U.S. patent application number 13/188412 was filed with the patent office on 2012-04-12 for wearable cpr assist training and testing device.
This patent application is currently assigned to ATREO MEDICAL, INC.. Invention is credited to Corey Centen, Nilesh Patel.
Application Number | 20120089054 13/188412 |
Document ID | / |
Family ID | 39618061 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120089054 |
Kind Code |
A1 |
Centen; Corey ; et
al. |
April 12, 2012 |
WEARABLE CPR ASSIST TRAINING AND TESTING DEVICE
Abstract
A wearable cardiopulmonary resuscitation assist device or system
including: a wearable article to be worn by a cardiopulmonary
resuscitation performer or a patient, for assisting administration
of cardiopulmonary resuscitation by the performer; at least one
sensor for measuring at least one parameter to assist in
cardiopulmonary resuscitation; at least one feedback component for
conveying feedback information based on the parameter to the
performer for assisting the performer in performing cardiopulmonary
resuscitation; and a processing unit, the processing unit being
configured to receive the at least one parameter from the at least
one sensor and to send information based on the parameter to the at
least one feedback component. Also a method for training or
improving cardiopulmonary resuscitation procedures using the
device.
Inventors: |
Centen; Corey; (Toronto,
CA) ; Patel; Nilesh; (Brampton, CA) |
Assignee: |
ATREO MEDICAL, INC.
Redmond
WA
|
Family ID: |
39618061 |
Appl. No.: |
13/188412 |
Filed: |
July 21, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11936184 |
Nov 7, 2007 |
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13188412 |
|
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60880228 |
Jan 16, 2007 |
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Current U.S.
Class: |
601/41 |
Current CPC
Class: |
G16H 20/30 20180101;
G09B 23/288 20130101; A61H 2201/5064 20130101; A61H 2201/5084
20130101; A61H 2201/5069 20130101; A61H 2201/5061 20130101; G16H
40/63 20180101; A61H 31/005 20130101 |
Class at
Publication: |
601/41 |
International
Class: |
A61H 31/00 20060101
A61H031/00 |
Claims
1. A cardiopulmonary resuscitation (CPR) device, comprising: a
wearable device, the wearable device being wearable as a glove; one
or more sensors disposed on the wearable device, the sensors
measuring one or more compression characteristics; at least one
feedback component disposed on the wearable device; a processing
unit disposed on the wearable device, the processing unit
configured to handle analog or digital data, and connected to the
one or more sensors and the feedback component; and a power source
disposed on the wearable device and connected to the one or more
sensors, the feedback component, and the processing unit.
2. The CPR device as recited in claim 1, wherein the one or more
compression characteristics are selected from depth, force,
frequency or acceleration.
3. The CPR device as recited in claim 1, in which the wearable
device is a glove that includes a disposable outer glove, and the
outer glove protects the one or more sensors.
4. The CPR device as recited in claim 1, in which the wearable
device is a glove that includes a disposable outer glove, and the
outer glove protects the processing unit.
5. The CPR device as recited in claim 1, in which the wearable
device is a glove that includes a disposable outer glove, and the
outer glove protects the power source.
6. The CPR device as recited in claim 1, wherein the one or more
sensors comprise: an accelerometer.
7. The CPR device as recited in claim 1, further comprising: a
storage medium.
8. The CPR device as recited in claim 1, wherein the one or more
sensors measure one or more operational parameters.
9. The CPR device as recited in claim 1, wherein the CPR recipient
is a human, or a mannequin, and the CPR provider is a human.
10. The CPR device as recited in claim 1, wherein the feedback
component includes a display.
11. The CPR device as recited in claim 10, wherein the display
comprises an LCD screen.
12. The CPR device as recited in claim 1, wherein the feedback
component includes a wireless communications device for
transmitting data over a wireless link.
13. The CPR device as recited in claim 1, wherein the glove
includes a fabric portion.
14. The CPR device as recited in claim 1, wherein the power source
comprises a battery.
15. The CPR device as recited in claim 1, further comprising:
adhesive electrodes which may adhere to the CPR recipient.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 11/936,184, filed Nov. 7, 2007, entitled WEARABLE CPR
ASSIST, TRAINING AND TESTING DEVICE, currently pending, which
claims benefit of U.S. Provisional Application No. 60/880,228,
filed Jan. 16, 2007, by the same inventors and commonly assigned,
both of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to CPR assist devices. In
particular, the present invention relates to CPR assist devices
that are wearable, and systems that include such devices.
BACKGROUND OF THE INVENTION
[0003] There are currently an estimated 40,000 incidences of
cardiac arrest every year in Canada, most of which take place
outside of hospital settings. The odds of an out-of-hospital
cardiac arrest currently stand at approximately 5%. In the U.S.,
there are about 164,000 such instances each year, or about 0.55 per
1000 population. There is a desire to decrease these
out-of-hospital incidences of cardiac arrest. Certain places, such
as sports arenas, and certain individuals, such as the elderly, are
at particular risk and in these places and for these people, a
convenient solution may be the difference between survival and
death.
[0004] Cardiopulmonary resuscitation (CPR) is a proven effective
technique for medical and non-medical professionals to improve the
chance of survival for patients experiencing cardiac failure. CPR
forces blood through the circulatory system until professional
medical help arrives, thereby maintaining oxygen distribution
throughout the patient's body. However, the quality of CPR is often
poor. Retention of proper CPR technique and protocol may be
inadequate in most individuals and the anxiety of an emergency
situation may confuse and hinder an individual in delivering proper
treatment.
