US20090264948A1 - Apparatus and method for maintaining a defibrillator battery charge and optionally communicating - Google Patents

Abstract

Defibrillator assemblies and methods to wirelessly transfer energy from an external source to a battery or other rechargeable power source within the defibrillator assembly. The transfer of energy may be through a non-contact interface on a defibrillator cradle or a docking station that mounts the defibrillator. The rate of energy transfer may be equal to the energy drain caused by self-discharge and automated self-testing. Accordingly, since the rate of energy transfer is lower than that required to run the defibrillator system continuously, several wireless methods of energy transfer may be used. In addition, the defibrillator assembly may communicate diagnostic and non-diagnostic data to the external source.

Description

TECHNICAL FIELD
• The invention relates to medical devices, and in particular, to wirelessly charging, a battery within a defibrillator.
BACKGROUND
• Cardiac arrest is a life-threatening medical condition that may be treated with external defibrillation. External defibrillation includes applying electrodes to the patient's chest and delivering an electric shock to the patient to depolarize the patient's heart and restore normal sinus rhythm. The chance that a patient's heart can be successfully defibrillated increases significantly if a defibrillation pulse is applied quickly.
• Until recently, only individuals such as paramedics, emergency medical technicians, police officers, and others trained in defibrillation techniques used defibrillators. However, in a cardiac arrest event the patient's need is urgent and the patient cannot wait for trained personnel to arrive. In recognition of the need for prompt treatment, automated external defibrillators (AEDs) are becoming more commonplace, and are available in venues such as health clubs, auditoriums, and most recently private homes. Ready availability of AEDs may mean that patients can get needed treatment promptly, and need not wait for emergency personnel to arrive. As a result, more lives may be saved.
• An AED may be used infrequently, whether it is placed in a commercial setting or in a private household. The battery within the AED will gradually discharge because of self-discharge and automated self-testing that is conducted on a periodic basis (daily, weekly, etc.). Since the AED is used infrequently, the battery status may not be checked on a regular basis. As a result, when the AED is brought into use, possibly years after purchase, the battery may not have sufficient energy to allow the AED to perform its intended function (ECG analysis and defibrillation).
• As part of ordinary maintenance procedures, AEDs deployed may be periodically checked. Typically in public venues a person, such as a security worker, may be assigned to make an inspection of each AED and confirm that the device is operational. The inspection may be relatively simple, because many AEDs perform one or more automatic self-diagnostic routines and provide one or more status indications that the device is operational or in need of service.
• As part of the inspection, the responsible person regularly reviews each AED and checks its associated status indicators. The responsible person may also be required to prepare and maintain records showing that the inspections have been performed, as well as log the status and repair history of the AEDs. However, in a public venue having several AEDs, the cost of inspection may be significant. Further, a deployed AED may be unprepared to provide defibrillation therapy if the responsible person fails to make an inspection, forgets to make an inspection, or makes an inspection error.
• These problems are exacerbated in a private venue or a household where an AED may be used even more infrequently, and thus the AED may have a larger chance of not being properly inspected. It may be more likely in a private venue or a household the user will forget about the AED due to the long time periods between AED uses. Thus, there is a greater chance in these private settings the AED battery will not be properly charged and that the user may not have purchased a replacement battery.
• Generally, disposable batteries power most AEDs. There are presently AEDs, which have an option for using rechargeable batteries. In these AEDs, removing them from the unit and connecting an AC-powered charger charge the batteries. A problem associated with using these AEDs using AC power is that the leakage current to the patient must be kept below the limits set by industry standards, which require the use of large isolation components, typically transformers. These devices, while they have proved effective as AEDs, are also larger and heavier and thus make the AEDs more difficult to use and transport.
• Another challenge with defibrillators is providing for user safety from the high voltages generated by the AED. In some AEDs, safety is provided by having no exposed, user-accessible contacts other than the defibrillation electrodes (pads). However, these AEDs utilize removable batteries that are inserted into the AED and removed when the battery is depleted. Having a traditional battery charger that is powered by the AC line power typically has user-accessible contacts that would have to be electrically isolated within the AED. This isolation would increase the cost and size of the AED.
