USRE40471E1 - AED with force sensor - Google Patents

Abstract

A force sensor, for use in combination with an automated electronic defibrillator (AED), includes a first conductive layer. A second conductive layer is spaced apart from the first conductive layer such that no electrical communication occurs between the first and second conductive layers. An electrical communication device is provided for establishing electrical communication between the first and second conductive layers responsive to the application of a force to said electrical communication means. A method of prompting a rescuer in the application of cardiopulmonary resuscitation to a victim includes the steps of:

• • sensing a force applied by the rescuer to the victim's sternum;
  • sensing an interval between successive applications of force to the victim's sternum;
  • comparing the force applied by the rescuer to the victim's sternum to a standard of force known to effect resuscitation;
  • providing a prompt to the rescuer that prompts the rescuer to vary the force delivered to approximate the force that is known to effect resuscitation,
  • comparing the interval between successive applications of force to the victim's sternum to a standard interval known to effect resuscitation; and
  • providing a prompt to the rescuer that prompts the rescuer to vary the interval of force application to approximate the interval that is known to effect resuscitation.

Description

TECHNICAL FIELD

The present invention relates to devices useful for assisting in the administration of cardiopulmonary resuscitation (CPR). More particularly, the present invention relates to a sensor for being disposed on the body of a victim to measure parameters related to the CPR.

BACKGROUND OF THE INVENTION

CPR is a technique used by a rescuer in an emergency situation to get oxygen into a victims blood when that persons heart has stopped beating and/or they are not breathing spontaneously. When performing CPR the rescuer creates blood circulation in the victims body by periodically compressing the victims chest.

The American Heart Association (AHA) recommends that the rescuer press down on the sternum with a force sufficient to depress it between 4 and 5 cm. The recommended rate for these periodic depressions is 100 times a minute (ILCOR Advisory Statement for Single-Rescuer Adult Basic Life Support). Chest compressions produce blood circulation as the result of a generalized increase in intrathoracic pressure and/or direct compression of the heart. The guidelines state “Blood circulated to the lungs by chest compressions will likely receive enough oxygen to maintain life when the compressions are accompanied by properly performed rescue breathing.” A victim can be kept alive using CPR provided the rescuer(s) are able to continue delivering properly performed chest compressions and rescue breaths.

Administering chest compressions and rescue breaths is a very physically demanding task. The quality of chest compressions and rescue breaths delivered can degrade as rescuers become fatigued. When a rescuer is fatigued they may not realize that they are compressing the chest with inadequate force.

Administering CPR is a very physically demanding procedure which is performed under stressful (i.e. life and death) circumstances. Under these circumstances, the rescuer is given the difficult tasks of estimating the time between compression's, and the distance which the chest is being compressed. Much of the difficulty in estimating the distance which the chest is being compressed stems from the relative position of the rescuer and the victim. When performing chest compression's, the rescuer positions his or her shoulders directly above the victim's chest, and pushes straight down on the sternum. In this position, the rescuer's line of sight is straight down at the victim's chest. With this line of sight, the rescuer has no visual reference point to use as a basis for estimating the distance that he or she is compressing the chest.

For this reason, there is a need in the art for a practical device which provides the rescuer with feedback to indicate that the rescuer is using proper compression force and that the rate of compressions is correct. A device of this type will provide rescuers with coaching which will enable them to deliver chest compressions consistently and beneficently. To be practical, this device should be one which is already at the rescue scene so that the rescuer is not required to bring an additional piece of equipment to the scene.

Because AEDs are being widely deployed, they are often present at a rescue scene. Prior art AEDs are only capable of defibrillation. There is a need in the industry for an AED which is capable of aiding a rescuer in administering proper chest compressions to a victim.

SUMMARY OF THE INVENTION

The present invention is an AED which is capable of detecting when a rescuer is performing CPR on a victim. This AED is also capable of providing a rescuer with helpful voice prompts to coach them through a CPR procedure. Rescuers who are trained in the use of AEDs are also trained in cardiopulmonary resuscitation (CPR) and will be able to make ready use of the AED of the present invention. AEDs are presently being widely deployed, and they are often on the scene when CPR is administered.

The present invention substantially meets the aforementioned needs. The present invention provides a sensor for sensing both the force applied to the victim's chest and the frequency with which the compressions are applied in order to assist a rescuer in resuscitating a stricken victim. Feedback, preferably by means of voice prompts, is provided to the rescuer by an emergency electronic device in communication with the sensor in order to optimally time the administration of chest compressions and to deliver a chest compression that provides an optimal amount of compression of the chest.

The present invention is a force sensor, for use in combination with an automated electronic defibrillator (AED), includes a first conductive layer. A second conductive layer is spaced apart from the first conductive layer such that no electrical communication occurs between the first and second conductive layers. Electrical communication means are provided for establishing an electrical communication path between the first and second conductive layers responsive to the application of a force to said electrical communication means.

The present invention includes a method of prompting a rescuer in the application of cardiopulmonary resuscitation to a victim having the steps of:

• • sensing a force applied by the rescuer to the victim's sternum;
  • sensing an interval between successive applications of force to the victim's sternum;
  • comparing the force applied by the rescuer to the victim's sternum in a standard of force known to effect resuscitation;
  • providing a prompt to the rescuer that prompts the rescuer to vary the force delivered to approximate the force that is known to effect resuscitation;
  • comparing the interval between successive applications of force to the victim's sternum to a standard interval known to effect resuscitation; and
  • providing a prompt to the rescuer that prompts the rescuer to vary the interval of force application to approximate the interval that is known to effect resuscitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an automated external defibrillator;

FIG. 2 is an exploded view of an electrode having the force sensor of the present invention;

FIG. 3 is a block diagram of an electrical system of the AED,

FIG. 4 is a perspective view of the force sensor used in conjunction with a pair of electrodes;

FIG. 5 is a perspective view of the force sensor of the present invention applied to a patent;

FIG. 6 is a perspective view of an electrode with the force sensor of the present invention disposed therein,

FIG. 7 is a perspective view of the force sensor ofFIG. 6 applied to the chest of a victim;

FIG. 8 is a cross sectional side view of the electrode of the present invention;

FIG. 9 is a top plan view of a further embodiment of the force sensor of the present invention;

FIG. 10 is a bottom plan view of the force sensor depicted inFIG. 9;

FIG. 11 is a cross sectional side view of the electrode of the present invention;

FIG. 12 is a cross sectional side view of the electrode of the present invention;

FIG. 13 is a top plan view of a further embodiment of the force sensor of the present invention;

FIG. 14 is a bottom plan view of the force sensor depicted inFIG. 13;

FIG. 15 is a cross sectional side view of the electrode of the present invention;

FIG. 16 is a cross sectional side view of the electrode of the present invention;

FIG. 17 is a top plan view of a further embodiment of the force sensor of the present invention;

FIG. 18 is a bottom plan view of the force sensor depicted inFIG. 17; and

FIG. 19 is a cross sectional side view of the electrode of the present invention;

FIG. 20 is a partial cut-away view of an embodiment of a packaged electrode system;

FIG. 21 is a cross-sectional view of an embodiment of a packaged electrode system and test apparatus;

FIG. 22 is a perspective assembly view an embodiment of a packaged electrode system;

