Automated external defibrillator system and method of use

Abstract

The present disclosure describes various aspects of an automated external defibrillator (AED) system including shock-delivery electronics, a battery configured to provide power to the shock-delivery electronics, power management circuitry configured to manage the shock-delivery electronics and the battery, at least one environmental sensor configured to monitor environmental conditions in which the AED system is installed, and a controller configured to control the power management circuitry and the at least one environmental sensor. The at least one environmental sensor includes a temperature sensor configured to provide temperature measurements, and the controller is further configured to adjust operation of the power management circuitry according to the temperature measurements provided by the temperature sensor. The present disclosure further describes associated methods of using the AED system.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 091,681, filed October 14, 2020, and entitled "AUTOMATED EXTERNAL DEFIBRILLATOR SYSTEMS WITH OPERATION ADJUSTMENT FEATURES ACCORDING TO TEMPERATURE AND METHODS OF USE."

[0002] FIELD OF THE DISCLOSURE Aspects of the present disclosure relate generally to automated external defibrillators (AEDs), and more particularly to compact AED systems. [Background technology]

[0003] While 86 million Americans have risk factors for sudden cardiac arrest (SCA), 12 million are at high risk. Cardiac events represent more causes of death in the United States than breast, lung, colon, and prostate cancer combined. More than 360,000 sudden cardiac arrests (SCAs) occur outside of hospitals each year. According to the American Heart Association, nearly 70% of these SCAs occur at home, outside the reach of the life-saving shock of an AED.

[0004] With each minute that passes following sudden cardiac arrest, the chances of survival decrease significantly. If an AED is not applied within 10 minutes of an SCA event, the chances of survival decrease to less than 1%.

[0005] One approach to increasing the chances of survival for SCA patients is to make AEDs more readily available and accessible to more people. However, AEDs currently available on the market are heavy, non-portable, expensive, and tend to be hesitant to use for people without medical training. For example, U.S. Patent Publication No. US 2018 / 0169426 (Patent Document 1), entitled "Automatic External Defibrillator Device and Methods of Use," (the disclosure of which is incorporated herein by reference in its entirety), provides a possible solution to overcoming the availability and accessibility issues by providing a compact AED device suitable for portability.

[0006] Aspects of the present disclosure provide techniques and structures that improve the performance of AEDs suitable for highly portable applications. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2018 / 0169426 Summary of the Invention [Means for solving the problem]

[0008] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all possible aspects, and is not intended to identify key or critical elements of all aspects or to delineate the scope of any or all aspects. Its purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description presented later.

[0009] In one aspect, an automated external defibrillator (AED) system according to an embodiment is described. The AED system includes shock delivery electronics, a battery configured to provide power to the shock delivery electronics, power management circuitry configured to manage the shock delivery electronics and the battery, at least one environmental sensor configured to monitor environmental conditions in which the AED system is installed, and a controller configured to control the power management circuitry and the at least one environmental sensor. The at least one environmental sensor includes a temperature sensor configured to provide a temperature measurement, and the controller is further configured to adjust operation of the power management circuitry according to the temperature measurement provided by the temperature sensor.

