WO2009034506A1

WO2009034506A1 - Remote status indicator for a defibrillator

Info

Publication number: WO2009034506A1
Application number: PCT/IB2008/053608
Authority: WO
Inventors: Alan Greenstein
Original assignee: Koninklijke Philips Electronics, N.V.
Priority date: 2007-09-12
Filing date: 2008-09-05
Publication date: 2009-03-19

Abstract

A defibrillator is described that performs self diagnostic tests such as of a battery or hydrogel contact pads and transmits data corresponding to the tests. A remote status indicator is located in a visible area, such as by magnetically attaching it to a refrigerator, which receives the transmitted data and produces a human perceptible output. The remote status indicator may include a charging circuit having an input for coupling to an energy source and an output for coupling to the battery of the defibrillator for charging the battery of the defibrillator. In some embodiments, the remote status indicator detects when the battery has been charged or pads replaced and produces an alert after a time interval associated with a maintenance time interval for the battery or pads.

Description

REMOTE STATUS INDICATOR FOR A DEFIBRILLATOR

[001] This invention relates generally to automatic external defibrillators (AEDs) and, more particularly, to systems and methods for maintaining an AED ready for use.

[002] Automatic external defibrillators have been in use for a number of years to treat individuals stricken with sudden cardiac arrest, one of the largest causes of death in the United States. Sudden cardiac arrest (SCA) most often occurs without warning, striking people with no previously recognized symptoms of heart disease. It is estimated that more than 1000 people per day are victims of sudden cardiac arrest in the United States alone. SCA results when the electrical stimulus of the heart no longer functions properly, causing an abnormal sinus rhythm. One such abnormal sinus rhythm, ventricular fibrillation (VF), is caused by abnormal and very fast electrical activity in the heart (fibrillation). As a result, the heart fails to adequately pump blood through the body. VF may be treated by applying an electric shock to a patient's heart through the use of a defibrillator. The shock clears the heart of abnormal electrical activity (in a process called "defibrillation") by producing a momentary asystole and providing an opportunity for the heart's natural rhythmic functioning to resume. When applied externally to the body of the patient, these electrical pulses are high energy pulses, typically in the range of 30 to 360 Joules of energy.

[003] Defibrillators have undergone an evolution over the past decade. Originally defibrillators were manual devices requiring both medical and technical expertise to operate. A physician would carefully set the controls of the defibrillator to apply a shock which diagnosis of the patient or experience with other patients in similar conditions indicated to be most likely to be effective. Following many years of experience with these manual defibrillators and motivated by advances in microprocessing and signal analysis, defibrillators have become more automated to the point where a two-pad electrode attached to a patient's chest can detect and diagnose VF and deliver an appropriate shock through the chest wall. However such automated defibrillators continued to be prescription devices used by medical professionals or under the auspices of a controlled emergency response program as described in U.S. Pat. No. 6,694,299. In the final months of 2004 AEDs have reached a level of sophistication and reliability which now enables them to be sold to laypersons without prescription, as over-the-counter (OTC) medical devices. AEDs may now be sold through retail channels (stores, websites, catalogs) and purchased by anyone in the United States for use at home in the event of a sudden cardiac arrest emergency.

[004] As a result of these advances, many homes and businesses now have defibrillators so that rapid defibrillation can be performed on a victim of SCA before medical personnel arrive on-site. However, emergency situations are relatively rare occurrences. A purchaser of a home AED may store the AED out of sight, and after many months, or even years, the existence and location of the home defibrillator may not come to mind when a cardiac incident occurs. The benefit of an on-site defibrillator may therefore be lost by unnecessarily waiting for emergency personnel to arrive with a defibrillator even when one is immediately at hand but misplaced or unidentified.

