Abstract:
A subject is connected to a monitoring system and videoed while being monitored. The monitoring system receives raw data from the subject and processes the raw data into waveform data, and transmits the waveform data to a marking device. The marking device simultaneously marks the waveform data with a waveform reference point and causes a light emitting diode to flash in the video, thereby creating a video reference point. A computer program locks the waveform reference point with the video reference point and thereby synchronizes the waveform data with the video.

Description:
FIELD OF THE INVENTION 
     The current invention relates to a system for synchronizing waveform data associated with a subject, and a video of the subject filmed while the waveform data is generated. Specifically, the invention relates to synchronizing an electrical penetration graph (EPG) of a feeding insect with a corresponding video recording of the insect taken during the EPG process. 
     BACKGROUND OF THE INVENTION 
     As generally indicated above, the current invention is addressed to a method and apparatus for synchronizing waveform data and an associated video. Although the method and apparatus are generally directed to the evaluation of insect behavior, the technology has multiple other applications associated with the evaluation of other processes and/or organisms, including human subjects. For example, the current invention could be used to synchronize a video of an individual taking a polygraph examination with the actual polygraph readout. The technology described in the current invention may also be used in conjunction with other biological/biomedical time-based evaluations such as electrocardiograms (EKGs) and other medical monitoring technologies. 
     The current invention was designed to monitor the feeding process of the glassy-winged sharpshooter ( Homalodisca vitripennis ). The insect spreads the bacterium associated with Pierce&#39;s disease ( Xylella fastidiosa ), which is responsible for millions of dollars in damage to California&#39;s grape vineyards as well as other commercial crops (on Sep. 26, 2008, photos of the glassy-winged sharpshooter were available at: http://danr.ucop.edu/news/MediaKit/photos/default.shtml). 
     Sharpshooters acquire the  Xylella fastidiosa  bacterium from infected plants and transmit it to healthy plants. After adult sharpshooters acquire the bacteria, it remains in the insect&#39;s mouthparts throughout the insect&#39;s life. Researchers (including the inventors) are attempting to combat Pierce&#39;s disease by better understanding how glassy-winged sharpshooters carry and spread the disease. 
     One means of studying the transmission of the disease is through an understanding of the way the insects feed. Electrical penetration graph (EPG) technology provides information regarding the way that the insect draws its fluid food from plants. The EPG process is initiated by attaching a gold wire to the body of a sharpshooter and placing the sharpshooter in a feeding position on the leaf of a host plant. A plant electrode is then placed in the soil adjacent to the plant or attached directly to a part of the plant. A lead wire from the plant electrode and the gold wire attached to the insect are then connected to a monitoring system. 
     When the stylets (the probing and penetrating mouth parts of the insect) connect with the host plant, an electrical circuit is completed. As the insect&#39;s stylets probe the host plant, the voltage in the circuit fluctuates. Researchers have been able to correlate the voltage fluctuations with certain feeding activities to better understand the biological mechanisms that facilitate the spread of the  Xylella fastidiosa  bacteria. 
     An analog-to-digital converter in the system controller converts the analog EPG voltage waveforms to a digital signal at a selectable sampling rate generally set at 100 samples per second. The digitized EPG voltage waveforms are displayed on a time-based chart that is similar in many ways to a human EKG chart. Concurrent with the EPG process, researchers also make a video recording of the insect as it feeds on the host plant. However, the prior art includes no means of precisely synchronizing the video recording of the insect with the concurrent EPG reading. 
     At least one researcher has attempted to synchronize the insect video with the EPG readout by creating a “master” video that includes both the EPG readout and the insect video within the same camera frame. Specifically, the researcher created a video that (within the same camera frame) included a video of the feeding insect concurrent with a computer monitor displaying the EPG readout that was generated as the insect was feeding. 
     However, this process was generally unsatisfactory because (among other things), the master video was essentially a video of a video and a computer monitor. Consequently the resolution of the master video was less than desired. For the information to be useful, an operator should be able to read the fine gradations on the EPG printout and the synchronization of the video and EPG data must be more precise than this method afforded. As indicated above, the EPG waveform signal is generally digitized at 100 samples per second, while standard video is displayed at 30 frames per second. 
     The need exists for a synchronizing system which provides a means of establishing a precisely synchronous playback of the video of the feeding insect with time-based waveform data produced by the EPG instrument. The current invention provides a reliable means of ensuring that the video and the waveform data can be accurately synchronized. 
