U.S. patent application number 10/754338 was filed with the patent office on 2004-07-22 for visual and aural user interface for an automated external defibrillator.
Invention is credited to Bertagnole, Shawn R., Nova, Richard C..
Application Number | 20040143298 10/754338 |
Document ID | / |
Family ID | 22326172 |
Filed Date | 2004-07-22 |
United States Patent
Application |
20040143298 |
Kind Code |
A1 |
Nova, Richard C. ; et
al. |
July 22, 2004 |
Visual and aural user interface for an automated external
defibrillator
Abstract
An automated external defibrillator (AED) (10) designed for use
by a rescuer with minimal or no training during a medical emergency
is provided. The AED implements a user interface program (22) which
guides the rescuer through operation of the AED and application of
CPR and defibrillation therapy to a patient by displaying a series
of visual instructions on a graphic display (14) or other visual
output device, and by providing additional aural instructions via a
speaker (18) or other aural output device. The rescuer merely needs
to press a start button (12) to initiate operation of the AED and
begin CPR and defibrillation instruction.
Inventors: |
Nova, Richard C.; (Kirkland,
WA) ; Bertagnole, Shawn R.; (Bothell, WA) |
Correspondence
Address: |
INGRASSIA FISHER & LORENZ, P.C.
7150 E. CAMELBACK, STE. 325
SCOTTSDALE
AZ
85251
US
|
Family ID: |
22326172 |
Appl. No.: |
10/754338 |
Filed: |
January 9, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10754338 |
Jan 9, 2004 |
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09972028 |
Oct 4, 2001 |
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6697671 |
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09972028 |
Oct 4, 2001 |
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09444037 |
Nov 19, 1999 |
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6334070 |
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60109168 |
Nov 20, 1998 |
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Current U.S.
Class: |
607/5 |
Current CPC
Class: |
A61N 1/39044 20170801;
A61N 1/3968 20130101; A61N 1/3993 20130101 |
Class at
Publication: |
607/005 |
International
Class: |
A61N 001/39 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A defibrillator capable of providing a user with defibrillator
and treatment instructions, the defibrillator comprising: a
processing unit; a visual output device coupled to the processing
unit for displaying instructions to the user; an aural output
device coupled to the processing unit for issuing instructions to
the user; and a memory coupled to the processing unit for storing
program code that, when executed by the processing unit, generates:
emergency notification instruction on at least one of the visual
and aural output devices; CPR instruction on at least one of the
visual and aural output devices; patient assessment instruction on
at least one of the visual and aural output devices; and
defibrillation therapy instruction on at least one of the visual
and aural output devices, wherein the emergency notification
instruction comprises: causing the defibrillator to establish a
communication link to an emergency response system; if the
communication link is established, notifying the user that the
communication link with the emergency response system has been
established; and if the communication link fails, instructing the
user to notify the emergency response system.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. application Ser. No.
09/972,028, filed Oct. 4, 2001, which is a continuation of U.S.
application Ser. No. 09/444,037, filed Nov. 19, 9999, and also
claims the benefit of provisional application serial no. 60/109,168
filed on Nov. 20, 1998.
FIELD OF THE INVENTION
[0002] This invention relates generally to defibrillators, and more
specifically to portable, automated external defibrillators having
a user interface for automatically providing an untrained rescuer
with visual and aural instructions for performing emergency
cardiopulmonary resuscitation and defibrillation therapy.
BACKGROUND OF THE INVENTION
[0003] The probability of surviving a heart attack depends on the
speed with which appropriate medical care is provided to the person
experiencing the heart attack. To decrease the response time to a
patient suffering a heart attack, it has been recognized that those
persons who are typically first to arrive at the scene of a medical
emergency, including medical technicians (EMTs), firefighters,
police and the public (hereinafter collectively referred to as
"first responders") should be provided with portable, automated
external defibrillators (AEDs). A first responder equipped with an
AED will have a greater likelihood of successfully treating the
patient than those who arrive later at the scene. An AED designed
for first responder use would therefore improve the overall success
rate of treating heart attack patients.
[0004] Because the probability of surviving a heart attack depends
on the speed with which appropriate medical care is provided to the
patient, the American Heart Association (AHA) promotes the
following "Chain of Survival" guidelines:
[0005] (1) Early access to emergency medical service (EMS), such as
by activating an emergency response system;
[0006] (2) Early CPR initiated by a rescuer to help the patient
survive until more advanced care arrives;
[0007] (3) Early defibrillation; and
[0008] (4) Early application of advanced cardiac life support
(ACLS), such as airway management, drugs, etc.
[0009] With the exception of item number 4, all of the above
guidelines can be performed by a first responder with minimal or no
training, if provided with sufficient instruction while at the
scene.
[0010] Even if the first responder does have some basic training in
device operation and cardiopulmonary resuscitation (CPR), he or she
may forget this basic training during the stress of reacting to a
heart attack. With wider deployment of AEDs in homes and public
venues, the minimally trained or even untrained use of
defibrillation devices will increase. Although some devices already
exist for providing CPR prompting and automatic defibrillation
therapy, these devices rely on several hours of training experience
and verbal cueing for the rescuer to follow. In addition, visual
prompting of CPR and defibrillation instructions is achieved only
through readable text prompts. Success is diminished due to having
to rely on memory recall of CPR and other training protocols. Even
retraining and certification every two years is inadequate to
ensure proper administration of CPR and defibrillation therapy.
[0011] Consequently, a defibrillator is needed which is capable of
successfully directing precise instructions to a first responder
with minimal or no training through a cardiorespiratory event,
i.e., CPR as well as AED device operation, by use of visual and
aural instructions. The defibrillator should be as simple and user
friendly as possible so as to remove any impediment to use by a
rescuer with minimal or no training. Further, the defibrillator
should be programmable so as to comply with any changes in the
standard protocols for CPR and AED operation.
