Patent Publication Number: US-8985326-B2

Title: Carrying case for defibrillator with integrated button tester

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to defibrillators for cardiac resuscitation and, in particular, to carrying cases for defibrillators. 
     Cardiac arrest is a life-threatening medical condition in which the patient&#39;s heart fails to provide blood flow to support life. A defibrillator can be used to deliver defibrillating shocks to a patient suffering from cardiac arrest. The defibrillator resolves this condition by delivering a high-voltage impulse to the heart in order to restore normal rhythm and contractile function in patients who are experiencing arrhythmia such as VF (ventricular fibrillation) or VT (ventricular tachycardia) that is not accompanied by spontaneous circulation. One type of defibrillator, the automated external defibrillator (AED), differs from manual defibrillators in that the AED can automatically analyze the electrocardiogram (ECG) rhythm to determine if defibrillation is necessary. The defibrillator analyzes the ECG signal for signs of arrhythmia. If VF is detected, the defibrillator signals the rescuer that a shock is advised. After the detection of VF or other shockable rhythm, the rescuer presses a shock button on the defibrillator to deliver a defibrillation pulse to resuscitate the patient. 
     Defibrillation must be delivered very soon after the onset of cardiac arrest in order to be effective. It is estimated that the chance of survival falls by 10% for every minute of delay to defibrillation beyond four minutes after cardiac arrest. Hence, AEDs are designed to be used by first responders, such as firefighters, police, or lay bystanders, who are the most likely to arrive at the patient&#39;s side first. Once an AED is brought to the patient, the rescuer must deploy and use it quickly. Such quick use is often challenging, because the rescuer may be unfamiliar with the AED&#39;s setup and operation. 
     External defibrillators act through electrode pads applied across the chest of the patient. The electrodes adhesively attach to the patient and are used both to acquire an ECG signal from the patient&#39;s heart and to apply the defibrillating shock. AED electrodes commonly are formed by locating a foil or metalized electrode between a flexible nonconductive backing and a conductive adhesive gel. The conductive adhesive attaches the electrode securely to the patient. Gels, however, will dry out (desiccate) over time and have a finite shelf life. A typical shelf life for an electrode with gel adhesive is about two years, after which the electrodes must be replaced. Some AEDs use electrodes which are simply replaced when the safe shelf life period has expired. Other AEDs have an internal self-test circuit which periodically tests the electrodes and detects desiccation by an impedance change. For self-test electrodes the electrodes are electrically connected to each other to form a continuous closed loop circuit that is tested. The closed loop circuit is broken when the electrode pads are deployed for use. 
     In the case of both self-tested electrodes and non-self-tested electrodes, it is typical that the electrodes will be connected to the AED while stored prior to use so that the rescuer does not need to connect them during the emergency; they are already pre-connected and ready for use. Pre-connected electrodes are commonly stored inside a protective container that is the same or co-located as a carrying case for an AED, so that the electrodes are protected from puncture or damage during storage, yet are instantly available for deployment when the AED case is opened. 
     Some AEDs also include accessories which aid in the administration of cardiopulmonary resuscitation (CPR) during the rescue. For example, the QCPR meter, sold by Philips Electronics North America, is a puck-like sensor which is placed on the patient&#39;s chest, and over which manual CPR compressions are applied. The QCPR meter contains force and motion sensors which provide an indication of the quality of the CPR applied via a signal cable to a defibrillator. 
     The AED may also include a pediatric mode accessory that, when applied to the AED, causes the AED to analyze and provide therapy appropriate to pediatric patients. The pediatric mode accessory may be shaped like a key which is inserted into an AED socket for use. When not in use, the key is stored elsewhere in the carrying case. 
     In addition, AED carrying cases may also include a fast response kit, which contains such rescue items as sterile gloves, scissors for cutting clothing away from a patient&#39;s chest, a razor for shaving excess chest hair, and a rescue breathing shield. A spare battery for the AED, spare electrode set, and written user guide may also be included in the carrying case. 