[0010] In another aspect, a method of using an external defibrillator (AED) system according to an embodiment is described. The AED system includes shock-delivery electronics, a battery configured to provide power to the shock-delivery electronics, power management circuitry configured to manage the shock-delivery electronics and the battery, at least one environmental sensor for monitoring environmental conditions in which the AED system is installed, and a controller configured to control the power management circuitry and the at least one environmental sensor. The method includes measuring a temperature of the AED system and adjusting operation of the power management circuitry according to the temperature so measured. The present invention provides, for example, the following. (Item 1) 1. An automated external defibrillator (AED) system, the AED system comprising: a shock generating electronic device; a battery configured to provide power to the shock delivery electronics; power management circuitry configured to manage the shock delivery electronics and the battery; at least one environmental sensor configured to monitor environmental conditions in which the AED system is installed; a controller configured to control the power management circuitry and the at least one environmental sensor; Equipped with the at least one environmental sensor includes a temperature sensor configured to provide a temperature measurement; The AED system, wherein the controller is further configured to adjust operation of the power management circuitry according to the temperature measurements provided by the temperature sensor. (Item 2) the power management circuitry is further configured to measure a voltage level of the battery; 2. The AED system of claim 1, wherein the controller is further configured to compare the voltage level of the battery so measured with at least one voltage threshold level, the voltage threshold level being selected based on the temperature measurement value provided by the temperature sensor. (Item 3) a user interface configured to display information to a user of the AED system; 3. The AED system of claim 2, wherein the controller is further configured to provide an indication at the user interface according to the voltage level of the battery so measured compared to the at least one voltage threshold level. (Item 4) 3. The AED system of claim 2, wherein the controller is further configured to instruct the power management circuitry to set a charge rate of the shock generation circuitry according to the voltage level of the battery so measured compared to the at least one voltage threshold level. (Item 5) 5. The AED system of claim 4, wherein the controller is configured to instruct the power management circuitry to reduce the charge rate of the shock generation circuitry when the voltage level of the battery falls below the at least one voltage threshold level. (Item 6) further comprising a wireless charging mechanism configured to wirelessly charge the battery; 3. The AED system of claim 2, wherein the power management circuitry is further configured to initiate a process of charging the battery according to the voltage level of the battery so measured compared to the at least one threshold level. (Item 7) a pair of pads for delivering an electric shock from the shock-generating electronics to a patient; the controller is further configured to measure face-to-face impedance values ​​between the pairs of pads; The controller is further configured to compare the face-to-face impedance values ​​between the pairs of pads so measured with at least one impedance threshold level, the impedance threshold level being based on the temperature measurements provided by the temperature sensor. 2. The AED system according to claim 1, selected based on: (Item 8) a user interface configured to display information to a user of the AED system; 8. The AED system of claim 7, wherein the controller is further configured to provide an indication to the user interface according to the face-to-face impedance value between the pair of pads so measured compared to the at least one impedance threshold level. (Item 9) 9. The AED system of claim 8, wherein the controller is configured to provide an indication to the user interface when the face-to-face impedance value exceeds the at least one impedance threshold level. (Item 10) 1. A method of using an automated external defibrillator (AED) system, the AED system including shock delivery electronics, a battery configured to provide power to the shock delivery electronics, power management circuitry configured to manage the shock delivery electronics and the battery, at least one environmental sensor for monitoring environmental conditions in which the AED system is installed, and a controller configured to control the power management circuitry and the at least one environmental sensor, the method comprising: measuring a temperature of the AED system; adjusting operation of said power management circuitry in accordance with said temperature so measured; A method comprising: (Item 11) measuring the voltage level of the battery; comparing said voltage level of said battery so measured with at least one voltage threshold level adjusted with respect to said temperature so measured; Item 11. The method of item 10, further comprising: (Item 12) The AED system further includes a user interface, and the method further comprises: Item 12. The method of item 11, further comprising providing an indication in the user interface according to the voltage level of the battery so compared. (Item 13) 12. The method of claim 11, further comprising modifying the charge rate of the shock generation circuitry according to the voltage level of the battery so measured compared to the at least one threshold level. (Item 14) Item 11. The method of item 10, wherein measuring the temperature of the AED system comprises measuring the temperature of the battery, measuring an internal temperature of an AED case, and measuring an environmental temperature. [Brief explanation of the drawings]

[0011] The accompanying drawings illustrate only some implementations and therefore should not be considered limiting of scope.

[0012] [Figure 1] FIG. 1 illustrates a block diagram of an exemplary AED including AED operation and communication blocks according to an embodiment.

[0013] [Figure 2] FIG. 2 illustrates a flow diagram of a process for adjusting the operation of an AED in light of measured battery temperature according to one embodiment.

[0014] [Figure 3] FIG. 3 illustrates a flow diagram of a process for adjusting the operation of an AED in consideration of measured pad temperature according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. Like numbers refer to like elements throughout.

[0016] While terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, it should be understood that these elements, components, regions, layers, and / or sections are not limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be referred to as a second element, component, region, layer, or section without departing from the teachings of the present invention.

[0017] Spatial relative terms such as "below," "below," "belowside," "below," "above," "upper," and the like may be used herein for ease of description to describe the relationship of one element or feature to another element or feature as illustrated in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures were turned over, elements described as "below" or "below" or "below" the other element or feature would be oriented "above" the other element or feature. Thus, the exemplary terms "below" and "below" can encompass both an orientation of above and below. A device may be oriented differently (rotated 90 degrees or at another orientation), and the spatial relative descriptors used herein interpreted accordingly. Additionally, it should also be understood that when a layer is referred to as being "between" two layers, it may be only the layer between the two layers, or one or more intervening layers may also be present.