     SUMMARY OF THE INVENTION 
     The current invention is directed to a system for synchronizing waveform data associated with a subject, and a video of the subject recorded while the waveform data is generated. The current invention includes a monitoring system that receives raw data from the subject, processes the raw data into waveform data, and transmits the waveform data. The current invention also includes a video camera and video recorder. The video camera videos the subject while the subject generates the waveform data. The video recorder records the video taken by the video camera. A marking device receives the waveform data from the monitoring system and creates a waveform reference point. Simultaneously, the marking device flashes a light emitting diode (LED) in the same camera frame with the subject, thereby creating a video reference point. The video and video reference point, along with the waveform data and the waveform reference point, are then directed to a controller. Installed on the controller is a computer program. The computer program includes a means to synchronize the waveform reference point with the video reference point. 
     In operation, an operator synchronizes the waveform data with the video by directing the computer program to synchronize the waveform reference point with the video reference point, thereby synchronizing the video with the waveform data. 
     The current invention is also directed to a waveform data and video marking device. The marking device is primarily comprised of an integrated circuit assembly, a marker switch assembly, and a waveform marker assembly. The integrated circuit assembly generates a pulse train and transmits the pulses through the marker switch assembly to the waveform marker assembly. Each of the pulses has a high portion and a low portion. An LED connected to the marker switch assembly flashes “on” when the marker switch assembly receives the high portion of a pulse. The LED is positioned in the same camera frame as the subject being videoed. 
     The waveform marker assembly is connected to the marker switch assembly. The waveform marker assembly transmits waveform output data associated with the subject being videoed. The waveform output data spikes downwardly when the waveform marker assembly senses a drop in voltage associated with the LED flash. 
     In operation, the marking device creates a video reference point when the LED flashes “on”, and simultaneously creates a waveform reference point when the waveform output data spikes downwardly. The marking device of the current invention thereby enables an operator to synchronize the waveform data with the video by synchronizing the waveform reference point with the video reference point. 
     The current invention is further directed to a method for synchronizing waveform data associated with a subject, and a video of the subject recorded during the waveform data generation. In accordance with the method of the current invention, an operator first starts the video recording process and initiates the electronic monitoring process. The results of the monitoring process are expressed as waveform data and the waveform data is transmitted to a marking device. The operator initiates the synchronization process by depressing a start button on the marking device. Depressing the start button causes an LED to flash “on” in the video, and the waveform output data to spike downwardly. When the operator releases the start button, the LED is extinguished and the waveform data is returned to an unaffected state. The monitoring and videoing process then continues until the operator terminates the process. 
     At the end of the process, a waveform data file is created. The waveform data file contains a compilation of the waveform data generated by the monitoring process. A video recording is also created. The video recording contains the results of the video recording process. After the process is terminated, an operator scrolls through the waveform data file and identifies and marks the first downward spike in the waveform data. The first downward spike is designated the waveform reference point. The operator also scrolls through the video recording and finds the first flash of the LED. The first flash of the LED in the video is designated as the video reference point. The operator then loads the waveform reference point and the video reference point into a computer program and instructs the computer program to synchronize the waveform reference point with the video reference point so that the waveform file is locked with the video file, thereby completing the synchronization process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an exemplary embodiment of the current invention. 
         FIG. 2  is a block diagram of the marking device shown in  FIG. 1 . 
         FIG. 3  is a circuit diagram of the marking device shown in  FIGS. 1 and 2 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present invention comprises a method and apparatus for synchronizing a video recording with waveform data. A block diagram of the invention is generally shown in  FIG. 1 . 
     As indicated supra, one means of combating the transmission of Pierce&#39;s disease is through an understanding of the way that glassy-winged sharpshooter insects feed. Electrical penetration graph (EPG) technology provides information regarding the way that the insects draw moisture and nutrients from plants. 
     As shown in  FIG. 1 , the EPG process is initiated by attaching a gold wire  20  to the body of a sharpshooter  22  and placing the sharpshooter  22  in a feeding position on a host plant  24 . A plant electrode  26  is then attached to the plant  24  or placed in the soil adjacent to the plant  24 . A lead wire  21  from the plant electrode  26  and the gold wire  20  attached to the insect  22  are then connected to an EPG monitoring system  28 . 
     When the stylets of the insect  22  make contact with the host plant  24 , an electrical circuit is completed. As the insect&#39;s stylets probe the host plant  24 , the voltage in the circuit fluctuates. The voltage fluctuations are processed into waveform data by the EPG monitor  28 . A portion of the transmission from the EPG monitor  28  is routed through a marking device  30  to a central processing unit (CPU) which functions as a controller  50 . A portion of the signal from the EPG monitor  28  is also routed directly to the controller  50 . The controller  50  samples the analog voltage fluctuations at a selectable rate of 100 samples per second, thereby creating a digitized waveform file. As shown in  FIG. 1 , the digitized waveform  29  is displayed on a data monitor  52  in a time-based format or printed out as a time-based chart. 