     Prior art AED carrying cases suffer a number of problems. First, the cover and handle on some prior art carrying cases hamper the application of therapy to the patient. Handles typically consist of strapping, which easily tangles with other gear stored or carried by the rescuer, delaying deployment. Handles may also be arranged to cover the AED cover latch, which may impede the ability of a glove-wearing rescuer to open the cover. Carrying case lids, when open, may be disposed such that they can easily be stepped on and broken by the rescuer, kicked shut by the rescuer, or otherwise impede access to the patient lying alongside. All of these characteristics serve to delay therapy. 
     Next, some carrying cases are arranged such that important contents are not visible at the time of deployment. A fast response kit, for example, may be stored in a separate pocket from the AED. A rescuer using such a carrying case may be delayed in finding and/or deploying the kit during rescue. 
     Prior art carrying case latches may be insufficiently robust to prevent inadvertent opening when the case is dropped, thus exposing the contents to damage or otherwise delaying the rescue. Some latches are simply Velcro closures. 
     Prior art carrying cases may be ill-disposed for ease of cleaning and checking of the contents, presenting risk of cross-contamination and malfunction during the next rescue. For example, some prior art AED carrying cases have no internal trays that are removable for cleaning. None have any means of testing internal components, such as a CPR guidance device or the defibrillator push buttons, prior to the rescue. If the AED contained in the carrying case has a ready-for-use indicator on its face, the case window may be too small to allow easy viewing of the indicator. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the principles of the present invention, a carrying case for a defibrillator is described which enables more rapid deployment and use during a cardiac rescue. Improvements include a relatively stiff and curved handle that is disposed at a 90 degree angle to both of the case hinge and the case latch. The shape and stiffness of the handle act to prevent entanglement with other gear during storage and removal. The orientation of the handle allows for use of the handle during rescue while simultaneously avoiding interference with latch actuation and lid opening. 
     In accordance with another aspect of the invention, a carrying case is described having a relatively rigid protective base and lid shell, connected by a double articulated hinge. The hinge is disposed such that, when in the open position, the carrying case base and lid are essentially co-planar. The case cannot be inadvertently closed while in the open position, and by the nature of the hinge, resists damage if stepped on while in the open position. A novel case seal between lid and base is described that prevents damage to any AED electrode or CPR meter wires that protrude from the case when the lid is inadvertently closed. Thus, the invention provides increased robustness and ease of use during rescue. 
     In accordance with yet another aspect of the invention, a carrying case is described with an improved arrangement of contents. All material required for cardiac rescue is immediately visible once the carrying case is opened. Provision for compact storage of electrode and CPR meter wire bundles is provided. Spares and other non-essential material are hidden, thus minimizing confusion during rescue. An automatic turn-on feature in the carrying case can optionally activate the defibrillator when the case lid is opened. An improved seal between lid and base is described which prevents pinching of wires if the lid is inadvertently closed during use. 
     In accordance with yet another aspect of the invention, a carrying case is described having improved ability to check and clean the cardiac rescue contents. The case may comprise an internal CPR meter holding bracket, a CPR meter test fixture, a light pipe for wider-angle viewing of a ready-indicator on an internal AED, a defibrillator button tester and/or trays removable for cleaning and/or replacement. 
     In accordance with yet another aspect of the invention, a carrying case with an improved closure latch is described. The latch is a rigid and hinged mechanism which consists of a spur and catch assembly that is held in positive engagement by a second hook and lock assembly. The latch may be opened with one hand and in one motion, and can be closed and locked by simply pressing the mechanism shut. When closed and locked the latch pull is flush to the carrying case for ease of deployment from the case storage location. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF DRAWINGS 
       In the drawings: 
         FIGS. 1   a  and  1   b  illustrate a defibrillator carrying case constructed in accordance with the principles of the present invention, in the closed and open positions respectively. 
         FIGS. 2   a  and  2   b  illustrate a preferred carrying case storage configuration for non-emergency spare battery and electrodes, respectively, which are hidden from sight during emergency use.  FIG. 2   c  illustrates a preferred embodiment of the carrying case interior arrangement. 