FIG. 23 is a cross sectional view of an embodiment of a packaged electrode system;

FIG. 24 is an partial cut-away view of an embodiment of a packaged electrode system;

FIG. 25 is cross sectional view of an embodiment of a packaged electrode system;

FIG. 26 is partial cut-away view of an embodiment of a packaged electrode system;

FIG. 27 is a cross-sectional view of an embodiment of a packaged electrode system;

FIG. 28 is perspective assembly view an embodiment of a packaged electrode system;

FIG. 29 is a cross-sectional view of an embodiment of a packaged electrode system;

FIG. 30 is a perspective view of an embodiment of a packaged electrode system;

FIG. 31 is a cross-sectional view of an embodiment of a packaged electrode system;

FIG. 32 is a partial cut-away view of an embodiment of a packaged electrode systsem;

FIG. 33 is a cross-sectional view of an embodiment of a packaged electrode system;

FIG. 34 is a cross-sectional view of a partial embodiment of a packaged electrode system;

FIG. 35 is a cross-sectional view of a partial embodiment of a packaged electrode system;

FIG. 36 is a cross-sectional view of a partial embodiment of a packaged electrode system; and

FIG. 37 is a cross-sectional view of a partial embodiment of a packaged electrode system.

DETAILED DESCRIPTION OF THE DRAWINGS

An AED is shown generally at22 in FIG.1.AED22 is used for emergency treatment of victims of cardiac arrest and is typically used by first responders.AED22 automatically analyzes a patient's cardiac electrical signal and advises the user to shock a patient upon detection of (1) ventricular fibrillation; (2) ventricular tachycardia; (3) other cardiac rhythms with ventricular rates exceeding 180 beats per minute and having amplitudes of at lease least 0.15 millivolts. When such a condition is detected,AED22 will build up an electrical charge for delivery to the patient to defibrillate the patient with a defibrillation shock. The operator ofAED22 is guided by voice prompts and an illuminated rescue (shock) button. Olson, et al. U.S. Pat. No. 5,645,571, incorporated herein by reference, discloses the general construction and manner of use of an AED.

AED22 includescase12 with carryinghandle14 andbattery80, thebattery80 being removably disposed within a battery compartment (not shown) defined incase12.Battery80 functions as an energy source forAED22.Visual maintenance indicator20 anddata access door44 are located on the outside ofcase12 to facilitate access by the operator. A data communicationserial port42 is situated behinddata access door44.Case12 also includespanel24 andelectrode compartment26 defined in a top portion thereof.Panel24 includesilluminable rescue switch18 anddiagnostic display panel36 with “electrodes”indicator light28.Panel24 andelectrode compartment26 are enclosed by selectivelycloseable lid27.

Electrode compartment26 containsconnector32 andelectrode package60.Electrode compartment26 hermetically encloses a patient interface which includes a pair ofelectrodes50 depicted inFIG. 2, and aforce sensor200,FIGS. 4-16.Electrodes50 andforce sensor200 are removably connected toconnector32 bylead wires52 andlead wire connector58.Electrodes50 are attachable to a patient prior to a rescue intervention procedure withAED22.

AED22 also includes a digital microprocessor-based electrical control system (see the block diagram ofFIG. 3) for controlling overall operation ofAED22 and for delivering a defibrillation shock pulse throughelectrodes50 viaconnector32 andlead wires52. The electrical control system further includes an impedance measuring circuit for testing the interconnection and operability ofelectrodes50 to detect several faults. For example, if the conductive hydrogel adhesive onelectrodes50 is too dry or ifelectrodes50 are not properly connected to connector32 a relatively high impedance (e.g. greater than about 20 ohms) will be present acrossconnector32. However, whenfresh electrodes50 are properly connected, the impedance acrossconnector32 will be between about 2 and 10 ohms.

To insureoperable electrodes50, an electrode self-test is conducted (e.g., daily or upon opening lid27) in which the interconnection and operability ofelectrodes50 are checked with the impedance measuring circuit. Ifelectrodes50 are missing or unplugged fromconnector32, ifelectrodes50 are damaged, or if the conductive hydrogel adhesive onelectrodes50 is too dry, the control system ofAED22 will illuminate “Electrodes”indicator light28 ondiagnostic display panel36.

Defibrillator22 also includes electrocardiogram (EKG)filter andamplifier104 which is connected betweenelectrode connector32 and A/D converter102. The EKG or cardiac rhythm of the patient is processed by filter andamplifier104 in a conventional manner, and digitized by A/D converter102 before being coupled toprocessor74.

The rescue mode operation ofdefibrillator22 is initiated when an operator openslid27 to access theelectrode package60. The opening of thelid27 is detected bylid switch90, which effectively functions as an on/off switch. In response to this action,power control circuit88 activatespower generation circuit84 and initiates rescue mode operation ofprocessor74.Processor74 then begins its rescue mode operation and initiates the generation of an audible voice prompt “To attempt a rescue, disconnect charger.” if a charger is connected whenlid27 is opened.

If the lid-opened self-test is successfully completed,processor74 initiates the generation of an audible “Place electrodes.” voice prompt. In response to this voice prompt, and following the instructions on the inside oflid27, the operator should removeelectrode package60 fromcompartment26, open the package,peel electrodes50 from the release liner and place the electrodes on the patient's chest. While this action is being performed,processor74 monitors the impedance signals received through A/D converter102 to determine whether the impedance across the electrodes indicates that they have been properly positioned on the patient. If the correct impedance is not measured,processor74 initiates the generation of a “Check electrodes.” voice prompt.

After detecting an impedance indicating the proper placement ofelectrodes50, and without further action by the operator (i.e., automatically),processor74 begins a first analyze sequence by initiating the generation of a “Do not touch patient. Analyzing rhythm.” voice prompt, and analyzing the patient's cardiac rhythm. In one embodiment,processor74 collects and analyzes a nine second segment of the patient's cardiac rhythm. The cardiac rhythm analysis program executed byprocessor74 is stored inprogram memory76. Algorithms of the type implemented by the rhythm analysis program are generally known and disclosed, for example, in the W. A. Tacker Jr. book Defibrillation of the Heart,1994. If theprocessor74 determines that the patient has a nonshockable cardiac rhythm that is not susceptible to treatment by defibrillation pulses (e.g., no pulse rather than a fibrillating rhythm), it initiates the generation of a “Check pulse. If no pulse, give CPR.” voice prompt. One minute after this voice prompt,processor74 repeats the initiation of the “Do not touch patient. Analyzing rhythm.” voice prompt and the associated cardiac rhythm analysis.

When a shockable cardiac rhythm is detected,processor74 begins a first charge sequence by initiating the generation of a “Charging.” voice prompt, and causes highvoltage generation circuit86 to operate in the charge mode. When the highvoltage generation circuit86 is charged,processor74 begins a first shock sequence by initiating the generation of a “Stand clear. Push flashing button to rescue.” voice prompt, and the flashing illumination ofrescue switch18. The operator actuation ofrescue switch18 will then causeprocessor74 to operate highvoltage generation circuit86 in the discharge mode, and results in the application of a defibrillation pulse to the patient to complete the first series of analyze/charge/shock sequences. In one embodiment, the first defibrillation pulse delivered bydefibrillator22 has an energy content of about two hundred joules.