[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It is further understood that the terms "comprises" and / or "comprising," as used herein, specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as " / ."

[0019] When an element or layer is referred to as "on," "connected to," "coupled to," or "adjacent to" another element or layer, it is understood that it may be directly on, connected to, coupled to, or adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as "directly on," "directly connected to," "directly coupled to," or "directly adjacent to" another element or layer, no intervening elements or layers are present. Similarly, when light is received or provided "from" an element, it can be received or provided directly from that element or from an intervening element. On the other hand, when light is received or provided "directly from" an element, no intervening elements are present.

[0020] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It is further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the relevant art and / or in the context of this specification, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0021] If more AEDs could be made available to more people with improved portability, lower cost, and enhanced ease of use, more lives could be saved in cases of SCA occurring outside of hospital settings. That is, just as EpiPen® injectors are prescribed for and carried by people diagnosed with potentially life-threatening allergies, portable AEDs could become necessary and routine items prescribed to those diagnosed as at risk for SCA. Portable, inexpensive, and user-friendly AEDs with safe and simple application protocols are desirable for such widespread adoption in the consumer market. Additionally, secure and streamlined connectivity to emergency personnel, external data sources, and peripheral devices would also be desirable.

[0022] One challenge to having a portable AED is the need to ruggedize the AED so that the system can be stored and operate in a variety of environmental conditions, such as low and high altitudes, low and high humidity, and low and high temperatures (e.g., −20° C. to +50° C.). Because various components within an AED may function differently in different environmental conditions, and even the patient's physical condition (e.g., skin temperature) can affect the operation of the AED, it would be desirable for a portable AED to be able to adapt to various environmental conditions during storage and operation, preferably in real time.

[0023] Referring now to FIG. 1 , an exemplary AED including an AED operational block and a communications block is illustrated according to one embodiment. The AED 100 includes features that allow the AED 100 to be connected to the outside world to provide additional functionality and enable usage scenarios not previously possible. The AED 100 includes an AED operational block 102, which includes various components that enable the AED 100 to generate and deliver an electric shock to a person experiencing sudden cardiac arrest within regulatory guidelines. As shown in the embodiment illustrated in FIG. 1 , the AED operational block 102 includes a controller 110, which coordinates various components including electrocardiogram (ECG) monitoring circuitry 120, which in turn is connected to pads 122. The pads 122 are configured for attachment to specific locations on an SCA patient for both acquisition of ECC signals and administration of an electric shock generated by shock generation electronics 124 (which is also controlled by the controller 110). The controller 110 also monitors the condition of the pads, for example, by measuring face-to-face pad impedance. Increased pad impedance may indicate that the adhesive attaching the pads to the SCA patient has dried out excessively and therefore may require replacement to maintain effective operation of the AED system.

[0024] Additionally, the AED operation block 102 includes a power management block 130, which in one embodiment is also controlled by the controller 110. The power management block 130 is configured to manage power consumption by various components within the AED operation block 102. For example, the power management block 130 monitors the charge status of a battery 132 that provides power to the shock delivery electronics 124. Thus, the controller 110 can alert the AED user if a low battery level is detected by the power management block 130. Similarly, the controller 110 can also coordinate the power management block 130 to control the on / off status of other components within the AED 100 to minimize power consumption by these other components while the AED is not in use. In one embodiment, for example, the power management block 130 is configured to completely power down the ECG monitoring circuitry 120 and the shock delivery electronics 124 when the AED is not in use. The controller 110 may include, for example, non-transitory memory for storing software instructions. The non-transitory memory may be communicatively coupled to a processor (e.g., a microprocessor) for executing software instructions stored on the non-transitory memory. The software instructions may include, for example, workflow information for operating the AED as described herein.

[0025] Continuing with reference to FIG. 1, the controller 110 is also connected to a memory 140 that stores information about the AED 100, such as usage history, battery status, shock administration and cardiopulmonary resuscitation (CPR) protocols, and other information used in the operation of the AED 100 (e.g., stored in a look-up table).

[0026] The controller 110 further controls a user interface (UI) block 150. The UI block 150 includes audio and / or visual prompts to instruct the AED user regarding use of the AED 100, such as delivered by a user interface (e.g., a tactile display such as a touchscreen, light-emitting diode (LED) indicators, a liquid crystal display, a speaker, switches, buttons, and other methods for displaying information to the user and / or for the user to control the AED). In certain embodiments, the UI block 150 may optionally include a microphone for receiving audio input from the AED user. In alternative embodiments, the UI block 150 may optionally include an interface with an external application, such as a native or web app on a mobile device configured to communicate with the AED 100.