         FIG. 3   a  is a detail view of an exemplary carrying case latch assembly.  FIGS. 3   b  and  3   c  illustrate the latch assembly opening action. 
         FIG. 4   a  is a perspective view of an exemplary carrying case hinge constructed in accordance with the principles of the present invention.  FIGS. 4   b  AND  4   c  illustrate the action of the hinge in concert with the carrying case halves. 
         FIG. 5  is a detail view of a carrying case handle constructed in accordance with the principles of the present invention. 
         FIG. 6   a  is a detail view of an exemplary carrying case seal as disposed on the top and bottom carrying case halves.  FIG. 6   b  illustrates the anti-pinch feature of the case seal. 
         FIG. 7  is a detail view of an exemplary carrying case light pipe for conveying the ready indication light signal from an internal stored defibrillator to the exterior of the case. 
         FIG. 8  illustrates the carrying case in use during a cardiac rescue. 
         FIG. 9   a  illustrates a CPR meter storage bracket for holding a CPR meter inside the carrying case.  FIG. 9   b  illustrates an alternate embodiment of a CPR meter storage bracket, which comprises features to allow testing of a stored CPR meter. 
         FIG. 10  illustrates one embodiment of a carrying case further comprising a defibrillator push button tester. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring first to  FIG. 1   a , a defibrillator carrying case  100  according to the principles of the present invention is shown in the closed position. The carrying case  100  is sized to contain and protect components needed for a cardiac arrest rescue, such as an AED with pre-connected electrodes, a CPR meter, a fast response kit, and associated spares, not shown. The carrying case  100  protective surfaces consist primarily of two case halves; a base  200  and a lid  300 . Base  200  and lid  300  are fabricated of a lightweight and substantially rigid structural material, such as plastic, metal or a composite material. The material resists puncture, abrasion, water ingress and shock to protect the interior contents. In a preferred embodiment, base  200  and lid  300  are constructed of molded structural foam polypropylene or like material. Base  200  comprises four base walls  212  and a base bottom  214 , together forming a base interior region  210 . Similarly, lid  300  comprises four lid walls  312  and a lid top  314 , together forming a lid interior region  310 . 
     As shown in  FIG. 1   a , a hinge  400  connects the carrying case halves together across one wall base wall  212  of base  200  and one lid wall  312  of lid  300 . Latch assembly  500  is disposed across base  200  and lid  300  across a different base wall  212  and lid wall  312  opposite the hinge  400  to securely hold the carrying case halves in the closed position. A rigid or semi-rigid and arcuate handle  600  is attached at both ends across a carrying case side adjacent to both the carrying case  100  hinged side and the latched side. Each of the hinge  400 , latch assembly  500 , and handle  600  are disposed such that all surfaces contacting the carrying case are flush with the carrying case surfaces when the case is closed. 
       FIG. 1   b  illustrates the carrying case  100  in the open position. The base walls  212  and base bottom  214  together form a base interior region base interior region  210 . Similarly, the lid walls  312  and lid top  314  together form a lid interior region  310 . A removable base tray  800  may be nested inside base interior region base interior region  210 , and a removable lid tray  820  may be nested inside lid interior region  310 . 
     Lid  300  or lid tray  820  may also comprise a case opening indicator  720 , preferably a magnet, which is affixed to the lid. So located, indicator  720  overlays a corresponding case opening sensor inside portable defibrillator  110  only when carrying case  100  is closed. Portable defibrillator  110  senses an open lid by the absence of indicator  720 , and thus turns itself on. It is noted that a feature that automatically turns portable defibrillator  110  off upon the shutting of lid  300  should be avoided, in order to prevent unnecessary delay and confusion involved with an inadvertent lid closure, and unintended defibrillator shutdown, during rescue. 