BRIEF SUMMARY OF THE INVENTION
[0012] In accordance with the present invention, a defibrillator
including a user interface for providing a rescuer with
instructions for deploying the defibrillator and administrating CPR
to a patient is provided. The user interface includes a visual
output device for providing the rescuer with visual instructions
for deploying the defibrillator and administering CPR to the
patient, an aural output device for providing the user with aural
CPR and defibrillation instructions, and a user input mechanism for
enabling the user to input responses to the visual and aural
instructions. The visual and aural output devices of the user
interface may also provide the user with visual and aural
instructions for notifying an emergency response system of the
medical emergency. The visual instructions provided by the visual
output device can be animated illustrations, textual prompts, etc.,
while the aural instructions may be audible tones, verbal prompts,
etc. In addition, the user input mechanism may enable the user to
skip or repeat instructions. The user input mechanism may be a
voice recognition module or a user activated switch or
actuator.
[0013] In accordance with further aspects of the invention, the
defibrillator includes a processing unit coupled to the visual and
aural output devices for executing program code stored in memory
which generates the emergency notification instructions, CPR
instructions and defibrillator operation instructions on the visual
and aural output devices. The emergency notification instructions
cause the defibrillator to either establish a communication link
directly with an emergency response system or cause the
defibrillator to instruct the user to notify the emergency response
system. The CPR instructions, on the other hand, instruct the user
to deliver an appropriate number of breaths and chest compressions
to a patient. The defibrillator operation instructions instruct the
user to attach the defibrillation electrodes of the defibrillator
to the patient and notify the rescuer when a shockable heart rhythm
has been detected. In accordance with other aspects of the
invention, the memory also stores program code which generates
patient assessment instructions which instruct the user to check
the patient's breathing and pulse.
[0014] In accordance with yet other aspects of the present
invention, a method and a computer-executable user interface
component are described which provide instructions to a user
operating the defibrillator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0016] FIG. 1A is an isometric view of an AED having a user
interface which automatically provides a rescuer with visual and
aural instructions for delivering CPR and/or defibrillation
therapy, that is formed in accordance with one actual embodiment of
the present invention;
[0017] FIG. 1B a top level view of an AED having a user interface
formed in accordance with an alternative embodiment of the present
invention;
[0018] FIG. 2 is a schematic block diagram of several of the key
components of the AEDs shown in FIGS. 1A and 1B;
[0019] FIG. 3 a flow chart illustrating the logic used by a user
interface program executed by the AED shown in FIG. 1A to provide
the rescuer with visual and aural instructions for delivering CPR
and/or defibrillation therapy;
[0020] FIG. 4 is a flow chart illustrating the logic used by the
user interface program to instruct the rescuer to notify an
emergency response system;
[0021] FIG. 5 is a flow chart illustrating the logic used by the
user interface program to cause the AED to notify an emergency
response system;
[0022] FIG. 6 is a flow chart illustrating the logic used by the
user interface program to instruct the rescuer to assess the
patient's condition;
[0023] FIG. 7 is a flow chart illustrating the logic used by the
user interface program to instruct the rescuer to attach the AED
electrodes to the patient;
[0024] FIGS. 8A and 8B are a flow chart illustrating the logic used
by user interface program to instruct the user to operate the AED
and deliver defibrillation therapy, if necessary;
[0025] FIG. 9 is a flow chart illustrating the logic used by the
user interface program to instruct the rescuer to deliver CPR;
and
[0026] FIGS. 10A-10J illustrate a number of visual instructions
provided by the AED in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] FIG. 1 depicts a portable, automated external defibrillator
(AED) 10 formed in accordance with one actual embodiment of the
present invention and designed for use by a first responder or
rescuer during a medical emergency. The AED 10 stores electric
charge and delivers the electric charge to a patient in the form of
an electric current pulse, i.e., a defibrillation pulse. The
defibrillation pulse is applied to the patient via a set of
electrodes 16 if the patient is experiencing a shockable heart
rhythm, such as ventricular fibrillation. In the actual embodiment
of the present invention depicted in FIG. 1A, the defibrillator 10
guides a rescuer with minimal training or no training whatsoever
through operation of the AED and application of CPR and
defibrillation therapy to the patient by displaying a series of
visual instructions on a liquid crystal display (LCD) 14 and by
providing additional aural instructions via a speaker 18. In the
actual embodiment of the present invention depicted in FIG. 1A, the
rescuer merely needs to press a start button 12 to initiate
operation of the defibrillator, and hence, begin CPR and
defibrillation instruction.
[0028] FIG. 1B illustrates an AED 10' formed in accordance with
another actual embodiment of the present invention. In this
embodiment, the display 14' comprises a number of illustrations 17
fixed to the top surface of the AED 10' and a light-emitting diode
(LED) 15 corresponding to each visual illustration 17. Accordingly,
as the rescuer is instructed to perform certain actions, the LED 15
beneath the visual illustration of that action is illuminated. For
example, when the rescuer is instructed to check the patient's
breathing, the LED 15a beneath the visual illustration of the check
breathing instruction 17a is illuminated. In yet another actual
embodiment of the present invention, the visual instructions for
AED operation and CPR are provided on a laminated card or flip
chart, which accompany the AED. In such an embodiment, the rescuer
would rely more heavily on the aural instructions generated by the
AED via the speaker 18 while following visual instructions along on
the card or chart. AED 10' also includes a shock button 11' and
start button 12'.
[0029] Now that the overall design of an AED capable of providing
both visual and aural CPR and defibrillation instructions has been
discussed, several key AED components will be discussed in more
detail. However, since the components of both AED 10 and AED 10'
are essentially the same, the description of these components will
be made with reference to AED 10 as depicted in FIG. 1A.
[0030] As shown in more detail in FIG. 2, the AED 10 includes a
microprocessor 24 which controls the operation of the AED 10. The
microprocessor 24 is connected to the display 14 (or LEDs 15 of AED
10'), the speaker 18, the start button 12, and the shock button 11.
The microprocessor 24 is also connected to a memory 20 which stores
a user interface program 22 formed in accordance with the present
invention to generate the visual instructions upon the display 14
(or illuminates the LEDs 15 of AED 10') and any accompanying aural
instructions transmitted via the speaker 18. In yet other
embodiments of the present invention, the memory stores a voice
recognition software module which allows the rescuer to operate the
AED 10 and respond to visual and/or aural instructions via voice
command rather than using the start and shock buttons. Such a
module in combination with a microphone would then provide the
rescuer with hands-free operation of the AED 10.