[005] Furthermore, defibrillators require some maintenance in order to be ready for an emergency. For example, the batteries of a defibrillator discharge over time even when not used for defibrillation. The batteries should be recharged or replaced in order for a defibrillator to maintain functionality. The electrodes of the defibrillator may include pads made of hydrogel that can gradually dry out, resulting in pads that do not have adequate conductivity when applied to a patient. The pads should be replaced to maintain functionality of the defibrillator. Many AEDs perform self tests of the battery and pads and beep or flash a warning light when these components need attention. However, if the AED is stored out of sight or the owners are traveling, these warnings may not be seen or heard. Accordingly, simply having a defibrillator on site may be insufficient to guarantee readiness for an emergency.

[006] Accordingly, it would be desirable to provide a system and method for promoting the awareness of an on-site defibrillator in an emergency situation and for facilitating maintenance of the defibrillator in a ready-to-use state.

[007] In accordance with the principles of the present invention, a remote status module is in wireless communication with a defibrillator having two electrodes, a battery, and a controller coupled to the electrodes and battery and programmed to control supply of power from the battery to the electrodes. The controller includes a transmitter and a test circuit coupled to the battery for testing the battery. The controller is further programmed to cause the transmitter to transmit data corresponding to an output of the test circuit. The remote status module includes a receiver for receiving the transmitted data. An indicator is coupled to the receiver and is operable to produce an output signal corresponding to the transmitted data. The remote status module may include a magnet for mounting the remote status indicator to a refrigerator or other ferromagnetic fixture.

[008] In another aspect of the present invention, the remote status module includes a charging circuit having an input for coupling to an outlet and an output for coupling to the battery of the defibrillator.

[009] In another aspect of the present invention, the remote status module detects charging of the battery and emits a signal indicating that the battery should be recharged following a time interval corresponding to the discharge time of the battery to a specific low-charge level.

[010] In the drawings:

[011] Figure 1 is a schematic representation of a home environment in which an AED and remote status indicator may be deployed in accordance with an embodiment of the present invention.

[012] Figure 2 is an isometric view of a remote status indicator in accordance with an embodiment of the present invention.

[013] Figure 3 is a schematic block diagram of an AED in accordance with an embodiment of the present invention.

[014] Figure 4 is a schematic block diagram of a remote status indicator in accordance with an embodiment of the present invention.

[015] Figure 5 is a schematic block diagram of an alternative embodiment of a remote status indicator in accordance with an embodiment of the present invention. [016] Referring to Figure 1, an automatic external defibrillator (AED) 10 may be stored in a closet 12, or other area of a building such as a cabinet, drawer, or the like. As a result, the AED 10 may not be readily seen by occupants of the building and therefore the AED 10 might not be maintained in condition for use should an emergency occur.

[017] Accordingly, a remote status indicator 14 is located remotely from the AED 10 such that it is regularly seen by occupants of the building. For example, the remote status indicator 14 may be mounted to a refrigerator 46 by means of a magnet. Other attachment means such as a contact adhesive or an eyelet for hanging the indicator from a hook may alternatively be employed. The remote status indicator 14 is in wireless communication with the AED 10 in order to actively produce alerts when the AED 10 needs to be serviced.

[018] Referring to Figure 2, the remote status indicator 14 in this embodiment includes a housing 18 bearing a status indicator 20, which can represent one or more indicators included in the remote status indicator 14. The status indicator 20 may include speakers, buzzers, or other sound producing device. The status indicator 20 may also be an LCD, LED, mechanically actuated display, or other visual indicator. In some embodiments, the status indicator 20 includes both audible and visual indicators. The remote status indicator 14 may include a magnet 22 secured to the housing for mounting the remote status indicator 14 to a ferromagnetic structure, such as a refrigerator. In some embodiments, the remote status indicator 14 emits a signal for paging the AED 10. In such embodiments, the remote status indicator 14 may include a button 24, or other input device that a user may actuate to cause the remote status indicator 14 to emit a paging signal. The AED 10 will in response emit an audible or visible signal upon receiving the paging signal in order to alert a user to its location.