     Additional detail of the interaction between latch assembly  500 , base  200  and lid  300  is shown in  FIG. 1   b , wherein base  200  is disposed with a case beveled catch  211  and base lock  213  which correspond to a beveled spur  511  and latch hook  515  respectively on latch assembly  500 .  FIG. 1   b  also illustrates an anti-pinch case sealing mechanism, comprising opposing base seal edge  216  and lid seal edge  316 , formed along the exposed edges of base walls  212  and lid walls  312  respectively. 
     The relatively rigid nature of the handle and the flush-mount design of its attachment to the carrying case  100  provide a smooth carrying case  100  profile shape of the case. Because carrying case  100  is typically stored in rescue vehicle compartments with other gear, the smooth overall profile and lack of mount protrusions allow the rescuer to grasp and pull the carrying case  100  out of the compartment without fouling other gear. Similarly, the latch mechanism and hinge are disposed to be flush to the carrying case  100  when closed and will not catch on other material when the carrying case  100  is pulled from the compartment. These features save precious seconds and reduce time to defibrillation. 
     The particular placement of the rigid handle  600 , latch assembly  500 , and hinge  400  on separate sides of the carrying case  100  solves several problems unaddressed by the prior art. By locating the handle away from the latch, the access to and operability of the latch is improved, especially for heavily gloved responders. By locating the handle away from the hinge, the handle is available for use in repositioning the carrying case  100  even when in the open position. 
     The present invention also improves the utility of the carrying case  100  when it is deployed next to a cardiac arrest patient.  FIG. 8  illustrates. A rescuer  10  typically takes position alongside the prone cardiac arrest patient  14  in order to provide CPR and monitoring of the patient. A portable defibrillator  110  stored within carrying case  100  is deployed on the patient to provide electrotherapy. Portable defibrillator  110  must be oriented such that its display can be easily viewed by the rescuer, and so is typically placed alongside the patient&#39;s head such that the bottom of the portable defibrillator  110  display is toward the rescuer. In this position, carrying case  100  offers the advantage that in the open position, the orientation of the hinge at the top of the portable defibrillator  110  display results in lid  300  always extending away from the rescuer and also cannot be opened to lie on the patient&#39;s face. It can be seen in  FIG. 8  that this advantage applies even when the rescuer deploys the portable defibrillator  110  on the other side of the patient. 
     In the open position, carrying case  100  is more stable and robust than prior art carrying cases. As shown in  FIG. 1   b , base  200  and lid  300  are substantially co-planar in the open position. The hinge  400  design, described in more detail below, allows lid  300  to rotate to 180 degrees and greater, and also allows for a slight and beneficial lateral movement from base  200 . Thus, when open, the top surface of lid  300  contacts the same surface as the bottom of base  200 . This provides a more stable platform for the rescue contents. The lid  300  in this position cannot inadvertently be kicked shut. In addition, the lateral movement feature provides enhanced resistance to damage because, if stepped on, hinge  400  will merely self-adjust the orientation of base  200  to lid  300  instead of breaking. 
     The height of the base wall  212  and the lid wall  312  need not be equal to achieve the aforedescribed advantages. However, the design of hinge  400  can be somewhat simplified if the base wall  212 , lid wall  312  are equal, because the top of lid  300  and the bottom of base  200  will completely contact the resting surface when carrying case  100  is open. 
     Several other advantages are offered by the carrying case  100  exterior features. The design of carrying case  100  promotes ease of maintenance. Light pipe  700  conveys a ready status light signal from an interior mounted AED to the carrying case  100  exterior. Light pipe  700  includes a means for diffusing the transmitted ready status light  111  signal, thereby making the indicator visible over a much wider angle of view.  FIG. 7  illustrates one embodiment of light pipe  700 , wherein the means for diffusing comprises etching or sandblasting an exterior surface  710  of light pipe  700 . The other surfaces of light pipe  700 , preferably constructed of clear acrylic or like material, are polished. The etching serves to diffuse the transmitted light signal over a wide angle, such that visual checks of the internal AED can be completed without opening carrying case  100 . 