Following the first series of analyze/charge/shock sequences,processor74 times out a short pause of about five seconds to allow the heart to reestablish its cardiac rhythm before beginning a second series of analyze/charge/shock sequences. The second series of analyze/charge/shock sequences is identical to the first series described above, except the energy content of the defibrillation pulse can be about two hundred joules or three hundred joules. If the second series of analyze/charge/shock sequences ends with the delivery of a defibrillation pulse,processor74 again times out a short pause of about five seconds before beginning a third analyze/charge/shock sequence. The third series is also identical to the first series, butprocessor74 controls the highvoltage generation circuit86 in such a manner as to cause the defibrillation pulse delivered upon the actuation of therescue switch18 to have an energy content of about three hundred and sixty joules.

Following the delivery of a defibrillation pulse at the end of the third series of analyze/charge/shock sequences, or after identifying a nonshockable cardiac rhythm,processor74 initiates the generation of a “Check Pulse. If no pulse, give CPR.” voice prompt.Processor74 then times a one minute CPR period to complete a first set of three series of analyze/charge/shock sequences. Rescue mode operation then continues with additional sets of three series of analyze/charge/shock sequences of the type described above (all with three hundred and sixty joule pulses).Processor74 ends rescue mode operation ofdefibrillator22 when a total of nine series of analyze/charge/shock sequences have been performed, orlid27 is closed.

Throughout the analyze, charge and shock sequences,processor74 monitors the impedance present acrossconnector32 to determine whetherelectrodes50 remain properly positioned on the patient. If the monitored impedance is out of range (e.g., too high if the electrodes have come off the patient, or too low is shortened),processor74 initiates the generation of a “Check Electrodes.” voice prompt, and causes highvoltage generation circuit86 to discharge any charge that may be present throughinternal load98. Rescue mode operation will resume whenprocessor74 determines that the electrodes have been properly repositioned on the patient.

FIG. 2 is an exploded view of aprior art electrode50.Electrode50 includes flexible, adhesive coated backing layer53 (preferably a polymeric foam), andpatient engaging layer54.Patient engaging layer54 is preferably a hydrogel material which has adhesive properties and which is electrically conductive. Hydrogel adhesive of this type is commercially available from LccTcc Corporation (Minnetonka, Minn.) and Tyco International Ltd. (Hamilton, Bermuda). Current disbursing flexibleconductive portion56 is preferably located betweenbacking layer53 and patient-engaginghydrogel layer54.Conductive portion56, as shown, need not be the same size asbacking layer53 and is preferably a homogeneous, solid, thinly deposited metallic substance, or a conductive ink.

Insulated lead wire52 is terminated with a wire terminal170. Wire terminal170 is electrically connected toconductive portion56 via conductive rivet174 and washer172. Conductive rivet174 is covered on a first side with insulating disk176. Conductive rivet174, washer172, and wire terminal170 are all covered on a second side with insulating pad178. Further examples of electrode pad construction for use withAED22 are described and shown in U.S. Pat. Nos. 5,697,955, 5,579,919, and 5,402,884, all hereby incorporated by reference.

For example, referring toFIGS. 20 and 21 an embodiment of a packagedelectrode system310 is shown to comprise anelectrode311 and a package orenclosure312. Also shown inFIG. 21 is atest apparatus313. Theelectrode311 is shown to comprise a non-conductive base orbacking layer314, a conductor orconductive layer315, alead316, and aconductive contact layer317. Thebase layer314 is preferably constructed of a thin, flexible polymeric substance such as a urethane foam, or a polyester or polyolefin laminate which provides structural base and insulative properties. Although thebase layer314 is shown to have a surface area which is substantially coextensive with the surface of thecontact layer317, it alternatively may be slightly larger. In such larger configurations, thebase layer314 may have a pressure sensitive adhesive disposed on its patient contact side for increased adhesion to the patient body.

Theconductive layer315 is shown to be disposed on the first or patient side ofbase layer314. It functions to transfer (disperse) current or voltage from the lead316 (or to the lead in a sensing application) to thepatient contact layer317. Although theconductive layer315 is shown to have a surface area which is smaller than that of thebase layer314 orcontact layer317, it may alternatively have a dimension which is larger than that shown, or even on which is coextensive with the base andcontact layers314 and317. Theconductive layer315 is preferably a homogeneous, solid, thinly deposited metallic substance, or a conductive ink material. Alternatively, theconductive layer315 may be formed of a flexible mesh material, a conductive adhesive or a deposited ink pattern. Flexible conductive ink compounds known in the art have a conductive filler of Gold, Silver, Aluminum or other conductive materials.

Thelead316 is preferably an insulated wire conductor which extends from a mating point with theconductive layer315, through thebase layer314, and then has a freely movable end. Various alternatives of thislead316 design exist and are useable consistent with the general teachings of the invention, including but not limited to uninsulated wire conductors and conductive strips or traces deposited between thecontact layer317 and the base314 orconductive layers315. Such a trace or strip may also extend just beyond thebase layer314 for connection with an ancillary connection means such as a wiring harness including conductive clip means.

Theconductive contact layer317 is preferably a thin layer of semi-liquid gel material. The gel maintains direct electrical contact with the skin, to reduce variations in conductance, and it permits such contact for long periods of time. The gel is a conductive, gelatinous compound which is also flexible for contoured adhesion to the body of a patient. The gel also preferably has a pressure sensitive, moisture resistant adhesive property. Compounds having these characteristics have been developed by Minnesota Mining and Manufacturing, Medtronic, and Lec Tec (Synkara TM), Corporations, all of Minnesota, U.S.A. Generally, these compounds have low resistivities. Thecontact layer317 is for direct contact with the patient's body to transfer current or voltage thereto or therefrom. Overall, although theelectrode311 and its constituent elements are shown to have circular configurations, they may alternatively be formed in various other shapes such as rectangular or square patches.

Thepackage structure312 is shown to have an envelope-like structure formed of a substantially continuous thin,homogeneous layer318 of a polymeric, preferably non-gas permeable, material. Alternatively, as shown inFIG. 38, thepackage387 embodiment may have a pouch-like structure formed of a pair of thin, flathomogeneous layers388 and389 which are sealed or otherwise merged together at their peripheries orouter edges390. And, although thepackage312 is shown to have a rectangular configuration various other configurations and shapes are also useable.

The package further comprises a pair ofconductive connectors319 and320 which are separated a predetermined distance from one another for contact with separate areas of thecontact layer317 of theenclosed electrode311. Theconnectors319 and320 are conductive areas which are shown to have a unitary construction with thepackage layer318. Thecontacts319 and320 may alternatively be formed of thin layer strips of conductive material, or a printed conductive ink, disposed on the interior side of thepackage layer318, extending from contact nodes to peripheral contact areas on the exterior of thepackage318. Yet another snap-type embodiment379 is shown inFIGS. 35 and 36 including aconnective member380 disposed on one side of thebase layer318, and acurrent dispersion member381 disposed on the opposite side and being connected to theupper member380 via an aperture in thebase318. Theupper member380 is shown360 have a base382 and amating notch383 for coupling thelower member381.