[0031] During defibrillation operation, the microprocessor 24
analyzes an electrocardiogram (ECG) of a patient using an automatic
heart rhythm detection algorithm also stored in memory 20 to
identify whether the patient is experiencing a shockable heart
rhythm, such as ventricular fibrillation. The detection algorithm
executed by the microprocessor 24 in the actual embodiment of the
present invention described herein is similar to that used in the
LIFEPAK.RTM. 500 defibrillator provided by Medtronic Physio-Control
Corp. of Redmond, Wash. Other known heart rhythm detection
algorithms may also be used without departing from the scope of the
present invention, such as those algorithms designed to comply with
standards promulgated by the Association for the Advancement of
Medical Instruments (AAMI). The ECG signals analyzed by the
detection algorithm are collected by the electrode 16 and passed
through a monitor circuit 28 to an analog-to-digital converter 26.
The analog-to-digital converter 26 then passes the digitized
signals to microprocessor 24. If the microprocessor 24 detects a
shockable rhythm, the microprocessor causes a charging circuit 30
to generate a current causing a storage capacitor (not shown) to
charge in preparation for delivery of a defibrillation pulse. When
the capacitor is fully charged, and delivery of the defibrillation
pulse initiated, a discharge circuit 32 coupled to the
microprocessor 24 and charge circuit 30 discharges the
defibrillation pulse to the electrodes 16 for application of the
defibrillation pulse to the patient.
[0032] In accordance with the present invention, the AED 10 will
provide visual and aural instructions to the rescuer via the
display 14 and the speaker 18, respectively, advising application
of a defibrillation pulse, in which case the rescuer would press a
shock button 11 to deliver the defibrillation pulse. However, in
another embodiment of the present invention, the AED will
automatically apply a defibrillation pulse to the patient if the
patient is experiencing ventricular fibrillation, without the
rescuer's intervention.
[0033] Although the above describes the application of
defibrillation therapy to a patient by the AED 10, the AED of the
present invention actually provides the rescuer with an intuitive
user interface for administering visual and aural instructions
necessary for operating the defibrillator to provide defibrillation
therapy, as well as instructions for administering CPR. The visual
instructions may include inter alia animated or graphic
illustrations that flash, move or remain static, textual prompts,
light emissions, etc, while the aural instructions may include
inter alia verbal prompts audible tones, etc. On a macro level, the
user interface can be considered to include the user interface
program 22, the display 14 or any other visual output device,
generator or mechanism, and the speaker 18 or any other aural
output device, generator or mechanism. The user interface of the
present invention may also include various user input devices or
mechanisms, e.g., shock button 11, start button 12, or voice
recognition for allowing the rescuer to input information and/or
commands. Since the visual and aural output devices, i.e., display
14 and speaker 18, have already been described, the user interface
program 22 of the present invention will be described in more
detail in connection with FIGS. 3-9.
[0034] FIG. 3 illustrates the logic of the user interface program
22 which is executed by the microprocessor 24 of the AED 10 to
provide the rescuer with visual and aural instructions via the
display 14 and speaker 18. In order to more fully appreciate the
circumstances under which the AED 10 would be used and the
advantages of providing a rescuer with visual and aural
instructions for providing defibrillation operation/therapy and
CPR, it is necessary to discuss the conditions under which the AED
10 would be deployed. Typically, a rescuer would witness or
encounter a patient who has collapsed or exhibited some other
symptoms associated with cardiac arrest. The rescuer may then
attempt to assess the patient and/or call for help, e.g., by
calling 911. If available, the rescuer would retrieve the AED 10
and power it on. As described above, the AED 10 is turned on by
pressing the start button 12. However, as also noted above, the AED
10 may be powered on by some alternative mechanism or method. It
will be appreciated that when the AED 10 is activated, the user
interface program 22 is initiated and proceeds as shown in FIG.
3.
[0035] The logic begins in FIG. 3 in a block 100 and proceeds to a
block 102 where it triggers the device to issue an aural power-on
indication to the user via the speaker 18, e.g., a power-on tone or
perhaps a voice prompt saying "Power On." In addition, a visual
power-on indicator is issued on the display 14. This could include
a textual "power-on" prompt on the display 14 or the illumination
of an LED. Next, in a block 104, the rescuer is instructed both
visually and aurally to check the patient's responsiveness. For
example, a visual instruction as shown in FIG. 10A is generated
upon the LCD 14 of the AED 10. Simultaneously, the rescuer is
issued a verbal instruction via the speaker 18 to "Shake and Shout"
the patient and ask "Are You Okay?"
[0036] In addition to providing the visual and verbal instructions
to check the patient's responsiveness, the user interface program
22 also causes the start button 12 to flash so as to indicate to
the rescuer that he or she may press the start button 12 to proceed
to the next instruction. The user interface program 22 may further
provide a verbal instruction to "Press Start Button to Continue"
via the speaker 18.
[0037] Accordingly, in a decision block 106, the user interface
program determines if the rescuer has elected to continue to the
next instruction. In accordance with the present invention, the
rescuer may continue to the next instruction, and hence, effect the
sequence of instructions generated by the user interface program 22
by pressing the start button 12 a single time. If the rescuer has
not pressed the start button 12 to indicate his or her desire to
skip to the next instruction, the logic proceeds from decision
block 106 to a decision block 108 where it determines if the
rescuer's time interval for taking action and continuing to the
next instruction has expired. If such time interval has not
expired, the logic will merely repeat decision blocks 106 and 108
until the rescuer either presses the start button 12 to continue to
the next instruction or until the rescuer action interval expires
and the user interface program 22 proceeds to the next instruction
automatically without further rescuer intervention.
[0038] It will be appreciated by those of ordinary skill in the art
that the user interface program 22 may provide the rescuer with the
option of continuing to the next instruction by pressing the start
button 12 (or by activating some other user input mechanism or
device such as another button or a voice command) or by waiting to
time-out to the next instruction at any appropriate point during
the user interface program 22 or any of its subroutines. However,
in an effort to avoid redundancy, decision blocks corresponding to
106 and 108 of FIG. 3 are not repeated in the remaining figures
after every such instruction. In addition, it will be appreciated
that whenever the rescuer is given the option to continue to the
next instruction, a verbal instruction to "Press Start Button to
Continue" may be issued via the speaker 18, and the start button 12
may be made to flash. In yet other embodiments of the present
invention, the rescuer is not provided the option of continuing to
the next instruction on demand. Rather, some or all of the
subsequent instructions are generated on a time-out basis. Such an
embodiment may be advantageous if completely hands-free operation
of the AED 10 or further simplification of the user interface
(e.g., elimination of the start and shock buttons) is desired.
