which produce a healthy and happy lifestyle. What is desired then is a way to emulate healthy brainwave activity in such a way as to cause entrainment, such that brainwave activity remains or returns to healthy levels. 
     There exists technology to perform brainwave entrainment; however these iterations fail in significant ways. For example, most iterations fail to provide a bi-polar based signal, fail to base these brainwave entrainments on natural therapeutic healing frequencies following natural circadian and ultradian rhythms, and fail to modulate the signals with a Pulse Width Modulation (PWM) using an eXclusive OR (XOR). Those iterations which do use bi-polar, XOR modulated natural healing frequencies, particularly those disclosed in U.S. patent application Ser. Nos. 11/307,348 and 11/949,717, lack the ability for one to receive the frequency stimulations necessary for brainwave entrainment unless one is within a very short distance of, or even touching, the entrainment apparatus. It is desirable then, to have a bi-polar, natural therapeutic frequency based circadian rhythm, XOR modulated brainwave entrainment device where one can receive the entrainment signals without being tethered to an apparatus, but rather can receive these signals while present at a given premises. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention disclosed and claimed herein addresses the above and other needs and provides means to achieve brainwave entrainment in mammals, including humans, within a premises using the AC power-line wiring. Rather than simply creating a trancelike state in the humans and animals within the premises, the present invention establishes a twenty-four hour circadian rhythm supportive of a mammal&#39;s internal circadian and subsequent ultradian rhythms for improved sleep and improved awake periods. A light sensitive photo-sensor is used to determine ambient light levels within the premises, which information is then transmitted to a microcontroller. The microcontroller, clocked by a quartz crystal with a fundamental resonance frequency very close to a Fibonacci number, then generates frequencies selected to induce brainwave entrainment either in support of natural sleep cycles during periods of relative darkness or in support of learning, expanded awareness and relaxation during periods of relative lightness. These frequencies, one significantly higher than the other, are then XOR modulated using an H-bridge. The output of the H-Bridge is then capacitive coupled to a premise&#39;s AC power-line. 
     The verified field of coverage includes a dwelling with 110 to 240 volts AC two-phase wiring in living and working spaces, with no single wiring run exceeding 100 meters from the apparatus&#39; connection to the power-line, and the overall load not exceeding 250 Amps for a single apparatus. Multiple apparatuses may be used for dwellings exceeding these limitations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a complete 24 hour Circadian Rhythm for humans. 
         FIGS. 2   a  and  2   b  show the typical prior art and result waveforms. 
         FIGS. 3   a  and  3   b  show the prior art with a PWM signal added. 
         FIG. 4  shows the new art for the invention of this instance. 
         FIG. 5  shows the preferred embodiment of the invention of this instance. 
         FIG. 6  shows an oscilloscope capture of an idle power-line. 
         FIG. 7  shows an oscilloscope capture of the detail of an idle power-line. 
         FIG. 8  shows an oscilloscope capture of an XOR modulated power-line. 
         FIG. 9  shows an oscilloscope capture of the detail of an XOR modulated power-line. 
         FIG. 10  shows an oscilloscope capture of more detail of an XOR modulated power-line. 
         FIG. 11  shows software flowchart for the microcontroller&#39;s stored program. 
     
    
    