[019] In some embodiments, the remote status indicator 14 includes an adapter for charging the batteries of the AED 10. In such embodiments, the remote status indicator 14 may include a plug 26 for insertion into an electrical outlet. In some embodiments, the plug 26 pivots into a bay 28 when not in use. A jack 30 may be provided on the housing for receiving a plug in electrical communication with the AED 10 to enable charging of the AED 10.

[020] Referring to Figure 3, the AED 10 may include an AED controller 32 for controlling the supply of current to electrodes 34 from a battery 36. The AED controller 32 also controls diagnostic functions such as evaluating a patient's electrocardiogram (ECG) signal for indications of ventricular fibrillation.

[021] The AED 10 may further include a diagnostic module 38 for performing self- tests of the AED 10 itself to determine if the AED 10 is in condition for use or needs servicing. In some embodiments, the diagnostic module 38 is coupled to a test circuit 40 coupled to the battery 36 for testing the charge stored by the battery. The diagnostic module 38 receives an output signal from the test circuit 40 and determines whether the charge level of the battery is adequate. In some embodiments, the electrodes 34 may have hydrogel contact pads 42 which to provide good electrical contact with a patient's skin. As previously discussed, the hydrogel contact pads 42 may become desiccated over time and lose their ability to provide good electrical contact. Accordingly, the test circuit 40 is coupled to the electrodes 34 and configured to periodically evaluate the contact pads 42 to determine whether the hydrogel is in good condition. For example, the test circuit 40 can measure the conductivity or the moisture content of the contact pads 42 in order to determine their condition. The diagnostic module 38 determines from the measurement whether the contact pads 42 are in condition for use or need to be replaced.

[022] If the diagnostic module 38 determines from the output of the test circuit 40 that the AED 10 is in need of servicing or will need servicing within a specific time period, the diagnostic module 38 causes a transmitter 46 to emit a status signal indicating this need. The status signal may communicate information such as whether the pads 44, battery 36, or both are in need of servicing. The status signal may communicate a time period until servicing is needed. In other embodiments, the signal simply indicates that the AED 10 in need of servicing without indicating what part of the AED 10 is in need of servicing or the time period until the AED 10 will become inoperative due to lack of servicing.

[023] In some embodiments, the diagnostic module 38 is also coupled to an indicator

48 such as an LCD or other display, and LED or other light emitting device, or a speaker or other sound producing device of the AED 10. The diagnostic module 38 may therefore also output information indicating the condition of the battery 36 or pads 44 on the indicator 48.

[024] In some embodiments, the diagnostic module 38 causes the transmitter to emit a periodic signal indicating that the AED 10 is in good functional condition. The remote status indicator 14 will detect a problem with the AED 10 by the absence of this periodic signal from the AED. In such embodiments, the diagnostic module 38 may be coupled to a clock 30 for controlling the time interval between such signals. In some embodiments, the periodic signal also communicates the current status of the AED 10 as determined by the output of the test circuit 40.

[025] Referring to Figure 4, a schematic block diagram of a remote status indicator is illustrated. The remote status indicator in this embodiment includes a controller 52 having a status module 54, check-up module 56, and paging module 58. The status module 54 is coupled to a receiver 60 for receiving the status signal and/or periodic signal from the transmitter 46 of the AED 10. The status module 54 may cause one or more of the indicators 20 of the remote status indicator to produce an output in response to the status signal and/or periodic signal.

[026] In some embodiments, the status module 54 produces an output whenever a status signal is received, such as in embodiments where the diagnostic module 38 of the AED controller 32 emits the status signal only when the AED 10 is in need of servicing. In other embodiments, the status module 54 analyzes either the status signal and/or the periodic signal to determine whether servicing is needed and causes the status indicator 20 to produce an output only if servicing is needed. In some embodiments, the status module 54 causes the status indicator 20 to produce an output if a specific period of time elapses without receiving a status signal. [027] The status indicator 20 produces an output communicating information such as which component of the AED 10 is in need of servicing (e.g. the contact pads 44 or battery 46). The status indicator 20 may communicate information regarding the status of the contact pads 44 or battery 46, such as the time before servicing is required, the charge level of the battery, or the like. In other embodiments, the status indicator 20 simply produces an audible or visible alert without providing other information. In embodiments having multiple status indicators, the status indicator 20 activated by the status module 54 may indicate which portion of the AED 10 needs servicing.