[0005] According to the journal of the American Medical Association
(2005), cardiopulmonary resuscitation (CPR) is often performed
inconsistently and inefficiently, resulting in preventable deaths.
Months after the completion of standard CPR training and testing,
an individual's competency at performing effective chest
compressions often deteriorates significantly. This finding was
found to hold true for untrained performers as well as trained
professionals such as paramedics, nurses, and even physicians.
[0006] The International Liaison Committee on Resuscitation in 2005
described an effective method of administering CPR and the
parameters associated with an effective technique. Parameters
include chest compression rate and chest compression depth. Chest
compression rate is defined as the number of compression delivered
per minute. Chest compression depth is defined as how far the
patient's sternum is displaced. An effective compression rate may
be 100 chest compressions per minute at a compression depth of
about 4-5 cm. According to a 2005 study at Ulleval University
Hospital in Norway, on average, compression rates were less then 90
compressions per minute and compression depth was too shallow for
37% of compressions.
[0007] It will be understood that "glove" may also refer to a
fingerless glove. By omitting the fingers on a glove-like wearable
article, the CPR assist device may be able to fit more CPR
performers and may be put on more easily. An example of a
fingerless CPR assist glove is shown in FIGS. 6-8. FIGS. 6 and 7
show the fingerless CPR assist glove from a top plan view (i.e.,
corresponding to the back of the hand), the latter being a cutaway
view showing components the inside of the glove. FIG. 8 shows
components inside of the fingerless glove from a bottom plan view
(i.e., corresponding to the palm of the hand). The fingerless glove
may include components similar to the fingered glove discussed
above. In the example shown, the fingerless CPR assist glove
includes a processing unit 10 located on top of the glove below the
wrist. There is also at least one sensor, which may include an
accelerometer 16 on the top of the glove, a pressure sensor 20 on
the bottom of the glove, and a pulse oximetry sensor 30 on the
bottom of the glove. In the example shown, the pressure sensor 20
is in the form of a pressure pad over the palm area. The pulse
oximetry sensor 30 is shown located in the middle of the palm, but
may be located at other suitable locations. The pulse oximetry
sensor 30 may be used to sense the patient's blood oxygenation
level and heart rate. The pulse oximetry sensor 30 may also be used
in the fingered glove discussed above. There is also at least one
feedback component, which may include a visual display 28 located
on a sleeve 26 on the top of the glove. There is also a power
supply 24, which may be located on the bottom of the glove, below
the wrist.
[0008] Positioning of the hands is another parameter that may be
considered when delivering CPR. It has been found that an effective
position for the hands during compression is approximately 2 inches
above the base of the sternum. Hand positioning for effective CPR
may be different depending on the patient. For example, for
performing CPR on an infant, an effective position may be to use
two fingers over the sternum.
[0009] Other studies have found similar deficiencies in the
delivery of CPR. One 2005 study at the University of Chicago found
that 36.9% of the time, less than 80 compressions per minute where
given, and 21.7% of the time, less than 70 compressions per minute
were given. The chest compression rate was found to directly
correlate to the spontaneous return of circulation after cardiac
arrest.
[0010] In addition to too shallow compressions, too forceful
compressions may also be problematic. Some injuries related to CPR
are injury to the patient in the form of cracked ribs or cartilage
separation. Such consequences may be due to excessive force or
compression depth. Once again, lack of practice may be responsible
for these injuries.
[0011] Therefore, a device to facilitate the proper delivery of CPR
in an emergency is desired. Furthermore, a device that can also be
used in objectively training and testing an individual may be
useful for the CPR training process and protocol retention.
[0012] Current solutions in emergency cardiac care mostly focus on
in-hospital treatment or appeal mostly to medical professionals.
CPR assist devices that tether to defibrillators can be found in
hospitals. However, these devices are often expensive and
inaccessible to the lay individual who does not have a
defibrillator on hand or cannot operate such a device. Furthermore,
such devices are often not portable nor are they easily accessible.
Simple devices with bar graph displays indicating compression force
are often cumbersome in design and non-intuitive in use. Such a
device may be uncomfortable to the patient and user and often has
minimal data output. Thus, misuse of such a device is probable
rendering it a hindrance rather than an aid.
[0013] There are currently mechanical systems for the delivery of
CPR that may be used in a hospital setting. Chest compression may
be delivered through a mechanism comprising mechanical movement
(e.g., piston movement or motor movement). One such device is the
AutoPulse.TM. by Revivant Corp, which has a computer-controlled
motor attached to a wide chest band that compresses the chest,
forcing blood to the brain when the heart has stopped beating.
[0014] Another device is the Q-CPR.TM. by Philips Medical, which is
used to assess CPR quality. This device includes a CPR module
connected to a defibrillation system. Although not currently
marketed as a training device, the Q-CPR currently exists as a
resuscitation aid and has future potential as a training
technology. The device includes a block that provides compression
depth and rate information to a rescuer through the display on the
defibrillator. The CPR module is a unit placed on the patient's
chest and under the hands of the individual performing the CPR. It
may be cumbersome and may not be suited for use by non-medical
professionals. The device has a multitude of instrumentation, which
may make it expensive. In addition, the patient's comfort and
safety may be a concern when an external, rigid device such as the
Q-CPR is being employed. If the user is not familiar with the
device, its use could result in injury. Other devices, such the
D-Padz.TM. by Zoll Medical employ similar technologies and thus
encounter similar disadvantages.