[0039] Returning to decision blocks 106 and 108, if either is
positive, the logic will proceed to a block 110 where an emergency
notification sequence is initiated by the user interface program
22. As will be described in more detail below, the emergency
notification sequence is a subroutine performed by the user
interface program 22 to notify the appropriate emergency response
system of the patient's collapse.
[0040] In one actual embodiment of the present invention, the
rescuer is instructed by the user interface program 22 to notify
the appropriate emergency response system. As will be described in
more detail below, in other actual embodiments of the present
invention, the AED 10 is programmed to notify the appropriate
emergency response system directly. The rescuer initiated emergency
notification sequence is depicted in more detail in FIG. 4. The
logic begins in FIG. 4 in a block 130 and proceeds to a block 132
where the rescuer is instructed via the display 14 of the
defibrillator to call an emergency response system telephone
number, such as 911. In the actual embodiment of the present
invention described herein, a visual instruction to call 911 as
shown in FIG. 10B is generated on the display 14 of the AED 10. A
verbal instruction to "Call 911" is simultaneously generated by the
speaker 18. Next, in a decision block 134, the user interface
program 22 determines if the rescuer has pressed the flashing start
button 12 to continue to the next instruction. If not, the logic
proceeds to a decision block 136 where it determines if the
rescuer's interval for notifying the emergency response system has
expired. As noted above, the user interface program 22 will proceed
to the next instruction either after the rescuer presses the
flashing start button 12 or after the rescuer action interval
expires. Consequently, when either of these conditions occurs, the
logic in FIG. 4 proceeds to a block 138 and returns to the main
user interface program 22 depicted in FIG. 3 so as to proceed to
the next instruction for positioning the patient in a block
112.
[0041] In another actual embodiment of the present invention, the
AED 10 is programmed to notify the emergency response system
itself, without human intervention. To do so, those of ordinary
skill in the art will recognize that the AED 10 must be equipped
with the necessary external interface to communicate with the
remote emergency response system. For example, the AED 10 may
communicate with the emergency response system via a wireless
communication link in which case the external interface of the AED
10 may include an antenna and transceiver for transmitting and
receiving radio signals. If communicating via a "wired"
communication link, e.g., a "wired" network, a remote
telephone/mode connection, a direct port-to-port connection, etc.,
the AED 10 will be equipped with the appropriate external interface
including the necessary circuitry for connecting to the wired
communication link and the necessary software for communicating via
the appropriate network protocol.
[0042] The device initiated emergency notification sequence
performed by the user interface program 22 is shown in more detail
in FIG. 5. Those of ordinary skill in the art will appreciate that
in the actual embodiment of the present invention described herein,
the device initiated emergency notification sequence is performed
as a parallel processing thread to the main user interface program
22. Consequently, the device initiated emergency notification
sequence will be performed and the appropriate emergency response
system notified while the user interface program 22 continues to
provide the rescuer with visual and aural CPR and defibrillation
instructions. Accordingly, any visual or aural instructions
generated by the device initiated emergency notification sequence
will interrupt any currently generated visual or aural instructions
provided by the main user interface program 22.
[0043] Returning to the substance of FIG. 5, the device initiated
emergency notification sequence begins in a block 140 and proceeds
to a block 142 where the AED 10 automatically dials a preprogrammed
telephone number for the emergency response system, e.g., 911.
Accordingly, in a block 144, the user interface program 22 issues
via the speaker 18 a verbal instruction confirming that "Emergency
Number Called." In addition, a visual, textual instruction of
similar nature is generated on the display 14 of the AED 10. Next,
in a decision 146 the logic determines if emergency notification
has been completed, i.e., that the AED 10 has successfully made a
connection with the emergency response system and transmitted
preprogrammed information regarding its location to the emergency
response system. If emergency notification has not been completed,
the logic proceeds to a decision block 148 where it determines if
the interval for completing the emergency notification has expired.
If not, blocks 146 and 148 are repeated until either the emergency
notification has been successfully completed or the emergency call
interval has expired.
[0044] Once emergency notification has been completed, the logic
proceeds from decision block 146 to a block 150 where a verbal
instruction is issued via the speaker 18 confirming that "Emergency
Notification Complete." In addition, a textual instruction of
similar nature is generated on the display 14 of the AED 10. The
logic then ends in a block 154. If emergency notification has not
been completed by the AED 10 and the emergency call interval has
expired, then the rescuer initiated emergency notification sequence
depicted in FIG. 4 is called in a block 152 so that the rescuer is
instructed to notify the emergency response in the conventional
manner.
[0045] It will be appreciated that the emergency response system
notified by either the rescuer or the device may be the public
emergency response system for local EMS such as police, fire, etc.
or a private emergency response system such as a private security
or alarm monitoring system. Consequently, the AED 10 is
preprogrammed with the appropriate telephone number for the desired
emergency response system. In the United States, the public
emergency response system is usually notified by calling 911.
However, in some remote areas of the U.S. and in many foreign
countries different telephone numbers are assigned to the local,
public emergency response system.
[0046] Finally, in yet other actual embodiments of the present
invention, the rescuer or device initiated emergency notification
sequence may take place separately from the AED 10. For example, if
the AED 10 is deployed from a docking station, the docking station
could execute the emergency notification sequence if it were
equipped with the necessary hardware and software.
[0047] Returning to FIG. 3, following initiation of the emergency
notification sequence in block 110, the AED 10 issues visual and
aural instructions to the rescuer to place the patient in a proper
patient treatment position. For example, the visual instruction
depicting proper positioning of the patient as shown in FIG. 10C is
generated on the display 14 of the AED 10. At the same time, the
rescuer is provided verbal instructions via the speaker 18 to "Turn
Victim to Their Back, while Supporting Their Head and Neck." Next,
in a block 114, a patient assessment sequence is initiated by the
user interface program 22. As noted above, the rescuer may have
pressed the start button 12 a single time to proceed to the patient
assessment sequence from the patient positioning instruction.
