U.S. patent application number 10/314667 was filed with the patent office on 2003-05-01 for defibrillators.
This patent application is currently assigned to ZMD Corporation, a Delaware corporation. Invention is credited to Faller, Frederick W., Hamilton, Ward.
Application Number | 20030083699 10/314667 |
Document ID | / |
Family ID | 25493276 |
Filed Date | 2003-05-01 |
United States Patent
Application |
20030083699 |
Kind Code |
A1 |
Hamilton, Ward ; et
al. |
May 1, 2003 |
Defibrillators
Abstract
Defibrillators are provided that include a graphical user
interface to assist a caregiver in administering resuscitation.
Inventors: |
Hamilton, Ward; (Amherst,
NH) ; Faller, Frederick W.; (Burlington, MA) |
Correspondence
Address: |
G. ROGER LEE
Fish & Richardson P.C.
225 Franklin Street
Boston
MA
02110-2804
US
|
Assignee: |
ZMD Corporation, a Delaware
corporation
|
Family ID: |
25493276 |
Appl. No.: |
10/314667 |
Filed: |
December 9, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10314667 |
Dec 9, 2002 |
|
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|
09952834 |
Sep 14, 2001 |
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Current U.S.
Class: |
607/5 |
Current CPC
Class: |
A61N 1/3904 20170801;
A61N 1/39 20130101; A61N 1/3993 20130101; A61N 1/39044
20170801 |
Class at
Publication: |
607/5 |
International
Class: |
A61N 001/39 |
Claims
What is claimed is:
1. A defibrillator comprising: electrodes configured to be attached
to a patient, to acquire data indicative of the patient's heart
rhythm and to deliver a defibrillating shock if appropriate; a
defibrillator control box connected to the electrodes; and on a
portion of the defibrillator control box, a series of graphics
configured to prompt a caregiver to perform a sequence of steps
appropriate for treating a victim of suspected cardiac arrest.
2. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to check the patient for
responsiveness.
3. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to call for emergency
assistance.
4. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to open the patient's
airway.
5. The defibrillator of claim 4 wherein the picture illustrates how
to open the patient's airway.
6. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to check the patient for
signs of circulation.
7. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to attach the electrodes
to the patient.
8. The defibrillator of claim 7 wherein the picture illustrates
where the electrodes should be attached.
9. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to stand clear of the
patient.
10. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to press a treatment
button to cause the defibrillator to administer a defibrillating
shock.
11. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to perform CPR.
12. The defibrillator of claim 1 wherein the graphics include
pictures illustrating procedures for chest compressions and rescue
breathing.
13. The defibrillator of claim 10 wherein the picture includes a
heart symbol indicating the location of the treatment button.
14. The defibrillator of claim 1 further comprising a treatment
button configured to be pressed by the caregiver to cause the
defibrillator to administer a defibrillating shock.
15. The defibrillator of claim 1 further including a light source
associated with each of the graphics in the series.
16. The defibrillator of claim 15 further comprising electronics
configured to sequentially illuminate the light sources.
17. The defibrillator of claim 16 wherein the graphics include one
or more pictures selected from the group consisting of: a picture
configured to prompt the caregiver to check the patient for
responsiveness; a picture configured to prompt the caregiver to
call for emergency assistance; a picture configured to prompt the
caregiver to open the patient's airway; a picture configured to
prompt the caregiver to check the patient for signs of circulation;
a picture configured to prompt the caregiver to attach the
electrodes to the patient; a picture configured to prompt the
caregiver to stand clear of the patient; and a picture configured
to prompt the caregiver to perform CPR.
18. The defibrillator of claim 16 wherein the graphics include a
picture configured to prompt the caregiver to press a treatment
button to cause the defibrillator to administer a defibrillating
shock.
19. The defibrillator of claim 16 further comprising electronics
configured to measure the time elapsed from the time at which the
caregiver turned the power on to activate the defibrillator, and at
least some of the light sources are sequentially illuminated based
on the elapsed time.
20. The defibrillator of claim 16 further comprising electronics
configured to be preprogrammed with times for the illumination of
the light sources, the times being based on a predetermined
algorithm.
21. The defibrillator of claim 19 or 20 wherein the graphics
include one or more pictures selected from the group consisting of:
a picture configured to prompt the caregiver to check the patient
for responsiveness; a picture configured to prompt the caregiver to
call for emergency assistance; a picture configured to prompt the
caregiver to open the patient's airway; a picture configured to
prompt the caregiver to check the patient for signs of circulation;
a picture configured to prompt the caregiver to attach the
electrodes to the patient; a picture configured to prompt the
caregiver to stand clear of the patient; and a picture configured
to prompt the caregiver to perform CPR.