[0015] The CPR-Ezy.TM. is a device that is independent from a
defibrillator. It is a solid plastic block that is designed to be
placed under the CPR performer's hands when performing CPR. Lights
on its surface indicate the amount of force applied during a
compression. Such a device may be bulky and awkward to use, and the
feedback provided is limited and not quantitative. It also does not
store information about the CPR performed.
[0016] Currently, a widely used technology in the training
environment is the CPR mannequin. One commonly used version is the
Resusci-Anne.TM. doll manufactured by Laerdal Medical inc. The
Resusci-Anne doll allows an individual to practice his or her CPR
while being subjectively monitored by an instructor. This technique
relies on the observational skills of the instructor and thus may
be prone to human error. Furthermore, for effective training to
take place, each student must be observed separately thereby
occupying a significant amount of time and decreasing the number of
students who can be trained at one time. In addition, Actar
Airforce Inc. develops Actar.TM. mannequins providing limited
feedback that are currently also used in CPR training. Again, such
mannequins rely on close monitoring by the instructor to be
effective for training.
[0017] Similar devices have also been disclosed, for example, in
U.S. Pat. Nos. 7,220,235, 7,074,199, 6,351,671, and 5,468,151.
Other CPR assist devices have been disclosed in U.S. Pat. No.
5,454,779, U.S. Pat. No. 5,645,522, US 2003/036044, U.S. Pat. No.
5,496,257, US 2006/019229, and EP 162616.
[0018] It would still be desirable to provide an easy-to-use and
inexpensive device to provide instruction for carrying out a proper
CPR procedure for training, testing, and/or emergency situations.
Such a device may be intuitive to use.
SUMMARY OF THE INVENTION
[0019] An aspect of the present invention provides a wearable CPR
assist device that may aid a performer in performing CPR. The
device may also be inexpensive and/or adaptive. The device includes
sensors for measuring various parameters during a CPR procedure,
and may be used for training, testing, and/or real life
emergencies. The device may provide instructions for performing CPR
in the form of audio and/or visual feedback. The feedback may
include information on parameters such as heart rate, compression
rate, compression depth, compression force, compression angle, hand
positioning, patient body temperature, patient body type, and
patient blood oxygen content. The device may be accessible and
usable to those trained and untrained in CPR.
[0020] The device may be in the form of an intuitive wearable
article, to be worn by the performer or by the patient, allowing
CPR to be administered as normal with no external devices
necessary. By including all sensors in fixed positions on the
device, the positioning of all sensors on the patient may be more
likely to be accurate and precise. In some aspects, the sensors may
be incorporated into a wearable glove to be worn by the performer
for increased wearability and ease of use.
[0021] In some aspects, there is provided a wearable
cardiopulmonary resuscitation assist device comprising: a wearable
article to be worn by a cardiopulmonary resuscitation performer or
a patient, for assisting administration of cardiopulmonary
resuscitation by the performer; at least one sensor on the article
for measuring at least one parameter to assist in cardiopulmonary
resuscitation; at least one feedback component on the article for
conveying feedback information based on the parameter to the
performer for assisting the performer in performing cardiopulmonary
resuscitation; and a processing unit on the article, the processing
unit being configured to receive the at least one parameter from
the at least one sensor and to send information based on the
parameter to the at least one feedback component.
[0022] In some aspects, there is provided a system for assisting
performance of cardiopulmonary resuscitation, the system
comprising: a wearable cardiopulmonary resuscitation assist device,
the device having: a wearable article to be worn by a
cardiopulmonary resuscitation performer or a patient, for assisting
administration of cardiopulmonary resuscitation by the performer;
at least one sensor on the article for measuring at least one
parameter to assist in cardiopulmonary resuscitation; and a base
unit in communication with the device, the base unit having: at
least one feedback component for conveying feedback information
based on the at least one parameter to the performer for assisting
the performer in performing cardiopulmonary resuscitation; and a
processing unit configured to receive the at least one parameter
from the at least one sensor and to send information based on the
at least one parameter to the at least one feedback component.
[0023] In some aspects, there is provided a method of training a
performer for cardiopulmonary resuscitation using a wearable
cardiopulmonary resuscitation assist device, the method comprising:
detecting at least one parameter for performing cardiopulmonary
resuscitation using at least one sensor on the device; analyzing
the at least one parameter compared to a desired cardiopulmonary
resuscitation method; and providing feedback to the performer based
on analysis of the at least one parameter.