[028] The check-up module 56 provides periodic reminders to potential users regarding the AED 10. For example, the check-up module 56 may provide periodic reminders indicating that potential users should become familiar with the location of the AED 10. The check-up module 56 may provide a reminder that communicates the location of the AED 10, such as by displaying the name of the room where the AED 10 is located or the distance between the status indicator and the AED. The check-up module 56 may provide periodic reminders to potential users to become familiar with the operating instructions for the AED 10 or to initiate the setup of the AED 10 if that has not been done.

[029] The paging module 58 receives a signal from an input 68, such as the button 24 and, in response, cause a transmitter 66 to emit a paging signal. The AED controller 32 is coupled to a receiver (not shown) for receiving the paging signal. In response to the paging signal, the AED controller 32 causes the AED indicator 48 to produce an audible or visible output in order to alert a user to the location of the AED 10. In other embodiments the location of or distance to the AED is displayed on a display indicator 20 of the status indicator 14 in response to the paging signal.

[030] In embodiments where the remote status indicator 14 includes an adapter for charging the battery 46 of the AED 10, the remote status indicator may include a charging circuit 70 coupling the plug 26 to the jack 30. In some embodiments, the charging circuit 70 may be used to recharge the battery 76 of the status indicator 14. The status module 54 may detect the charging of the AED battery 36 and update the status of the AED 10 within the remote status indicator 14 to indicate the time when the battery was last charged. The status module 54 may, in some embodiments, cause the status indicator 20 to produce an output following a time after charging corresponding to a preset time of standby operation for the battery 36 to be discharged to a low-charge level, at which point the battery 36 should be charged to maintain its readiness for use.

[031] Referring to Figure 5, in this embodiment of the present invention, a remote status indicator does not wirelessly receive signals from the AED 10, but rather is synchronized with the AED 10 such that it can provide alerts according to expected maintenance needs of the AED 10.

[032] In the embodiment of Figure 5, the controller 52 include a synchronization module 72 for synchronizing the remote status indicator 14 with the AED 10. The synchronization module 72 is initiated by a user at the time the AED 10 is put into service and uses a clock 64 to measure the time intervals until servicing of the AED is normally expected to be needed. Alternatively, the user may manually input data regarding the current condition of the AED. For example, the AED 10 may produce an output of data with its indicator 48, which the user may then input to the synchronization module 72. The status module 54 examines the inputs to the synchronization module 72 and, using the clock 64 and the information of the input data, provide alerts at a time when the battery 46 and/or contact pads 44 are expected to need servicing.

[033] In other embodiments, the input may be one or more buttons that may be pushed when servicing occurs. For example, a button on the remote status indicator can be pressed at the time the battery 36 of the AED has been recharged or replaced or the pads 34 replaced. The synchronization module 72 records the time of these events or initializes a corresponding timer in the module. The status module 54 then uses these time markers to alert the user when these service functions are expected to be needed in the future. The status module 54 may determine when the contact pads or battery are likely to need servicing based on either expiration of a timer interval or by comparing the recorded time with the output of the clock 64 and produce an output on the status indicator 20 indicating that the battery or pads need servicing as discussed above. In the embodiment of Figure 5, the paging module 58 and transmitter 66 may be omitted in order to provide a device that does not require circuits for either sending or receiving wireless communication. The check-up module 56 may likewise be omitted to provide a simplified device.

Claims

WHAT IS CLAIMED IS:

1. A defibrillator system comprising: a defibrillator having electrodes, a battery, and a controller coupled to the electrodes and battery, the controller programmed to control supply of power from the battery to the electrodes and having a transmitter and a test circuit operable to test the battery, the controller operable to cause the transmitter to transmit data corresponding to an output of the test circuit; and a remote status module comprising an attachment device adapted to attach the remote status module to a surface, a receiver operable to receive the transmitted data, and an indicator coupled to the receiver and operable to produce a perceptible output corresponding to the transmitted data.