22. The defibrillator of claim 16 further comprising electronics
configured to acquire data from the electrodes, and at least some
of the light sources are sequentially illuminated based on the data
acquired from the electrodes.
23. The defibrillator of claim 16 wherein at least some of the
light sources are sequentially illuminated based on the time
elapsed from the time at which a shock was last delivered to the
patient.
24. The defibrillator of claim 15 wherein the light sources
comprise LEDs.
25. The defibrillator of claim 1 further comprising electronics
configured to provide audio prompts to the caregiver.
26. The defibrillator of claim 25 wherein the audio prompts are
associated with the series of graphics and are given sequentially
to guide the caregiver through the sequence of steps.
27. The defibrillator of claim 15 further comprising electronics
configured to provide audio prompts to the caregiver.
28. The defibrillator of claim 27, further comprising electronics
configured to sequentially illuminate the light sources, wherein
the audio prompts are associated with the series of graphics and
with the sequential illumination of the light sources, to guide the
caregiver through the sequence of steps.
29. The defibrillator of claim 26 or 28 further comprising
electronics configured to measure the time elapsed from the time at
which the caregiver turned the power on to activate the
defibrillator, and at least some of the audio prompts are timed to
occur based on the elapsed time.
30. The defibrillator of claim 26 or 28 further comprising
electronics configured to acquire data from the electrodes, and at
least some of the audio prompts are timed to occur based on the
data acquired from the electrodes.
31. The defibrillator of claim 26 or 28 wherein at least some of
the audio prompts are timed to occur based on the time elapsed from
the time at which a shock was last delivered to the patient.
32. The defibrillator of claim 1 wherein at least some of the
graphics are provided on a cover portion of the defibrillator
control box.
33. The defibrillator of claim 1 wherein at least some of the
graphics are provided on the outside of the cover portion of the
defibrillator.
34. The defibrillator of claim 33 wherein the graphics on the cover
portion include a picture indicating that the cover should be
removed from the defibrillator.
35. The defibrillator of claim 33 wherein the cover portion
includes a space provided for local emergency information.
36. The defibrillator of claim 35 wherein the cover portion
includes a window behind which a card bearing local emergency
information can be placed.
37. The defibrillator of claim 1 wherein at least some of the
graphics are provided in the form of backlit, translucent
images.
38. The defibrillator of claim 1 wherein at least some of the
graphics are provided in the form of an electronic display.
39. The defibrillator of claim 1 wherein at least some of the
graphics are provided in the form of a decal.
40. The defibrillator of claim 1 further comprising buttons,
associated with at least some of the graphics, which, when pressed,
cause more detailed audio prompts related to the associated graphic
to be output by the defibrillator.
41. A system for prompting a caregiver in a resuscitation sequence
for a patient who may be suffering from cardiac arrest, comprising
electrodes constructed to acquire data, indicative of the heart
rhythm of the patient and indicative of whether the electrodes are
properly placed on the patient, a defibrillator control box,
connected to the electrodes, constructed to analyze data received
from the electrodes and to measure the time elapsed since the
defibrillator control box was activated by the caregiver and/or
since the last shock was delivered to the patient; and a user
interface constructed to display information concerning the
appropriate step of the resuscitation sequence to be performed by
the caregiver at a particular time, based on the data received from
the electrodes and the elapsed time.
42. A defibrillator comprising: electrodes configured to be
attached to a patient, to acquire data indicative of the patient's
heart rhythm and to deliver a defibrillating shock if appropriate;
a defibrillator control box connected to the electrodes; a
treatment button configured to be pressed by a caregiver to deliver
a defibrillating shock, the location of the treatment button being
indicated by a heart symbol; and electronics configured to cause
the heart symbol to be temporarily illuminated if a shock is
advised based on ECG analysis performed by the defibrillator
control box.
43. The defibrillator of claim 1 wherein the graphics include one
or more pictures indicating that the caregiver should place a
passive airway support under the shoulders of the patient.
44. The defibrillator of claim 1 wherein the graphics include a
picture configured to prompt the caregiver to check to see if the
patient is breathing.
45. The defibrillator of claim 20 wherein the algorithm takes into
account one or more of the following items of data: (a) the time
elapsed from the time at which the previous light source in the
sequence was first illuminated, and/or (b) the time elapsed from
the last time a shock was delivered to the patient, and/or (c) the
results of ECG analysis.
46. The defibrillator of claim 26 or 28 further comprising
electronics configured to be preprogrammed with times for the
generation of the audio prompts, the times being based on a
predetermined algorithm.