     Concurrent with the EPG process, researchers also make a video recording of the insect&#39;s  22  feeding behavior. The video is taken by a video camera  54  and recorded by a video recorder  56 . The video signal is sent to the controller  50  and displayed on a video monitor  58 . For the sake of simplicity, a video monitor  58  and a data monitor  52  are depicted separately in  FIG. 1 . However, it should be understood that both the insect video and the digitized waveform can be displayed in a split screen format on a single monitor. Although the video and the waveform data can be displayed together, the prior art provides no means of precisely synchronizing the video with the waveform data. The current invention provides a method and apparatus for precisely synchronizing the video with the time-based waveform data. 
     As further shown in  FIG. 1 , the signal from the EPG monitor  28  is directed to the marking device  30 . A light emitting diode (LED)  32  is also connected to the marking device  30 . The LED  32  is positioned within the same camera frame as the insect  22  so that the video camera  54  image of the insect  22  includes the LED  32 . 
     In operation, the synchronization process is initiated when an operator depresses a marking device start button  34  or other control mechanism on (or connected to) the marking device  30 . When the start button  34  is depressed, the marking device  30  causes the LED  32  to flash rhythmically and simultaneously induces a pre-set spiking pattern  33  in the waveform data  29 . An operator may depress the marking device start button  34  if the recording is started and stopped, or at any time during a data recording session. 
     At the conclusion of a data and video recording session, an operator scrolls back through the video to the first video frame that evidences a flash of the LED light  32 . The operator then “marks” that frame as the video reference point. The operator also scrolls back through the waveform data  29  to the first marking device-induced downwardly spike  51  in the waveform data  29 . The operator “marks” this point  51  in the waveform data  29  as the waveform reference point. 
     After the reference points have been marked, the operator loads the reference points into a commercially available software program called The Observer XT™ manufactured and sold by Noldus Information Technology (see http://www.noldus.com/site/doc200401012 for a description of The Observer XT™, as viewed Sep. 26, 2008). The Observer XT™ program also prompts the operator for the samples per second taken by the waveform data digitizer and the frames per second recorded by the digital video recorder. When the user instructs the program to synchronize the data, the software performs the function and the waveform data is precisely synchronized with the video. 
       FIGS. 2 and 3  depict a block diagram and a circuit diagram (respectively) of the marking device  30  disclosed in  FIG. 1 . As shown in  FIGS. 2 and 3 , the marking device  30  is comprised primarily of an integrated circuit assembly  36 , a marker switch assembly  38  and a waveform marker assembly  40 , and powered by a conventional 12 volt power supply  31 . Note that in  FIG. 3 , the single digit numbers associated with the integrated circuit assembly  36  and the waveform marker assembly  40  denotes the respective pins associated with the input/output of electrical current to/from devices in the respective assemblies  36 ,  40 . 
     As shown in  FIG. 3 , in the preferred embodiment, the integrated circuit assembly  36  includes an LM555 timer integrated circuit chip  35  configured as an astable oscillator. In alternative embodiments, the integrated circuit may be comprised of any electrical component consistent with the function as described herein. 
     When the marking device starter button  34  (also labeled as SW 1  in the  FIG. 3  circuit diagram) is depressed, the integrated circuit chip  35  outputs a pulse train from pin  3  to the marker switch assembly  38 . The combined values of R 1 , R 2  and R 3  plus the capacitance of C 1  determines the pulse frequency. As shown in  FIG. 3 , in the preferred embodiment, the respective resistance values for R 1 , R 2 , and R 3  are 100 kΩ, 1MΩ, and 1MΩ respectively, and the capacitance of C 1  is 0.1 μF, which results in an operating frequency of between 7 Hz and 3.5 Hz. The frequency can be adjusted by varying the resistance of R 3 . 
     As best shown in  FIG. 3 , the integrated circuit pulse is transmitted to the marker switch assembly  38 . The marker switch assembly  38  is primarily comprised of a high-power metal-oxide-semiconductor field-effect transistor (MOSFET)  39  (also labeled Q 1  in the  FIG. 3  circuit diagram). When the MOSFET  39  receives the high portion of a current pulse from the integrated circuit assembly  36 , it places the MOSFET  39  in conduction. When the MOSFET  39  is in conduction, current flows through the MOSFET  39  and the LED  32  is illuminated (i.e. the LED is flashed “on”). The low portion of the pulse turns the MOSFET  39  off so that the LED  32  is flashed “off”. 