Although not depicted in FIG. 3, the rescuer can also repeat the
patient positioning instruction (as well as any other instruction
provided by the user interface program 22) by pressing the start
button 12 twice. In addition, if the rescuer wishes to discontinue
operation of the AED 10 completely, the rescuer merely presses the
start button 12 and holds it for a predetermined time to power off
the AED 10.
[0048] Returning to block 114, the rescuer is instructed to assess
the patient's condition once the patient has been placed in the
appropriate position. The patient assessment sequence is shown in
more detail in FIG. 6. The logic in FIG. 6 begins in a block 160
and proceeds to a block 162 where the user interface program 22
instructs the rescuer to check the patient's breathing. More
specifically, a visual instruction to check the patient's breathing
as shown in FIG. 10D is generated on the display 14 of the AED 10,
while the rescuer is verbally instructed via the speaker 18 to
"Tilt Head, Lift Chin" and "Look, Listen and Feel for Breathing."
The rescuer is then provided a verbal instruction via the speaker
18 as follows "If Breathing, Press Start Button Once to Continue."
Consequently, in decision 164 if it is determined that the patient
is breathing, i.e., if the start button has been pressed once, the
logic proceeds to a decision block 166 where the user interface
program 22 instructs the rescuer to place the patient in the
recovery position. More specifically, a visual instruction as shown
in FIG. 10J is generated on the display 14 of the AED 10, while the
rescuer is verbally instructed via the speaker 18 to "Roll Victim
to Their Side If Breathing" and "Stay with Victim Until Help
Arrives." Next, in a block 168, the logic waits for a predetermined
or x number of minutes, e.g., two minutes, before returning to
block 162 and reinitiating the patient assessment sequence.
[0049] Returning to decision block 164, if the rescuer does not
indicate that the patient is breathing by pressing the start button
12 once, the logic will proceed to a decision block 170 where it
determines if the time interval for the rescuer to take action has
expired or if the rescuer has pressed the start button 12 two times
to proceed to the next instruction. If neither of these conditions
have been satisfied, blocks 164 and 170 are repeated until either
the rescuer indicates the patient is breathing or until the rescuer
action interval expires or the rescuer presses the start button 12
twice to proceed to the next instruction.
[0050] Upon expiration of the rescuer action interval or an
indication from the rescuer to continue to the next instruction,
the logic proceeds to a decision block 172 where it determines if
rescue breathing or CPR delivery was just performed. If not, then
it is necessary for the AED 10 to instruct the user to deliver
rescue breaths before continuing further. To determine whether
rescue breathing or CPR delivery was just performed, the user
interface program 22 determines whether it has previously
instructed the user to deliver rescue breaths as part of the
patient assessment sequence or if it has prompted the rescuer to
deliver breaths as part of a CPR delivery sequence (described in
more detail below) immediately prior to prompting the rescuer to
check the patient's breathing. If the result of decision block 172
is positive, the logic proceeds to a block 174 where the AED 10
instructs the rescuer to deliver a predetermined or y number of
rescue breaths to the patient where y, for example, is the number
of rescue breaths currently recommended under a given standard
protocol when a patient is not breathing and a pulse check has not
yet been conducted. In accordance with the AHA HeartSaver CPR
protocol for adult CPR delivery, this number is presently two. As
for generation of the appropriate instruction, the microprocessor
24 of the AED 10 generates a visual instruction as shown in FIG.
10E on the display 14 of the AED 10 and simultaneously causes the
speaker 18 to issue a verbal instruction as follows: "If not
breathing, give two slow breaths. Tilt, head, lift chin, pinch
nose. Blow. (Pause) Blow. (Pause)."
[0051] It will be appreciated by those of ordinary skill in the art
that following each verbal instruction to "blow," there will be a
pause of an appropriate length of time before issuing the next
verbal "blow" instruction so as to provide the rescuer with
sufficient time to perform the instruction. Under the AHA
HeartSaver CPR protocol this pause is 1.5 to 2 seconds.
Accordingly, the rescuer is guided to perform the instructed task
at appropriate time intervals. Alternatively, rather than repeating
the verbal instruction to blow, the speaker 18 may repeat an
audible tone at predetermined time intervals to assist the rescuer
in executing the blow instruction. Further, the corresponding
visual instruction generated on the display 14 may be synchronized
with the verbal instruction such that the visual instruction
flashes at the same time as the verbal instructions are
repeated.
[0052] Returning to blocks 172 and 174, after rescue breathing has
been performed, the logic proceeds to a block 176 where the rescuer
is instructed to check the patient's pulse. More specifically, the
user interface program 22 causes the microprocessor 24 to generate
a visual instruction to check the patient's pulse as shown in FIG.
10F on the display 14 of the AED 10. Simultaneously, a verbal
instruction is issued via the speaker 18 for the rescuer to "Check
Pulse." If the rescuer presses the start button 12 to indicate that
a pulse has been detected, the logic proceeds to a block 180 where
the rescuer is instructed to deliver a predetermined or z number of
rescue breaths to the patient, where z, for example, is the number
of rescue breaths currently recommended under a given standard
protocol when a pulse is detected, but a patient is not breathing.
In accordance with the current AHA HeartSaver CPR protocol, the
appropriate number of rescue breaths to be delivered when a pulse
has not been detected is twelve. The user interface program 22
instructs the microprocessor 24 to generate a visual instruction to
deliver rescue breaths as shown in FIG. 10E on the display 14 of
the AED 10. A simultaneous verbal instruction is provided via the
speaker 18 as follows: "If Not Breathing, Give Twelve Slow Breaths.
Tilt Head, Lift Chin, Pinch Nose. Blow. (Pause) Blow. (Pause) Blow
. . . . " As noted above, a pause of a length appropriate to allow
the user to perform the blow instruction follows each such
instruction. For example, under the AHA HeartSaver CPR protocol
this pause is five seconds. Upon completion of the visual and
verbal instruction to deliver rescue breathing, the logic of FIG. 6
returns to block 162 where the patient assessment sequence is
reinitiated and the rescuer is once again instructed to check the
patient's breathing.