SUMMARY
• The invention overcomes the problems of the prior art. The invention provides medical device systems and methods to wirelessly transfer energy from an external source to a battery within the medical device. The invention transfers the energy through a non-contact interface through a cradle means or a docking station means. The rate of energy transfer is generally equal to the energy drain caused by self-discharge and automated self-testing. Accordingly, since the rate of energy transfer is lower than that required to run the medical device continuously, several wireless methods of energy transfer may be used. The present invention provides wireless energy transfer methods, such as inductively, capacitively, acoustically, optically, and electromagnetically transferring energy from an external source to a medical device. In addition, the invention may optionally provide the capability for the medical device to communicate diagnostic and non-diagnostic data to the external source.
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1 is a perspective view of a portable defibrillator in accordance with the present invention;
• FIG. 2 is a perspective drawing of an automated external defibrillator in a cabinet docking station according to an embodiment of the invention.
• FIG. 3 is a perspective drawing of an automated external defibrillator in a bracelet docking station according to another embodiment of the invention.
• FIG. 4 is a block diagram illustrating a system for wirelessly charging an automated external defibrillator and optionally transmitting data from an automated external defibrillator, according to an embodiment of the invention.
• FIG. 5 is a schematic representation illustrating an embodiment for wirelessly charging an automated defibrillator, according to the present invention;
• FIG. 6 is a schematic representation illustrating another embodiment for wirelessly charging an automated defibrillator, according to the present invention;
• FIG. 7 is a flow diagram illustrating a technique for wirelessly charging a medical device such as an AED according to an embodiment of the invention;
• FIG. 8 is a flow diagram illustrating a technique for wirelessly charging a medical device such as an AED according to another embodiment of the invention;
• FIG. 9 is a flow diagram illustrating a technique for wirelessly charging and communicating with a medical device such as an AED according to an embodiment of the invention.
DETAILED DESCRIPTION
• The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Skilled artisans will recognize that the examples provided herein have many useful alternatives that fall within the scope of the invention.
• The present invention is not limited to automatic external defibrillators and may be employed in many various types of electronic and mechanical devices for treating patient medical conditions such as external defibrillators, implantable defibrillators, pacemakers, cardioverter defibrillators, and neurostimulators. For purposes of illustration only, however, the present invention is below described in the context of automatic external defibrillators.
• AED10 is capable of administering defibrillation therapy to a patient.AED10 includes an electrical source (not shown) that can generate one or more shocks to defibrillate the heart of a patient. The shocks may be delivered to the patient via two electrodes (not shown), which may be hand-held electrode paddles or adhesive electrode pads placed externally on the skin of the patient.
• The electrodes may be packaged in a sealed pouch (not shown), such as an airtight foil bag, which protects the electrodes from the environment. The electrodes may include substances that may degrade or dry out when exposed to air. For example, the electrodes may include a hydrogel layer that hydrates the patient's skin, forms an interface with the patient, promotes adhesion of the electrodes to the skin and reduces the risk of burns. The electrodes may be stored in a pouch to prevent the hydrogel from drying out and losing its desirable properties. The pouch may be stowed insideAED10 or inside cabinet12 (FIG. 2 &FIG. 3).
• Anoperator using AED10 typically opens the pouch, retrieves the electrodes and places the electrodes in the correct positions on the patient's chest. In some models ofAED10, the operator may also couple the electrodes to AED10 by plugging an electrical connector into a receptacle onAED10.
• Electrodes of the kind described above are intended for use on one occasion. Following use, the electrodes are discarded, andAED10 may be supplied with a fresh pouch. Even if the electrodes are not used, however, the electrodes may have a shelf life. The pouch should be replaced when the shelf life expires.
• AED10 includes an internal power source62 (FIG. 4).Power source62 for many models ofAED10 is a battery. Battery power is advantageous in many respects. First, in many situations, the patient may be far from an electrical outlet. In those situations,AED10 may rely upon a battery to supply the energy for the defibrillation shocks. Second, a power supply in the form of a battery makesAED10 portable and useful in a wider variety of emergency situations.