2. The defibrillator system of claim 1, wherein the defibrillator further comprise hydrogel pads attached to the electrodes, the test circuit being operable to test the condition of the hydrogel pads and the controller programmed to cause the transmitter to transmit data corresponding to an output of the test circuit indicating the condition of the hydrogel pads.

3. The defibrillator system of claim 2, wherein the test circuit is operable to measure the conductivity of the hydrogel pads.

4. The defibrillator system of claim 1, wherein the remote status module further comprises a timer coupled to the indicator, the indicator operable to periodically produce a perceptible output instructing a user to check the defibrillator according to the output of the timer.

5. The defibrillator system of claim 1, wherein the remote status module further comprises a charging circuit, the charging circuit operable to regulate charging of the battery in response to being selectively coupled to a power source and the defibrillator.

6. The defibrillator system of claim 1, wherein the indicator is at least one of a light, a speaker, and a display.

7. The defibrillator system of claim 1, wherein the remote status module further comprises a paging module operable to receive an input from a user and to transmit a paging signal responsive to the input, and wherein the defibrillator comprises a receiver operable to receive the paging signal, the receiver coupled to an indicator and operable to cause the indicator to produce a perceptible output in response to receiving the paging signal.

8. The defibrillator system of claim 1 wherein the attachment device comprises a magnet.

9. A defibrillator system comprising: a defibrillator having electrodes, a battery, and a controller coupled to the electrodes and battery, the controller programmed to control supply of power from the battery to the electrodes and having a test circuit operable to test the battery; and a remote status module comprising an attachment device adapted to attach the remote status module to a visible surface, a timer having an input and coupled to an indicator, the timer operable to cause the indicator to produce a perceptible output upon expiration of a period following receiving a signal at the input, the period corresponding to a preset time associated with discharge time of the battery.

10. The defibrillator system of claim 9, wherein the remote status module further comprises a charging circuit having an input and an output, the charging circuit operable to charge the battery of the defibrillator when the input of the charging circuit is coupled to a power source and the output is coupled to the defibrillator, wherein the charging circuit is operable to couple a signal to the input of the timer upon completion of charging the battery.

11. The defibrillator system of claim 9, wherein the input is coupled to a button operable to couple the signal to the input upon being depressed by a user.

12. The defibrillator system of claim 9 wherein the attachment device comprises a magnet.

13. A method for maintaining a defibrillator in readiness for use comprising: charging or replacing the battery of a defibrillator; starting a time period maintained by a remote status module after charging or replacing the battery, the time period associated with an expected discharge time of the battery; locating the remote status module remotely from the defibrillator; and upon expiration of the time period issuing a human perceptible output from the remote status module.

14. The method of claim 13, wherein starting the time period further comprises starting a timer in the remote status module upon receiving a signal from a battery charger.

15. The method of claim 13, wherein producing a human perceptible output further comprises producing at least one of a visible and an audible signal by the remote status module.

16. The method of claim 13, wherein locating the remote status module further comprises magnetically attaching the remote status module to a surface.

17. A method for maintaining a defibrillator in readiness for use comprising: synchronizing a remote status module with a defibrillator; locating the remote status module remotely from the defibrillator; generating a human perceptible output at the remote status module in response to expiration of a time period based on the synchronizing step and an expected time at which the defibrillator need maintenance.

18. The method of claim 17, wherein synchronizing the remote status module with the defibrillator comprises providing an input to the remote status module indicating that maintenance has been performed.

19. The method of claim 17, wherein synchronizing the remote status module with the defibrillator comprises transmitting from the defibrillator to the remote status module one or more status indications.

20. The method of claim 19, wherein synchronizing the remote status module with the defibrillator comprises initializing the remote status module at the time the defibrillator is put into service.