[0053] Returning to decision block 178, if the rescuer does not
indicate that a pulse has been detected by pressing the start
button 12, the logic proceeds to a decision block 182 where it
determines if the rescuer action interval has expired or if the
rescuer has pressed the start button 12 twice to continue to the
next instruction. If the result of decision block 182 is negative,
blocks 178 and 182 are repeated until either a pulse has been
detected by the rescuer or until the rescuer action interval has
expired or the rescuer has proceeded to the next instruction. In
the latter case, if the rescuer action interval expires, or if the
rescuer proceeds to the next instruction, it is assumed that a
pulse has not been detected. Accordingly, the microprocessor 24 is
instructed to return in a block 184 to the main user interface
program 22 to a decision block 116 so that further instruction can
be delivered to the rescuer for operating the AED 10 and providing
defibrillation therapy to the patient, if necessary.
[0054] The user interface program 22 determines in decision block
116 if a predetermined or n number of total shocks have already
been delivered to the patient, where n is the number of total
shocks currently recommended under a given standard protocol.
Current standards vary geographically and according to associated
medical direction. In some EMS systems, the maximum total number of
shocks that may be given to a patient is nine. It will be
appreciated, that if the maximum number of shocks have already been
delivered to the patient without resulting in successful conversion
of the patient's heart to a normal rhythm, that further
defibrillation therapy may be fruitless without ACLS intervention.
Consequently, if the maximum total number of shocks has already
been delivered, the user interface program 22 will instruct the
user to deliver CPR in a block 126 rather than repeat the AED
operation sequence.
[0055] On the other hand, if a maximum total number of shocks has
not already been delivered, the logic will proceed from decision
block 116 to decision block 120 where the user interface program 22
determines if the electrodes 16 of the AED 10 have been attached to
the patient. It will be appreciated that upon initial power-on of
the AED 10, the rescuer may not have already attached the
electrodes 16 to the patient. Consequently, the AED 10 must
instruct the rescuer to do so. Accordingly, the logic proceeds to a
block 122 where an electrode attachment sequence is initiated by
the user interface program 22. However, if the electrodes have
already been attached, the user interface program 22 will skip the
electrode attachment sequence and proceed directly to initiating an
AED sequence for providing defibrillation therapy in a block
124.
[0056] The logic implemented by the user interface program 22 to
perform the electrode attachment sequence is shown in more detail
in FIG. 7. The logic of the electrode attachment sequence begins in
a block 240 and proceeds to a block 242 where the microprocessor 24
generates the visual instruction for electrode attachment shown in
FIG. 10H on the display 14 of the AED 10. Although not shown, if
the electrodes 16 are sealed within an electrode package, an
additional visual instruction may be displayed for the electrode
package opening action. Simultaneously with the visual instruction,
a verbal instruction is issued via the speaker 18 to "Apply
Adhesive Pads to Bare Chest." Once the instructions have been given
for electrode attachment, the logic proceeds to a block 244 where
it determines if the electrodes have been properly attached to the
patient so that a proper connection between the electrodes and the
AED 10 has been established. If so, the AED 10 issues both visual
and verbal instructions via the display 14 and speaker 18,
respectively, indicating "Adhesive Pads Connected" in a block 246.
Next, in a block 248, processing returns to the main user interface
program 22 at block 124 where the AED sequence for operating the
device to deliver defibrillation therapy is initiated.
[0057] Returning to decision block 244, if a proper connection
between the patient, electrodes and AED 10 has not been
established, the logic proceeds to a decision block 248 where it
determines if a time interval allowed for connecting the electrodes
16 to the patient has expired. If not, decision blocks 244 and 248
are repeated until either a proper electrode connection has been
established or the electrode connection interval expires. If the
electrode connection interval expires without proper connection
being established, the logic proceeds to a decision block 250 to
determine if the electrode attachment sequence currently being
performed was interrupt driven due to detachment of the electrodes
from the patient during treatment or if the electrode attachment
sequence is being implemented for the first time following
deployment of the defibrillator and initial instructions to the
rescuer to attach the electrodes. If interrupt driven, it is likely
that the electrodes have become detached during CPR delivery or
perhaps during the AED sequence. Accordingly, it is prudent for the
rescuer to reassess the patient's condition and deliver CPR before
attempting to reattach the electrodes. Accordingly, the logic
proceeds from decision block 250 to a block 256 where the patient
assessment sequence is initiated to instruct the rescuer to again
assess the patient for breathing and pulse. Following patient
assessment, the logic proceeds to a block 258 where a CPR delivery
sequence of instructions described in more detail below is provided
to the rescuer. Following patient assessment and CPR delivery, the
logic of FIG. 7 returns to block 242 where the rescuer is again
provided instructions for attaching the electrodes 16 to the
patient.
[0058] Returning to decision block 250, if the current electrode
attachment sequence was not interrupt driven, i.e., if the sequence
was called from the main user interface program 22 in block 122,
the logic proceeds from decision block 250 to a block 252 where the
CPR delivery sequence is initiated. It will be appreciated that
since the electrode attachment sequence was called in this instance
for the first time after power-on, patient assessment has just been
instructed. Therefore, CPR may be delivered without reassessing the
patient. However, following CPR delivery, the patient assessment
sequence is repeated in a block 254. The logic then returns to
block 242 and the rescuer is instructed once again to attach the
electrodes 16 to the patient. As is readily apparent from the above
discussion, the electrode attachment sequence may continue
indefinitely until proper connection of the electrodes 16 is
established. Accordingly, the rescuer will be instructed repeatedly
to assess the patient's condition and deliver CPR until emergency
assistance arrives.
[0059] As noted above, once proper connection of the electrodes 16
has been established, the logic of the main user interface program
22 proceeds to a block 124 where an AED sequence is initiated which
instructs the rescuer in proper operation of the defibrillator so
as to provide defibrillation therapy to the patient, if necessary.
The logic of the AED sequence is shown in more detail in FIGS. 8A
and 8B. The logic begins in FIG. 8A in a block 190 and proceeds to
a block 192 where an automatic heart rhythm detection algorithm is
activated and executed by the microprocessor 24 based on the ECG
signals received from the electrodes 16.