[0024] In some aspects, there is provided a method of improving
performance of cardiopulmonary resuscitation by a performer to a
patient in need of such treatment, the method comprising: providing
a wearable cardiopulmonary resuscitation assist device to be worn
by the performer or the patient; detecting at least one parameter
for performing cardiopulmonary resuscitation using at least one
sensor on the device; analyzing the at least one parameter compared
to a desired cardiopulmonary resuscitation method; and providing
feedback to the performer based on analysis of the at least one
parameter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Aspects of the present invention will be discussed in detail
below, with reference to the drawings in which:
[0026] FIG. 1 is an illustration of a CPR assist device in the form
of a CPR assist glove being used to perform CPR;
[0027] FIG. 2 is a block diagram illustrating an overview of a CPR
assist system;
[0028] FIG. 3 is a top plan view of a CPR assist glove;
[0029] FIG. 4 is a top plan cutaway view showing components inside
of the CPR assist glove of FIG. 2;
[0030] FIG. 5 is a bottom plan cutaway view showing components
inside of the CPR assist glove of FIG. 2;
[0031] FIG. 6 is a top plan view of a fingerless CPR assist
glove.
[0032] FIG. 7 is a top plan cutaway view showing components inside
of the fingerless CPR assist glove of FIG. 5;
[0033] FIG. 8 is a bottom plan cutaway view showing components
inside of the fingerless CPR assist glove of FIG. 5;
[0034] FIG. 9 is a top plan view of a simplified CPR assist
glove;
[0035] FIG. 10 is a top plan view of a wrist-wearable form of the
CPR assist device;
[0036] FIG. 11 shows example visual feedback provided by the CPR
assist device;
[0037] FIG. 12 is a schematic view of a system including the CPR
assist device and a base unit;
[0038] FIG. 13 is a flowchart illustrating a use of the CPR assist
device for assisting a CPR performer; and
[0039] FIG. 14 is a flowchart illustrating a use of the CPR assist
device with the base unit.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The CPR assist device may be used to assist a CPR performer
to carry out a CPR procedure on a patient. The device may also be
used to train a CPR performer to properly perform CPR. The device
may also be used to test whether a CPR performer is performing
proper CPR. As such, although referred to as a CPR assist device,
the device may be used not only for assisting in performance of
CPR, but also or in the alternative be used for training or testing
purposes. All examples and embodiments discussed in the present
application are for purposes of illustration only and are not
intended to be limiting.
[0041] The CPR assist device may include a wearable article
containing the following basic components: a sensor and a feedback
component. The device may also include a processing unit such as a
microcontroller, and a power source or connection to a power
source. Although the description and examples may refer to a
microcontroller, the processing unit may be an analog circuitry, a
microprocessor, or other suitable electronics. The device may also
include a long-term memory, and data transmission means. These
components will be described in greater detail in the respective
sections below.
[0042] In some aspects, the CPR assist device is part of a system,
and the CPR assist device may include a wearable article containing
a sensor. The system may further include a base unit, the base unit
having a feedback component and a processing unit. The base unit
and the CPR assist device may be in communication, such that
parameters sensed by the device or other related data may be
communicated to the base unit, and the base unit then performs any
necessary analysis of the parameter or data and conveys the result
to the performer via the feedback component. The base unit may
contain other components or modules for other functions, as will be
discussed below.
[0043] The CPR assist device will be first discussed independent of
the base unit, and later will be discussed as part of a system
including the base unit.
[0044] In some aspects, the CPR assist device is in the form of a
CPR assist glove, as shown in FIG. 1. The CPR assist glove 2 may be
worn by a CPR performer 4, to assist in providing CPR to a patient
6. The CPR assist glove 2 as shown is only one non-limiting example
of the CPR assist device. Variations to the device are possible, as
will be discussed below.
[0045] FIG. 2 is a block diagram showing an overview of the
connectivity between the different components described above in an
aspect of the device, where the device is to be used independent of
the base unit. In the example shown, the device includes a
processing unit (e.g., a microcontroller), a power source, at least
one sensor, and at least one feedback component. The dashed arrows
indicate the flow of power while the solid arrows indicate the flow
of data. The processing unit 10 receives power from a power source
12 and delivers the power to at least one feedback component which
may include a visual feedback 14 and an audio feedback 15, and at
least one sensor which may include an accelerometer 16, an
electrocardiogram (ECG) sensor 18, a pressure sensor 20, and an
angle sensor 22. Data from each sensor 16, 18, 20, 22 is sent to
the processing unit 10, which performs any necessary processing and
analysis, and sends the processed or analyzed data to the feedback
components 14, 15 for conveying to the performer. Although the
above description is with reference to the device being used
independent of a base unit, the components and the power and/or
data flow may be similar where a base unit is used. Where a base
unit is used, some components may be found on the base unit instead
of the device, but the power and/or data flow may not be affected
by this difference.
[0046] The CPR assist device may be in the form of any wearable
article incorporating these components. The device may be
configured to allow the sensors to pick up the patient information
by directly contacting the patient, or by other direct or indirect
methods. In some aspects, the sensors are configured to be brought
into close proximity with the patient during CPR. By this is meant
that the sensors may be brought up against the patient, though not
necessarily in direct skin contact.
[0047] In some aspects, the CPR assist device is in the form of a
glove that may be worn by the CPR performer, which will be referred
to here as a CPR assist glove or simply a glove. Although this
description may refer to the CPR assist device as being in the form
of a glove, a person skilled in the art would understand that other
wearable forms are possible that still provide the functions
described herein.
[0048] Because the CPR assist device is wearable, it may be
adaptable to situations in which an unwieldy device may be
undesirable, for example in performing CPR on a small infant.
Wearable Article
[0049] The CPR assist device may be wearable by the performer or by
the patient, and the wearable article may be adapted accordingly.