Referring toFIG. 21, thesystem310 may also include atest apparatus313. Thetest apparatus313 includes acurrent source323, preferably a battery,test circuitry324, preferably including measurement components and status indication components such as an analog meter, LCD digital display or light emitting diodes, andconnectors321 and322 for coupling with thepackage312connectors319 and320. In use, thetest apparatus313 is connected to thepackage connectors319 and320. Thetest circuitry324 is then activated to form a closed current loop to determine whether continuity exists with respect to theenclosed electrode311, thereby indicating whether theelectrode311 is still functional. Additionally, aload386 formed of for example a conductive and semi-conductive material layers385 and386, may be added to the current loop as for example is shown inFIG. 37, for purposes of measuring the magnitude of current flow for more precise measurement ofelectrode311 condition.

In the case of theelectrode system310, a current loop is formed including theconnector319, the gel of the contact layer317 (along a substantially horizontal plane), and theconnector320 which is located at a remote location on thecontact layer314 with respect to theconnector319. Current conducts easily in fresh, semi-liquid gel of thecontact layer317. In contrast, no current conducts, or current conduction is attenuated, in stale, dried gel. This is indicative of the need to dispose of the stored electrode without using it. And, this condition is determinable without the need to open thepackage312 and thereby risk compromising the freshness or sterility of aviable electrode311.

Referring toFIGS. 22 and 23, another packagedelectrode system330 is shown to comprise anelectrode331 and a package or enclosure332. Theelectrode331 is shown to comprise anon-conductive base layer333, and aconductive gel layer336. A conductive snap-type connector having aconnection member335 disposed on one side and acurrent dispersion member334 disposed on the second side is also shown. The package332 is shown to have at least onebody layer337 with a pair ofcontacts338 and339 disposed at predetermined locations to electrically connect with thegel layer336 and contact335. In a test mode, a current loop is formed between theconnector339,gel layer336,connector portions334 and335 andconnector338.

Referring toFIGS. 24 and 25, another packagedelectrode system345 is shown to comprise an electrode346 and anenclosure347. The electrode346 is shown to comprise anon-conductive base layer348, aconductive gel layer355, and a pair of separateconductive layers349 and350, each of which are shown to have a lead351 and352 extending therefrom and terminating in aconnective node353 and354. Thelead pair351 and352 (andlayer pair349 and350) provide a redundant circuit path for increased reliability of use in emergency settings. Thepackage347 is shown to have at least onebody layer356 with a pair ofcontacts357 and358 disposed at predetermined locations to electrically couple withconnective nodes353 and354. In a test mode, a current loop is formed between aconnector357 or358, it's respectiveconnective node353 or354 and lead351 or352, and its respectiveconductive layer349 or350. In a properly functioning electrode346, current conducts through thegel355 from oneconductive layer349 to the other350, and then back to the test apparatus through the above-mentioned path.

Referring toFIGS. 26 and 27, another packagedelectrode system364 is shown to comprise anelectrode365 and aunitary package366. Theelectrode365 is shown to compromise anon-conductive base layer367, and aconductive gel layer370. A snap-type connector withmembers368 and369 electrically couples thegel layer370.

Thepackage366 is shown to have at least onebody layer371 which is coupled to theelectrode365base layer367 at tear-awayperforated lines373. Aconnector372 is shown disposed for contact with theelectrode365gel layer370. In a test mode, a current loop is formed between theconnector372, thegel layer370, and theconnector members368 and369.

Referring toFIGS. 28 and 29, another packagedelectrode system397 is shown to comprise anelectrode398 and a package. Theelectrode398 is shown to comprise anon-conductive base layer401, aconductive gel layer402, and a lead404 having aconductor405 and aninsulator406, which is shown to be embedded directly in thegel layer402. Alternatively, the lead may be connected to a conductive current dispersion layer (not shown). Aconductive test strip403 is also shown to be adhered to the surface of thegel402 at a location remote from thelead404 for test purposes, and which is designed to release from thegel402 upon removal of thepackage layer399.

The package is shown to have a pair oflayers399 and400 which overlap to form aninterior cavity407 and area sealingly connected at theirperipheries408. In a test mode, a current loop is formed between the lead404, thegel layer402 and thetest strip403, which like thelead404 is shown extended through thepackage periphery408 for contact with an external test apparatus.

Referring toFIGS. 31 and 32, another packagedelectrode system414 is shown to comprise anelectrode415 and an enclosure. Theelectrode415 is shown to comprise anon-conductive base layer417, and a conductiveadhesive gel layer418 which is connected to a snap-type connection node421 or the like, and an associatedlead420. The package is shown to comprise a single top layer ofnon-conductive material416 which is laminated or adhesively mated to theelectrode base layer417. In use thegel layer418 is removable from thepackage layer416. Atest strip419 is disposed on the interior of the package, adhesively connected to thegel layer418, and extending to the package exterior. In a test mode, a current loop is formed between the lead420,node421,gel layer418 and thetest strip419.

Referring toFIGS. 33 and 34, another packagedelectrode system427 is shown to comprise a pair ofelectrodes428 and429 and a package. Theelectrodes428 and429 are shown to comprise non-conductive base layers430 and433, and conductive gel layers431 and434.Leads432 and435 extend from therespective gel layers431 and434. The package is shown to have a pair of overlappinglayers442 and443 which are sealed at theirperipheries441 to form anenclosure440 housing theelectrodes428 and429. Importantly, theelectrodes428 and429 are oriented with theirrespective gel layers431 and434 mating with a resistive layer437 (and an optional separator layer436) formed of a conductive/resistive material as known in the art. Aconductive lead439 or strip extends from the resistive layer through thepackage periphery441, as do the electrode leads432 and435.

In a test mode, a current loop is formed between, for example, alead432, agel layer431, theresistive layer437, and the remaininggel layer434 and lead435. The circuit can be altered to include thelead439.

FIG. 3 is a block diagram ofelectrical system70 ofAED22. The overall operation ofAED22 is controlled by a digital microprocessor-basedcontrol system72 which includes aprocessor74 interfaced toprogram memory76,data memory77,event memory78 andreal time clock79. The operating program executed byprocessor74 is stored inprogram memory76. Electrical power is provided by thebattery80 which is removably positioned within the battery compartment ofAED22 and is connected topower generation circuit84.

Power generation circuit84 is also connected tolid switch90,watch dog timer92,real time clock79 andprocessor74.Lid switch90 is a magnetic read relay switch in one embodiment, and provides signals toprocessor74 indicating whetherlid27 is open or closed.Data communication port42 is coupled toprocessor74 for two-way serial data transfer using an RS-232 protocol.Rescue switch18,maintenance indicator20, the indicator lights ofdiagnostic display panel36, thevoice circuit94 and piezoelectricaudible alarm96 are also connected toprocessor74.Voice circuit94 is connected tospeaker34. In response to voice prompt control signals fromprocessor74,circuit94 andspeaker34 generate audible voice prompts for consideration by a rescuer.