47. The defibrillator of claim 46 wherein the algorithm takes into
account one or more of the following items of data: (a) the time
elapsed from the time at which the previous light source in the
sequence was first illuminated, and/or (b) the time elapsed from
the last time a shock was delivered to the patient, and/or (c) the
results of ECG analysis.
Description
TECHNICAL FIELD
[0001] This invention relates to defibrillators, and more
particularly to automatic external defibrillators (AEDs).
BACKGROUND
[0002] Resuscitation treatments for patients suffering from cardiac
arrest generally include clearing and opening the patient's airway,
providing rescue breathing for the patient, and applying chest
compressions to provide blood flow to the victim's heart, brain and
other vital organs. If the patient has a shockable heart rhythm,
resuscitation also may include defibrillation therapy.
[0003] There are many different kinds of abnormal heart rhythms,
some of which can be treated by defibrillation therapy ("shockable
rhythms") and some which cannot (non-shockable rhythms"). For
example, most ECG rhythms that produce significant cardiac output
are considered non-shockable (examples include normal sinus
rhythms, certain bradycardias, and sinus tachycardias). There are
also several abnormal ECG rhythms that do not result in significant
cardiac output but are still considered non-shockable, since
defibrillation treatment is usually ineffective under these
conditions. Examples of these non-shockable rhythms include
asystole, electromechanical disassociation and other pulseless
electrical activity. Although a patient cannot remain alive with
these non-viable, non-shockable rhythms, applying shocks will not
help convert the rhythm. The primary examples of shockable rhythms,
for which the caregiver should perform defibrillation, include
ventricular fibrillation, ventricular tachycardia, and ventricular
flutter.
[0004] After using a defibrillator to apply one or more shocks to a
patient who has a shockable ECG rhythm, the patient may
nevertheless remain unconscious, in a shockable or non-shockable
perfusing or non-perfusing rhythm. If a non-perfusing rhythm is
present, the caregiver may then resort to performing CPR for a
period of time in order to provide continuing blood flow and oxygen
to the patient's heart, brain and other vital organs. If a
shockable rhythm continues to exist or develops during the delivery
of CPR, further defibrillation attempts may be undertaken following
this period of cardiopulmonary resuscitation. As long as the
patient remains unconscious and without effective circulation, the
caregiver can alternate between use of the defibrillator (for
analyzing the electrical rhythm and possibly applying a shock) and
performing cardio-pulmonary resuscitation (CPR). CPR generally
involves a repeating pattern of five or fifteen chest compressions
followed by a pause during which two rescue breaths are given.
[0005] Defibrillation can be performed using an AED. The American
Heart Association, European Resuscitation Council, and other
similar agencies provide protocols for the treatment of victims of
cardiac arrest that include the use of AEDs. These protocols define
a sequence of steps to be followed in accessing the victim's
condition and determining the appropriate treatments to be
delivered during resuscitation. Caregivers who may be required to
use an AED are trained to follow these protocols.
[0006] Most automatic external defibrillators are actually
semi-automatic external defibrillators (SAEDs), which require the
caregiver to press a start or analyze button, after which the
defibrillator analyzes the patient's ECG rhythm and advises the
caregiver to provide a shock to the patient if the electrical
rhythm is shockable. The caregiver is then responsible for pressing
a control button to deliver the shock. Following shock delivery,
the SAED may reanalyze the patient's ECG rhythm, automatically or
manually, and advise additional shocks or instruct the caregiver to
check the patient for signs of circulation (indicating that the
defibrillation treatment was successful or that the rhythm is
non-shockable) and to begin CPR if circulation has not been
restored by the defibrillation attempts. Fully automatic external
defibrillators, on the other hand, do not wait for user
intervention before applying defibrillation shocks. As used below,
automatic external defibrillators (AED) include semi-automatic
external defibrillators (SAED).
[0007] Both types of defibrillators typically provide an auditory
"stand clear" warning before beginning ECG analysis and/or the
application of each shock. The caregiver is then expected to stand
clear of the patient (i.e. stop any physical contact with the
patient) and may be required to press a button to deliver the
shock. The controls for automatic external defibrillators are
typically located on a resuscitation control box.
[0008] AEDs are typically used by trained medical or paramedic
caregivers, such as physicians, nurses, emergency medical
technicians, fire department personnel, and police officers. The
ready availability of on-site AEDs and caregivers trained to
operate them is important because a patient's chances of survival
from cardiac arrest decrease by approximately 10% for each minute
of delay between occurrence of the arrest and the delivery of
defibrillation therapy.