[0027] The AED operation block 102 as shown in FIG. 1 further includes optional features such as wireless charging circuitry 160 and an accelerometer 162. For example, if a portion of the battery 132 includes a rechargeable battery configured for wireless charging, the wireless charging circuitry 160 is used to charge the rechargeable battery. Optionally, the power management block 130 can be used to control the wireless charging circuitry 160 to trigger a battery charging process when it is detected that the charge level of the rechargeable battery in the battery 132 has fallen below a preset threshold. Alternatively, the power management block 130 can trigger the battery charging process using a wired connection to an external power source (e.g., an electrical wall outlet, a car charger, or a generator (not shown)) when the charge level falls below the preset threshold. The optional accelerometer 162 can be used to determine whether the AED is being moved. If readings from the accelerometer indicate that the AED has been moved, an AED location check may be performed to determine new GPS coordinates, and / or a temperature check may be performed using the AED temperature sensor to determine environmental conditions at the new AED location.

[0028] Additionally, an environmental sensor block 164 can be used to monitor the environmental conditions in which the AED 100 is installed. For example, the environmental sensor block 164 can include one or more of a temperature sensor, a hygrometer, an altimeter, and other sensors for monitoring the environment around the AED 100 and / or around one or more components within or coupled to the AED 100. By way of example, the environmental sensor block 164 monitors the temperature of the battery 132 and / or pads 122 and / or the relative humidity of the environment in which the AED is installed.

[0029] Still referring to FIG. 1 , the AED 100 includes a communications block 170, also controlled by the controller 110. The communications block 170 provides connectivity to external systems and entities outside the AED, such as emergency medical services, hospital emergency rooms, physicians, electronic health record systems, and other medical equipment, such as ventilators and external ECG devices. In one embodiment, the communications block 170 optionally includes a cellular modem 172 and a Bluetooth® modem 174. Optionally, the communications block 170 includes, for example, a Wi-Fi modem 176 for providing wireless connectivity to and from external devices, one or more wired connections 178 for providing a direct wired connection to the AED 100, such as via a local area network (LAN), cable, telephone line, or optical fiber. The communications block 170 may also optionally include a satellite modem 180 for providing remote communications via satellite. The various communication modes within the communications block 170 are configured to comply with regulatory guidance related to wireless technologies, such as coexistence, security, and electromagnetic compatibility. By having a single controller (e.g., a microprocessor) control various blocks within the AED 100, the circuit design and firmware configuration of the AED 100 is significantly more integrated than other AEDs with multiple processors, while allowing for reduced power consumption of the device.

[0030] Environmental conditions such as temperature and humidity affect both the performance of an AED during use and the degradation rate of AED components during storage and transportation. For example, it has long been recognized that adhesives on pads degrade more rapidly at higher temperatures; therefore, others have proposed adjusting the periodic pad replacement schedule according to the temperature conditions where the AED is stored and used, even if the AED and pads are not deployed prior to replacement. The battery that powers AED operation also has a degradation rate that varies with temperature. For example, U.S. Patent No. 6,980,859 to Powers, et al., notes that the degradation rate of disposable batteries is similar to that of pads with respect to temperature.

[0031] Additionally, it is recognized herein that the specific temperature of the battery and pads can affect the safe operation of the AED, both during transport / storage and during shock delivery. By taking into account the ambient temperature and / or the temperature of specific components within the AED, adjustments can be made by the power management module and / or by a controller within the AED operation block to enable safer and more reliable operation of the AED.

[0032] I. Temperature Considerations in Battery Charge Level Assessment

[0033] Ambient or battery temperature can be taken into account in understanding the charging status of the battery. This temperature information can then be used to adjust the rate at which the shock delivery electronics in the AED are charged. For example, the charging rate of the shock delivery electronics can be reduced when the battery is at a low temperature or low battery to avoid brownout situations in which the controller and other circuits are unable to function due to a low power supply voltage from the battery.