Highvoltage generation circuit86 is also connected to and controlled byprocessor74. Circuits such as highvoltage generation circuit86 are generally known, and disclosed, for example, in the commonly assigned Persson et al. U.S. Pat. No. 5,405,361, which is hereby incorporated by reference. In response to charge control signals provided byprocessor74, highvoltage generation circuit86 is operated in a charge mode during which one set of semiconductor switches (not separately shown) cause a plurality of capacitors (also not shown), to be charged in parallel to the 12V potential supplied bypower generation circuit84. Once charged, and in response to discharge control signals provided byprocessor74, highvoltage generation circuit86 is operated in a discharge mode during which the capacitors are discharged in series by another set of semiconductor switches (not separately shown) to produce the high voltage defibrillation pulses. The defibrillation pulses are applied to the patient byelectrodes50 throughconnector32 connected to the highvoltage generation circuit86.

Impedance measuring circuit100 is connected to bothconnector32 andreal time clock79.Impedance measuring circuit100 is interfaced toprocessor74 through analog-to-digital (A/D)converter102.Impedance measuring circuit100 receives a clock signal having a predetermined magnitude fromclock79, and applies the signal toelectrodes50 throughconnector32. The magnitude of the clock signal received back fromelectrodes50 throughconnector32 is monitored byimpedance measuring circuit100. An impedance signal representative of the impedance present acrosselectrodes50 is then generated bycircuit100 as a function of the ratio of the magnitudes of the applied and received clock signals (i.e., the attenuation of the applied signal).

For example, ifelectrodes50 within anunopened package60 are connected bylead wires52 andconnector58 is properly connected toconnector32 onAED22, a relatively low resistance (e.g., less than about 10 ohms) is present acrosselectrodes50. If thehydrogel adhesive54 onelectrodes50 is too dry, or theelectrodes50 are not properly positioned on the patient, a relatively high resistance (e.g., greater than about two hundred fifty ohms) will be present across theelectrodes50. The resistance acrosselectrodes50 will then be between about twenty-five and two hundred fifty ohms whenfresh electrodes50 are properly positioned on the patient with good electrical contacts. It should be noted that these resistance values are given as exemplary ranges and are not meant to be absolute ranges. The impedance signal representative of the impedance measured bycircuit100 is digitized by A/D converter102 and provided toprocessor74.

Impedance measuring circuit110 is connected toconnector32 andreal time clock79, and is interfaced toprocessor74 through analog-to-digital (A/D)converter102. Impedance measuring circuit110 receives a clock signal having a predetermined magnitude fromclock79, and applies the signal to forcesensor200 throughconnector32. The magnitude of the clock signal received back fromforce sensor200 throughconnector32 is monitored by impedance measuring circuit110. An impedance signal representative of the impedance present acrossforce sensor200 is then generated by circuit110 as a function of the ratio of the magnitudes of the applied and received clock signals (i.e., the attenuation of the applied signal). The impedance signal representative of the impedance measured by circuit110 is digitized by A/D converter102 and provided toprocessor74.

FIG. 4 is a plan view of apatient interface120 for use withAED22.Patient interface120 includesconnector58 which is adapted to releasably mate withconnector32 ofAED22. Fourlead wires52A,52B,52C, and52D are all terminated withconnector58.Patient interface120 also includes aforce sensing pad102 which includes aforce sensor200.Lead wires52C and52D are electrically connected to forcesensor200.Electrodes50A and50B each include backinglayer53, patient engaginghydrogel layer54,conductive portion56, and insulatingpad78.

FIG. 5 is a plan view illustratingpatient interface120 applied tohuman torso98 of thevictim112.Force sensing pad102 is applied over the sternum oftorso98.Force sensing pad102 may be adhered with pressure sensitive adhesive.Force sensing pad102 includesforce sensor200 which is electrically connected to leadwires52C and52D.

Electrode50A is shown applied to the upper right chest oftorso98.Electrode50A is electrically connected to leadwire52A.Electrode50B is applied to the lower left side oftorso98 and is electrically connected to leadwire52B.Lead wires52A,52B,52C, and52D are terminated withconnector58.Connector58 is adapted to make releasable, electrical contact withconnector32 ofAED22.

Those skilled in the art will readily recognize thatelectrodes50A,50B andforce sensing pad102 may be placed in locations ontorso98 other than those shown inFIG. 5 without deviating from the spirit or scope of this invention.

FIG. 6 is a plan view of apatient interface130 for use withAED22.Interface130 includes a second preferred embodiment offorce sensor200.Patient interface130 includesconnector58 which is adapted to releasably mate withconnector32 ofAED22. Fourlead wires52A,52B,52C, and52D are all terminated withconnector58.Patient interface130 also includesforce sensor200 which is positioned betweenbacking layer153 and insulatingpad178 ofelectrode150A.Lead wires52C and52D are electrically connected to forcesensor200.Electrodes150A and150B each include patient engaginghydrogel layer54, andconductive portion56.

FIG. 7 is a plan view illustratingpatient interface130 applied totorso98.Force sensor200 is positioned over the sternum oftorso98.Force sensor200 is electrically connected to leadwires52C and52D.Electrode150A is shown applied totorso98.Electrode150A is electrically connected to leadwire52A.Electrode150B is applied to the lower left side oftorso98 and is electrically connected to leadwire52B.Lead wires52A,52B,52C, and52D are terminated with connector58 (not shown).Connector58 is adapted to make releasable, electrical contact with connector32 (not shown) ofAED22.

FIG. 8 is a cross section illustrating an embodiment of aforce sensor200.Force sensor200 has afirst side210 and asecond side220.Force sensor200 includes asubstrate202. Aconductive pattern204A,204B is situated on each side of the substrate layer.Substrate202 may be any thin (e.g. about 0.002″ to 0.020″) nonconductive sheet of material. Plastic film materials such as polyester, polycarbonate, PVC, etc. have been found to work well assubstrate202.Conductive patterns204A,204B may be any conductive material such as copper foil, nickel foil, or conductive ink. In apreferred embodiment substrate202 is 5 mil polyester andconductive patterns204A,204B are silver conductive ink.

Substrate202 includesapertures208.Conductive pads206A and206B are situated on each side ofsubstrate202 as shown in FIG.8.Conductive pads206A,206B are preferably made of a deformable, conductive material. Materials which have been found suitable include conductive silicone rubber, conductive foam rubber, and conductive urethane rubber.

FIG. 9 is a plan view illustratingfirst side210 offorce sensor200 withconductive pads206A,206B removed.Conductive pattern204A is seen situated onsubstrate202.Apertures208 are cut throughconductive pattern204A,substrate202, andconductive pattern204B,underlying substrate202.

FIG. 10 is a plan view illustratingsecond side220 offorce sensor200 withconductive pads206A,206B removed.Conductive pattern204B is seen situated onsubstrate202. As also shown inFIG. 9,apertures208 are cut throughconductive pattern204B,substrate202, andconductive pattern204A,underlying substrate202.

Referring now to both FIG.9 andFIG. 10,conductive patterns204A,204B each includeconductive traces212A,212B.Wire terminals214A,214B are arranged make electrical contact withconductive traces212A,212B respectively.Wire terminals214A,214B are attached tosubstrate202 withrivets216A,216B andwashers218A,218B.Lead wires222A,222B are terminated withwire terminals214A,214B.

Those with skill in the art will recognize that other methods may be used to attachlead wires222A,222B toconductive traces212A,212B. Possible methods include soldering, the use of a connector designed to mate with flexible circuits, and the use of conductive adhesive.