• AED10 also comprises an energy storage device (not shown), such as one or more capacitors, and a charging circuit (not shown), such as a flyback charger. When a defibrillation shock is needed, the charging circuit transfers energy from the power supply to the energy storage device. When the energy stored in the energy storage device reaches a desired level,AED10 is ready to deliver defibrillation therapy. The therapy may be delivered automatically or manually.
• AED10 may further include a microprocessor (not shown) that controls various functions ofAED10. The microprocessor may govern charging of the energy storage device, for example, or may evaluate heart rhythms of the patient sensed via the electrodes, or may deliver the defibrillation shocks automatically. The microprocessor may further execute a routine that performs a self-diagnostic test ofAED10 and acquire status information as a function of performing the self-diagnostic routine. The microprocessor may further acquire ECG data collected during a use ofAED10 on a patient and/or scene audio information recorded during use on a patient.
• Status information pertains to the operating status ofAED10 and its attendant components. Status information may include, for example, data indicative ofAED10 being in good working order. Status information may also include data indicative of a fault or potential problem withAED10, such as data indicative of a failed or damaged component. Data indicating that the battery is low, or that the battery is failing to hold a charge, are additional examples of AED status information. Status information may also include data indicating that the electrodes or other components are nearing the end of their shelf life, ECG data collected during use ofAED10 on a patient, and scene audio information recorded during use on a patient.
• AED10 may include one ormore output elements20 that convey status information to a person. As shown inFIG. 1,output elements20 include visual annunciators, such as light-emitting diodes (LEDs) that illuminate or darken to convey status information.Output elements20 may, for example, indicate whetherAED10 is in good working order, whether the battery is ready, or whetherAED10 needs service.Output elements20 may include other or additional annunciators, such as a liquid crystal display (LCD), a cathode ray tube (CRT) display, a strobe, or a speaker that is capable of delivering an audible signal or a spoken message.
• FIG. 2 is a perspective drawing of an automated external defibrillator (AED)10 in anexemplary docking station12.AED10 anddocking station12 are illustrative of the practice of the invention, and for simplicity, the invention will be described in terms or AEDs and docking stations. The invention is not limited to docking stations and AEDs, however, but may include other devices, including a cradling device and other types of emergency medical devices.
• In the example ofFIG. 2,docking station12 is a cabinet, comprising acompartment14 that receivesAED10 and a hingeddoor16 that closes to secureAED10 insidecompartment14.AED10 is portable. When an operator needs to useAED10, the operator may opendoor16 andlift AED10 fromcompartment14.Cabinet12 also includes abase18.
• Hingeddoor16 ofcabinet12 includes awindow22. WhenAED10 rests incompartment14 anddoor16 is closed,output elements20 may be visible throughwindow22.Base18 ofcabinet12 also includes AEDstatus output elements24 that may be redundant ofoutput elements20 onAED10. In other words,output elements24 ofcabinet12 may convey the same status information asoutput elements20 ofAED10.Output elements24 may also convey AED status information in a different way than that conveyed byAED10.Cabinet12 may, for example, employ a simplified “OK-NOT OK” indicator system, whileAED output elements20 may be more specific about the nature of any problems.
• The redundant presentation of status information may be advantageous in several respects. First, instead of facilitating observation ofoutput elements20 onAED10,window22 may impede observation ofoutput elements20. BecauseAED10 may be recessed incompartment14, for example,output elements20 may not be visible throughwindow22 from all angles. Further,window22 may be cracked or dirty or reflective of light sources that wash out the visual annunciators.Output elements24 may also be larger or brighter thanoutput elements20, allowing the status information to be perceived from a greater distance or from a wider angle of view. Thus, a person wishing to perform a routine visual check on the status ofAED10 may obtain status information about AED10 more readily.
• Cabinet12 presents status information viaoutput elements24 upon receiving the status information fromAED10. As will be described in more detail below,AED10 may establish a communication link withcabinet12, and may communicate status information tocabinet12 wirelessly.
• In addition to AEDstatus output elements24,base18 includes docking stationstatus output elements26. Docking stationstatus output elements26 may includevisual annunciators28, aspeaker30 and adisplay screen32.Visual annunciators28 may comprise, for example, LEDs.Display screen32 may comprise, for example, an LCD or CRT display.