     DETAILED DESCRIPTION 
     The invention of this instance is designed to induce brainwave entrainment following the twenty-four hour daily Circadian Rhythm as depicted in  FIG. 1 . The Light  47  and Dark  46  and  46   a  legend at the top of the figure indicate the relative light and dark periods of the daily cycle, where non-nocturnal mammals are awake during the light  47  periods and asleep during the dark  46  and  46   a  periods. Sleep Stages  41  and Awake Ranges of brainwave activity  42  are shown on the left side of the figure. These stages  41  and ranges  42  relate to relative brainwave frequencies in the range of 1 Hz to 55 Hz as observed in EEG monitoring. An hourly scale  45  is depicted across the bottom of the figure starting at 22:00 hours (10 PM on the left and running for twenty-four hours ending at 22:00 hours the next day on the right. Period  41   a  shows the classical circadian rhythms of sleeping, which are correctly termed ultradian rhythms of sleep. Period  42   a  shows the inventors observed daytime ultradian rhythms with their respective period names.  43  represents the brainwave ranges during sleep and  44  represents the brainwave activity when awake for non-nocturnal mammals. 
     The present invention induces brainwave entrainment by modulating a Very High Frequency (VHF) carrier signal that is injected over a premise&#39;s AC power-line wiring and XOR modulating it with a Very Low Frequency (VLF) square wave following the observed and plotted brainwave frequencies of 1 to 55 Hz depicted in  FIG. 1 . Additionally, the present invention may also use higher frequency harmonics in the range of 55 Hz to 5,000 Hz of the lower frequency brainwaves in order to extend the effective range of the emitted signals over the power-line. 
     Existing apparatuses and methods rely upon methods different than the present invention&#39;s to modulate a carrier wave over a premise&#39;s power-lines. In all cases where a carrier signal is modulated in the related art the modulated signal is logically AND&#39;d with the higher frequency carrier signal.  FIGS. 2   a  and  3   a  represents the prevalent prior art of all such devices using what is commonly called in this field as a Power-Line Communication (PLC) interface. As shown in  FIG. 2   a  typical PLC  220  consists of a line matching transformer  208  and non-polarized high voltage capacitors  211   a  and  211   b  to connect one side of the transformer  208  to the premise&#39;s AC power-line  209 . The lower frequency modulating input  203  or  203   a  is logically AND&#39;d with the VHF carrier signal input ( 202  or  202   a ) to cause current to flow from +V  200  through transistors  204  and  206  or MOSFETs  205  and  207 .  FIG. 2   b  shows the resultant waveforms created across load  208  of the line matching transformer, illustrating the logical AND function.  FIG. 3   a  illustrates the same type of PLC  320  being driven by a different transistor  304  and  306  or MOSFET  305  and  307  arrangement, and still using a logical AND function as shown in the resulting waveforms in  FIG. 3   b.    
     Premises power-line specific carrier wave frequencies XOR modulated with lower frequencies make it possible to induce brainwave entrainment in all mammals within the premises using the present invention as shown in  FIGS. 4   a ,  4   b  and  5 . The use of the high current capable MOSFET H-Bridge  413  (comprised of MOSFETs  404 ,  405 ,  406  and  407  shown within the dashed line) and correctly selected capacitances for line coupling capacitors  411   a  and  411   b  based upon the carrier frequency allow the line matching transformer (not required in this invention) which is commonly used in PLCs to be removed. Inductor  412  is added to the ground connection of the H-Bridge to reduce transients occurring on the AC power-line  409 . All four of the MOSFETs are protected with reverse bias diodes across their respective source and drain connections as shown in  FIG. 4 . The H-Bridge  413  is connected to the +V DC power source  400  and through inductor  412  to ground potential  401 . Input  402  is connects to the VHF PWM carrier signal  420  and input  403  connects to the VLF modulating signal  410 .  408  represents the effective load across the bipolar output of H-Bridge  413 .  FIG. 4   b  shows the resultant unique wave forms produced using this XOR modulation and H-Bridge line driving technique.  410  is the square wave modulating signal that feeds input  403  of H-Bridge  413 .  410  is generally a 50% duty cycle square wave at the desired frequency intended to cause brainwave entrainment and is generally between 1 Hz and 5,000 Hz. While monitored brainwave frequencies tend not to exceed 50 Hz, this apparatus supports higher resonant multiples of the brainwave frequencies between 1 and 50 Hz to support a greater range of distance between the subject mammals and the emitting premises power-line wiring.  420  is the variable duty cycle PWM square wave carrier signal and is selected to be high enough in frequency, generally between 500 KHz and 2.4 MHz, to overcome the effective of inductive loading on the premise&#39;s power-lines, and to support the capacitive coupling to the power-line.  430  is the resulting bipolar XOR modulated square wave observed across load  408 . 