     Removable base tray  800  and lid tray  820  also promote ease of maintenance in the carrying case  100 . Cardiac rescues typically involve bodily fluids and other contaminants, which must be removed from equipment after each use. Base tray  800  and lid tray  820  can easily be removed to clean the interior surfaces of carrying case  100 . Replaceability of base tray  800  and lid tray  820  also offers other advantages, such as replacement of a damaged tray, reconfiguration if a different internal equipment configuration is needed, or if there is no time for cleaning prior to the next cardiac rescue. 
       FIGS. 2   a ,  2   b  and  2   c  illustrate a preferred embodiment of the arrangement of carrying case  100  interior contents. Carrying case  100  is generally configured such that when the lid  300  is opened, the rescue equipment that is most immediately needed is visible to the user and ready to use. Equipment that is not immediately needed is hidden from view in order to reduce clutter and confusion.  FIG. 2   a  illustrates an embodiment of carrying case  100  wherein a spare battery  112 , normally not needed at the beginning of a cardiac rescue, is stowed behind a CPR meter storage bracket  922  and subsequently hidden from view by a stored CPR meter  140 .  FIG. 2   a  also shows an electrode storage slot  912  that is installed at the handle-end of carrying case  100  for containing a pre-connected set of electrodes  120 . Electrode storage slot  912  secures electrodes  120  in an instantly-visible and accessible manner. Co-pending and co-assigned U.S. application Ser. No. 12/827,142 entitled “PINCH CASE FOR DEFIBRILLATOR ELECTRODE PADS AND RELEASE LINER”, fully incorporated herein, describes a preferred embodiment of electrode storage slot  912  and electrodes  120  which can be employed in carrying case  100 . 
     Both of electrode storage slot  912  and CPR meter storage bracket  922  are shown in  FIG. 2   a  as installed in base tray  800  within base interior region  210 . However, it is understood that either fixture may also be installed directly into base interior region  210  without the need for base tray  800  at all. 
       FIG. 2   b  illustrates the relative arrangement of portable defibrillator  110 , CPR meter  140  and electrodes  120  within base interior region  210 . portable defibrillator  110  is disposed to the right side, CPR meter  140  disposed on CPR meter storage bracket  922  in the center, and electrodes  120  disposed in electrode storage slot  912 . Each is instantly visible and accessible when portable defibrillator  110  is opened. In addition, electrodes  120  and CPR meter  140  are pre-connected to portable defibrillator  110 , and connection wires stowed out of the way. Thus, the operator may begin deploying the equipment immediately upon opening the case. 
       FIG. 2   b  also shows a set of spare electrodes  122  stowed out of sight behind a panel formed in lid tray  820 . It is understood that lid tray  820  may be integrated with and form part of lid interior region  310  instead of being a separate removable component. 
     Turning now to  FIG. 2   c , additional cardiac rescue components fast response kit  160  and pediatric mode key  180  are shown stowed for immediate deployment in lid interior region  310 . Fast response kit  160  may be completely removable as a kit from carrying case  100  for opening elsewhere in the rescue. Pediatric mode key  180  may be press-fit into a similarly shaped indentation in lid tray  820 , as shown, and/or may be connected to carrying case  100  via a retractable tether stowed behind the lid tray  820  panel. When portable defibrillator  110  is to be used on a pediatric patient, the operator simply inserts pediatric mode key  180  into a pediatric mode changing slot  113 . Portable defibrillator  110  senses the insertion and changes into a pediatric mode of operation. 
       FIG. 2   c  also shows the disposition of light pipe  700  over ready status light  111 . When lid  300  is shut, light pipe  700  overlays ready status light  111 . Any indicator light signal on ready status light  111  is then transmitted through light pipe  700  to the exterior of portable defibrillator  110  for ease of viewing without having to open the case. 
