AUTOMATED WEARABLE BELT CARDIAC DEFIBRILLATOR

Abstract

An automated wearable belt cardiac defibrillator (BCD) for wearing by a subject, comprising: at least two patches adapted for adhering to the subject each comprising a defibrillation electrode and an ECG sensor; and a BCD controller connected to each of the patches, wherein the patches comprise an adhesive adapted for long-term adhering of the patches to the subject, wherein the adhesive is a biocompatible adhesive, wherein the patches and adhesive are adapted for movement of the subject while the patches are adhered to the subject, wherein the patches are replaceable, wherein the controller is housed in a belt for wearing by the subject, wherein the belt is adapted for being flexible, wherein the adaptation for being flexible comprises a plurality of compartments for housing components of the controller, wherein a method for usage of the BCD comprises: following completion of an operational period, positioning of the patches to alternative locations on the subject wherein each of the alternate locations represents an alternate shock vector.

Claims

1. A flexible automated wearable belt cardiac defibrillator (BCD) for wearing by a subject, the subject having a body, the BCD comprising: at least two disposable patches adapted for adhering to the body of the subject, each patch comprising a defibrillation electrode, wherein at least one patch includes an ECG sensor; and a controller that is separate from the patches and connected via a connection cable to each patch, wherein the patches comprise an adhesive adapted for long-term adhering of the patches to the body of the subject, wherein the patches and the adhesive are adapted for movement of the subject while the patches are adhered to the body of the subject, wherein the controller is housed in a flexible belt comprising a plurality of compartments for wearing by the subject, is adapted for being flexible, and is not required to be in contact with the body of the subject, and wherein the adaptation for being flexible comprises distributing components of the controller between the plurality of compartments.

2. The BCD of claim 1, wherein the controller components comprise a battery, at least one high voltage and high energy capacitor, and controller electronics, and wherein each of the controller components is housed in a separate one of the plurality of compartments.

3. (canceled)

4. The BCD of claim 1, wherein the long-term is between one day and 10 days.

5. (canceled)

6. The BCD of claim 1, wherein the patches comprise a gel for enhancing electrical contact.

7. The BCD of claim 1, wherein the adhesive is a biocompatible adhesive.

8. The BCD of claim 1, wherein at least one of the patches comprises a vibration element.

9. The BCD of claim 8, wherein the vibration element is adapted for vibrating to alert the subject prior to an impending shock delivery by the defibrillation electrode.

10. (canceled)

11. (canceled)

12. The BCD of claim 1, wherein the at least two patches include at least three patches for providing at least two defibrillation vectors.

13. The BCD of claim 1, wherein the controller comprises a controller vibration pad.

14. The BCD of claim 13, wherein the controller vibration pad is adapted to generate vibration to alert the subject of an impending shock to be delivered by the defibrillation electrode.

15. The BCD of claim 1, wherein the controller comprises an audio output device adapted to generate an alarm sound in case of an impending a shock about to be delivered by the defibrillation electrode.

16. The BCD of claim 15, wherein the audio output device is adapted to sound an alarm following administering of a defibrillating shock.

17. (canceled)

18. The BCD of claim 1, wherein the controller is adapted for storage and/or analysis of ECG sensor data sensed by the at least one ECG sensor.

19. The BCD of claim 18, wherein the controller comprises an ECG event button adapted to be pressed to create a time stamp in the collected ECG sensor data.

20. The BCD of claim 19, wherein pressing of the ECG event button initiates recording via a microphone.

21. The BCD of claim 1, wherein the controller is adapted to measure impedance between each patch and a body of the subject to determine strength of an electrical connection therebetween.

22. The BCD of claim 1, wherein the controller comprises an abort button adapted for aborting an impending shock from the defibrillation electrode.

23. (canceled)

24. The BCD of claim 1, wherein the controller comprises a controller motion sensor and/or the BCD comprises an ECG motion sensor.

25. The BCD of claim 24, wherein one or both of controller motion sensor and the ECG motion sensor are adapted for determining data related to movement of the subject.

26. (canceled)

27. The BCD of claim 1, wherein the patches comprise connectors for connecting or disconnecting interconnection cables between the patches and/or between the patches and the controller.