[0034] An example of a process for using temperature data to regulate the operation of an AED is shown in Figure 2. The process 200 of Figure 2 begins with a start step 202, followed by a step 210 for measuring the temperature of a battery within the AED, such as the battery 132 of the AED 100. For example, the environmental sensor block 164 may include a thermometer, thermocouple, or thermistor device (e.g., a resistance temperature detector) for measuring the temperature of the battery 132 and / or the external environment in which the AED 100 is being used. Optionally, the ambient temperature of the AED or another component within the AED may be used as a proxy for the battery temperature.

[0035] Process 200 proceeds to step 212 and measures the voltage level of the battery ("batt_level"), thus providing an indication of the amount of charge that can be provided by the battery at the time of interest (e.g., the time the measurement is made). For example, the measurement of the voltage level of battery 132 can be performed by power management block 130. [Table 1]

[0036] In one example, a lookup table (e.g., Table 1 shown herein) can be used to determine a particular battery level threshold below which the battery voltage will be considered low or very low. For example, if the battery voltage is determined to be low, the AED controller may send a notification to the user. Due to the battery temperature dependence of the measured battery voltage, it is recognized herein that the low and very low battery level thresholds should be adjusted according to the battery temperature. Table 1 reflects an exemplary set of thresholds deemed suitable for effective operation of an exemplary AED. While Table 1 shows temperature values ​​as measured at the battery, it should be noted that another temperature reading in a different part of the AED, such as the ambient temperature or the internal temperature of the AED case, can be used as a proxy for battery temperature. The threshold temperature level can be adjusted depending on where the temperature measurement is made.

[0037] The thresholds shown in Table 1 relate to specific battery temperatures, but linear or nonlinear interpolation approaches can be used to extend the data in Table 1 to temperatures below, above, and between the listed values. For example, nonlinear regression (e.g., nonlinear least-squares fit) can be used to find a suitable function that best fits a given set of data points. An example approach can be found at http: / / www.xuru.org / rt / NLR.asp.

[0038] 2 , decision 220 is made to determine whether the measured battery temperature is above a high temperature threshold (e.g., 25° C.). If the answer to decision 220 is yes, the value of variable batt_temp to be used in threshold interpolation is set to the high temperature threshold (e.g., 25° C.) in step 222. If the answer to decision 220 is no, process 200 proceeds to decision 224, where a determination is made whether the measured battery temperature is below a low temperature threshold (e.g., −20° C.). If the answer to decision 224 is yes, batt_temp is set to the low temperature threshold (e.g., −20° C.) in step 226. If the answer to decision 224 is no, batt_temp is set to the measured battery temperature value in step 228.

[0039] From steps 222, 226, and 228, process 200 proceeds to step 230, where a voltage threshold low_level (i.e., the voltage value below which the battery charge level will be considered too low for safe operation of the AED) is calculated for a given value of the variable batt_temp. The equation used to calculate low_level takes into account the variable batt_temp as set in steps 222, 226, or 228. As explained above, this equation can be obtained by calculating an equation that fits the data given in Table 1. Similarly, in step 232, a voltage threshold crit_level (i.e., the voltage value below which the battery charge level will be considered too low for safe operation of the AED) is calculated for a given value of the variable batt_temp. A determination is then made in decision 240 whether the value of batt_level measured in step 212 is below the calculated voltage threshold crit_level from step 232. If the answer to decision 240 is yes, an indication that the battery charge level is very low is written in the AED controller in step 242. If the answer to decision 240 is no, a determination is made in decision 244 whether the value of batt_level is below the calculated voltage threshold low_level from step 230. If the answer to decision 244 is yes, an indication that the battery charge level, while not critically low, is still considered low is written in the AED controller in step 246. If the answer to decision 244 is no, an indication that the battery charge level is normal is written in step 248. Following step 242, 246, or 248, the operation of the AED is adjusted in step 250 according to whether the battery level is very low, low, or normal.

[0040] For example, if an AED is being actively used to prepare to shock a patient and the battery voltage level is determined to be low or very low using process 200, the power management block may slow down the charging rate of the shock delivery electronics to avoid rapidly draining the battery. In another example, process 200 may be performed during the AED's self-test routine. In such a case, if the battery voltage level is low or very low, an alert may be sent to the registered user of the AED to recommend charging the AED battery as soon as possible. Alternatively, the power management block may automatically enable wired or wireless charging of the battery. Finally, process 200 is terminated at end step 260.