In some aspects, the CPR assist device includes a glove as the
wearable article, and is referred to as a CPR assist glove. Other
possibilities for the wearable article may include a palm strap, a
wrist strap, a partial glove, a vest, a watch, a ring, a bracelet,
a belt, a mitten, or other similar articles. The wearable article
may be of a suitable size and configuration to contain all the
components of the device. In some aspects, the wearable article may
be configured to allow at least one sensor housed in the wearable
article to come into close proximity with the patient. Where the
wearable article is to be worn by the patient, the wearable article
may be adapted so that it can be easily put on the patient by the
performer. This may be by making the wearable article to be widely
adjustable, such as by providing Velcro.TM. straps or zippers.
[0050] The various components described above may be housed in
separate compartments on the wearable article. The compartments for
each component may be interchangeable, or more than one component
may share one compartment. Some components may be more effective
when housed in certain positions or in certain compartments, for
example pressure sensors may be more effective located on the palm
of the performer. These compartments may be padded to protect the
components and the device may be made from a material that is
easily cleaned and resistant to water and stain damage. The
material of the wearable article may be a fabric material that can
be stretched or otherwise adjusted (e.g., with a buckle or strap)
to fit differently-sized performers. In some aspects, the various
components may be removable from the device and the wearable
article portion may be easily replaced or cleaned. This may allow
for a sterile device each time CPR is performed. In another aspect
of the invention, the device may have an outer layer that is at
least water-resistant and that can be cleaned or disposed of after
use. This outer layer may protect the device inside and the device
components from contamination, and may eliminate or decrease
concerns related to health or disease transmission. In some
aspects, the wearable article may be made with sterile or
sterilizable materials such as plastics. For example, in the case
of a CPR assist glove, the glove may be a plastic shell that may be
easily cleaned and sterilized.
[0051] One example of the device in the form of a CPR assist glove
is shown in FIGS. 3-5. FIGS. 3 and 4 show the glove from a top plan
view (i.e., corresponding to the back of the hand), the latter
being a cutaway view showing the components inside of the glove.
FIG. 5 shows the inside of the glove from the bottom plan view
(i.e., corresponding to the palm of the hand). The example shown
includes three types of sensors: an electrocardiogram (ECG) sensor
18 with electrodes 19, an accelerometer 16, and pressure sensors
20. Other types of sensors may be included. The ECG sensor 18 may
be located on the top of the glove (i.e., corresponding to the back
of the hand) as shown, and may be connected to two electrodes 19
located on two opposing fingertips. The electrodes are illustrated
here as being located on the pads of the thumb and the last finger,
however other locations for the electrodes are possible (e.g., on
other fingers or located on the palm), and more than two electrodes
may be used. The accelerometer 16 may be housed along the lateral
side of the hand opposite the thumb or on the top of the glove as
shown. The accelerometer 16 does not need to be in contact with the
patient, and thus may be located on the side or on the top of the
glove. There may be four pressure sensors 20 located on the corners
of the palm. Other configurations for the pressure sensors are
possible, and there may be more or less than four pressure sensors
20. A processing unit 10 may be positioned on the superior side of
the arm, just below the wrist. A power source 24 may be positioned
on the opposite side of the arm, just below the wrist. The example
CPR assist glove is also shown with additional pressure sensors 20a
located on the fingertips. These additional pressure sensors 20a
may be used where CPR is performed on an infant, in which case it
may be desirable to have pressure sensors on the fingertips.
[0052] The location of these components may vary depending on what
suits an individual performer and may be modified for different CPR
efficiency and performer comfort. This layout may be different if
different sensors were used, or if additional components were
added. Certain sensors may be better located in certain positions,
for example ECG sensors may be better located on the bottom side of
the glove in order to come into close proximity with the patient.
The configuration may be similar or different when used in a
wearable article other than a glove. For example, in the case where
the wearable article is a palm strap, the ECG sensors may be
located on the palm rather than on the fingers.
[0053] Other aspects that are not shown may include a feedback
component such as a display, for example a liquid crystal display
(LCD). Other types of feedback components are discussed further
below. The feedback component may be connected to the device or may
be connected to a separate computing device, such as a computer, a
base unit, or a receiving station, that may receive information
from the device. Data may be transmitted to a separate computing
device running software that may analyze and/or interpret the
sensed data. Transmission of data may be by wired transmission or
wirelessly using a transmission module in the device. The
transmission module may be part of the processing unit, as
described further below.
[0054] Although one layout of the components on a CPR assist glove
is shown in the Figures, the layout may be different. For example,
as already discussed, to allow for accurate and efficient infant
CPR, the CPR assist glove may additionally or alternatively have
sensors located in the fingertips of the glove to allow for
two-finger CPR to a newborn infant. For example, pressure sensors
on the fingertips may allow for determination of compression force
during infant CPR. Other layouts may be suitable for different
sensors and different applications. Infant CPR may also be measured
using other sensors at other locations, for example, using an
accelerometer located on the back of the hand for measuring
compression depth, measurements of the performer's hand position
can be made in the Z-axis (i.e., up-down direction).
[0055] In some aspects where the CPR assist device is in the form
of a glove, there may be a wrist support added to the glove that
may help someone with a weaker wrist or an ailment such as
arthritis provide solid CPR. Furthermore, such a support may help
improve the endurance of a performer during CPR and reduce
ill-effects to the performer's wrist. The support may also serve to
encourage effective CPR form by positioning the superior side of
the hand (i.e. the back of the hand) perpendicular to the arm.