28. The BCD of claim 1, wherein the controller is adapted for data communication with a remote monitoring center (RMC).

29. The BCD of claim 28, wherein ECG data sensed by the ECG sensor is transmitted to the RMC for analysis and storage.

30. The BCD of claim 28, wherein detected arrhythmia events are transmitted to the RMC.

31. The BCD of claim 28, wherein the controller comprises a GPS receiver adapted for determining the geolocation of the BCD, and wherein the determined location is transmitted to the RMC.

32. The BCD of claim 28, wherein the controller comprises a microphone and an audio device and is adapted for initiating a voice call with the RMC.

33. The BCD of claim 1, wherein the controller is adapted for wireless communication with an external device.

34-50. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Aspects, embodiments and features disclosed herein will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. Like elements may be marked with like numerals in different figures, where:

[0034] FIG. 1 shows an exemplary schematic drawing of a BCD according to some embodiments;

[0035] FIGS. 2A-2D show exemplary schematic drawings of a BCD according to some embodiments;

[0036] FIG. 3 shows an exemplary schematic drawing of a BCD according to some embodiments;

[0037] FIG. 4 shows an exemplary schematic drawing of a BCD according to some embodiments;

[0038] FIGS. 5A-5G show exemplary schematic drawings of a BCD according to some embodiments;

[0039] FIGS. 6A-6B show exemplary schematic drawings of a BCD according to some embodiments;

[0040] FIGS. 7A-7B show exemplary schematic drawings of the components of a BCD according to some embodiments.

DETAILED DESCRIPTION

[0041] Exemplary embodiments disclosed herein relate to a wearable AED (BCD) and method of use. FIG. 1 shows an exemplary schematic drawing of a BCD according to some embodiments. FIG. 1 shows a BCD 100 comprising a removable patch strip (RPS) 110 and a defibrillator controller 120. RPS 110 comprises one or more defibrillation (shocking) patches 116 and ECG sensors 118. RPS 110 comprises a soft structural base 122 comprising a soft material. In some embodiments, RPS 110 is biocompatible. In some embodiments, RPS 110 is held in place on the subject using a biocompatible adhesive (not shown). Defibrillator controller 120 monitors the subject's heart using sensors 118 and triggers defibrillation patches 116 if required. Sensors 118 and defibrillation patches 116 are connected to defibrillator controller 120 using wires 124. In some embodiments, defibrillation patches 116 comprise either a constant gel layer or a gel release mechanism (not shown) for releasing gel prior to defibrillation to improve conductivity of the defibrillation shock.

[0042] FIGS. 2A-2D show exemplary schematic drawings of a BCD according to some embodiments. As shown in FIGS. 2A-2D, a BCD 200 comprises a stretchable top 212, an RPS 110 and a controller 120. RPS 110 comprises one or more defibrillation (shocking) patches 116 and ECG sensors 118. RPS 110 is sized to removably slide into a pocket 214 of top 212. In some embodiments, top 212 comprises a stretch material. In some embodiments, top 212 comprises a washable material.

[0043] As shown in the plan view of FIG. 2B, pocket 214 has borders 222 made to hold RPS 110 firmly in position while leaving an opening 224 for RPS 110 to touch the torso of the subject. ECG sensors 118 and defibrillation patches 116 are therefore continuously in contact with the skin.

[0044] FIG. 2C shows RPS 110 inserted into pocket 214. It should be appreciated that stretchable top 212 holds RPS 110 and thus sensors 118 and defibrillation patches 116 pressed against the torso of a subject without the need for adhesives or adjusting straps. Further, a top 212 can be switched with another top 212 where RPS 110 can be removed from a first top 212 and placed in a second top 212. This exchange can allow for laundering of the first top 212, and vice versa.

[0045] In some embodiments, BCD 200 is adapted for use by a female subject. As shown in FIG. 2D, RPS 110 and pocket 214 are adapted to position defibrillation patches 116 above the right breast 226 of the subject.

[0046] FIG. 3 shows an exemplary schematic drawing of a BCD according to some embodiments. As shown in FIG. 3, a BCD 300 comprises a top 212, an RPS 310 and a defibrillator controller 320. BCD 300 is the same as BCD 200 apart from defibrillator controller 220 which is replaced with defibrillator controller 320. Controller 320 is integrated into RPS 310 and the components of controller 320 are distributed across RPS 310. This distribution spreads the controller components over a larger area (compared to controller 220) and thus provides enhanced weight distribution and greater comfort for the patient. In some embodiments, a housing 322 of controller 320 is cylindrical. In some embodiments, multiple housings 322 are provided for the components of controller 320.