     The apparatus of the present invention is depicted schematically in  FIG. 5 . AC Line  1  represents the connection between the apparatus and the premises power-line. This connection  1  provides both the source power for the apparatus&#39; AC to DC power supply  2  and the connection point to apparatus&#39; line coupling capacitors  3  and  4 . Power Supply  2  provides a stepped-down and regulated direct current power source for the MOSFET H-Bridge  10  and for Voltage Regulator  6  which is used to further reduce the direct current voltage to meet the operating requirements of Microcontroller  7 . Inductor  5  connected between the negative output of Power Supply  2  and the apparatus&#39; ground reduces the transients that may appear across AC Line  1  and reduces the affect of these transients on the entire apparatus. Line coupling capacitors  3  and  4  are non-polarized capacitors with a working voltage of at least two times the AC line  1  voltage. Photocell  12  provides ambient lighting information by changing the voltage that appears on Analog to Digital Conversion (ADC) Input  13  through Bias Resistor  14 . LED indicator  15  provides a simple operation indication. Fibonacci Number Quartz Crystal  11  provides the precision timing for operating Microcontroller  7 . Microcontroller  7  has stored program capabilities along with the ability to produce a VHF PWM square wave signal  8  that is XOR&#39;d with a lower frequency modulation square wave signal  9 . 
     Microcontroller  7  must be capable of generating a precision Very High Frequency carrier square wave generated as a duty cycle variable Pulse Width Modulation signal  8  in the range of 500 Kilohertz to at least 2.4 Megahertz, which is output to one input of the MOSFET H-Bridge  10  shared gates. The duty cycle must be variable to support variations in the VHF carrier and line coupling capacitors to reduce the load across the H-Bridge output. Higher duty cycles also may be needed to extend the range of the emitted entrainment signals. Microcontroller  7  must also be capable of generating a precise very low frequency modulation signal  9  as a constant 50% duty cycle square wave in the range of 1 Hertz to 5,000 Hertz, which is output to the other shared gated input of the MOSFET H-Bridge  10 . 
     The two outputs of the MOSFET H-Bridge line driver  10  are capacitive coupled to the AC Power-Line source  1  using a preferred value of 10,000 picofarads 1,000 Volt capacitors  3  and  4 . The values of the line coupling capacitors  3  and  4  are selected to provide a large resistance to the 50 to 60 Hertz AC component frequency, while simultaneously presenting a low resistance to the 500 Kilohertz to 2.4 Megahertz carrier frequency. Values for capacitors  3  and  4  may fall between 1,000 picofarads to 470,000 picofarads and should be rated for a working voltage of at least two times the AC line  1  voltage. The formula for determining the relative resistive impedance, or reactance of capacitors  3  and  4  is 1/(2piFC) where F is Frequency in Hertz and C is Capacitance in Farads. Thus, for a capacitance of 10,000 picofarads the reactive impedance at 2,000,000 Hz is 7.958 ohms and at 60 Hz it is 265,258 ohms. 
     The preferred frequency of Fibonacci Crystal  11  used to provide the timing element for Microcontroller  7  is 24 Megahertz as it within one percent (1%) of a Fibonacci Number and sufficiently high enough to provide the effective clocking frequency for Microcontroller  7  to enable it to generate the required VHF carrier PWM signal. The inventors have found that all apparatuses used to generate electrical signals designed to interact with living, organic systems should use only quartz crystals whose fundamental frequency is as close as practically possible with modern manufacturing techniques to a natural Fibonacci number, typically within one percent. 24 Megahertz is such a frequency, being less than one percent from 24,157,817 which is a Fibonacci number. 
     Power Supply  2  provides power to the apparatus by converting the incoming 240 VAC to 110 VAC 50 Hz to 60 Hz line power to a regulated DC voltage in the range of five to twenty-four volts and is capable of maintaining regulation within ten percent of the desired DC voltage at a minimum of 0.5 Amps of DC current. 
     Photocell  12  is connected to Microcontroller  7  using an analog to digital converting (ADC) capable input  13  and is used to determine ambient light levels within the premises, such ambient light levels being used to affect the stored program causing it to generate either daytime or nighttime ultradian signals when the premises are respectively light or dark. Bias Resistor  14  provides a positive voltage reference for ADC input  13 . 