• Docking stationstatus output elements26 convey status information that is not redundant of status information conveyed by AEDstatus output elements24. The status information conveyed by docking stationstatus output elements26 may include status information pertaining toAED10, or status information pertaining tocabinet12. Further, as will be described below,AED10, orcabinet12, or both, may be connected to a network and the status information is conveyed to health care providers responsible for the care of a patient on which the AED was used or to service personnel responsible for maintaining the AED.
• Visual annunciators28 may convey, for example, thatcabinet12 is in good working order, or that the communication interfaces ofcabinet12 are working properly.Speaker30 may convey, for example, an alarm signaling thatdoor16 is open or ajar, or verbal instructions concerning use ofAED10 orcabinet12.Display screen32 may convey any information in text or visual form, such as a pictorial instruction for openingdoor16, or a text warning thatAED10 is out of service.
• FIG. 3 is a perspective drawing of anotherAED40 in acradling station42. InFIG. 3, cradlingstation42 is a wall-mounted bracket, rather than a cabinet.Bracket42 includes a shapedbase44 that receivesAED40 and supportsAED40.Bracket42 also includesclasps46, which, in cooperation withbase44, retainAED40 andsecure AED40 tobracket42.Clasps46 may be flexible. When an operator needs to useAED40, the operator may pullAED40 fromclasps46 and liftAED40 out ofbase44.
• AED40 may include one ormore output elements48 that convey status information aboutAED40, andbase44 may include AEDstatus output elements50 that may be redundant ofoutput elements48. As will be described in more detail below,AED40 may establish a communication link withbracket42.AED40 may communicate status information tobracket42, whichbracket42 may present viaoutput elements50 onbase44.
• Output elements48 and50 may be similar tooutput elements20 and24 shown inFIG. 2. Althoughoutput elements48 are not recessed in a compartment or obscured by a window,output elements48 may be small or difficult to read at a distance.Output elements50 may be more easily perceived from a greater distance or from a wider angle of view, allowing a person to readily obtain status information aboutAED40.
• Base42 includes cradling stationstatus output elements52. Like docking stationstatus output elements26 shown inFIG. 2, cradling stationstatus output elements52 may includevisual annunciators54, aspeaker56 and adisplay screen58.
• The embodiments of an AED, docking station, and cradling station shown inFIGS. 1,2, and3 are for purposes of illustration. The invention is not limited to the arrangements depicted. For example, the invention encompasses embodiments in which the docking station output elements are positioned above the AED, or on multiple sides of the AED. The invention encompasses embodiments that include more or fewer output elements than are shown. The invention also encompasses embodiments that include docking elements to retain the AED other than clasps, shaped bases, cabinets, and doors. Docking elements may include clamps, lids, covers, trays, shelves, drawers, latches, and the like.
• FIG. 4 is a block diagram illustrating anexample defibrillator assembly60 in which adocking station66 wirelessly transfers energy from an external source to a battery109 (FIG. 5).Assembly60 may also optionally provide the capability forAED64 to communicate diagnostic and non-diagnostic data todocking station66.Assembly60 provides an energy transfer rate (typically power) by at least an amount that offsets the power drain caused by self-discharge and periodic automatic testing of the AED in order to adequately maintain the charge ofbattery109. Since this energy rate is lower than that required to continuously runAED64,assembly60 may transfer power betweendocking station66 andAED64 wirelessly without any user-accessible contacts. This lack of user accessible contacts maintains the integrity ofassembly60 and provides increased user isolation from high voltages generated byAED64. In general, the present invention utilizes an electrostatic or electromagnetic field coupled between charginginterface70 indocking station66 and charginginterface68 inAED64 to wirelessly transfer energy. However, it is fully contemplated that other types of wireless techniques could be utilized to transfer energy, such as acoustically and optically without departing from the spirit of the present invention. Further,AED64 anddocking station66 may be either of the embodiments depicted inFIGS. 1,2, and3, but are not limited to those embodiments. It is preferable thatbattery109 is a rechargeable battery, however, it is fully contemplatedbattery109 could include any type of power storage device such as a non-rechargeable battery or a large capacitor.
• In a further aspect of the present invention,AED64 wirelessly communicates withdocking station66 throughcommunication interface67 andcommunication interface69, respectively. In particular,AED64 includes acommunication interface67 that establishes a communication link with acommunication interface69 indocking station66 through charginginterface68 and charginginterface70 respectively. The method of communication through charginginterfaces68 and70 is discussed in more detail below.