[0047] FIG. 4 shows an exemplary schematic drawing of a BCD according to some embodiments. As shown in FIG. 4, a BCD 400 comprises a stretchable top 412, an RPS 410, a defibrillator controller 420 and an external device 422. RPS 410 comprises one or more defibrillation patches 416 and ECG sensors 418. RPS 410 is sized to removably slide into a pocket 414 of a top 412 of BCD 400. Top 412 is the same as top 212 described above.

[0048] Non-limiting examples of external device 422 are a smart watch or smartphone. External device 422 is in wireless communication with defibrillation patches 416, ECG sensors 418 and defibrillation controller 420. A non-limiting example of a wireless communication protocol is Bluetooth. External device 422 is a computing device and runs software to monitor the subject's heart using data received wirelessly from sensors 418, and triggers defibrillation patches 416 if required by communicating with controller 420 and/or defibrillation patches 416. In some embodiments, controller 420 is integrated into RPS 410 similarly to the way controller 320 is integrated into RPS 310.

[0049] FIGS. 5A-5G show exemplary schematic drawings of a BCD according to some embodiments. As shown in FIG. 5A BCD 500 comprises replaceable patches 510A and 510B (referred to also simply as “patches 510”) and a defibrillation controller belt (or simply “belt”) 520. Each of patches 510A, 510B comprises both a defibrillation electrode 516 and an ECG sensor 518.

[0050] In some embodiments, each of patches 510 includes include three or more ECG sensors 518 for sensing simultaneous sensing vectors. Multiple sensing electrodes per EC sensor 518 provides better sensing and detection of VF and discrimination of non-VF arrhythmias.

[0051] In some embodiments, each of patches 510 includes three or more defibrillation electrodes 516 for providing multiple simultaneous shock vectors. for better coverage of the heart and reduction of defibrillation threshold energy.

[0052] Patches 510A, 510B are affixed to the body of the subject using a biocompatible adhesive that is non-irritating for skin, is adapted both for extended use and for ensuring adhesion while that the subject continues to be active and mobile. A non-limiting example of a suitable adhesive may be KM40C by Katecho LLC of Des Moines, Iowa. In some embodiments, extended use covers a period of over 7 days. In some embodiments, extended use covers a period of over 10 days.

[0053] In some embodiments, patches 510A, 510B comprise gel for enhancing electrical contact. In some embodiments, defibrillation electrode 516 performs ECG signal measurement and ECG sensor 518 is not required.

[0054] In some embodiments, replaceable patches 510A, 510B include a vibration element 530 used to alert the patient prior to shock delivery. In some embodiments, replaceable patches 510A, 510B are replaced periodically. In some embodiments, replaceable patches 510A, 510B are disposable. In some embodiments, BCD 500 comprises more than two patches 510. Cables 522 provide electrical connectivity between patches 510 and cables 524 provide electrical connectivity between patches 510 and controller belt 520. As shown in FIG. 5G, each of patches 510 includes connectors 544 for connecting of cables 522 and 524 to patches 510. When one or more of patches 510 are replaced, they are disconnected at connectors 544 from cables 522 and/or 524, and new patches 510 also including connectors 544 are connected to cables 522 and/or 524. In some embodiments, controller belt 520 includes a switching component in order to carry both of sensing signals and shock current on the same electrode.

[0055] Controller belt 520 has the form of a flexible belt. Belt 528 comprises a flexible material. Controller belt 520 is flexible and wearable and comprises an adjustment means 542 such a belt adjustment means known in the art in order to fit controller belt 520 comfortably around the waist or torso of the subject. Alternatively, belt 520 may be worn on another part of the body or may be carried.