[0060] Following activation of the automatic rhythm detection
algorithm in block 192, the AED 10 notifies the rescuer that
analysis has begun and instructs the rescuer to stand clear. More
specifically, a visual instruction to stand clear as shown in FIG.
101 is generated by the microprocessor 24 on the display 14 of the
AED 10. In addition, the following verbal instruction is issued via
the speaker 18: "Analyzing Patient, Stand Clear. Do Not Touch
Patient!" After the instruction has been issued, the logic proceeds
to a decision block 196 where it determines whether CPR should be
delivered prior to any shock. It will be appreciated that certain
standard, accepted defibrillation protocols advise that CPR should
be delivered before any defibrillation therapy. In the actual
embodiment of the present invention described herein, the AED 10 is
preprogrammed to require that CPR be delivered preceding a shock in
accordance with such accepted protocols. Consequently, the logic
automatically proceeds from decision block 196 to a decision block
198 where it determines if a predetermined or j number of CPR
cycles CPR has already been delivered to the patient by the
rescuer, where j is the number of CPR cycles currently recommended
under a given, standard CPR protocol. Current standards vary
according to medical direction. In some EMS systems six cycles or
ninety seconds of CPR are delivered prior to defibrillation. In
other words, the logic determines in decision block 196 whether
sufficient CPR has been delivered so that defibrillation therapy
may continue. If not, the logic proceeds to a block 202 where
processing returns to the main user interface program 22 at a block
126 where the CPR delivery sequence of instructions is
initiated.
[0061] Returning to decision block 196, in another actual
embodiment of the present invention, the automatic rhythm detection
algorithm is designed to automatically advise delivery of CPR
preceding a shock. If so, the AED sequence will skip the
determination of whether a sufficient number of cycles of CPR has
been delivered and instead proceed directly to block 202 so
processing may resume in the main user interface program 22 with
delivery of CPR instructions in a block 126.
[0062] Returning to decision block 198, if the appropriate number
of CPR cycles has already been delivered, the logic proceeds to a
decision block 200 and continues with the AED sequence so that
defibrillation therapy may be delivered if necessary. In decision
block 200, the logic decides whether a predetermined or n number of
consecutive shocks have already been delivered to the patient.
Again, in accordance with the current AHA guidelines the maximum
number of consecutive shocks allowed is three. If a maximum number
of shocks has been delivered consecutively without successful
conversion of the patient's heart to a normal heart rhythm,
defibrillation therapy will not continue. Rather, processing will
return in a block 202 to the main user interface routine so that
CPR delivery can be instructed to the user in a block 126. However,
if the maximum number of consecutive shocks has not yet been
reached, the logic will proceed in FIG. 8A from decision block 200
to a decision block 204 where it determines whether or not the
automatic rhythm detection algorithm has detected a shockable
rhythm. As those of ordinary skill in the art will recognize, not
all abnormal heart rhythms are treatable by defibrillation therapy.
However, CPR may still be of benefit to the patient. Accordingly,
if a shockable rhythm is not detected, processing will return in
block 202 to the main user interface program 22 so that the CPR
delivery sequence of instructions may be initiated in a block
126.
[0063] On the other hand, if a shockable rhythm is detected in
decision block 204, the logic proceeds to a block 205 in which the
AED instructs the user verbally that "Shock Advised, Stand Clear."
In addition, the microprocessor 24 generates a corresponding visual
instruction such as that shown in FIG. 101 on the display 14 of the
AED 10. After the rescuer is instructed that a shock has been
advised and to stand clear, the AED 10 initiates charge of an
energy storage component, e.g., a capacitor, for the device. As
those of ordinary skill in the art will appreciate, charging may
not be necessary at this point if the energy storage component was
precharged and thus, was ready to deliver the shock immediately.
However, in the actual embodiment of the present invention
described herein, the energy storage component is not, in fact,
precharged. Therefore, in a block 208, the AED 10 instructs the
user both visually (in text format) and verbally that the energy
storage component is "Charging." Next in a decision block 210, the
logic determines whether the AED 10 is ready to deliver a
defibrillation shock, i.e., whether the energy storage component is
fully charged. If not, blocks 208 and 210 are merely repeated until
the energy storage component has become fully charged.
[0064] Once the device is ready to shock, the logic proceeds to a
block 212 on FIG. 8B in which the rescuer is instructed to "Press
Shock Button" in order to trigger delivery of the defibrillation
pulse to the patient. Further visual instruction to press the shock
button are given to the rescuer by causing the shock button 11 to
flash repeatedly. In another actual embodiment of the present
invention, the AED 10 is programmed to deliver the shock
automatically without further rescuer intervention if a shockable
rhythm is detected and the energy storage component is fully
charged. In such embodiment, the AED 10 would not include a shock
button 11. Regardless of whether the rescuer presses the shock
button 11 to initiate the delivery of the defibrillation pulse or
whether the AED 10 is programmed to deliver the shock
automatically, the logic proceeds from block 212 to a decision
block 214 where it determines if the shock has been delivered. If
not, the logic proceeds to a decision block 216 where it determines
if the shock delivery interval has expired. If not, blocks 214 and
216 are repeated until the shock is either delivered (as initiated
by the rescuer pressing the shock button 11 or automatically by the
AED 10) or until the shock delivery interval has expired. If the
shock is delivered, the rescuer is instructed both verbally and
visually that "Shock Delivered." The logic then returns to block
192 on FIG. 8A to reactivate the automatic rhythm detection to
determine whether the patient's heart has been converted to a
normal rhythm.
[0065] If the shock delivery interval has expired before a
defibrillation pulse is delivered to the patient, the logic
proceeds to a decision block 220 where it determines if the rescuer
or AED 10 has had a predetermined or k number of chances to shock
the patient. In the actual embodiment of the present invention
described herein, the rescuer is given three opportunities to shock
the patient. If those three opportunities have not yet been
provided, the logic returns to block 192 of FIG. 8A so that the
automatic rhythm detection algorithm can be reactivated and the
patient's heart rhythm analyzed once again. If the rescuer has had
the acceptable number of opportunities to shock the patient but has
refrained from doing so, processing returns to the main user
interface program 22 in FIG. 3 at a block 126 so that the rescuer
may be instructed to deliver CPR to the patient.