     Referring to  FIG. 3   a , an embodiment of a latch assembly  500  for carrying case  100  is illustrated. Latch assembly  500  comprises a relatively flat latch pull  510  having a beveled spur  511  for engaging a corresponding beveled catch  211  disposed on base wall  212 . Latch assembly  500  also comprises a latch plate  514  which slidably translates relative to latch pull  510  against latch spring  516 . A portion of latch plate  514  extending below latch pull  510  serves as a manual operating surface to compress the latch plate  514  against latch spring  516 . Latch pull  510  is preferably constructed of a rigid and strong material, such as metal or plastic, that can withstand impact and operational abuse. 
       FIG. 3   b  illustrates the geometry and operation of latch assembly  500  with carrying case  100  closed. In the closed position, the beveled spur  511  and beveled catch  211  are held in compressive contact primarily through the holding tension of latch assembly  500  relative to base  200  and lid  300 . As shown in  FIG. 3   a , latch hook  515  further engages base lock  213  formed in base wall  212  to securely hold the beveled spur  511  against beveled catch  211 . The combination of beveled spur  511  and latch hook  515  thus prevent the latch from popping open even if the case is dropped.  FIG. 3   b  also shows a preferred configuration of base wall  212 , whose exterior surface is substantially co-planar with the latch pull  510  exterior surface, except for the indented operating area just under beveled spur  511 . 
       FIG. 3   c  illustrates the operation of latch assembly  500  to open carrying case  100 . The operator releases latch assembly  500  by pressing upward on latch plate  514  against latch spring  516 , which in turn releases latch hook  515  from base lock  213 . The beveled spur  511  and beveled catch  211  are suitably angled with respect to the base wall  212  surface, so that upon the release of latch hook  515 , the operator can smoothly rotate latch assembly  500  about latch pin  518  and away from base wall  212  for opening. Thus, the opening operation can be accomplished with one hand and in one motion. Upon subsequent release of the latch plate  514 , latch spring  516  returns latch plate  514  to its initial position which is ready for closing. 
     Further inspection of  FIG. 3  also shows how latch assembly  500  is closed and locked. To latch carrying case  100  closed, the operator merely presses latch pull  510  about latch pin  518  until the angled interior surface of latch hook  515  and the upward-facing angled surface of beveled catch  211  are in contact. The operator firmly presses latch pull  510 , thereby causing latch hook  515  to slide upward and along the contact surface, opposed by latch spring  516 , until latch hook  515  engages into base lock  213 . Alternatively, the operator may press upward and then release latch plate  514 , while pressing latch pull  510 , to cause latch hook  515  to engage base lock  213 . 
     Referring to  FIG. 4   a , carrying case  100  preferably comprises a hinge  400 , similar to a floating hinge, for hingably connecting lid  300  to base  200 . Hinge  400  comprises an articulated body  414  which is interposed between lid  300  and base  200 . Articulated body  414  is in turn connected to base  200  on each end by a bottom hinge pin  410 , and also to lid  300  on each end by a top hinge pin  410 . Articulated body  414  is constructed of a rigid material which can add strength to the structure when carrying case  100  is closed, and can also add structural strength to carrying case  100  when carrying case  100  is open. Articulated body  414  is preferably made of the same material as base  200  and lid  300 . Bottom hinge pin  410  and top hinge pin  410  are of stainless steel or similar material. 
       FIGS. 4   b  and  4   c  illustrate the operation of hinge  400  in the closed and open positions respectively. As illustrated in  FIG. 4   b , hinge  400  is disposed such that when carrying case  100  is closed, an articulated body  414  surface is flush to the surfaces of base wall  212  and  312 .  FIG. 4   c  shows carrying case  100  open. In the open position, both  312  and articulated body  414  are rotated from their closed position, such that an opposite articulated body  414  surface is flush to the open faces of base  200  and lid  300 . 
     In addition to the advantages offered by the flush construction, hinge  400  provides structural strength and protection to the hinge area formed between base wall  212  and lid wall  312 . In addition, the articulated nature of articulated body  414  allows a limited amount of translational shifting between base wall  212  and lid wall  312 , such that the hinge area can absorb crushing forces, such as those incurred when being driven over or stepped upon, that may break other hinge designs. As can be seen from inspection of  FIGS. 4   b  and  4   c , hinge  400  does so by allowing crushing forces to be distributed over the rounded surfaces of base wall  212  and  312  which contact articulated body  414  instead of in the concentrated area of bottom hinge pin  410  and top hinge pin  410 . In the open position, hinge  400  also allows the opposing surfaces of base wall  212  and  312  to counter crushing forces from above. 