• Communication interface69 may further be connected to a network. The network may comprise, for example, a public switched telephone network, a cellular telephone network, a local area network, a wide area network, a global computer network such as the Internet, an integrated services digital network, or the like. In some venues in whichAED64 anddocking station66 may be deployed, the venue may include a dedicated security network or a private building maintenance network. The network may include hard-wired electrical or optical communication links, wireless links, or a combination thereof. One method of communicating through a network is disclosed in U.S. patent application Ser. No. 10/378,001 filed Feb. 28, 2003 titled “Medical Device Status Information System”, the entire content of which is incorporated herein by reference.
• AED64 includes adata collection module84 that monitors the status ofAED64, collects ECG data during use ofAED64, and records scene audio information duringAED64 use on a patient.Data collection module84 is a processor that executes one or more self-diagnostic routines. The self-diagnostic routines may be initiated bydata collection module84, or may be initiated in response to a change in the condition ofAED64, such as a component malfunction. By execution of a self-diagnostic routine,data collection module84 performs one or more internal self-tests to acquire status information about the state of readiness ofAED64.Data collection module84 may evaluate and identify matters that can be customer serviceable, such as battery or electrode replacement, and matters that may require a professional service call.AED64 may record the status information, patient ECG data, and patient scene audio data inmemory86, and may transfer some or all of the data viacommunication interface67 and charginginterface68. When the results of the self-tests indicate thatAED64 is “ready” for use, for example,status indicators88 may provide a visible or audible indication of readiness.Status indicators88 may comprise any ofoutput elements20 or48 described in connection withFIGS. 2 and 3.
• AED64 may further communicate the collected data todocking station66 via communication interfaces67 and69. Communication betweenAED64 anddocking station66 may be made by a plurality of communication techniques through charginginterfaces68 and70. In the embodiment shown inFIG. 4,AED64 anddocking station66 may engage in two-way communication. The methods of data transfer are discussed in further detail below.
• AED64 anddocking station66 communicate via the wireless links provided by charginginterfaces68 and70. These wireless links are implemented so thatAED64 may be quickly and easily removed fromdocking station66 without hindrance. Communication betweenAED64 anddocking station66 may also communicate via a physical communication link. When dockingstation66 receivesAED64, mating acoustic or optical components indocking station66 andAED64 may engage, thereby enabling communication.
• Docking station66 includes a self-diagnostic module90 that monitors the status ofdocking station66. Self-diagnostic module90 is a processor that executes a self-diagnostic routine to perform internal self-tests and to acquire status information aboutdocking station66. The self-diagnostic routines may be initiated by self-diagnostic module90 or may be initiated in response to a change in the condition ofdocking station66. Self-diagnostic module90 may evaluate and identify matters that can be customer serviceable and matters that may require a professional service call.
• In addition, self-diagnostic module90 may collect, aggregate or interpret data received fromAED64. In some circumstances, self-diagnostic module90 may use status information fromAED64 and from self-tests to pinpoint the source of a problem. Self-diagnostic module90 may record the status information inmemory92, and may present some or all of the status information via one ormore status indicators94.Status indicators94 may include AED status output elements, such as AEDstatus output elements24 and50 inFIGS. 2 and 3, which convey AED status information redundantly.Status indicators94 may also include output elements such as docking stationstatus output elements26 and52 inFIGS. 2 and 3.Status indicators94 may convey status information pertaining toAED64, status information pertaining todocking station66.
• Docking station66 further includes apower source91. UnlikeAED64, which is portable and is usually battery-powered,docking station66 typically is stationary and may be line-powered. The invention is not limited to a line-powered docking station, however, but includes a docking station having a power source such as batteries or solar cells.
• With reference toFIG. 5, showing a schematic representation illustrating an embodiment for wirelessly charging an automated defibrillator, the present invention utilizes an electromagnetic or electrostatic field coupled betweendocking station66 andAED64 to transfer energy wirelessly. In the embodiment ofFIG. 5, the energy is coupled inductively. Whiledocking station66 is preferably connected to AC line power, this embodiment preferably does not use line frequency to transfer the energy. This is to avoid large inductors and relatively low rates of data transfer during communications betweendocking station66 andAED64. Preferably, the energy is modulated at a higher frequency, which allows for smaller magnetic components and quicker transfer of data during communications. For example, at 600 KHz the magnetic components can be extremely small and allow for a data transfer of 10,000 times faster than that of line power.