[0066] Returning now to FIG. 3, after the patient's condition has
been assessed by the rescuer, the rescuer has attached the
defibrillation electrodes 16 to the patient, and the patient's
heart rhythm has been monitored for a shockable heart rhythm such
as ventricular fibrillation, the logic proceeds to a block 126
where the CPR delivery sequence is initiated by the user interface
program 22. The CPR delivery sequence is shown in more detail in
FIG. 9. The logic in FIG. 9 begins in a block 230 and proceeds to a
block 232 where the rescuer is instructed to deliver a
predetermined or p number of chest compressions to the patient.
More specifically, the visual instruction for delivering chest
compression shown in FIG. 10G is generated on the display 14 of the
AED 10. In the present example, p is the number of compressions
required under the AHA CPR protocol for an adult, which is
typically 15. In addition to the visual instruction provided by the
AED 10, a verbal instruction is provided simultaneously via the
speaker 18 to "Place Heel of Hand in Middle of Chest Centered along
Nipple Line. Press Firmly 15 Times. Press. (Pause) Press. (Pause) .
. . ." As discussed above, the pauses between verbal instructions
to "Press" are of appropriate length for the rescuer to perform the
instruction. Under the AHA HeartSaver protocol, 80 to 100
compressions per minute are recommended. Hence, the rescuer may
synchronize his or her actions with the timed verbal
instruction.
[0067] Once the rescuer has delivered the predetermined number of
compressions in block 232, the logic proceeds to a block 234 where
the rescuer is instructed to deliver q breaths to the patient,
where y is a predetermined number of breaths preprogrammed into the
user interface program 22. In the present example, q is the number
of breaths required under the AHA CPR protocol for an adult,
typically two. The visual instruction for delivery breaths
generated by the microprocessor 24 on the display 14 of the AED 10
is shown in FIG. 10E. A verbal instruction to "Tilt head, lift
chin, pinch nose. Blow. (Pause) Blow. (Pause)." is then provided
simultaneously with the visual instruction shown in FIG. 10E.
[0068] Next, in a decision block 236, the logic determines if a
predetermined or r number of CPR cycles has been delivered. In
other words, the logic determines if blocks 232 and 234 been
executed a predetermined number of times. In the actual embodiment
of the present invention described herein, r is the number of CPR
cycles recommended under the AHA CPR protocol for an adult,
typically four. However, it will be appreciated that this number as
well as any of the others mentioned above may vary depending on the
protocol preprogrammed into the user interface program 22. If the
recommended number of CPR cycles has not been delivered, blocks
232, 234 and 236 are repeated until the appropriate number of
cycles has been delivered. At that point, processing returns in a
block 238 to the routine from which the CPR delivery sequence was
called, e.g., user interface program 22, electrode attachment
sequence, etc. Those of ordinary skill in the art will appreciate
that in other actual embodiments of the present invention, an
alternative test for determining when CPR has been sufficiently
performed can be implemented in decision block 236. For example,
block 236 may determine whether CPR has been delivered for a
predetermined time interval t. For example, under the AHA protocol
for CPR for an adult, time t is one minute.
[0069] Returning to FIG. 3, once the CPR delivery sequence has been
performed in block 126, the logic returns to block 116 and blocks
116-126 are repeated indefinitely. Consequently, the user will
continuously be instructed to administer CPR and defibrillation
therapy until emergency services arrive or until the device is
powered down. It will be appreciated that power down could occur by
loss of battery or AC power to the AED 10 or by the rescuer
pressing the start button 12 continuously for a period of time long
enough to distinguish such a button press from a button press which
would merely indicate that the rescuer wishes to proceed to the
next instruction. In yet other embodiments, power down is achieved
by pressing an "off" button.
[0070] While a number of actual embodiments of the present
invention have been illustrated and described, it will be
appreciated that various changes can be made therein without
departing from the spirit and scope of the invention. For example,
although the user interface program 22 depicted in FIG. 3 is
described above in accordance with the actual embodiment of the AED
10 shown in FIG. 1 having an LCD display 14, it will be appreciated
that the user interface program 22 may also be implemented by the
alternative embodiment of the AED 10' depicted in FIG. 1B with
minimal changes. More specifically, rather than generate the
appropriate visual instruction on an LCD, visual instructions would
be provided to the user by illuminating the LED 15 appearing below
the fixed visual instruction 17 as appropriate.
[0071] In yet other embodiments of the present invention, the
verbal instructions provided to the rescuer simultaneously and in
synchronization with the visual instructions could be repeated
periodically until the rescuer proceeds to the next instruction.
Consequently, the rescuer would continually receive each verbal
instruction until the next action is taken. In yet other
embodiments, the rescuer could proceed to the next instruction by
issuing a voice command to the AED 10 rather than by pressing a
button. In such embodiments, the AED 10 would be required to have
installed a voice recognition module and microphone as noted above.
In yet other embodiments of the present invention, the user
interface program 22 can prompt the user to input information
regarding the patient that would assist the user interface program
in providing more patient specific instructions to the rescuer. For
example, the user interface program 22 could generate visual and/or
verbal instructions to enter information via the start button 12 to
distinguish whether the patient is an adult, child, or infant.
Accordingly, the number of chest compressions, rescue breaths, etc.
required during CPR delivery and/or the maximum number for total
and consecutive shocks would change accordingly.
[0072] It will further be appreciated that the visual and aural
instructions provided by the intuitive user interface of the
present invention may vary from those noted above and illustrated.
For example, more information and instruction may be provided to a
lay person for clarity and to reduce anxiety. In addition,
instructions may be provided with less medical jargon. Accordingly,
an even more user friendly user interface is provided. Those of
ordinary skill in the art will also recognize that as accepted CPR
and defibrillation protocols change, e.g., by adding, deleting or
reordering instructions, the AED 10 may be reprogrammed with a
simple software upgrade to the user interface program 22 to achieve
compliance. For example, the AED 10 may be reprogrammed to add
visual and/or aural instructions to unobstruct the patient's
airway. Finally, it will be appreciated that any defibrillation
device, e.g., a manual defibrillator, a semi-automatic
defibrillator or a fully automatic defibrillator, may be equipped
with the user interface of the present invention.
* * * * *