Abstract:
A method of simultaneously presenting current and stored ECG waveform data on a portable, external defibrillator during a rescue. The stored ECG waveform data may also be used in a rescue or training exercise.

Description:
PRIORITY CLAIM TO PROVISIONAL APPLICATION 
       [0001]    This application claims priority to provisional patent application entitled, “Defibrillator with Video Status Screen in Standby Mode” filed on Mar. 21, 2005 and assigned U.S. Application Ser. No. 60/663,908. The entire contents of the provisional patent application mentioned above are hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention is generally directed to portable cardiac defibrillation systems with video displays, and relates more particularly to the use of video displays for supplying rapid standby status of a portable defibrillator through single-button activation while the defibrillator is in a non-operative state. 
       BACKGROUND OF THE INVENTION 
       [0003]    Automatic external defibrillators (AEDs) are usually portable defibrillators that are designed to be operated by users with minimal training. AEDs are attached to a patient via electrode pads that allow an AED to send electrical shock energy to a patient for treating sudden cardiac arrest (SCA). Because AEDs can be used by non-medical personnel, they are being deployed in a myriad of locations outside of traditional medical settings. As a result, more and more non-medical establishments are purchasing portable AEDs for deployment in non-medical environments. To facilitate this deployment in various non-medical environments, portable AEDs are typically only powered by stand alone battery systems. 
         [0004]    AEDs are usually standby devices that are used infrequently and that remain in storage for long periods of time. This standby storage time can be on the order of months or even years. Minimizing power consumed by the AED while it is in standby mode during storage may extend the battery life of the system and reserve battery power for rescue attempts using the AED. 
         [0005]    Since AEDs are in standby mode for long periods of time, knowing the operational status of a standby AED is very important. The operational status of an AED can be determined by various internal self tests. These tests may cover general operations, battery life, memories, software, etc. The results of these tests can be communicated to a user via simple interfaces, such as light emitting diodes (LEDs), or via richer interfaces, such as video displays. 
         [0006]    The operation of rich user interfaces, such as video displays, generally requires additional processing power from the main processor of the AED. However, fully powering up the entire AED device may unnecessarily consume significant electrical power relative to the shelf life of a portable AED. In addition to the problem of fully powering up the entire AED device, another problem exists with conventional AEDs that display status information only during the full power up of the AED. 
         [0007]    Many conventional AEDs only provide status information prior to a rescue operation when the AED conducts self tests of its hardware, firmware, or software or any combination thereof. Conventional AEDs can also require a user to navigate through multiple menus in order to obtain status information about the AED. 
         [0008]    For example, to obtain status information of conventional AEDs, a user usually must wait while the AED conducts internal self-tests prior to the AED being placed in a fully operational state. Once these internal self-tests are completed, the user usually must navigate through several menus on the AED in order to view status information. And if the user only desired status information of the AED without the need of powering up the AED into its fully operational state, then the user would also need to activate a switch on the AED in order to place the AED back into a non-operative state. Waiting to place an AED back into its non-operative state or standby mode can be a significant problem in situations in which numerous AEDs are checked in a series or close in time. 
         [0009]    For example, a security guard making rounds in a multistory building to check status of AEDs on each floor could encounter significant delays or waiting periods with conventional AEDs. That is, with conventional AEDs that require full power operation to perform self-tests, navigation through numerous menus to obtain status information, and that require the user to turn-off the AEDs once they reach their fully operative state could require a significant amount of time of a security guard who is patrolling the multi-story building. 
         [0010]    Hence, there is a need in the art to provide rich status information, such as using a video display for presenting information about a portable AED and without consuming significant electrical power of the portable AED. There is also a need in the art for an AED that can provide rapid status information without requiring a user to navigate through complex or numerous menus. And a further need exists in the art for an AED that can provide status information without entering into a fully operational state and while the AED remains in a standby mode. 