[0056] Controller belt 520 contains all the components of a defibrillator controller (such as controller 720, high voltage capacitors, batteries, electronics, high voltage shock circuits, alarm system, communication system, operating software as well as detection algorithm software) embedded in a flexible manner. In the form of a flexible belt, controller 520 is portable and well suited for comfortable wearing by a patient on a daily basis and may be shifted around the waist of the subject (or worn elsewhere) for comfort. As shown in FIG. 5B, controller belt 520 comprises a belt 528 comprising a flexible material and compartments 526 for housing of the components of defibrillation controller 520. It should be appreciated that distributing the components of defibrillation controller 520 between compartments 526 provides the required flexibility and overcomes the discomfort of wearing or carrying a box. It should further be appreciated that controller belt 520 does not need to touch the patient's body or skin and therefore is not a source of skin irritation. Only patches 510 need to be in contact with the patient's skin. It should further be appreciated that the controller is not attached to the subject via a patch touching the subject's skin.

[0057] Wiring (not shown) between compartments 526 provides for the electrical connections between the components of controller 520. In some embodiments, compartments 526 are cylindrical in shape. In some embodiments, compartments 526 have the form of a pocket. In some embodiments, compartments 526 are rectangular in shape. In some embodiments, belt 520 is a lightweight belt. In some embodiments, belt 520 including the patches 526 and cables 524 weighs less than 500 g.

[0058] Cables 524 enables removal of controller belt 520 from the subject for placing proximal to the patient while patches 510 remain attached to the subject to enable, for example, sleeping. In some embodiments, cables 524 are extendable for placing controller belt 520 further away from the subject. In some embodiments, compartments 526 are attached to controller belt 520 using flexible spacers (not shown).

[0059] In some embodiments, replaceable patches 510A, 510B can be placed in alternate locations to eliminate skin damage which may occur due to long-term usage of the patch in one position. A method for overcoming skin irritations which may be caused by patches and adhesives is shown in FIGS. 5C-5F. Defibrillators typically have one shocking electrode on the right side of the chest and a second shocking electrode on the left abdomen to provide a known shock vector. The inventors have determined that alternative shock vectors are possible, thus allowing periodic movement of the patches 510 to alternative positions to reduce long-term skin irritation.

[0060] In FIG. 5C, patches 510A and 510B are shown as located on the right side of the chest and left abdomen respectively. When a patch position location change is desired (normally within a week to avoid skin irritation), a second shock vector is provided by positioning patch 510A to the left side of the chest while patch 510B is positioned to the right side of the abdomen as shown in FIG. 5D. A third shock vector is provided by positioning patch 510B on the upper right side of the chest while patch 510A is positioned to the left upper side of the back as shown in FIG. 5E.

[0061] Alternating the sides for patches 510 enables use of relatively large patches compared to standard AED patches (desirable for conductivity) while reducing potential discomfort of subjects.

[0062] In the embodiment of FIG. 5F, controller 520 comprises batteries 536, a capacitor 538 and electronics 540. In the embodiment of FIG. 5F, wiring 534 provides for the electrical connections of the components of controller 520. It should be appreciated that the separation of the components of controller 520 into separate compartments 526 provides for greater comfort as belt 528 remains flexible and the weight is distributed around belt 528.

[0063] FIGS. 6A-6B show exemplary schematic drawings of a BCD according to some embodiments. As shown in FIG. 6A BCD 600 comprises replaceable patches 610 and defibrillation controller belt 620. Each of patches 610 comprises both of a defibrillation electrode 616 and an ECG sensor 618. Patches 610 are affixed to the body of the subject using biocompatible adhesive. Patches 610 are of smaller dimensions than patches typically used in the art. In some embodiments, patches 610 are smaller than 8×8 cm. The smaller size enables changing of the patch location periodically to enhance patient tolerance to such patches.

[0064] To enable sufficient energy to be conveyed by defibrillation electrodes 616 to the heart of a subject during a shock, more than two patches 610 are affixed to the subject. Multiple defibrillation electrodes 616 provide multiple shock vectors between the affixed defibrillation electrodes 616. As shown in FIG. 6B, a defibrillation vector “A” passes between electrode 616C through the heart 650 to electrode 616A, while defibrillation vector “B” passes between electrode 616B through heart 650 to electrode 616A. Although FIGS. 6A-6B show three patches 610, it should be appreciated that more than three patches may be used depending on the size of the patches and the amount of energy to be conveyed in a shock.

[0065] In some embodiments, patches 610 comprise gel for enhancing electrical contact. In some embodiments, replaceable patches 610 are replaced periodically. Cables 622 provide electrical connectivity between patches 610 via connectors 644 and cables 624 provide electrical connectivity between patches 610 (via connector 644) and controller belt 620 as described above with reference to FIGS. 5A-5G. Controller belt 620 is the same as controller belt 520 as described above.