[0041] Although process 200 is shown with separate determinations for low and very low battery levels, any one of these determinations may be eliminated for simple calculations while remaining within the scope of this disclosure. Additionally, the specific values ​​shown in Table 1 and used in the calculations in process 200 are exemplary only and are not intended to be limiting. Process 200 may be performed, for example, in controller 110 or power management block 130 of AED 100 of FIG. 1.

[0042] II. Estimating Pad Impedance Based on Temperature

[0043] Another way to consider temperature during AED operation is in determining pad status. As discussed above, pads used in delivering an electric shock to an SCA patient deteriorate over time, and pad deterioration accelerates when stored at higher temperatures. One way to quantify pad deterioration is by performing face-to-face impedance measurements between pairs of pads. The face-to-face measurement process may involve enabling electrical communication between the two pad faces (e.g., by direct contact between portions of each side of the pad or by electrically coupling a conductive wire between the two pad faces), sending an electrical signal through the pad, and determining its impedance. The temperature dependence of pad impedance can be considered during AED use (i.e., when the pads are applied to an SCA patient) without explicit measurement and adjustment for a specific temperature, since voltage / current detection during the first few seconds of the shock delivery protocol takes into account any pad impedance fluctuations. However, alternating current (AC) face-to-face measurements of pad impedance adjusted for temperature can be used to check for pad deterioration. [Table 2]

[0044] Table 2 shows experimentally measured face-to-face impedance between pairs of exemplary pads at different temperatures. The face-to-face impedance of pads stored at a given temperature for one year increased only slightly after three years of storage at the same temperature. While elevated impedance measurements are an indication that the pads may be deteriorating, it is recognized from the values ​​in Table 2 that pad impedance measurements also increase at lower temperatures. [Table 3]

[0045] Similar to the battery voltage level threshold determination, the pad impedance threshold may be empirically derived for a particular operating temperature and then extrapolated using linear interpolation. Table 3 shows exemplary values ​​of empirically determined pad impedance thresholds at different temperatures. Linear interpolation may then be used to adjust the pad impedance threshold at temperatures between the low and high temperature thresholds (e.g., −20° C. and 25° C., respectively).

[0046] An example of a process for adjusting AED operation according to the determined condition of the pads is shown in FIG. 3. Process 300 of FIG. 3 begins with a start step 302, followed by step 310 for measuring the temperature of a pad associated with or stored within the AED. As described above with respect to temperature measurements in the battery, pad temperature measurements may be performed by the environmental sensor block 164 of AED 100 shown in FIG. 1, and ambient temperature or the temperature of another component within the AED may be used as a surrogate for pad temperature. Process 300 then proceeds to measuring the pad impedance (i.e., a face-to-face impedance measurement) of the pads in step 312. Pad impedance measurements may be performed, for example, by controller 110 of FIG. 1.

[0047] Continuing with reference to FIG. 3 , decision 320 is made to determine whether the measured pad temperature exceeds a high temperature threshold (e.g., 25° C.). If the answer to decision 320 is yes, the value of variable pads_temp to be used in threshold interpolation is set to the high temperature threshold (e.g., 25° C.) in step 322. If the answer to decision 320 is no, process 300 proceeds to decision 324, where a determination is made whether the measured pad temperature is below a low temperature threshold (e.g., −20° C.). If the answer to decision 324 is yes, pads_temp is set to the low temperature threshold (e.g., −20° C.) in step 326. If the answer to decision 324 is no, pads_temp is set to the measured pad temperature value or a surrogate thereof in step 328.

[0048] From steps 322, 326, and 328, process 300 proceeds to step 330, where an impedance threshold high_level (i.e., the value above which the pad impedance will be considered too high for safe use of the pad) is calculated for a given temperature value of the variable pads_temp. The formula used to calculate high_level takes into account the variable pads_temp as set in steps 322, 326, or 328.

[0049] Still referring to FIG. 3 , a determination is made in decision 340 whether the measured pad impedance value exceeds the calculated threshold high_level from step 330. If the answer to decision 340 is yes, an indication is written in the AED controller in step 342 that the pads may be degraded and therefore unsafe for further use. If the answer to decision 340 is no, an indication is written in the AED controller that the pad condition is normal in step 348. Following step 342 or 348, the operation of the AED is adjusted in step 350 according to whether the pad condition is determined to be degraded or normal. For example, if the pad condition is determined to be normal, an indication may be displayed on the AED or sent to a registered user that the pad self-test indicates that the pad condition is normal and that they are ready for use. If the self-test indicates that the pads may be degraded, an alert may be sent to the registered user to prompt them to replace the pads as soon as possible, or if the AED is used to deliver electric shocks to SCA patients, an alert may be displayed in the user interface to warn the user that the pads may be degraded and AED performance may be compromised. Process 300 is terminated at end step 360. Process 300 may be performed, for example, in controller 110 of AED 100 of FIG. 1.