       SUMMARY OF THE INVENTION 
       [0011]    The inventive status indicating system may comprise a portable automatic external defibrillator (AED) with a video display that presents status information fairly quickly in response to a single button activation and without the AED entering into a fully operational state. That is, the inventive status indicating system of a portable AED may display status information on a video display while the AED is in a non-operative state and without requiring navigation through any complex menus and without requiring any self-tests of the AED. A non-operative state of the AED usually includes situations in which the AED is performing less than all of its primary functions. For example, a non-operative state usually includes situations in which an AED is not performing a rescue on a patient. Functions that may occur during non-operative states in AEDs may include self-tests and active status indicator events. 
         [0012]    The video display may present status information with a graphical user interface while the AED is in the non-operative state. The status information may be presented upon activation of touch-screen technology or electromechanical inputs, such as buttons, built into the AED. When the AED is in a fully operational state, such as during a rescue, the video display may present live or stored electrocardiograms (ECGs). 
         [0013]    The inventive system may comprise a low-power standby processor for monitoring user inputs, controlling status indicators, and determining when to power up the main processor of the AED. The standby processor can perform basic operations, such as monitoring user inputs and controlling status indicators without having to power up all of the system elements of the AED. Status indicators and the status video display may present information about the AED such as the results of internal tests, memory tests and battery status that are performed prior to activation of a status button or touch-screen technology. 
         [0014]    When an operator requests the status of the AED, such as when a status button is activated by an operator, the AED may display status information on the video display. If the AED is in standby mode when the status display is requested by the operator, the low-power standby processor will activate the main processor only to display the status information on the video display and without causing the main processor to place the AED into a fully operational state. This activation of the main processor only to display status information, referred to as a standby status display, may conserve battery power of the AED system while still providing a rich video presentation of status information to the operator. 
         [0015]    The inventive status indicating system may comprise a video display positioned within an AED. The video display may comprise any type of changeable visual presentation technology that is capable of displaying text or graphic (or both) output from a computer processor. For example, the video display may comprise liquid crystal display (LCD) technology, plasma displays, flat-screen display technology, three-dimensional or holographic technology, video projection technology, cathode ray tube (CRT) technology, and other similar display technology. 
         [0016]    The display driver electronics, as well as the display itself, may provide for rapid update between images or frames so as to enable full-motion video when the AED is an fully operational state, such as during a rescue. A touch sensitive element may be positioned over, or incorporated within, the display as to enable touch-screen functionality for user inputs to the AED. Additionally, or in the alternative, user inputs may be accepted via buttons, switches, voice recognition, or other user input mechanisms known to one of ordinary skill in the art. 
         [0017]    According to another alternate exemplary aspect, the inventive status indicating system can comprise a speaker for presenting oral or audible status information from a speaker in addition, or in the alternative, to presenting status information on a video display. Such embodiments would operate similar to the ones mentioned above: oral or audible status indication can be provided fairly rapidly while the AED is in a non-operative state in response to activation of a button, such as status button or an on/off power button. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  illustrates a plan view of an AED according to one exemplary embodiment of the invention. 
           [0019]      FIG. 2  is a functional block diagram illustrating the main processor, standby status processor, and user interface elements according to one exemplary embodiment of the invention. 
           [0020]      FIG. 3  illustrates an AED video screen displaying an electrocardiogram according to one exemplary embodiment of the invention. 
           [0021]      FIG. 4  illustrates an AED video screen displaying status information according to one exemplary embodiment of the invention. 
           [0022]      FIG. 5  is a logic flow diagram highlighting exemplary steps for an AED using a video display to present standby status information to a user according to one exemplary embodiment of the invention. 
           [0023]      FIG. 6  is a functional block diagram illustrating the standby status processor, video display and a light sensor for detecting the ambient environment. 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0024]    The inventive status indicating system may comprise an automatic external defibrillator (AED) with a built-in video display that presents status information without placing the AED into a fully operational state and in response to single button activation. The display driver electronics, as well as the display itself, may provide for rapid update between images or frames so as to enable full-motion video when the AED is in a fully operational state. The video display may be used to display patient ECGs, operator instructions, system status, training scenarios, or other information, video or user interface elements relevant to the functionality or use of the AED. 