FIG. 11 is a section view offorce sensor200 with a compressive force F applied. Whenforce sensor200 is used, it is placed between two objects, such as the sternum of a cardiac arrest victim and the heel of a rescuer's hand. When the rescuer presses down with the heel of his or her hand, the force results in pressure distributed across the area of the heel of his or her hand.

When pressure is applied to forcesensor200,conductive pads206A,206B extrude throughapertures208. Whenpads206A,206B contact each other, they complete an electrical circuit betweenconductive layer204A andconductive layer204B. Increasing the force F applied to forcesensor200 increases the surface area of the electrical connection betweenconductive pads206A,206B, thereby decreasing the electrical resistance betweenpads206A,206B. The electrical resistance of the circuit betweenconductive layer204A andconductive layer204B is therefore indicative of the magnitude of the force F applied to forcesensor200.

FIGS. 12-14 illustrate a further preferred embodiment offorce sensor200.Force sensor200 includes afirst substrate222. Aconductive pattern224 is situated onfirst substrate222. As in the previous embodiment,substrate222 may be any thin (e.g. about 0.002″ to 0.010″) nonconductive sheet of material. Plastic film materials such as polyester, polycarbonate, PVC, etc. have been found to work well assubstrate222.Conductive pattern224 may be any conductive material such as copper foil, nickel foil, or conductive ink. In a preferredembodiment substrate layer222 is 5 mil polyester andconductive pattern224 is silver conductive ink.

Force sensor200 includessecond substrate226. Aconductive pattern228 is situated onsecond substrate226.Second substrate226 is situated onfirst substrate222.First substrate222 andsecond substrate226 may be held together with a layer of pressure sensitive adhesive (not shown).

Substrate222 includesapertures230. Aconductive pad232 is situated on, and makes electrical contact withconductive pattern224 as shown in FIG.14.Conductive pad232 is preferably made of a deformable, conductive material. Materials which have been found suitable include conductive silicone rubber, conductive foam rubber, and conductive urethane rubber.

FIG. 13 is a plan view illustratingsecond substrate226 andconductive pattern228.

FIG. 14 is a plan view illustratingfirst substrate222 andconductive pattern224.

FIG. 15 is a section view of theforce sensor200 ofFIG. 12 with a force F applied. Whenforce sensor200 is used, it is placed between two objects, such as the sternum of a cardiac arrest victim and the heel of a rescuers hand. When the rescuer presses down with the heel of his or her hand, the force results in pressure distributed across the area of the heel of his or her hand.

When a force F is applied to forcesensor200,conductive pad232 extrudes throughapertures230. Whenconductive pad232 contactsconductive pattern228 it completes an electrical circuit betweenconductive pattern224 andconductive pattern228. Increasing the force F applied to forcesensor200 increases the surface area of the electrical connection betweenconductive pads232 andconductive pattern228, thereby reducing the electrical resistance betweenpad232 andpattern228. Accordingly, change in contact area creates a change in electrical resistance which is indicative of the force applied to forcesensor200.

FIGS. 16-18 illustrate another third embodiment offorce sensor200. In thisembodiment force sensor200 includes afirst substrate242. Twoconductive patterns244A,244B are situated onfirst substrate242.

Force sensor200 includessecond substrate246 which includesapertures250.Second substrate246 is comprised of a non-conductive material. Polyester, polyethylene, and polypropylene have been found to be suitable materials forsecond substrate246. Aconductive pad252 is situated onsecond substrate246. As in the previous embodiments,conductive pad232 is preferably made of a deformable, conductive material.

FIG. 17 is a plan view illustratingfirst substrate242 andconductive patterns244A,244B. Theconductive patterns244A,244B are arranged so that they are in close proximity to each other.Small gaps256 are left betweenconductive paths244A,244B so that there is no direct electrical contact betweenconductive paths244A,244B.

FIG18 is a plan view illustratingsecond substrate246 andapertures250.

FIG. 19 is a section view of theforce sensor200 ofFIGS. 16-18 with a force F applied. Whenforce sensor200 is used, it is placed between two objects, such as the sternum of a cardiac arrest victim and the heel of a rescuers hand. When the rescuer presses down with the heel of his or her hand, the force F results in pressure distributed across the area of the heel of his or her hand.

When pressure is applied to forcesensor200,conductive pad252 extrudes throughapparatus250. Whenconductive pad252 contacts conductivepatterns244A,244B it completes an electrical circuit betweenconductive pattern244A andconductive pattern244B. Increasing the force applied to forcesensor200 increases the surface area of the electrical connection betweenconductive pad252 andconductive patterns244A,244B. This change in contact area creates a change in electrical resistance which is indicative of the force applied to forcesensor200.

Referring toFIGS. 4 and 5 inoperation force sensor200 is positioned on the sternum of avictim112. The rescuer places the heel of his or her hand ontoforce sensor200 and delivers chest compressions to the chest of thevictim112.Force sensor200 and impedance measuring circuit110 produce an electrical signal proportional to the force applied to the victim's chest. This signal indicates toprocessor74 the rate and magnitude of the chest compressions which thevictim112 is receiving. This signal also allowsprocessor74 to determine the precise time that a rescuer has begun (or stopped) CPR.

Processor74 compares the measured rate of chest compressions to a range of desired values.

If the current chest compression rate value delivered by the rescuer is less than the desired range,processor74 will produce a control signal which causesvoice circuit94 andspeaker34 to generate an appropriate voice prompt such as “faster”. If the current chest compression rate value is greater than the desired range,processor74 will produce a control signal which causesvoice circuit94 andspeaker34 to generate an appropriate voice prompt such as “slower”.

Processor74 also compares the measured chest compression force to a range of desired values. If the chest compression force delivered by the rescuer is less than the desired range,processor74 will produce a control signal which causesvoice circuit94 andspeaker34 to generate an appropriate voice prompt such as “harder”. If the chest compression force is greater than the desired range, processor will produce a control signal which causesvoice circuit94 andspeaker34 to generate an appropriate voice prompt such as “softer”.

AED22 may also provide other types of audible feedback to the rescuer. For example,AED22 may give an audible signal each time the force measured usingforce sensor200 reaches a desired value.

The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof. Therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Claims (46)

1. An automated electronic defibrillator (AED) for use by an operator in assisting in resuscitating a victim, comprising:

a force sensor applicable to a skin surface of the victim and being responsive to the application of a force to said force sensor,

an AED control system being in electrical communication with the force sensor, the AED control system processing a signal communicated from the force sensor related to the magnitude of force applied thereto and to the frequency of application of the force thereto; and

AED prompting means operably coupled to the AED control system for receiving communication signals from the AED control system and for communicating prompts to the operator for use by the operator in resuscitating the victim, the prompts being related to the signal communicated to the AED control system by the force sensor related to the magnitude of force applied to the force sensor and to the frequency of application of the force to the force sensor.

2. The AED ofclaim 1 wherein the force sensor is responsive to the relative magnitude of the force applied thereto and communicates a signal related to said force magnitude to the AED control system.

3. The AED ofclaim 2 wherein the AED control system communicates signals relating to the relative magnitude of force applied to the force sensor to the AED prompting means for transmission as a prompt to the rescuer.

4. The AED ofclaim 1 wherein the AED control system determines the interval between a succession of force applications applied to the force sensor.