[0009] Trained lay caregivers are a new group of AED operators. For
example, spouses of heart attack victims may become trained as lay
caregivers. Lay caregivers rarely have opportunities to
defibrillate or deliver CPR, and thus they can be easily
intimidated by an AED during a medical emergency. Consequently,
such lay providers may be reluctant to purchase or use AEDs when
needed, or might tend to wait for an ambulance to arrive rather
than use an available AED, out of concern that the lay provider
might do something wrong.
[0010] Some trained medical providers. e.g., specialists such as
obstetricians, dermatologists, and family care practitioners, also
rarely have the opportunity to perform CPR and/or defibrillate, and
thus may be uneasy about doing so. Concerns about competence are
exacerbated if training is infrequent, leading the caregiver to
worry that he or she may not be able to remember all of the
recommended resuscitation protocol steps and/or their correct
sequence.
[0011] Similarly, both medical and lay caregivers may be hesitant
to provide CPR and rescue breathing, or may be unsure when these
steps should be performed, particularly if their training is
infrequent and they rarely have the opportunity to use it.
SUMMARY
[0012] The invention provides a graphical user interface for use
with an AED. The graphical user interface includes a set of
graphics that clearly indicate the steps that should be performed
by a trained caregiver administering resuscitation to a victim of
cardiac arrest. The graphics, which may be accompanied by audio
prompts and/or other visually displayed messages, provide visual
reminders that will assist and encourage trained caregivers who
might not otherwise feel competent to perform cardiac resuscitation
including the use of an AED. In the case of caregivers who are
confident of their training and skills, the visual prompts may aid
the caregiver in more quickly and efficiently performing the
required steps in the resuscitation sequence.
[0013] In one aspect, the invention features a defibrillator
including: (a) electrodes configured to be attached to a patient,
to acquire data indicative of the patient's heart rhythm and to
deliver a defibrillating shock if appropriate; (b) a defibrillator
control box connected to the electrodes; and (c) on a portion of
the defibrillator control box, a series of graphics configured to
prompt a caregiver to perform a sequence of steps appropriate for
treating a victim of suspected cardiac arrest.
[0014] Some implementations of the invention may include one or
more of the following features. The graphics include one or more of
the following pictures: a picture configured to prompt the
caregiver to check the patient for responsiveness, a picture
configured to prompt the caregiver to call for emergency
assistance, a picture configured to prompt the caregiver to open
the patient's airway, a picture configured to prompt the caregiver
to check the patient's pulse, a picture configured to prompt the
caregiver to attach the electrodes to the patient, a picture
configured to prompt the caregiver to stand clear of the patient, a
picture configured to prompt the caregiver to press a treatment
button to cause the defibrillator to administer a defibrillating
shock, and a picture configured to prompt the caregiver to perform
CPR. Preferably, the pictures illustrate how the steps are to be
performed, e.g., how to open the patient's airway, where the
electrodes should be attached, and how to perform chest
compressions and rescue breathing.
[0015] Generally, if the defibrillator is an SAED, the
defibrillator will further include a treatment button configured to
be pressed by the caregiver to cause the defibrillator to
administer a defibrillating shock. The location of the treatment
button may be indicated by a graphic. e.g., a heart symbol.
[0016] In some implementations, the defibrillator further includes
a light source associated with each of the graphics in the series.
The defibrillator may include electronics configured to
sequentially illuminate the light sources. The sequential
illumination may be controlled by electronics configured to measure
the time elapsed from the time at which the caregiver turned the
power on to activate the defibrillator, at least some of the light
sources being sequentially illuminated based on the elapsed time.
Alternatively, or in addition, sequential illumination may be
controlled by electronics configured to be preprogrammed with times
for the illumination of the light sources, at least some of the
times being based on the time elapsed from (a) the time at which
the previous light source in the sequence was first illuminated or
(b) the time when a shock was delivered to the patient. The
sequential illumination of some of the light sources may be
controlled by electronics configured to acquire data from the
electrodes, at least some of the light sources being sequentially
illuminated based on the data acquired from the electrodes. The
light sources may be illuminated based on an algorithm, e.g., an
algorithm that takes into account one or more of the following
items of data: (a) the time elapsed from the time at which the
previous light source in the sequence was first illuminated, and/or
(b) the time elapsed from the last time a shock was delivered to
the patient, and/or (c) the results of ECG analysis.
[0017] In some implementations, the defibrillator also includes
electronics configured to provide audio prompts to the caregiver.
The audio prompts may be timed in any of the manners described
above with regard to the sequential illumination of the light
sources. Generally, the audio prompts are associated with the
series of graphics and are given sequentially to guide the
caregiver through the sequence of steps, and the audio prompts are
also associated with the sequential illumination of the light
sources.