     In the preferred embodiment, the MOSFET  39  is a 2N7000-type component. In alternative embodiments, the marker switch assembly  38  may be comprised of any electrical component or combination thereof consistent with the function as described herein. 
     In addition to flashing the LED  32 , the marking device  30  also affects the output waveform data. As shown in  FIGS. 2 and 3 , during most of the monitoring process, the waveform signal is essentially unaffected as the signal passes from the EPG monitor  28  through the waveform marker  40  to the controller  50 . During this period the input voltage of the waveform marker assembly  40  operational amplifier  41  (at pin  8 ) is essentially a constant 12 volts. 
     However, as best shown in  FIG. 3 , when the high portion of the current pulse from the integrated circuit  41  places the MOSFET  39  in conductance, current passes through the LED  32  and correspondingly the voltage at R 6 , R 7 , and pin  8  of the operational amplifier  41  spikes downwardly. 
     When the amplifier  41  senses a voltage drop (at pin  8 ), it causes the voltage output of the amplifier  41  at pin  6  to also spike downwardly, thereby causing a corresponding downwardly spike  51  in the waveform output data (see  FIG. 1 ). When the LED flashes off, the voltage of the amplifier  41  (at pin  8 ) returns to its pre-spike level and the waveform output data (at pin  6 ) also returns to its pre-spike form. The alternating high and low portions of the pulse train issued by the integrated circuit chip  41  cause the LED  32  to flash on and off and the waveform output data  29  to simultaneously spike downwardly  51  and then pop back up to its normal pre-spike level in a rhythmic spiking pattern  33  (see  FIG. 1 ). 
     In the preferred embodiment, the operational amplifier  41  is a CA3140-type component. However, in alternative embodiments, the amplifier  41  may be comprised of any electrical component or combination thereof consistent with the function as described herein. Similarly, in the preferred embodiment, the resistance at R 6  and R 7  is 4.99 kΩ and 5 kΩ respectively. Adjusting the resistance of R 7  modifies the extent of the downwardly voltage spike seen at pin  8  of the amplifier  41 . 
     In operation, the synchronization process is initiated when an operator depresses a marking device start button  34  or other control mechanism on (or connected to) the marking device  30 . As best shown in  FIG. 3 , depressing the start button  34  closes a circuit in the marking device integrated circuit assembly  36 , resulting in a current pulse from the integrated circuit chip  35 . The current pulse is directed to the marker switch assembly  38 . When marker switch assembly  38  receives the current pulse, the high portion of the pulse places a MOSFET  39  in the marker switch assembly  38  in conductance. When the MOSFET  39  is in conductance, current flows through the LED  32 , causing the LED  32  to flash “on”. The LED is visible in a video camera frame along with the feeding insect. 
     When the LED flashes “on”, pin  8  of an operational amplifier  41  in the waveform marker assembly  40  senses a voltage drop. Consequently the output waveform data (at pin  6 ) spikes downwardly so that when the LED  32  flashes “on”, the output waveform data spikes downwardly. 
     As indicated above, at the conclusion of a data and video recording session, the operator opens the data and video files in The Observer software program, then reverses the video to the first video frame that evidences a flash of the LED  32 . The operator then “marks” that frame as a video reference data point. The operator also scrolls back through the waveform data to the first waveform spike and “marks” that point as a waveform reference point. After the reference points have been marked, the operator uses the functions of The Observer™ computer program to synchronize the marked data point on the video with the marked data point on the EPG readout. 
     Once The Observer™ has synchronized the video and the wave form data, the two files are essentially “locked” together and the synchronization process is complete. The data is then configured to be further analyzed by scientists and/or other evaluators. 
     For the foregoing reasons, it is clear that the invention provides an innovative method and apparatus for synchronizing a video with simultaneously recorded waveform data. The current invention may be modified and customized as required by a specific operation or application, and the individual components may be modified and defined, as required, to achieve the desired result. For example, although the invention was originally intended to monitor a feeding insect, the invention may be modified to monitor any subject, including human subjects. In further embodiments, the invention may be applied to any endeavor that involves a data generating process that is simultaneously videoed. In these further alternative embodiments, the subject of the evaluation may be an electrical or mechanical process so that no living organisms are involved. 
     Although the materials of construction are not described, they may include a variety of compositions consistent with the function of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.