• Charging interfaces68 and70 may comprise an internal and external charging circuit respectively. Charging interfaces68 and70 may provide inductive coupling accomplished by applying an AC signal atdocking station66 throughinductor100 andresistor102, creating magnetic fields aboutinductor100. WhenAED64 is docked todocking station66, the magnetic field is coupled intoinductor104, which produces a corresponding current. WhenAED64 indicates that all tests have passed andAED64 is ready for use,transistor106 allows current to pass through tobattery109. This allowsAED64 to recharge.
• With reference toFIG. 6, showing a schematic representation illustrating another embodiment for wirelessly charging an automated defibrillator, the energy could be coupled capacitively. Once again, charginginterfaces68 and70 may comprise an internal and external charging circuit respectively. In these circuits, proper alignment of a first pair ofplates120 connected to apower source122 withindocking station66 and a second pair ofplates124 withinAED64 provides for capacitive coupling. Alternatively, the defibrillation electrodes, if connected toAED64, could be used as the second pair of plates. Another embodiment includes acousticallycoupling docking station66 toAED64, preferably at a frequency outside of the audible range. Another embodiment includes optically couplingdocking station66 andAED64 using a light source illuminating photovoltaic cells mounted onAED64.
• As stated above, the embodiment to transfer energy discussed above may be combined with methods for transferring data betweenAED64 anddocking station66 through modulation of the energy. The data could be stored bydocking station66 in a removable memory medium such as a floppy disk or flash memory card, or it could be transmitted to a receiving station through a telephone line or cellular telephone link or a network.
• With reference toFIG. 5, one embodiment may be to utilizeresistor102 to set both the current flowing throughinductor100 and to create a voltage sensed byintegrator110 and acomparator112.Integrator110 andcomparator112 may be operational amplifiers configured to implement the integration and comparing function respectively. WhenAED64 is not present atdocking station66, a specific voltage drop will be detected acrossresistor102 andintegrator110. IfAED64 is docked indocking station66 and is receiving current frominductor104, the voltage detected acrossresistor102 andintegrator110 will be lower sinceAED64 presents a load to the circuit. Thus, a simple piece of data, the presence or absence ofAED64 is transmitted.
• In another embodiment,AED64 can alert the user of the need for refurbishment ofAED64 after it has been used on a patient. IfAED64 determines it is not “ready” (e.g., it has been used and needs refurbishing or has failed a self test), thendata collection module84 will turn offtransistor106 to block current flow. This transmits additional data, however,docking station66 cannot distinguish between the absence ofAED64 or whenAED64 is not “ready”. Therefore,AED64 is fitted withmagnet114, which produces a magnetic field. Atdocking station66 voltage is applied toresistor116, which is connected to a hall-effect switch118. It is noted thatswitch118 could also be a reed switch or any other magnetic sensor without departing from the spirit of the invention. IfAED64 is docked todocking station66,hall effect switch118 detects the magnetic field produced bymagnet114 and produces a signal. This signal may be used to instructdocking station66 to begin interfacing withAED64. Additionally, the signal may be utilized in conjunction withcomparator112 to distinguish from a no-load situation whenAED64 is not docked and a no-load situation whenAED64 is docked, but not ready to interface. Alternatively,magnet114 could be used to activatehall effect switch118 wired to a conventional alarm monitoring system such that the alarm monitoring service would be alerted to the removal ofAED64 fromdocking station66.
• In another embodiment,AED64 may provide different current loads todocking station66 based on varying AED status. The resulting voltages are sensed bydocking station66 with distinct voltages equating to different device information (e.g., battery low, service requested, etc.). In this embodiment, a variable load device would be included onAED64 and by replacingcomparator112 with an analog-digital converter or incorporating multiple comparators. These different current loads could be used to distinguish between the absence ofAED64, the presence ofAED64 that has been used on a patient, the presence of anAED64 that has failed a self test, or other useful information. The number of levels of current that can be reliably distinguished limits the number of different status messages.
• In another embodiment,AED64 could vary the load on a cycle-by-cycle basis to transmit digital information, one bit per cycle. Alternately in another embodiment,AED64 could modulate the load at a frequency higher than that used to transmit the power. This carrier frequency could be frequency modulated, phase modulated, or amplitude modulated to transmit digital information.