[0056] As shown in FIG. 3, the CPR assist glove may also have a
sleeve 26 on top of the top side of the glove to help the performer
position his or her second hand above the hand wearing the glove.
This sleeve 26 may also contain sensors or other circuitry. This
sleeve 26 may also be a convenient place to provide a display 28
for visual feedback to the performer or to provide selection
choices (e.g., via a displayed menu) for the performer.
[0057] It will be understood that "glove" may also refer to a
fingerless glove. By omitting the fingers on a glove-like wearable
article, the CPR assist device may be able to fit more CPR
performers and may be put on more easily. An example of a
fingerless CPR assist glove is shown in FIGS. 6-8. FIGS. 6 and 7
show the fingerless CPR assist glove from a top plan view (i.e.,
corresponding to the back of the hand), the latter being a cutaway
view showing components the inside of the glove. FIG. 8 shows
components inside of the fingerless glove from a bottom plan view
(i.e., corresponding to the palm of the hand). The fingerless glove
may include components similar to the fingered glove discussed
above. In the example shown, the fingerless CPR assist glove
includes a processing unit 10 located on top of the glove below the
wrist. There is also at least one sensor, which may include an
accelerometer 16 on the top of the glove, a pressure sensor 20 on
the bottom of the glove, and a pulse oximetry sensor 30 on the
bottom of the glove. In the example shown, the pressure sensor 20
is in the form of a pressure pad over the palm area. The pulse
oximetry sensor 30 is shown located in the middle of the palm, but
may be located at other suitable locations. The pulse oximetery
sensor 30 may be used to sense the patient's blood oxygenation
level and heart rate. The pulse oximetry sensor 30 may also be used
in the fingered glove discussed above. There is also at least one
feedback component, which may include a visual display 28 located
on a sleeve 26 on the top of the glove. There is also a power
supply 24, which may be located on the bottom of the glove, below
the wrist.
[0058] In some aspects, the CPR assist device may be simplified,
for example as a simple glove as shown in FIG. 9. In the example
shown, there is no sleeve, and feedback to the CPR performer is
conveyed by an audio feedback. A processing unit 10 and an ECG
sensor 18 are also shown as an example, however other sensors and
components may be present. In such a simplified device, the device
may be inexpensive and may be disposable.
[0059] In some aspects, there may be only one large hole for all
the fingers to slide through, or the device may be in the form of a
palm strap or wrist strap. An example of a wrist-wearable CPR
assist device is shown in FIG. 10, which may be a wrist-strap or
may be a wristwatch. The wearable article may be composed of
several connected pieces, and may be made of hard or flexible
plastic material instead of or in combination textiles. The
wearable article may be customized and fitted for the CPR
performer. It will be understood that the components discussed
above may be present in these different variations, and may be
positioned at different locations as suitable.
[0060] Although the wearable article has been described as a glove,
it should be understood that the CPR assist device may be in the
form of other wearable articles. The CPR assist device may be in
the form of an intuitively wearable article (e.g., similar to a
common article of clothing), where the performer can simply put on
the device and perform CPR as normal, or the device can be put on
the patient easily with no modifications to the CPR procedure and
no external devices to worry about. By including sensors in fixed
positions in the CPR assist device rather than separately or
externally, the sensors may be more likely to be placed in correct
positions on the patient than when using external sensors.
Sensors
[0061] The CPR assist device may include a number of different
sensors for detecting patient information and parameters of the CPR
being performed. Such information may include depth of compression,
compression rate, compression angle, patient heart rate, hand
positioning, patient body temperature, patient body type, and
patient blood oxygenation level. Sensors include physiological
sensors, pressure sensors, position sensors, and movement sensors.
Discussed below are pressure sensors, accelerometers, and ECG
sensors. Other sensors may be used in addition to or as
alternatives to these sensors. Other sensors may be incorporated
into the device in order to obtain additional information as
desired.
[0062] Data from the sensors may be processed or analyzed and
provided as feedback to the performer. The raw data or processed
data may additionally or alternatively be stored in a memory in the
device or in a separate computing unit, such as a base unit, for
later retrieval. The raw data or processed data may additionally or
alternatively be transmitted to a separate computing device.
Pressure Sensors
[0063] Pressure sensors may allow for detection of compression rate
and for providing the CPR performer with feedback information based
on the amount of force applied during CPR. The pressure sensors may
be selected to be comfortable for the patient, since these may be
directly against the patient's chest. Therefore, flexibility,
durability, and thinness may be desirable properties. In some
aspects, the pressure sensors may be thin, tactile, single element
load sensors based on the piezoelectric effect, such as Tekscan
Flexiforce.TM. sensors. By piezoelectric effect, it is meant that
the electrical resistance of each pressure sensor varies inversely
with applied pressure. Other types of pressure sensors may be used,
such as a mechanical sensor or a capacitive sensor. A possible type
of pressure sensor may include sensory components embedded into the
wearable article itself, for example in the form of interwoven
conductive and non-conductive yarns which result in capacitance
changes as the yarns are compressed. Another possible type of
pressure sensor may use a strain gauge, which may determine
deformation during compression and translate this deformation to
pressure. Yet another possible pressure sensor may use
piezoresistive integrated semiconductor technology such as force
sensitive resistors (FSR).