[0018] At least some of the graphics may be provided on a cover
portion of the defibrillator control box. These graphics may be
provided on the inside and/or outside of the cover. If the graphics
are provided on the outside of the cover, they may include a
picture indicating that the cover should be removed from the
defibrillator. The cover may include a space provided for local
emergency information, e.g., a window behind which a card bearing
local emergency information can be placed.
[0019] The graphics may be provided in any desired manner, for
example, in the form of backlit, translucent images, as an
electronic display, or in the form of a decal.
[0020] In another aspect, the invention features a system for
prompting a caregiver in a resuscitation sequence for a patient who
may be suffering from cardiac arrest. The system includes: (a)
electrodes constructed to acquire data, indicative of the heart
rhythm of the patient and indicative of whether the electrodes are
properly placed on the patient, (b) a defibrillator control box,
connected to the electrodes, constructed to analyze data received
from the electrodes and to measure the time elapsed since the
defibrillator control box was activated by the caregiver and/or
since the last shock was delivered to the patient: and (c) a user
interface constructed to display information concerning the
appropriate step of the resuscitation sequence to be performed by
the caregiver at a particular time, based on the data received from
the electrodes and the elapsed time.
[0021] In yet another aspect, the invention features a
defibrillator including: (a) electrodes configured to be attached
to a patient, to acquire data indicative of the patient's heart
rhythm and to deliver a defibrillating shock if appropriate; (b) a
defibrillator control box connected to the electrodes; (c) a
treatment button configured to be pressed by a caregiver to deliver
a defibrillating shock, the location of the treatment button being
indicated by a heart symbol; and (e) electronics configured to
cause the heart symbol to be temporarily illuminated if a shock is
advised based on ECG analysis performed by the defibrillator
control box.
[0022] In preferred implementations the graphical interface
illustrates the entire sequence of resuscitation activities that
are recommended by the American Heart Association. As a result, the
graphical interface helps both experienced and novice users to get
through the early steps of patient care that are included in the
AHA's resuscitation protocols.
[0023] Moreover, because "a picture is worth a thousand words", the
graphical interface reminds the caregiver of how the steps in the
AHA's resuscitation protocols should be performed. For example,
rather than simply prompting the caregiver to "check airway", the
graphical interface reminds the caregiver that this means that the
caregiver should perform the head-tilt chin lift maneuver. To
provide the same information using audio or textual prompts alone
could inundate the caregiver with detailed information that could
confuse the caregiver. The graphical interface allows the caregiver
to use his or her visual senses in order to remember what to do at
each step during the rescue. The pictures may, also, be helpful
when the rescue is being performed in a noisy environment when
voice prompts may be hard to hear.
[0024] Other features and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
DESCRIPTION OF DRAWINGS
[0025] FIG. 1 is a perspective view of an AED with its cover
on.
[0026] FIG. 2 is a perspective view of the AED of FIG. 1 with the
cover removed.
[0027] FIG. 3 is a plan view of the graphical interface decal used
on the cover of the AED of FIG. 1.
[0028] FIG. 4 is a plan view of the graphical interface decal used
on the control box of the AED of FIG. 1, as shown in FIG. 2.
[0029] FIG. 5 is a flow chart indicating audio prompts provided
during use of the AED of FIG. 1 and steps to be performed by the
caregiver in response to the graphical and audio prompts.
[0030] FIG. 6 is a plan view of a graphical interface decal used on
the underside of the cover of the AED of FIG. 1.
DETAILED DESCRIPTION
[0031] Referring to FIG. 1, an automated external defibrillator 10
includes a removable cover 12 and a control box 14. The
defibrillator 10 is shown with cover 12 removed in FIG. 2. An
electrode assembly 16 (or a pair of separate electrodes) is
connected to the control box 14 by a cable 18. Electrode assembly
16 is stored under cover 12 when the defibrillator is not in
use.
[0032] Control box 14 includes a power button 15 and a status
indicator 17. Status indicator 17 indicates to the caregiver
whether the defibrillator is ready to use.
[0033] The cover 12 includes a cover decal 20 (FIGS. 1 and 3)
including a logo 22 and a series of graphics 24, 26 and 28. Logo 22
may provide information concerning the manufacturer of the device
and that the device is a defibrillator (e.g., "Zoll AED", as shown
in FIG. 3, indicating that the device is a Semi-automatic External
Defibrillator available from Zoll Medical). Graphics 24, 26 and 28
lead the caregiver through the initial stages of a cardiac
resuscitation sequence as outlined in the AHA's AED treatment
algorithm for Emergency Cardiac Care pending arrival of emergency
medical personnel. (See "Guidelines 2000 for Cardiopulmonary
Resuscitation and Emergency Cardiovascular Care. Supplement to
Circulation," Volume 102, Number 8, Aug. 22, 2000, pp. I-67.) Thus,
graphic 24, showing the caregiver and patient, indicates that the
caregiver should first check the patient for responsiveness, e.g.,
by shaking the patient gently and asking if the patient is okay.