[0066] FIGS. 7A-7B show exemplary schematic drawings of the components of a BCD according to some embodiments. As shown in FIG. 7, BCD 700 comprises a defibrillation electrode 716, an ECG sensor 718 and a controller 720. In some embodiments, BCD 700 also comprises a vibration pad 714. One or more of these components are in communication with an external device 722 and/or a remote monitoring center (RMC) 724. Embodiments of controllers 120, 220, 320, 420, 520, and 620 are the same as controller 720. Embodiments of patches/electrodes 116, 118, 216, 218, 316, 318, 416, 418, 516, 518, 616, and 618 have the same characteristics as defibrillation electrodes 716 and sensors 718. In some embodiments, such as shown in FIG. 7B, electrodes 716 and sensors 718 are combined into a single patch 715 as with patches 510 or 610. In some embodiments, vibration patch 714 is integrated into one or both of patches 716 and 718.

[0067] It should be appreciated that the components of controller 720 as described below may be provided in a single housing (such as but not limited to the housings of controllers 120 or 420) or alternatively may be distributed into multiple housings such as but not limited to the embodiment of FIG. 5A-5B where controller 720 components are stored in compartments 526, or the embodiment of FIG. 3 where controller 720 is housed in housing 322.

[0068] In some embodiments, the ECG sensors 718 and controller are adapted for sensing simultaneous sensing vectors. The adaptation includes sensing from three or more sensing electrodes placed on two or more patches for better sensing and detection of VF and discrimination of non-VF arrhythmias.

[0069] In some embodiments, defibrillation electrodes 716 are adapted for providing multiple simultaneous shock vectors. The adaptation includes providing three or more shock electrodes each placed on a patch 715 for better coverage of the heart and reduction of defibrillation threshold energy.

[0070] In some embodiments, controller 720 comprises an activation switch 728 to turn BCD 700 ON once the patches are in place. In some embodiments, controller 720 comprises an audio output device 726 to generate an alarm sound such as beeping or buzzing to alert the patient in case VT or VF was detected and a shock is about to be delivered. Additionally, audio device 726 may play audio messages from RMC 724, or messages related to the BCD 700 status. In some embodiments, controller 720 also comprises a microphone 730 for hearing comments from the subject. In some embodiments, audio output device 726 sounds an audible alarm following administering a defibrillating shock to warn/notify passers-by.

[0071] In some embodiments, ECG data as sensed by sensor patch 718 is collected for storage by controller 720, analysis by controller 720 and/or transmission to RMC 724 for analysis and storage. In some embodiments, controller 720 includes an ECG event button 752 for creating a time stamp in the collected ECG data such as but not limited to when a patient feels an arrythmia or other sensation the patient wishes to record. In some embodiments, ECG event button 752 initiates recording via microphone 730 such that the patient can state the reason for pressing ECG event button 752. In some embodiments, ECG data is continually buffered but only stored/recorded by controller 720 when ECG event button 752 is pressed including recording a time period before ECG event button 752 was pressed.

[0072] In some embodiments, controller 720 comprises visual indication means such as a display 732 and/or status lights 734 for displaying the status of BCD 700 and/or displaying messages related to BCD 700 and use thereof. In some embodiments, controller 720 measures impedance of patches 716, 718 to the body of the subject to determine the strength of the electrical connection therebetween. In some embodiments, controller 720 displays the measured strength of the electrical connection of a patch 716 and/or 718 to the skin of the subject. In some embodiments, controller 720 indicates the level of connection of patches 716 and/or 718 with the skin of the subject. In some embodiments, controller 720 indicates a suggested period for replacement or movement of patches 716, 718.

[0073] In some embodiments, controller 720 comprises a vibration device 736 to generate vibration to alert the patient in case VF was detected and a shock is about to be delivered. Additionally or alternatively, in some embodiments, a vibration alert is delivered to the subject via vibration patch 714.

[0074] In some embodiments, controller 720 comprises an abort button 738 used to abort a shock in a case the patient feels fine but the BCD 700 is alerting that a shock is about to be delivered. In some embodiments, controller 720 comprises an emergency call button 740. In some embodiments, safety switch 754 electrically disconnects controller 720 from defibrillation patch 716. In some embodiments, safety switch 754 is activated by abort button 738.