5. The AED ofclaim 4 wherein the AED control system communicates signals relating to the interval between a succession of force applications applied to the force sensor to the AED prompting means for transmission as a prompt to the rescuer.

6. The AED ofclaim 1 wherein the force sensor comprises:

a first conductive layer;

a second conductive layer being spaced apart from the first conductive layer, the first and second conductive layers being electrically isolated from one another; and

electrical communication means for establishing electrical communication between the first and second conductive layers responsive to the application of a force to said electrical communication means.

7. The AED ofclaim 6 wherein at least a part of the electrical communication means of the force sensor are formed of an extrudable, electrically conductive material, the electrical communication means being extruded by the application of a force to said electrical communication means, at least one extrusion thereof establishing a path of electrical communication between the first and second conductive layers responsive to the application of said force.

8. The AED ofclaim 7, the force sensor further including a flexible, nonconductive layer being disposed between the first and second conductive layers.

9. The AED ofclaim 8 wherein the first and second conductive layers of the force sensor are formed of conductive ink printed on opposed sides of the nonconductive layer.

10. The AED ofclaim 9, the force sensor further including a plurality of holes defined through the nonconductive layer and through the first and second conductive layers printed thereon.

11. The AED ofclaim 10, the force sensor further including a first extrudable, conductive layer disposed on the first conductive layer and a second extrudable, conductive layer disposed on the second conductive layer, the first and second extrudable, conductive layers being extrudable into the plurality of holes defined through the nonconductive layer and through the first and second conductive layers responsive to a force applied thereto to form an electrically communicative connection between the first and second conductive layers.

12. The AED ofclaim 6 wherein the first and second conductive layers of the force sensor are formed of conductive, metallic foil.

13. The AED ofclaim 1 wherein the force sensor is disposed in a hole defined in an electrode.

14. The AED ofclaim 6 wherein the magnitude of the force applied to the force sensor is inversely proportional to the impedance existing between the first and second conductive layers.

15. The AED ofclaim 6 wherein the impedance existing between the first and second conductive layers of the force sensor is related to the magnitude of the force applied to the force sensor.

16. A method of prompting a rescuer in the application of cardiopulmonary resuscitation to a victim comprising the steps of:

sensing a force applied by the rescuer to the victim by means of a force sensor;

sensing an interval between successive applications of force to the victim's sternum; by means of a processor operably coupled to the force sensor,

the processor comparing the force applied by the rescuer to the victim's sternum to a standard of force known to effect resuscitation;

the processor providing a prompt to the rescuer that prompts the rescuer to vary the force delivered to approximate the force that is known to effect resuscitation;

the processor comparing the interval between successive applications of force to the victim's sternum to a standard interval known to effect resuscitation; and

the processor providing a prompt to the rescuer that prompts the rescuer to vary the interval of force application to approximate the interval that is known to effect resuscitation.

17. An automated electronic defibrillator (AED) for use by an operator in assisting in resuscitating a victim, having a charging circuit for developing a high voltage charge, at least two electrodes for application to the person of a victim, the at least two electrodes being in electrical communication with the charging circuit, a control circuit communicatively coupled to the charging circuit and the electrodes for detecting certain biological parameters of the victim and for controlling the delivery of a voltage charge from the charging circuit through the at least two electrodes to the victim, comprising:

means for prompting a rescuer in the delivery of cardiopulmonary resuscitation (CPR) to the victim, the means for prompting a rescuer further including the control system being in electrical communication with a force sensor, the AED control circuit processing a signal communicated from the force sensor related to the magnitude of force applied thereto and to a frequency of application of the force thereto.

18. The AED ofclaim 17 wherein the means for prompting a rescuer includes a force sensor applicable to a skin surface of the victim and being responsive to the application of a force to said force sensor.

19. The AED ofclaim 17 wherein the means for prompting a rescuer An automated electronic defibrillator (AED) for use by operator in assisting in resuscitating a victim, having a charging circuit for developing a high voltage charge, at least two electrodes for application to the person of a victim, the at least two electrodes being in electrical communication with the charging circuit, a control circuit communicatively coupled to the charging circuit and the electrodes for detecting certain biological parameters of the victim and for controlling the delivery of a voltage charge from the charging circuit through the at least two electrodes to the victim, comprising:

means for prompting a rescuer in the delivery of cardiopulmonary resuscitation (CPR) to the victim, the means for prompting a rescuer including the control system being in electrical communication with a force sensor, the AED control circuit processing a signal communicated from the force sensor related to the magnitude of force applied thereto and to a frequency of application of the force thereto andfurther includesing prompting means operably coupled to the AED control circuit for receiving communication signals from the AED control circuit and for communicating prompts to the rescuer for use by the rescuer in resuscitating the victim, the prompts being related to the signal communicated to the AED control circuit by a force sensor related to the magnitude of force applied to the force sensor and to the frequency of application of the force to the force sensor.

20. The AED ofclaim 19 wherein the force sensor is responsive to the relative magnitude of the force applied thereto and communicates a signal related to said force magnitude to the AED control system.

21. The AED ofclaim 20 wherein the AED control circuit communicates signals relating to the relative magnitude of force applied to the force sensor to the AED prompting means for transmission as a prompt to the rescuer.

22. The AED ofclaim 21 wherein the AED control system determines the interval between a succession of force applications applied to the force sensor.

23. The AED ofclaim 22 wherein the AED control circuit communicates signals relating to the interval between a succession of force applications applied to the force sensor to the AED prompting means for transmission as a prompt to the rescuer.

24. An automated electronic defibrillator (AED) for use by an operator in assisting in resuscitating a victim, having a charging circuit for developing a high voltage charge, at least two electrodes for application to the person of a victim, the at least two electrodes being in electrical communication with the charging circuit, a control circuit communicatively coupled to the charging circuit and the electrodes for detecting certain biological parameters of the victim and for controlling the delivery of a voltage charge from the charging circuit through the at least two electrodes to the victim, comprising:

means for prompting a rescuer in the delivery of cardiopulmonary resuscitation (CPR) to the victim, the means for prompting a rescuer including a force sensor applicable to a skin surface of the victim and being responsive to the application of a force to said force sensor, the force sensor having,

a first conductive layer;

a second conductive layer being spaced apart from the first conductive layer, the first and second conductive layers being electrically isolated from one another; and

electrical communication means for establishing electrical communication between the first and second conductive layers responsive to the application of a force to said electrical communication means.

25. The AED ofclaim 24 wherein at least a part of the electrical communication means of the force sensor are formed of an extrudable, electrically conductive material, the electrical communication means being extruded by the application of a force to said electrical communication means, at least one extrusion thereof establishing a path of electrical communication between the first and second conductive layers responsive to the application of said force.

26. The AED ofclaim 25, the force sensor further including a flexible, nonconductive layer being disposed between the first and second conductive layers.

27. The AED ofclaim 26 wherein the first and second conductive layers of the force sensor are formed of conductive ink printed on opposed sides of the nonconductive layer.

28. A patient interface for use with an automated electronic defibrillator (AED) comprising:

a patient connection interface adapted to be positioned externally on a victim and operably connected to the AED, the patient connection interface including:

means for selectively delivering a signal to the AED representative of the victim's cardiac electrical signal;

means for selectively delivering a defibrillation shock pulse from the AED to the victim; and

means for selectively delivering a signal to the AED indicative of a magnitude of chest compression when the victim is receiving cardiopulmonary resuscitation (CPR).