Next, graphic 26, showing a telephone and an emergency vehicle,
indicates that the caregiver should call for emergency assistance
prior to administering resuscitation. Finally, graphic 28 indicates
that after these steps have been performed the caregiver should
remove the lid 12 of the defibrillator, remove the electrode
assembly 16 stored under the lid, and turn the power on by
depressing button 15. The graphics are arranged in clockwise order,
with the first step in the upper left, since this is the order most
caregivers would intuitively follow. However, in this case the
order in which the caregiver performs the steps is not critical,
and thus for simplicity no other indication of the order of steps
is provided.
[0034] The cover may also include a slot 28 (FIG. 1), through which
a card bearing local emergency information can be inserted and a
transparent window 30, communicating with slot 28, through which
the card can be viewed. Alternatively, or in addition, this
information can be displayed on a decal to be applied to the cover
by a user, e.g., phone number decal 32 (FIG. 1) applied to area 34
(FIG. 3) of cover decal 20. These features allow the emergency
information to be customized for a particular location and to be
easily updated if changes occur.
[0035] The control box includes a control box decal 40, shown in
FIGS. 2 and 4. Decal 40, like decal 20, includes a series of
graphics 42-49 (FIG. 4). In this case, the graphics are configured
to lead the caregiver through the entire resuscitation sequence, as
will be explained below with reference to FIG. 5. Decal 40 also
includes a center graphic 50, which includes representations of a
hand 52 and a heart 54 (FIG. 4). Center graphic 50 overlies a
treatment button which, when depressed, causes the defibrillator to
deliver a defibrillating shock to the electrode assembly 16.
[0036] Each of the graphics on control box decal 40 is accompanied
by a light source that can be temporarily illuminated to indicate
that the illuminated step should be performed at that particular
time. These light sources guide the caregiver, step-by-step,
through the resuscitation sequence, indicating which graphic should
be viewed at each point in time during resuscitation.
[0037] The light source for each of the graphics 42-49 is
preferably an adjacent LED (LEDs 56, FIG. 2). The heart 54 may be
translucent and backlit by a light source in the control box (not
shown). Alternatively, the heart 54 may include an adjacent LED
(not shown) and/or the hand 52 may include an LED 57 as shown.
[0038] LEDs 56 and 57 are mounted on the control box and are
visible through openings in the decal 40. When the heart 54 and/or
hand 52 is illuminated, this indicates to the caregiver that the
underlying treatment button should be depressed to administer a
defibrillating shock, as will be discussed in further detail
below.
[0039] Programmable electronics within the control box 14 are used
to determine when each of the light sources should be
illuminated.
[0040] The illumination and subsequent turning off of the LEDs
adjacent to graphics 42-45 is based on the amount of time that has
elapsed since the caregiver turned the power on by depressing
button 15. The elapsed time is measured by the programmable
electronics and used to illuminate each of the LEDs associated with
graphics 42-45 in turn. A time lapse of about 2 to 15 seconds is
allowed between each illumination, to allow the caregiver an
appropriate amount of time to perform each step. These time
intervals vary from a few seconds for graphic 42 (check
responsiveness) to 10 or more seconds for graphic 44 (open airway,
check for breathing).
[0041] The illumination of the LED adjacent to graphic 46 is based
on the elapsed time, while the subsequent turning off of this LED
is based on whether the impedance measured by the programmable
electronics indicates that the electrodes of electrode assembly 16
have been correctly positioned on the patient. This LED remains lit
until the correct impedance between the electrodes is detected,
e.g., an impedance of less than 300 ohms.
[0042] The illumination and turning off of the LEDs adjacent to
graphics 47-49, and of the light behind heart 54, is based on ECG
data that is acquired by electrode assembly 16 and analyzed by the
programmable electronics, as will be discussed below with reference
to FIG. 5.
[0043] The programmable electronics may also provide audio prompts,
timed to coincide with the illumination of the light sources, as
will also be discussed below with reference to FIG. 5.
[0044] FIG. 5 illustrates, in flow chart form, the use of the
graphics on decal 40, and accompanying visual and audio prompts, by
a caregiver performing resuscitation. The text in boxes indicates
steps performed by the caregiver. The text in caption balloons,
with ear symbols indicates audio prompts generated by the
defibrillator.