     In the preferred embodiment a 12 VDC switching type power supply  2  is used to step-down the 240 VAC to 110 VAC 50 Hz to 60 Hz alternating current source to 12 volts direct current for the apparatus&#39; power supply. The 12 VDC is used to power the high current capable MOSFET H-Bridge line driver  10  and is further reduced by a low dropout (LDO) power regulator  6  which provides a regulated 3.3 VDC to Microcontroller  7 . Light Emitting Diode (LED)  15  is connected to an output port  17  on Microcontroller  7  capable of directly driving LED  15 . A series resistor (not shown) may be used to reduce the current to LED  15  to prevent it from being damaged and to protect output port  17  from too much current being drained or sourced. 
     Injecting low frequencies over premises AC power-lines is problematic due to both the 60 Hertz (Hz, or cycles per second frequency) nature of alternating current (or 50 Hz in other areas of the world) and varying inductive and resistive loads present on the power-lines. Most AC line modulation schemes have been adopted for either carrying audio (as in power-line intercom or telephone extensions) or data (as in HPNA or X10) from a transmitting source to a receiving station, or even a transceiver application. While the apparatus and methods presented in this invention may be applied to these applications, the primary application of the present invention is to cause brainwave entrainment in mammals within homes and other buildings. It is critical whenever imposing a carrier wave on a premise&#39;s AC power-line wiring that such injected signals do not interfere with the operation of equipment or appliances connected to the same AC power-line.  FIG. 6  is an oscilloscope capture of a typical US 120 VAC 60 Hz power-line sine wave  60  without the apparatus of the present invention attached to the line.  FIG. 7  is a detailed 2 microsecond portion  70  of the same power-line as shown in  FIG. 6 , again without the present invention attached to the line. These two  FIGS. 6 and 7 , establish the baseline images of a typical premise&#39;s AC power-line waveforms. 
       FIG. 8  shows the same premise&#39;s AC power-line waveform  80  with the apparatus of the present invention attached to the power-line and actively producing a 2,000,000 Hz carrier signal that is XOR modulated with a 440 Hz square wave. There is no noticeable disruption of the baseline AC power-line waveform  60  as seen in  80 . Subsequent monitoring and testing of typical appliances and AC powered devices in the premises, including digital televisions, analog televisions, desktop and laptop personal computers, ranges, refrigerators, air conditioners and the like showed no observable or measurable affects to these by the present invention being actively connected to the power-line. 
       FIG. 9  details a 2 microsecond portion  90  of the same power-line waveform with the apparatus of the present invention actively connected to the power-line. Modulation of the power-line can be seen within this segment  90  in the range of about twelve volts.  FIG. 10  is the same 2 microsecond detailed segment  90  of the power-line waveform with the voltage per division of the oscilloscope reduced from 50 volts to 5 volts. Definite modulation of the AC power-line  100  can be seen in the range of twelve volts. This range of modulation will vary based upon loading of the AC power-line. 
     As further evidence of the modulation, the carrier frequency was reduced from 2,000,000 Hz to 1,500,000 Hz which is in the receiving range of Amplitude Modulated (AM) radio receivers. The apparatus of the present invention was connected to the power-line wiring and activated with a 440 Hz XOR modulated square wave and an AM radio was tuned to 1,500,000 Hz and the AM radio audibly demodulated the 440 Hz square wave as heard over its speaker. The AM radio was then used to validate the existence of the modulated carrier waver throughout the premises. Similar AM radio receivers were subsequently used to validate the effective range of the apparatus both inside and outside the premises, and it was discovered the effective radio frequency range of the apparatus was limited to the premises itself and a 2 meter perimeter outside the physical premises. No indication was found of any back-feeding of the signal into neighboring premises. 
     As evidence of the achievement of brainwave entrainment, the apparatus of the present invention was installed in a home on its AC power-line wiring in an area away from the sleeping quarters. Persons in the home used an ambulatory EEG sleep monitoring system to record their sleep patterns and these were compared to the timing and signals produced by the present invention and it was found that the recorded brainwave signals followed the apparatus&#39; generated XOR modulated nighttime signals. Subsequent sleep monitoring without the present invention active showed irregular sleep patterns, confirming the present invention did induce brainwave entrainment. 