[0075] In some embodiments, controller 720 is in wireless communications with an RMC 724. In some embodiments, controller 720 notifies RMC 724 of an administered defibrillation shock. In some embodiments, controller 720 continuously analyzes the signal from ECG patch 718 to determine whether an arrhythmia has occurred. In some embodiments, detected arrhythmia events are stored by controller 720. In some embodiments, detected arrhythmia events are transmitted to RMC 724. In some embodiments, controller 720 comprises a GPS receiver 742, and the location of controller 720 is transmitted along with any information transmitted to RMC 724. In some embodiments, a patient can initiate a voice call with medical staff at the RMC 724 using microphone 730 and audio output 726.

[0076] In some embodiments, controller 720 includes a motion sensor 748. Motion sensor 748 may include one or more of a gravity sensor, linear acceleration sensor, rotation vector sensor, step counter, step detector, accelerometer and/or gyroscope. In some embodiments, sensor patch 718 includes a motion sensor 750. Motion sensor 750 may include one or more of a gravity sensor, linear acceleration sensor, rotation vector sensor, step counter, step detector, accelerometer and/or gyroscope. In some embodiments, one or both of motion sensors 748, and 750 may determine data related to movement of the patient. In some embodiments, movement data is collected by controller and combined with the ECG data provided sensor patch 718. In some embodiments, motion sensor data, indicative of the movement of the patient, is used as part of monitoring of syncope by controller 720 and/or by RMC 724.

[0077] In some embodiments, controller 720 comprises batteries 744 that can be replaceable and/or rechargeable. In some embodiments, rechargeable batteries 744 use either wireless charging or are charged using a cable (not shown) connected to the controllers from a power source.

[0078] In some embodiments, controller 720 is in wireless communication with external device 722. Non-limiting examples of external device 722 include a smartphone or smart watch. External device 722 comprises a software application (app) 746 for running on the external device. In some embodiments, app 746 presents the status of BCD 700 using the display of the external device such as, for example, to indicate a need for charging of BCD 700 or to indicate an error in the functioning of BCD 700. In some embodiments, the audible, visual and/or vibrating indication of an impending shock is provided by app 746 using the display, audio, and/or vibrating functions of external device 722. In some embodiments, an abort button is provided by app 746 and the touchscreen capability for activating the abort button is provided by external device 722. In some embodiments, an indication of the impending shock or activation of a shock is transmitted from controller 720 to external device 722 for further transmission by external device 722 using the built-in data communication functionality of external device 722 to a RMC 724, such as for emergency response. In some embodiments, app 746 provides BCD 700 status information. In some embodiments, app 746 provides guided instructions for patch placement and rotation. In some embodiments, data from ECG patch 718 is provided to app 746 for analyzing of the signal from ECG patch 718 to determine whether an arrhythmia has occurred. In some embodiments, detected arrhythmia events are stored by app 746 on device 722. In some embodiments, detected arrhythmia events are transmitted by app 746 to RMC 724 using the communication features of device 722. In some embodiments, event button 752 is activated via app 746.

[0079] In some embodiments, when BCD 700 detects asystole after delivering a shock, BCD 700 delivers high voltage temporary external percutaneous heart pacing via patches 716. In some embodiments, the pacing is ventricular demand pacing (VVI). In some embodiments, the pacing is provided at a rate of 35 BPM.

[0080] In some embodiments, each patch 716, 718 comprises multiple perforations throughout the patch allowing for breathing of the skin while the patch is applied.

[0081] In the claims or specification of the present application, unless otherwise stated, adjectives such as “substantially” and “about” modifying a condition or relationship characteristic of a feature or features of an embodiment, are understood to mean that the condition or characteristic is defined to within tolerances that are acceptable for operation of the embodiment for an application for which it is intended.

[0082] It should be understood that where the claims or specification refer to “a” or “an” element, such reference is not to be construed as there being only one of that element.

[0083] In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of components, elements or parts of the subject or subjects of the verb.

[0084] While this disclosure describes a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of such embodiments may be made. The disclosure is to be understood as not limited by the specific embodiments described herein, but only by the scope of the appended claims.