[0064] The pressure sensor may be used to detect the occurrence of
CPR compressions. This may allow the CPR assist device to inform
the performer of the number of compressions remaining in a cycle.
By a "cycle" is meant a pre-determined number of compressions
followed by a pre-determined number of breaths. One cycle may
consist of 30 compressions and two breaths, though other orders and
numbers of compressions and breaths may also be suitable. The
specific number of compressions and breaths per cycle may be based
on accepted CPR guidelines and may change as CPR guidelines are
changed. The device may tell the performer how many compressions he
or she has performed, or it may tell the performer how many
compressions are remaining in a specific cycle. The pressure sensor
may be used to calculate the compression rate. Upon completion of
each cycle, compression rate information may be calculated by
timing the duration of the cycle. This data may be relayed to the
performer, so that he or she can adjust his or her compression
speed for a subsequent cycle. The compression rate information may
also be provided in real-time so that the performer can adjust
speed during a cycle. The pressure sensor may also be used to
collect force data. The performer may be provided with force
readings from the sensor, for example at four locations on the
palm. This information feedback may allow the performer to
distribute force more evenly with his or her hand.
[0065] One example of the software to interpret the pressure sensor
data is now described. Only one pressure sensor may be needed in
determining the compression rate. The pressure sensor may generate
a voltage signal proportional to the pressure sensed. The
occurrence of a compression may be detected based on the signal
exceeding a predetermined threshold value. The number of
compressions already performed or yet to be performed for a cycle
may be calculated and may be communicated to the performer. The
maximum force applied during a compression may also be calculated
from the sensor signal and may be communicated to the performer as
an average per cycle or in real-time per compression. To calculate
the compression rate, the number of compressions is divided by
amount of time (e.g., in minutes) it took to complete the
compressions. There may be a separate timer (e.g., in the
processing unit) responsible for providing the time, or there may
be a timer included with the pressure sensor. The compression rate
may also be provided as feedback to the performer as an average or
in real-time. Other pressure data may be calculated and provided to
the performer.
Accelerometer
[0066] The accelerometer may carry out motion and position
detection. One type of position detection is to detect the position
of the performer's hand in relation to the patient or to a desired
position for performing CPR. Information sensed by the
accelerometer may be used to calculate the compression depth and
compression angle. There may be separate accelerometers for
measuring compression depth and compression angle, or a single
accelerometer may be used to carry out both measurements. The
acceleration may be used to measure addition information, which
again may be done by the same single accelerometer or may be done
by additional accelerometers.
[0067] In an example, the accelerometer may measure acceleration
and tilt in two Cartesian axes, specifically the X (i.e.,
forward-backward) and the Y (i.e., left-right) directions. One
example of a suitable accelerometer is the ADXL202 by Analog
Devices. In another example, the accelerometer may measure
acceleration and tilt in three Cartesian axes, specifically the X,
Y and Z (i.e. up-down) directions. One example of a suitable
accelerometer for this is the ADXL330 by Analog Devices. This
component may be used to measure the angle of each compression as
well as the average compression depth throughout a cycle of CPR.
Alternatively, the compression angle may be measured by a separate
accelerometer that may be located separate from the accelerometer
for measuring compression depth. In the case of a CPR assist glove,
an accelerometer for measuring compression depth may be located on
the back of the hand, while a separate accelerometer for measuring
compression angle may be located on the side or the top of the
wrist. The separate angle sensor may be designed into the
processing unit on the top side of the wrist.
[0068] The ADXL202 is based on MEMS technology. Enclosed in a 5
mm.times.5 mm.times.2 mm package, the accelerometer incorporates a
polysilicon spring extended structure. Deflection of this spring
structure is measured using a capacitor and the deflection is
translated into an output signal. The ADXL330 may be available in a
small, low profile 4 mm.times.4 mm.times.1.45 mm package on a
single monolithic integrated circuit, with a signal conditioned
voltage output. This accelerometer measures acceleration with a
minimum full-scale range of +/-3 g. It can also measure the static
acceleration of gravity in tilt-sensing applications, as well as
dynamic accelerations resulting from motion, shock, or vibration.
Other accelerometers may also be suitable, such as those with
higher maximum acceleration measured and/or better measurement
resolution.
[0069] Where compression angle is measured by a separate
accelerometer, this may be done using a standard accelerometer
similar to that used for measuring compression depth. In an
example, the compression angle is measured by an accelerometer
measuring acceleration in the X and Y axes, such as the ADXL322 by
Analog Devices. Data from the compression angle measuring
accelerometer may be passed through a data filter, such as a low
pass filter. Trigonometric algorithms may then be used to determine
the angle of the compression from the measured data. The
compression angle sensor may be located in a fixed position
relative to the performer's arm (e.g., on the wrist) to provide
more accurate information on the angle of the performer's arm
relative to the patient's body. Where the processing unit is
located on the top side of the wrist, the angle sensor may be
integrated into the processing unit. Using this compression angle
data, feedback may be provided to the performer to help maintain
the performer's arms at a desired angled (e.g., ninety degrees)
relative to the patient's chest.
[0070] Measurements by the accelerometer along the Z-axis (i.e., up
and down) may be used to calculate the compression depth.