         [0025]    The inventive status indicating system may comprise a low power standby processor. The standby processor can react to operator inputs, power the main processor on and off to perform basic system status tests, power the main processor on and off for full operation of the AED, operate status indicators, and power the main processor for the purpose of only displaying a video status screen in certain situations. Performing these operations with the standby processor, which may be a very low power device, may conserve the AED&#39;s battery power and may extend battery life of the system. 
         [0026]    Turning now to the drawings, in which like reference numerals refer to like elements,  FIG. 1  illustrates a plan view of an AED  100  with a built-in video display  170  according to one exemplary embodiment of the invention. The video display  170  may comprise any type of changeable visual presentation technology that is capable of displaying text or graphic (or both) output from a computer processor. For example, the video display may comprise liquid crystal display (LCD) technology, plasma displays, flat-screen display technology, three-dimensional or holographic technology, video projection technology, cathode ray tube (CRT) technology, and other similar display technology. 
         [0027]    An operator may interact with the AED  100  and navigate through menu and graphical user interfaces on display  170  using a touch sensitive element overlaying, or incorporated into, video display  170  when the AED is in a fully operative state such as during a rescue. Additionally, or in the alternative, an operator may interact with the AED  100  and navigate menu and graphical user interfaces on video display  170  using buttons  180 . 
         [0028]    According to one inventive aspect of the status indicating system, an operator of an AED  100  may obtain status information presented on the video display  170  of the AED  100  by pressing a single button or touching the touch screen  280  and without navigating through any menus on the video display  170  and while the AED  100  is in an non-operative state. A non-operative state of the AED  100  usually includes situations in which an AED  100  is not performing a rescue on a patient. To obtain this standby status information on the video display  170 , an operator can touch the display  170  or one of the buttons  180  that may be designated as a “status information” button  180 . 
         [0029]    The standby processor and related circuitry is not illustrated in  FIG. 1 , but is contained within a housing  110  of the AED  100 . On/off button  130  may be used by an operator to switch AED  100  between operational mode and standby mode. While the on/off button appears to the user to turn off AED  100  completely, the AED may actually be placed into a standby mode or non-operative state where the main processor may be powered off and a very low power standby processor may be operating to monitor activation of the touch screen of the display or the status information button  180 . 
         [0030]    During standby operation, the standby processor (not illustrated in  FIG. 1 ) may power up the main processor only to perform periodic tests of AED  100  such as memory, charging circuits, and battery power level. 
         [0031]    During the periodic tests, the standby processor can power up the main processor for only performing these self tests without the entire AED entering into a fully operational state. In other alternative embodiments, the standby processor could perform these self tests without using the main processor. 
         [0032]    During standby operation, the standby processor may also use indicator light  140  to display overall system status, such as green illumination if all system tests pass or red illumination if AED  100  requires attention due to a system test failure or a low battery warning. The standby processor may also audibly or aurally indicate the status of the AED  100  using speaker  160 . For example, the standby processor may chirp the speaker  160  when operator attention is required. 
         [0033]    According to an alternate exemplary embodiment, the speaker  160  can be used for presenting oral or audible status information in addition, or in the alternative, to presenting status information on the video display  170 . It is envisioned that some AEDs  100  may not have a video display  170  but will usually have a speaker  160 . In such embodiments, oral or audible status indication can be provided with the speaker  160  in which the main processor  220  will supply appropriate audio signals that convey status information of the AED  100 , similar to the information that would be conveyed with the video display  170 . 
         [0034]    To obtain status information from an the AED  100 , an operator can obtain such status information by depressing one or more of buttons  180 . The standby processor may detect this request and activate the main processor  220  for only displaying a status report on video display  170  or presenting audio signals to the speaker  160  that convey status of the AED  100 . 