29. The patient connection ofclaim 28, wherein the means for selectively delivering a signal to the AED comprises at least one sensor having at least one lead wire attached to the sensor.

30. The patient connection ofclaim 29, wherein the sensor is a force sensor, and the signal delivered to the AED is related to a force applied to the sensor.

31. A method of interfacing an automated electronic defibrillator (AED) with a victim comprising the steps of:

positioning a patient interface externally on the victim, the patient interface having at least two electrodes and at least one sensor;

connecting the patient interface to the AED;

using the AED to sense a signal representative of the victim's cardiac electrical signal from the at least two electrodes;

using the AED to sense a signal from the sensor indicative of a magnitude of chest compression when the victim is receiving cardiopulmonary resuscitation (CPR);

determining if the magnitude of chest compressions received by the victim during CPR is effective for resuscitation by using the AED to analyze the signal from the sensor;

prompting the rescuer in response to the step of determining if the magnitude of chest compressions received by the victim during CPR is effective; and

using the AED to selectively deliver a defibrillation shock pulse from the AED to the victim through the at least two electrodes.

32. The patient connection ofclaim 29, wherein the sensor senses a force applied to the sensor, and wherein the signal from the sensor is proportional to the force applied to the sensor.

33. The method ofclaim 31, wherein the step of determining if the magnitude of chest compressions received by the victim during CPR is effective determines whether the rescuer effectively depressed the sternum between about4 and5 cm.

34. An automated external defibrillation system for use by a rescuer to resuscitate a victim comprising:

a patient connection interface adapted to be positioned externally on a victim, the patient connection interface including:

at least two electrodes, each having at least one lead wire attached to the electrode that selectively delivers a signal representative of the victim's cardiac electrical signal (EKG) and that selectively delivers a defibrillation shock pulse to the victim; and

at least one sensor having at least one lead wire attached to the sensor that selectively delivers a signal indicative of a magnitude of chest compression when the victim is receiving cardiopulmonary resuscitation (CPR); and

an automatic external defibrillator (AED) having:

charging circuitry that is in electrical communication with the at least two electrodes via the lead wires and selectively develops a high voltage charge for defibrillation of the victim;

EKG cardiac sensing circuitry that is in electrical communication with the at least two electrodes via the lead wires and selectively receives the signal representative of the victim's cardiac electrical signal;

CPR sensing circuitry that is in electrical communication with the at least one sensor via the lead wires and selectively receives the signal indicative of the magnitude of chest compressions;

voice circuitry that selectively generates audio prompts for the rescuer; and

a processor and associated memory and control logic operably connected to the charging circuitry, the EKG sensing circuitry, the CPR sensing circuitry and the voice circuitry that executes programmed instructions to selectively perform the steps comprising:

automatically analyzing the victim's cardiac electrical signal;

automatically analyzing the signal indicative of the magnitude of chest compression;

generating audio prompts to instruct the rescuer on appropriate instructions to perform both CPR and defibrillation based on the steps of analyzing the magnitude of chest compression and the victim's cardiac electrical signal; and

controlling delivery of the high voltage charge from the charging circuitry to the victim via the at least two electrodes at a time coordinated with audio prompts that instruct the rescuer.

35. The system ofclaim 34 wherein the processor analyzes the signal indicative of the magnitude of chest compression to determine if the indicated magnitude of chest compression is within a desired range.

36. The system ofclaim 35 wherein the desired range is based on a force and the sensor senses a force applied to the sensor.

37. The system ofclaim 35 wherein the desired range is based on a chest compression and the processor analyzes the signal indicative of the magnitude of chest compression to determine whether the rescuer effectively depressed the sternum between about4 and5 cm.

38. The system ofclaim 35 wherein the desired range is based on a rate and the processor analyzes the signal indicative of the magnitude of chest compression to determine a rate of chest compressions.

39. An automated external defibrillation system for use by a rescuer to resuscitate a victim comprising:

a patient connection interface adapted to be positioned externally on a victim, the patient connection interface including:

means for selectively sensing and delivering a signal representative of the victim's cardiac electrical signal (EKG) and for selectively delivering a defibrillation shock pulse to the victim; and

means for selectively sensing and delivering a signal indicative of at least one parameter associated with the victim receiving cardiopulmonary resuscitation (CPR); and

an automatic external defibrillator (AED) having:

means for selectively developing a high voltage charge for defibrillation of the victim in electrical communication with the patient interface;

means for selectively generating audio prompts for the rescuer; and

means operably connected to the means for selectively developing a high voltage charge and the means for selectively generating audio prompts for the rescuer for selectively controlling operation of the AED, including:

means for automatically analyzing the victim's EKG signal;

means for automatically analyzing the CPR signal;

means for generating audio prompts to instruct the rescuer on appropriate instructions to perform both CPR and defibrillation in response to the means for automatically analyzing the EKG signal and the means for automatically analyzing the CPR signal; and

means for selectively delivering the high voltage charge from the means for selectively developing a high voltage charge at a time coordinated with audio prompts generated by the means for generating audio prompts.

40. The system ofclaim 39, wherein the means for selectively sensing and delivering a signal representative of the victim's cardiac electrical signal (EKG) and for selectively delivering a defibrillation shock pulse to the victim comprises a pair of electrodes, each electrode having at least one lead wire attached thereto.

41. The system ofclaim 39, wherein the means for selectively sensing and delivering a signal indicative of at least one parameter associated with the victim receiving CPR comprises a sensor having at least one lead wire attached thereto.

42. The system ofclaim 41, wherein the CPR signal includes a signal indicative of the magnitude of chest compression and the means for automatically analyzing the CPR signal analyzes the signal indicative of the magnitude of chest compression to determine if the magnitude of chest compression is within a desired range.

43. The system ofclaim 42, wherein the desired range is based on a force.

44. The system ofclaim 42, wherein the desired range is based on a rate.

45. The system ofclaim 42 wherein the desired range is based on a chest compression and the means for selectively controlling operation of the AED analyzes the signal indicative of the magnitude of chest compression to determine whether the rescuer effectively depressed the sternum between about4 and5 cm.

46. A method of prompting a rescuer in the resuscitation of a victim comprising the steps of:

positioning a patient connection interface externally on a victim, the patient connection interface including at least two electrodes and at least one sensor;

connecting the patient connection interface to an automatic external defibrillator (AED);

using the AED and the at least two electrodes to selectively sense and automatically analyze a signal representative of the victim's cardiac electrical signal (EKG);

using the AED and the at least one sensor to selectively sense and automatically analyze a signal indicative of a magnitude of chest compression when the victim is receiving cardiopulmonary resuscitation (CPR);

automatically causing voice circuitry in the AED to generate audio prompts to instruct the rescuer on appropriate instructions to perform both CPR and defibrillation based on the steps of automatically analyzing the victim's EKG and automatically analyzing the signal indicative of a magnitude of chest compression when the victim is receiving CPR; and

automatically causing the AED to selectively deliver a high voltage charge from a charging circuitry to the victim via the at least two electrodes at a time coordinated with audio prompts generated by the voice circuitry.

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