[0045] Thus, when a person collapses and a caregiver suspects that
the person is in cardiac arrest (100), the caregiver first gets the
defibrillator and turns the power on (102). If the unit passes its
internal self tests, and is ready for use, this will be indicated
be indicator 17, as discussed above. Next, the defibrillator
prompts the caregiver with an introductory audio message, e.g.,
"Stay calm. Listen carefully." (Audio prompt 104.)
[0046] Shortly thereafter, the defibrillator will prompt the
caregiver with an audio message indicating that the caregiver
should check the patient for responsiveness (audio prompt 106).
Simultaneously, the LED adjacent graphic 42 will light up,
directing the caregiver to look at this graphic. Graphic 42 will
indicate to the caregiver that she should shout "are you OK?" and
shake the person (step 108) in order to determine whether the
patient is unconscious or not.
[0047] After a suitable period of time has elapsed (e.g., 2
seconds), if the caregiver has not turned the defibrillator power
off (as would occur if the patient were responsive), the
defibrillator will give an audio prompt indicating that the
caregiver should call for help (audio prompt 110). Simultaneously,
the LED adjacent graphic 42 will turn off and the LED adjacent
graphic 43 will light up, directing the caregiver's attention to
graphic 43. Graphic 43 will remind the caregiver to call emergency
personnel (step 112), if the caregiver has not already done so.
[0048] After a suitable interval has been allowed for the caregiver
to perform step 112 (e.g., 2 seconds since audio prompt 110) the
defibrillator will give an audio prompt indicating that the
caregiver should open the patient's airway and check whether the
patient is breathing (audio prompt 114). The LED adjacent graphic
43 will turn off, and the LED adjacent graphic 44 will light up,
directing the caregiver's attention to graphic 44, which shows the
proper procedure for opening a patient's airway. This will lead the
caregiver to lift the patient's chin and tilt the patient's head
back (step 116). The caregiver may also position an airway support
device under the patient's neck and shoulders, if desired, as
discussed below with reference to FIG. 7. The caregiver will then
check to determine whether the patient is breathing.
[0049] After a suitable interval (e.g., 15 seconds since audio
prompt 114), the defibrillator will give an audio prompt indicating
that the caregiver should check for signs of circulation (audio
prompt 118), the LED adjacent graphic 44 will turn off, and the LED
adjacent graphic 45 will light up. Graphic 45 will indicate to the
caregiver that the patient should be checked for a pulse or other
signs of circulation as recommended by the AHA for lay rescuers
(step 120).
[0050] After a suitable interval (e.g., 5 to 7 seconds since audio
prompt 118), the defibrillator will give an audio prompt indicating
that the caregiver should attach electrode assembly 16 to the
patient (audio prompt 122), the LED adjacent graphic 45 will turn
off, and the LED adjacent graphic 46 will light up. Graphic 46 will
indicate to the caregiver how the electrode assembly 16 should be
positioned on the patient's chest (step 124). The defibrillator
will periodically repeat audio prompt 122 every 15 seconds until
the electrodes are properly connected to the patient.
[0051] When the impedance data received from the electrode assembly
indicates that the electrodes are properly positioned and in
contact with the patient's skin, the defibrillator will stop audio
prompt 122 and turn off the LED adjacent graphic 46. At this point,
the LED adjacent graphic 47 will light up, and the defibrillator
will give an audio prompt indicating that the patient's heart
rhythm is being analyzed by the defibrillator and the caregiver
should stand clear (audio prompt 126). While this LED is lit, the
defibrillator will acquire ECG data from the electrode assembly,
and analyze the data to determine whether the patient's heart
rhythm is shockable. This analysis is conventionally performed by
AEDs.
[0052] If the defibrillator determines that the patient's heart
rhythm is not shockable, the defibrillator will give an audio
prompt such as "No shock advised" (audio prompt 128). The LEDs next
to graphics 48 and 49 will then light up, and the defibrillator
will give an audio prompt indicating that the caregiver should
again open the patient's airway, check for breathing and a pulse,
and, if no pulse is detected by the caregiver, then commence giving
CPR (audio prompt 130, step 132). Graphics 48 and 49 will remind
the caregiver of the appropriate steps to perform when giving
CPR.
[0053] Alternatively, if the defibrillator determines that the
patient's heart rhythm is shockable, the defibrillator will give an
audio prompt such as "Shock advised. Stand clear of patient. Press
treatment button." (Audio prompt 134.) At the same time, the heart
54 and/or hand 52 will light up, indicating to the caregiver the
location of the treatment button. At this point, the caregiver will
stand clear (and warn others, if present, to stand clear) and will
press the heart 54, depressing the treatment button and
administering a defibrillating shock (or a series of shocks, as
determined by the defibrillator electronics) to the patient (step
136).