         [0035]    While AED  100  is in standby mode, the standby processor may detect that the operator has depressed on/off button  130 . At this time, the standby processor may power on the main processor of AED  100  placing the system in full operational mode, as in a rescue for a patient. In full operational mode, patient electrodes  125 , which may attach to AED  100  via connector  120 , can be used to monitor ECG information from a patient to determine if the patient&#39;s cardiac rhythm is suitable for defibrillation shock. If so, the operator may be instructed to press shock button  150  to initiate an electrical shock through the patient electrodes  125  attached at connector  120 . During this procedure, ECG information may be displayed on video display  170 . Video display  170 , along with speaker  160 , may also be used to present real-time instructions and feedback to the operator. 
         [0036]    Referring now to  FIG. 2 , this figure illustrates a functional block diagram of the processors and user interface elements according to one exemplary embodiment of the invention. In this exemplary embodiment, a standby processor  250  may accept user inputs, perform system tests by powering up the main processor  220 , or activating the main processor  220  to display status information without placing the entire AED  100  into a fully operational state. While AED  100  is in standby mode, the standby processor  250  may accept user inputs from buttons  180 , on/off button  130  and touch screen  270 . An operator may request the display of status information by depressing one or more of user input buttons  180 . The standby processor  250  may detect a status request and activate the main processor  220  to only display a status report on video display  170 . This display of status information about the AED may be performed by the low power standby processor  250  activating the main processor  220  and without placing the entire AED  100  into a fully operational state. 
         [0037]    While AED  100  is in standby mode, standby processor  250  may detect that the operator has depressed on/off button  130 . At this time, standby processor  250  may power on main processor  220  of AED  100  placing the system in operational mode. While on/off button  130  can be used by the standby processor  250  to power main processor  220  on and off, the other user interface buttons  180  and touch screen  170  may be used by both the standby processor  250  and the main processor  220 . For example, display driver  290 , which can drive video display  170 , may be addressed in standby mode by the main processor  220  for displaying standby status information. In full operational mode, main processor  220  can communicate with the display driver/processor  290  for displaying ECGs; operator instructions; menus; or other operational information, images, or video. Likewise, user inputs from buttons  180  or touch sensitive element  270  may be monitored by both main processor  220  and standby processor  250 . 
         [0038]    According to one exemplary embodiment of the invention, standby processor  250  may comprise a general purpose processor such as the MSP430F1232, an ultra-low-power microcontroller, made by Texas Instruments. However, one of ordinary skill in the art will appreciate that standby processor  250  may comprise a microcontroller, microprocessor, DSP processor, application specific logic, programmable logic, or numerous other forms without departing from the spirit and scope of the invention. 
         [0039]    Main processor  220  may comprise a general purpose processor but it may not be as lower power relative to the standby processor  250 . The main processor  220  communicates with the display driver/processor  290 . The display driver/processor  290  may comprise a video processor that has the sole function of controlling the operation of the video display  170 . While the display driver/processor  290  is illustrated as a separate physical component relative to the main processor  220 , one of ordinary skill in the art recognizes that the display driver  290  could be part of the main processor  220  in other alternative embodiments (not illustrated). Similarly, though not illustrated, the standby processor  250  could form a part of the main processor  220 . That is, it is envisioned that the main processor  220  in future embodiments could comprise a low power, sleep mode similar to the one of the standby processor  250 . 
         [0040]    Meanwhile, memory  210  is illustrated as separate from, and could be shared by, both standby processor  250  and main processor  220 . However, one of ordinary skill in the art will appreciate that each processor may  220 ,  250  have its own internal or external memory where each memory may be volatile, nonvolatile, or a combination thereof. These memories may or may not be shared between the two processors. Further, one or more memory ports (not illustrated) that are positioned on the outside of the housing for the AED  100  may be used for receiving one or more removable, portable memory devices, such as memory cards (not illustrated). The main processor  220  or the standby processor  250  (or both) may read or write (or both) to the memory devices (not illustrated). 