[0050] Additional operation of the AED may be modified based on the temperature and pad impedance measurements described above. For example, thresholds for CPR feedback, such as the compression rate threshold and / or compression depth threshold, may be modified. The CPR impedance threshold may also be adjusted based on the temperature and / or pad impedance measurements.

[0051] The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. While several exemplary embodiments of the present invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without substantially departing from the novel teachings and advantages of the present invention. For example, the AED 100 may further include a global positioning system (GPS) transceiver as part of the satellite modem 180. The AED 100 may then use the GPS signal to determine, for example, its geographic location and altitude, which information may be used in considering environmental conditions in which the AED is installed, such as those described above. Alternatively, the GPS data may be obtained using another component in the communications block 170, such as the cellular modem 172, the Bluetooth modem 174, the Wi-Fi modem 176, and / or the wired connection 178.

[0052] The features described above and claimed below can be combined in various ways without departing from the scope thereof. The following examples illustrate some possible non-limiting combinations.

[0053] (A1) An automated external defibrillator (AED) system includes shock delivery electronics, a battery configured to provide power to the shock delivery electronics, power management circuitry configured to manage the shock delivery electronics and the battery, at least one environmental sensor configured to monitor environmental conditions in which the AED system is installed, and a controller configured to control the power management circuitry and the at least one environmental sensor, wherein the at least one environmental sensor includes a temperature sensor configured to provide a temperature measurement, and the controller is further configured to adjust operation of the power management circuitry according to the temperature measurement provided by the temperature sensor.

[0054] With respect to the AED system represented as (A2)(A1), the power management circuitry may be further configured to measure a voltage level of the battery, and the controller may be further configured to compare the so-measured voltage level of the battery with at least one voltage threshold level, which may be selected based on temperature measurements provided by the temperature sensor.

[0055] (A3) With respect to an AED system designated as (A1) or (A2), a user interface may be configured to display information to a user of the AED system, and the controller may be further configured to provide an indication in the user interface according to the voltage level of the battery so measured compared to at least one voltage threshold level.

[0056] (A4) For an AED system represented as any of (A1)-(A3), the controller may be further configured to instruct the power management circuitry to set a charge rate for the shock generation circuitry according to the battery voltage level so measured compared to at least one voltage threshold level.

[0057] (A5) For an AED system represented as any of (A1)-(A4), the controller may be configured to instruct the power management circuitry to reduce the charge rate of the shock generation circuitry when the voltage level of the battery falls below at least one voltage threshold level.

[0058] (A6) With respect to the AED system represented as any of (A1)-(A5), the wireless charging mechanism may be configured to wirelessly charge the battery. According to the voltage level of the battery so measured compared to at least one threshold level, the power management circuitry may be further configured to initiate a process of charging the battery.

[0059] With respect to the AED system represented as any of (A7)(A1)-(A6), a pair of pads may be provided for delivering an electric shock from the shock-generation electronics to a patient. The controller may be further configured to measure a face-to-face impedance value between the pair of pads, and the controller may be further configured to compare the measured face-to-face impedance value between the pair of pads with at least one impedance threshold level. The impedance threshold level may be selected based on a temperature measurement provided by a temperature sensor.

[0060] With respect to an AED system represented as any of (A8)(A1)-(A7), a user interface may be configured to display information to a user of the AED system, and the controller may be further configured to provide an indication to the user interface according to the face-to-face impedance value between the pair of pads so measured compared to at least one impedance threshold level.

[0061] (A9) For an AED system represented as any of (A1)-(A8), the controller may be configured to provide an indication on the user interface when the face-to-face impedance value exceeds at least one impedance threshold level.

[0062] (B1) A method of using an automated external defibrillator (AED) system includes an AED system including shock-delivery electronics, a battery configured to provide power to the shock-delivery electronics, power management circuitry configured to manage the shock-delivery electronics and the battery, at least one environmental sensor for monitoring environmental conditions in which the AED system is installed, and a controller configured to control the power management circuitry and the at least one environmental sensor. The method includes measuring a temperature of the AED system and adjusting operation of the power management circuitry according to the temperature so measured.