       FIG. 5  illustrates a preferred embodiment of carrying case handle  600 . The handle is comprised of a substantially rigid or semi-rigid material, like thermoplastic elastomer, which can flex but return to original shape. Handle  600  is preferably rounded or arcuate to allow for quick deployment without catching on other equipment. Shoulder strap pins  612  for mounting an optional shoulder strap, the strap not shown, may be molded into handle  600 . 
     Handle  600  is attached to carrying case  100  as described previously and as seen in  FIG. 1 .  FIG. 5  shows each end of handle  600  comprises a handle anchor  610 , which is formed to be flush-mounted to opposite sides of carrying case  100  with known fasteners, not shown, such as screws or rivets. Flush-mounting may be completed by covering the fasteners with handle anchor cover plates  613 . Once so disposed, the entire silhouette of carrying case  100  with handle  600 , as viewed toward the lid top  314 , presents a continuous smooth line which resists catching on adjacent material when carrying case  100  is pulled from its storage location. 
     Now referring to  FIGS. 6   a  and  6   b , a closure seal  750  between base  200  and lid  300  is described. In prior art carrying cases, protruding electrode wires could be damaged or severed when the lid was inadvertently forced shut against the case base. To minimize damage to wires in the unlikely event that carrying case  100  is inadvertently shut during use, a closure seal  750  is formed in the opposing exposed edges in base walls  212  and lid walls  312 . A preferred embodiment of the closure seal  750  is shown in the section view  FIG. 6   b . Each lid wall  312  edge that faces a base wall  212  edge comprises a lid seal edge  316  that protrudes from and is offset from the exterior surface. A lid closure stop, not shown, causes a serpentine gap between base  200  and lid  300  when lid  300  is closed, through which a protruding electrode lead wire  121  can pass without damage. If additional protection from outside elements is desired, each of base seal edge  216  and lid seal edge  316  may be lined with a flexible elastomeric material which fills the gap when the lid is closed, but which allows electrode lead wire  121  to pass without damage. 
     Another embodiment of the present invention is a carrying case which incorporates features that enable testing of the internal contents. One such feature enables testing of the CPR Meter  140  during storage and prior to deployment so that the rescuer is confident that the CPR meter will provide accurate instruction during use. Another feature enables the physical testing of the portable defibrillator  110  buttons, which has never been contemplated in prior art carrying cases. Such a test can periodically confirm the proper mechanical operation of the defibrillator shock button. 
       FIG. 9   a  is a more detailed illustration of the CPR meter storage bracket  922  shown in  FIGS. 2   a - c . Bracket  922  may be removably clipped into carrying case  100  with a CPR meter bracket base mount  921 . CPR meter  140  is then clipped into CPR meter holding clip  923 , which is offset upward from the bracket base such that the face of the CPR meter  140  is about coplanar with the face of the defibrillator  110  stored adjacent. Thus, both meter  140  and defibrillator  110  are immediately visible to the user. In addition, the space under the stored CPR meter  140  is available for storing other rescue items, such as a spare battery  112 . 
     Now referring to  FIG. 9   b , an alternate embodiment of CPR meter storage bracket  922  comprises a CPR meter test fixture  924 . Like CPR meter storage bracket  922 , CPR meter test fixture  924  is disposed to securely hold CPR meter  140  during storage. CPR meter test fixture  924  differs from the previously described CPR meter storage bracket  922 , however, by comprising a test fixture base  925  and a vertically movable clip  926 , connected with an internal spring means having a known spring constant, such as elastic band  927 , coil spring, leaf spring, or underlying compressible material. Fixture base  925  is fixed to case bottom  200 . CPR meter  140  is removably attached to movable clip  926  similar to that shown in  FIG. 2 . 