         [0041]    Referring now to  FIG. 3 , this figure illustrates an AED video display  170  for presenting an electrocardiogram (ECG) when the AED  100  is in a full operational mode according to one exemplary embodiment of the invention. During full operational mode, such as during a rescue, main processor  220  may be active. While in an active state, main processor  220  may provide information to present on video display  170  including patient ECG waveforms. AED  100  may display live ECG waveforms  340  from a patient on video display  170 . AED  100  may also display recorded waveforms  320  that are stored in memory  210 . Waveforms  320  stored in memory  210  may be useful in reviewing a rescue event or for training an AED operator. 
         [0042]    Referring now to  FIG. 4 , this figure illustrates video display  170  for presenting status information  400  according to one exemplary embodiment of the invention. Standby processor  250  can respond to an operator&#39;s request to display the status of AED  100  by presenting system status information  400  on video display  170 . The status information may comprise information such as self test results  410 , battery status  420 , patient electrode pad expiration date  430 , the presence or non-presence of electrode pads, or various other system information  440  such as software or firmware (or both) version numbers and memory capacities. 
         [0043]    Standby processor  250  may display this status information screen on video display  170  by activating the main processor  220  and without placing the entire AED  100  into a full operational mode. During a full operational mode, such as during a rescue, main processor  220  can control the display processor  290  to present rescue information such as ECG waveforms  320 ,  340  or other rescue information as illustrated in  FIG. 4 . 
         [0044]      FIG. 5  illustrates a logic flow diagram  500  of a method for presenting standby status information on a video display  170  according to one exemplary embodiment of the invention. Logical flow diagram  500  highlights some key functional features of standby processor  250 . One of ordinary skill in the art will appreciate that process functions of standby processor  250  may comprise firmware code executing on a microcontroller, microprocessor, or DSP processor; state machines implemented in application specific or programmable logic; or numerous other forms without departing from the spirit and scope of the invention. In other words, the invention may be provided as a computer program which may include a machine-readable medium having stored thereon instructions which may be used to program a computer (or other electronic devices) to perform a process according to the invention. 
         [0045]    The machine-readable medium may include, but is not limited to, floppy diskettes, optical disks, CD-ROMs, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, magnet or optical cards, flash memory, or other type of media/machine-readable medium suitable for storing electronic instructions. 
         [0046]    Certain steps in the processes or process flow described in all of the logic flow diagrams referred to below must naturally precede others for the invention to function as described. However, the invention is not limited to the order or number of the steps described if such order/sequence or number does not alter the functionality of the present invention. That is, it is recognized that some steps may not be performed, while additional steps may be added, or that some steps may be performed before, after, or in parallel other steps without departing from the scope and spirit of the present invention. 
         [0047]    Further, one of ordinary skill in programming would be able to write such a computer program or identify the appropriate hardware circuits to implement the disclosed invention without difficulty based on the flow charts and associated description in the application text, for example. Therefore, disclosure of a particular set of program code instructions or detailed hardware devices is not considered necessary for an adequate understanding of how to make and use the invention. The inventive functionality of the claimed computer implemented processes will be explained in more detail in the following description in conjunction with the Figures illustrating process flows. 
         [0048]    Step  510  is the first step in the process and can comprise a waiting step. In this step, standby processor  250  operates in a power saving sleep mode and can be woken by events that it acts upon briefly before returning back to the sleep mode. In the exemplary embodiment of the method illustrated in  FIG. 5 , three events may activate standby processor  250  from its sleep mode. These events include, but are not limited to, a power button event, a self test timer event, or a status request event. After an event that takes standby processor  250  out of its sleep mode, the standby processor  250  can activate the main processor  220 . Once the main processor  220  is activated, it can determine what type of event awoke the standby processor  250  from its sleep mode. The main processor  220  and standby processor  250  will eventually transition back through step  590  into the sleep mode of step  510  where standby processor  220  waits for the next wake event and the main processor  220  is deactivated or turned off completely to conserve power. 
         [0049]    In decision step  520 , standby processor  250  activates the main processor  220  to determine what type of event is occurring. If the wake event comprises a power button  130  being pressed, the process continues to step  525  in which the main processor  220  enters into a full operational mode such as for a rescue event. In full operational mode, main processor  220  is powered on to perform the main operations of AED  100 . For example, main operations of the AED  100  can include patient heart rhythm analysis and possible delivery of defibrillation shocks to the patient. Once the main processor  220  is enabled, standby processor  250  transitions from step  525  into step  590  where standby processor  250  returns to sleep mode of step  510 . Functions of standby processor  250  may occur in parallel to operational functions of main processor  220 . 