• With reference toFIG. 7, a flow diagram illustrating a technique for wirelessly charging a medical device such as an AED is shown. Atstate140,docking station66 has detectedAED64 has been docked and is in physical contact withdocking station66. This can happen in a variety of methods some of which are discussed above, such ashall effect switch118 detecting a magnetic field produced bymagnet114 and producing a signal used to instructdocking station66 to begin interfacing withAED64. However, other types of detection methods are fully contemplated, such as optical detection, user input at the docking station indicating whetherAED64 is docked, and using a proximity sensor, without departing from the spirit of the invention. OnceAED64 is detected as being docked then dockingstation66 begins transferring energy to AED64 as shown instate142. As mentioned already the energy transfer can occur using many methods such as inductive, capacitive, acoustic, optical, and electromagnetic. As stated, the energy rate of transfer (typically power) is generally equal to or greater than the drain tobattery109 caused by self discharge and periodic automatic testing to maintain the charge ofbattery109. Therefore, ifAED64 remains docked for a long period of time, the energy rate of transfer will eventually chargebattery109. Atstate144docking station66 detects thatAED64 has been removed. For example,AED64 is needed for use on a patient. WhenAED64 is detected as removed,docking station66 stops transferring energy as shown at state146. The process then begins again when it is detected that AED is docked atdocking station66 shown atstate140.
• With reference toFIG. 8, a flow diagram illustrating another embodiment for wirelessly charging a medical device such as an AED is shown. Similar tostate140,state150 detects whenAED64 is docked indocking station66. In contrast to the embodiment ofFIG. 7, whenAED64 is docked, it begins to communicate todocking station66 whetherbattery109 is fully charged or not atstate152.AED64 can communicate this status in any of the methods discussed above. Ifbattery109 is fully charged or charged to within 90% of capacity, then dockingstation66 will transfer energy at a level that maintains the battery consumption ofAED64 atstate154. Ifbattery109 is not fully charged or below a charge of 90%, then dockingstation66 will transfer energy at a rate slightly above a level that would maintain the battery consumption ofAED64 atstate156. This allows for enough energy to slowly chargebattery109. This charging capacity is more than adequate for an AED that is used infrequently. IfAED64 is removed from dockingstate66, then any energy transfer fromdocking station66 is stopped as shown atstate158. This process then begins again whenAED64 is placed back indocking station66 as shown atstate150.
• With reference toFIG. 9, a flow diagram illustrating another embodiment for wirelessly charging a medical device such as an AED is shown. Similar tostate140 and110,state160 detects whenAED64 is docked indocking station66. WhenAED64 is docked, it begins to communicate todocking station66 whetherbattery109 is fully charged or not atstate162.AED64 can communicate this status in any of the methods discussed above. Ifbattery109 is fully charged or charged to within 90% of capacity, then dockingstation66 will transfer energy at a level that maintains the battery power consumption ofAED64 atstate164. Ifbattery109 is not fully charged or below a charge of 90%, then dockingstation66 will transfer energy at a rate slightly above a level that would maintain the battery power consumption ofAED64 atstate166. Regardless of which energy rate is chosenAED64 begins to transmit AED status data and patient ECG and scene audio data todocking station66 using any of the methods discussed above atstate168.Docking station66 then determines whether it is receiving the data atstate170. If no data is being received,docking station66 interrogatesAED64 and instructs it to start sending the data. If data is being received,docking station66 then waits for data indicating that the data transmission is complete atstate172. If the transmission is complete andAED64 is still docked, then dockingstation66 continues to transfer energy at the desired rate. If the transmission is not complete andAED64 is still docked, then dockingstation66 continues to monitor whether the data is being received atstate170. IfAED64 is removed fromdocking station66 at any moment in the present embodiment, the power and data transfer is interrupted and the process returns tostate160.
• One skilled in the art will appreciate that the present invention can be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims that follow.

Claims (7)

1-22. (canceled)

23. A method comprising:

receiving line power into a docking station; and

wirelessly coupling the received line power to a defibrillator docked at the station.

24. The method ofclaim 23, in which the coupling is capacitive.

25. The method ofclaim 23, in which the coupling is inductive.

26. The method ofclaim 23, in which the coupling is optical.

27. The method ofclaim 23, in which the coupling is electromagnetic.

28-35. (canceled)

Images