     CPR meter test fixture  924  with attached CPR meter  140  is disposed such that when lid  300  is closed, lid  300  compresses the CPR meter  140  and movable clip  926  by a known and fixed distance, shown as “d” in  FIG. 9 . The internal spring means thus generates a known counterforce on the CPR meter  140  force sensor as it is pressed against lid  300 . An exemplary level of counterforce is about 4 kg, with a range of 2 kg-5 kg, with an exemplary fixed spring compression of 2 inches, with a range of between ¾ inch-3 inches. 
     Portable defibrillator  110 , when it awakens for self-testing under its own internal periodic self-testing protocol, can be configured to also activate the attached CPR meter  140  and receive a signal corresponding to the sensed force. By comparing the sensed force with the known force, the defibrillator  110  can determine whether the CPR meter force sensor is operating properly and within calibration. If not, defibrillator  110  can generate a self-test failure alert. 
     With the carrying case lid  300  in the open position and the defibrillator  110  activated for self-testing, the CPR meter distance sensing can be tested by CPR meter test fixture  924  as well. In this embodiment, the difference in height between the CPR meter test fixture  924  in the uncompressed and fully compressed positions is also known. A user tests the CPR meter motion sensor by compressing the CPR meter  140  and movable clip  926  to the fully compressed position. Defibrillator  110  senses the CPR meter compression signal and compares it to the known distance. If the sensed and known distances differ in excess of an acceptable tolerance band, defibrillator  110  generates a self-test failure alert. Of course, defibrillator  110  can be configured to aurally and visually guide the user during the execution of this test. 
     An optional defibrillator push button tester  930  may also be incorporated into carrying case lid  300 .  FIG. 10  illustrates one embodiment of the button tester  930 , which comprises finger-like actuators  932 ,  933  extending from the bottom of an actuator case  934  mounted inside lid  300 . Shock button actuator  932  is disposed such that its end is positioned over the defibrillator shock button  114  when the lid is shut. Similarly, on/off button actuator  933  is disposed such that its end is positioned over the defibrillator on/off button  115  when the lid is shut. Push button tester  930  also comprises a button tester sensor  934  to sense a periodic activation signal, issued from the underlying defibrillator when the defibrillator  110  awakes for a periodic self test. Button tester sensor  934  is preferably a light sensor or wireless sensor that senses a corresponding light or wireless signal that emanates from the defibrillator when it activates for self-testing. Push button tester  930  also comprises a button tester power supply  935  such as a replaceable battery with sufficient energy to operate periodically, preferably on a monthly basis, over an extended period of time. 
     Push button tester  930  is disposed to receive the periodic activation signal from defibrillator  110 , such as by the flashing of ready status light  111 , and subsequently extend actuators  932 ,  933  to press the respective underlying defibrillator push buttons. Defibrillator  110  senses the resulting operation of the push button, by sensing a change of continuity across the push button&#39;s electrical circuit, and passes the result to the self-test algorithm. If the defibrillator fails to sense an expected push button operation, it issues a self-test failure alert. Once the button self-test is complete, both defibrillator  110  and push button tester  930  revert to a standby mode of operation to save battery power. 
     Another embodiment of the defibrillator push button tester  930  requires no coordination with the self-test activation of the defibrillator  110 . In this embodiment, the push button tester  930  actuates the actuator  932 , 933  on an independent schedule, and holds the actuator  932 , 933  down, i.e. button pressed, for a period of time long enough to overlap with a defibrillator self-test. The actuator  932 , 933  then releases for a second period of time long enough to overlap with the next defibrillator self-test. In this embodiment, the underlying defibrillator must only sense the change in button position from one self-test to the next to determine whether the button is operating properly. 
     Other variations within the scope of the aforedescribed invention will readily occur to those skilled in the art. For instance, the orientation of the latch could be reversed such that latch assembly  500  is pinned to base  200  instead of to lid  300 . Other arrangements of the interior contents may be advantageous depending on the relative size and shape of the stowed components