[0054] After step 136 has been performed, the defibrillator will
automatically reanalyze the patient's heart rhythm, during which
audio prompt 126 will again be given and graphic 47 will again be
illuminated. The analyze and shock sequence described above will be
repeated up to three times if a shockable rhythm is repeatedly
detected or until the defibrillator is turned off or the electrodes
are removed. After the third shock has been delivered, the device
will illuminate LEDs 48 and 49 and issue the audio prompts 130/132.
The device will keep LEDs 48 and 49 illuminated for a period of
approximately one minute indicating that if CPR is performed, it
should be continued for the entire minute. "Continue CPR" audio
prompts may be repeated every 15-20 seconds during this period to
instruct the user to continue performing chest compressions and
rescue breathing.
[0055] After approximately one minute has elapsed, the device will
extinguish LEDs 48 and 49 and illuminate LED 47. Audio prompt 126
(stand clear, analyzing rhythm) will also be issued and a new
sequence of up to three ECG analyses/shocks will begin.
[0056] If the caregiver detects circulation during step 132, the
caregiver may turn off the defibrillator and/or remove the
electrodes. Alternatively, the caregiver may not perform further
CPR, but nonetheless allow the device to reanalyze the ECG after
each one minute CPR period in order to provide repeated periodic
monitoring to ensure the patient continues to have a non-shockable
rhythm.
[0057] Thus, in the continuing presence of a shockable rhythm, the
sequence of three ECG analyses and three shocks, followed by one
minute of CPR, will continue indefinitely. If, instead, a
non-shockable rhythm is or becomes present, the sequence will be
analyze/no shock advised, one minute of CPR, analyze/no shock
advised, one minute of CPR, etc. When a shock is effective in
converting the patient's heart rhythm to a heart rhythm that does
not require further defibrillating treatment, the sequence will be:
analyze/shock advised, shock (saves patient), analyze/no shock
advised, one minute CPR period (if pulse is detected then caregiver
will not do CPR during this period), analyze/no shock advised, one
minute CPR period, etc., continuing until the caregiver turns the
defibrillator (e.g., if the caregiver detects a pulse) or the
electrodes are removed.
[0058] If electrode contact is lost at any time (as determined by
the impedance data received from the electrode assembly), this will
result in an appropriate audio prompt, such as "check electrodes"
and illumination of the LED adjacent graphic 46.
[0059] Other embodiments are within the scope of the following
claims.
[0060] For example, the graphics on the center decal can be
accompanied by any desired light source. For instance, if desired,
all of the graphics can be translucent, and can be backlit.
Alternatively, the graphics can be provided in the form of LED
images, rather than on a decal.
[0061] While it is generally preferred that audio prompts and
visual (light source) prompts be used, these features may be
omitted if desired.
[0062] Moreover, while the electrodes have been illustrated in the
form of an integral electrode assembly, separate electrodes may be
used. In preferred implementations, generally all of the
graphically illustrated steps are shown at the same time. e.g., as
illustrated by the decal described above. This arrangement allows
the caregiver to see the steps that will be performed next and thus
anticipate the next step and begin it early if possible. However,
alternatively, the graphics can be displayed one at a time, e.g.,
by using a screen that displays one graphic at a time or backlit
graphics that are unreadable when not back lit. This arrangement
may in some cases avoid overwhelming novice or lay rescuers,
because it does not present the caregiver with too much information
all at the same time.
[0063] If desired, each graphic could have an associated button
which, when pressed causes more detailed audio prompts related to
that graphic to be output by the defibrillator.
[0064] The cover 12 of the AED may include a decal on its
underside, e.g., decal 200 shown in FIG. 7. Decal 200 illustrates
the use of the cover as a passive airway support device, to keep
the patient's airway open during resuscitation. Graphic 202 prompts
the caregiver to roll the patient over and place cover 12 under the
patient's shoulders, and graphic 204 illustrates the proper
positioning of the cover 12 under the patient to ensure an open
airway.
[0065] While such a graphic is not included in the decal shown in
FIG. 4, the decal 40 may include a graphic that would prompt the
user to check to see if the patient is breathing. Such a graphic
may include, e.g., a picture of the caregiver with his ear next to
the patient's mouth. The graphic may also include lines indicating
flow of air from the patient's mouth.
[0066] "Illuminated", "light up", and similar terms are used herein
to refer to both a steady light and a blinking light. A blinking
light may be used, if desired, to more clearly draw the user's
attention to the associated graphic.
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