[0063] (B2) With respect to the method represented as (B1), the method may include measuring the voltage level of the battery and comparing the voltage levels of the battery so measured.

[0064] (B3) With respect to the method represented as (B1) or (B2), the AED system may further include a user interface, and the method may further include providing an indication in the user interface according to the voltage levels of the batteries so compared.

[0065] (B4) With respect to the method represented as any of (B1)-(B3), the method may include modifying the charge rate of the shock generation circuitry according to the battery voltage level so measured compared to at least one threshold level.

[0066] (B5) With respect to the method expressed as any of (B1)-(B4), the method may include measuring the temperature of the AED system, including one selected from the group consisting of measuring the temperature of the battery, measuring the internal temperature of the AED case, and measuring the environmental temperature.

[0067] Thus, many different embodiments arise from the above description and drawings. It is understood that literally describing and illustrating every combination and subcombination of these embodiments would be unduly repetitive and confusing. Therefore, this specification, including the drawings, is to be construed as constituting a complete written description of every combination and subcombination of the embodiments described herein, and the manner and process of making and using them, and supporting any claim to any such combination or subcombination.

Claims

1. 1. An automated external defibrillator (AED) system, the AED system comprising: a shock generating electronic device; a battery configured to provide power to the shock delivery electronics; power management circuitry configured to manage the shock delivery electronics and the battery; at least one environmental sensor configured to monitor environmental conditions in which the AED system is installed; a controller configured to control the power management circuitry and the at least one environmental sensor; Equipped with the at least one environmental sensor includes a temperature sensor configured to provide a temperature measurement; the controller is further configured to adjust operation of the power management circuitry according to the temperature measurements provided by the temperature sensor; the power management circuitry is further configured to measure a voltage level of the battery; the controller is further configured to compare the voltage level of the battery so measured with at least one voltage threshold level, the voltage threshold level being selected based on the temperature measurement provided by the temperature sensor; and wherein the controller is further configured to instruct the power management circuitry to set a charge rate for the shock delivery electronics according to the voltage level of the battery so measured compared to the at least one voltage threshold level.

2. a user interface configured to display information to a user of the AED system; 10. The AED system of claim 1, wherein the controller is further configured to provide an indication at the user interface according to the voltage level of the battery so measured compared to the at least one voltage threshold level.

3. 2. The AED system of claim 1, wherein the controller is configured to instruct the power management circuitry to reduce the charge rate of the shock delivery electronics when the voltage level of the battery falls below the at least one voltage threshold level.

4. further comprising a wireless charging mechanism configured to wirelessly charge the battery; 10. The AED system of claim 1, wherein the power management circuitry is further configured to initiate a process of charging the battery according to the voltage level of the battery so measured compared to the at least one threshold level.

5. 1. A method of operating an automated external defibrillator (AED) system, the AED system including shock delivery electronics, a battery configured to provide power to the shock delivery electronics, power management circuitry configured to manage the shock delivery electronics and the battery, a temperature sensor configured to provide a temperature measurement, and a controller configured to control the power management circuitry and the temperature sensor, the method comprising: the temperature sensor measuring the temperature of the AED system; the power management circuitry measuring a voltage level of the battery; the controller comparing the voltage level of the battery so measured with at least one voltage threshold level, the voltage threshold level being selected based on the temperature measurement provided by the temperature sensor; the controller instructing the power management circuitry to set a charge rate for the shock-delivery electronics according to the voltage level of the battery so measured compared to the at least one voltage threshold level; the controller measuring face-to-face impedance values ​​between pairs of pads, the pairs of pads configured to deliver an electric shock from the shock delivery electronics to a patient; the controller comparing the face-to-face impedance values ​​so measured between the pairs of pads with at least one impedance threshold level, the impedance threshold level being selected based on the temperature measurements provided by the temperature sensor; the controller providing an indication via a user interface when the face-to-face impedance value exceeds the impedance threshold level. A method comprising:

6. The method of claim 5 further comprising the controller providing an indication of the charging rate via a user interface.

7. 6. The method of claim 5, further comprising the controller instructing the power management circuitry to reduce the charge rate of the shock-delivery electronics when the voltage level of the battery falls below the at least one voltage threshold level.

8. 6. The method of claim 5, further comprising the power management circuitry charging the battery, the AED system including a wireless charging mechanism configured to wirelessly charge the battery.

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