       FIG. 11  is the software flowchart for the stored program in Microcontroller  7 . The software starts at step  20  and upon initialization  21  the firmware verifies the hardware is operational by validating internal and external signals and then measures the ambient light levels at  22  on ADC input  13 . If ADC input  13  is within the daytime light levels control passes to step  23  and the daytime program steps are loaded. If the ADC input  13  is within nighttime light levels control passes to step  24  and the nighttime program steps are loaded. Both steps  23  and  24  pass control to step  25  where a programmatic step duration timer is started. Control passes to step  26  and the PWM Carrier signal is turned on at the normal duty cycle. Duty cycles of the PWM will change based upon the state of the lower frequency modulation signal to maintain a consistent ‘On’ time for the H-Bridge if a duty cycle other than 50% is used. Selection of the duty cycle is tied to the selection of the line coupling capacitor values and driving capabilities of the specific H-Bridge. A longer duty cycle requires a higher driving capability and a lower capacitance to avoid damaging the H-Bridge or creating unwanted signals on the AC power-line. 
     At step  27  a second timer is started based upon the frequency of modulated lower frequency and the modulated lower frequency is set to a logical one (1). Control is passed to step  28  and the processor waits for an interrupt. At step  29  the processor determines which interrupts occurred. If the step timer completed, which is typically in the range of 1 to 5 minutes control is passed to step  34 . If the VLF modulation frequency timer expired control is passed to step  30 . At step  30  the VLF modulated frequency timer the interrupt is reset and the VLF output is toggled from either a 1 to 0 or a zero to a 1, depending upon its current state. Step  31  determines the new state of the VLF output and If the VLF output is now a 0 control is passed to step  33  and the duty cycle of the PWM output is inverted. If the VLF output is now a 1 control is passed to step  32  and the PWM duty cycle is retuned to its normal value. Both steps  32  and  33  resume operation waiting for an interrupt at step  28 . 
     If step  29  determined the interrupt is the step timer, the software passes control to step  34  and the processor determines if this step is completed. If not then the step timer is reset and control is passed to step  28  to wait for another interrupt. If the step is done control passes to step  35  and the ADC input level is checked to see if there was a change in ambient light levels from the previous check. If there was a change the software restarts by going to Start at step  20  to confirm the light change and load the appropriate daytime or nighttime program. If there was no change the control is passed to step  36  and the software checks if this is the last frequency, or step, for this program. If it is the last step then the software returns to the start  20 . If it is not the last step then control is passed to step  38  to load the next step then step  39  sets its timer and the program resumes waiting on an interrupt at step  28 . 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Definition List 1 
               
             
          
           
               
                   
                 Term 
                 Definition 
               
               
                   
                   
               
               
                   
                 AC 
                 Alternating Current 
               
               
                   
                 ADC 
                 Analog to Digital Converter 
               
               
                   
                 AM 
                 Amplitude Modulated 
               
               
                   
                 DC 
                 Direct Current 
               
               
                   
                 EEG 
                 Electroencephalography 
               
               
                   
                 HPNA 
                 Home Power-line Network Access 
               
               
                   
                 Hz 
                 Hertz—Cycles Per Second 
               
               
                   
                 LED 
                 Light Emitting Diode 
               
               
                   
                 MOSFET 
                 Metal Oxide Substrate Field Effect 
               
               
                   
                   
                 Transistor 
               
               
                   
                 PLC 
                 Power-line Communication 
               
               
                   
                 PWM 
                 Pulse Width Modulation 
               
               
                   
                 VHF 
                 Very High Frequency (above 100,000 Hz) 
               
               
                   
                 VLF 
                 Very Low Frequency (below 10,000 Hz) 
               
               
                   
                 XOR 
                 eXclusive OR logical function