         [0050]    If the wake event determined in step  520  by the main processor  220  is a self test timer, the main processor  220  can perform periodic system tests starting with step  530  where built-in self tests are performed. In an alternate embodiment, not illustrated, the standby processor  250  could be designed to conduct these self tests alone and without using the main processor  250 . 
         [0051]    The self test timer can be internal to standby processor  250  or it may be a circuit (not illustrated) that is external to standby processor  250 . An example of a period of the self test timer may be one day. According to this example, self tests would be performed once each day. One of ordinary skill in the art will appreciate that this timer period may differ from this example and may be a constant or vary according to other system parameters without departing from the scope and spirit of the present invention. 
         [0052]    The self tests performed according to the self test timer may include the main processor  220  testing system memory  210 , validating software/firmware, checking charging circuits, or other internal tests of AED  100 . Next, standby processor  250  transitions to step  535  where battery tests are performed, and then to step  540  where patient electrode pads are tested. Then, in step  545 , the results of these test functions may all be stored in the memory  210  of AED  100 . Once self tests are completed, standby processor  250  transitions from storage step  545  into step  590  where standby processor  250  returns to sleep mode of step  510 . 
         [0053]    If the wake event determined in step  520  is an operator status request, the main processor  220  can communicate with the display driver/processor  290  to present AED system status on video display  170 . This starts with collecting the system information to display. According to one exemplary aspect of the inventive status indicating system, the main processor  220  and standby processor  250  do not present any complex menus on the display  170  so that an operator of an AED can readily obtain status information about the AED  100  from a single press of a button  180  or activation of a touch screen  270  without navigating through complex menus and without the main processor  220  performing any time-consuming and power-consuming self tests. In the exemplary embodiment illustrated in  FIG. 5 , collecting information to display begins in step  570  in which information is usually recalled from memory  210  by main processor  220  based on a prior periodic test, as discussed above in step  545 . 
         [0054]    In step  575 , information collected or recalled in step  570  may be formatted for presentation on video display  170 . Finally, in step  580 , the status information is displayed to the operator. This presentation of information on the display  170  may continue until a display timer expires or the operator presses one of buttons  180  again or touch screen  270 . An example of the duration for the display can be between ten and thirty seconds. According to a preferred exemplary embodiment, the duration is ten seconds. One of ordinary skill in the art will appreciate that this duration for displaying status information may differ from this example and may be a constant or a variable length without departing from the scope and spirit of the present invention. At completion of the display of status information, standby processor  250  transitions from display step  580  into step  590  where standby processor  250  returns to the sleep mode of step  510 . 
         [0055]    Referring now to  FIG. 6 , this figure illustrates a functional block diagram of the standby status processor, video display and a light sensor for detecting the ambient environment. Prior to requesting the main processor  220  to present status information on video display  170 , standby processor  250  may sample light sensor  610  to determine the ambient light level around the AED  100 . 
         [0056]    Display driver  290  may control the intensity, brightness, and/or contrast of video display  170 . Standby processor  250  can set these parameters within display driver  290  based on ambient light levels sampled from light sensor  610 . The standby processor  250  can also store these parameters in memory  210  so that the main processor  220  can access them when it is in a full operative state, such as during a rescue. This environmentally responsive determination of display parameters may provide for a more readable video display  170 . This feature may also conserve AED battery power, for example, by providing a dimmer display in a dark environment of the AED  100 . 
         [0057]    Alternative embodiments of the inventive system will become apparent to one of ordinary skill in the art to which the present invention pertains without departing from its spirit and scope. Thus, although this invention has been described in exemplary form with a certain degree of particularity, it should be understood that the present disclosure has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts or steps may be resorted to without departing from the spirit or scope of the invention. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description.