Measurements along the X-axis (i.e., back to front) and/or the
Y-axis (i.e., left to right) may be used to calculate the angle of
compressions. Feedback information to the performer about the
compression angle may help the performer to perform compressions
perpendicularly to the patient's chest. This may be the case when
the accelerometer takes measurements along these two axes only. If
the accelerometer provides measurements in different axes, the
calculations may be different, and may provide additional
information (e.g., compression angles in more than one plane). The
measurements and calculations from different accelerometers may be
adjusted as necessary in order to obtain the desired
information.
[0071] In the example described above, acceleration measurements in
the measurement axes may be converted into a digital format where
necessary using suitable analog to digital conversion circuitry.
The digital information may then be analyzed by the processing
unit. This analysis may involve integrating the acceleration
measurements twice to obtain displacement measurements. The data
may also be filtered using standard filtering algorithms in order
to obtain cleaner data.
[0072] Similarly, the compression angle may be calculated from the
accelerometer measurements and an average compression angle for
each cycle may be communicated to the performer. The compression
angle may also be calculated for each compression and this
information may be provided in real-time to the performer.
[0073] Although the discussion above was with regards to a specific
accelerometer, other accelerometers may be used in the CPR assist
device. Other possible accelerometers may detect movement in only
one axis, in any two axes, or in all three axes of direction.
Having measurements in all three axes may be useful. Measurements
in the Z axis (i.e., up-down direction) may be used to determine
displacement in the direction of compression, however since the
accelerometer may not be perfectly level, measurements in the X and
Y axes may be used to determine the inclination of the
accelerometer in order to more accurately calculate the compression
depth. The accelerometer may also detect angular movement in
addition to or in place of movement in the Cartesian axes.
Measurements from the accelerometer may be used to calculate
different compression parameters and this information may be
provided to the performer.
[0074] Although the accelerometer was described as providing
position and movement detection, the CPR assist device may have
separate position and movement sensors. Other possible position
sensors include optical sensors and ultrasonic position sensors.
Other possible movement sensors include tilt sensors.
ECG Sensor
[0075] The CPR assist device may include an ECG sensor to detect
the heart rate of the patient and this information may be provided
to the performer. The ECG sensor may include at least two
electrodes through which the patient's ECG is detected. The ECG
sensor may also include a ground electrode. Where two electrodes
are used in a CPR assist glove, the electrodes may be placed on the
tips or bases of two opposing fingers or on the palm of the hand.
Only two electrodes may be required to measure non-specific ECG
data, such as heart rate and QRS complex peaks, although additional
electrodes may be used for recording other physiological data.
[0076] In an example, the ECG sensor may be fairly small and
compact, to reduce the space it requires on the device. One example
is the MSOP-8 package. The sensor may include an amplifier to
amplify the signal from the electrodes, for example where the
sensed physiological signal is of small amplitude. Other signal
processing, such as filtering or noise reduction, may be included
in the sensor. The amplifier may be a combination of an
instrumentation amplifier and a dual op-amp. Other configurations
for amplifying the sensor signal may be used as suitable to the
application.
[0077] Filtering of the amplified signal may not be required if the
desired ECG data is detectable from the signal received from the
electrodes, for example, where the QRS complex of a typical ECG
waveform is distinguishable and the effect of noise is negligible.
Cable artifact that may contribute noise to the signal may be
reduced by keeping the electrodes fixed in place on the glove, and
keeping any wires attached to the electrodes short and also fixed
in place.
[0078] An additional op-amp may be used to prevent baseline
wandering. This may allow for the signal to maintain a constant DC
level, regardless of the impedance being presented to the
electrodes by the skin of the patient, which may vary over time.
This additional op-amp may be used as an analog integrator to
integrate the DC signal from the instrumentation amplifier, and
this may be fed back to the instrumentation amplifier. This may
prevent wavy traces from occurring in the ECG waveform, which may
simplify programming of a heart rate detector by keeping threshold
levels relatively steady.
[0079] The electrodes may be standard electrodes, which may be
gel-based or dry, clip-ons, reusable or disposable, or other common
electrode types. In the case of dry electrodes, a conductive
metallic strip positioned in the fingers of the glove may serve as
the sensor area. In the case of disposable gel clip-on electrodes,
the electrodes may be clipped onto the fingers of the glove and the
adhesive pulled back to expose the gel. This configuration may be
suitable when the patient's chest is exposed. The adhesive
electrodes may adhere to the patient's chest, marking the correct
hand position for CPR so that this correct position only has to be
found once. The correct hand position for CPR may be instructed by
the CPR assist device, for example via a visual or audio feedback.
The connection between the electrodes and the fingers on the glove
may be a simple conductive link established by simply pressing the
fingers down against the electrodes.
[0080] An example of the software to interpret the ECG sensor data
is now described. The heart rate may be calculated from the ECG
signal using a simple algorithm. An ECG reading is taken for a
pre-determined length of time, such as six seconds, and the number
of heart beats that occur during that time are counted. The
performer may be instructed by the device not to move the
electrodes until the pre-determined length of time has passed. The
performer may be provided with feedback (e.g., a visual or audio
countdown) as to how much longer the electrodes have to be in
place. The number of beats during that length of time is multiplied
by a suitable factor to calculate the number of heart beats per
minute (e.g., where the length of time is six seconds, the number
of heart beats detected would be multiplied by ten). The calculated
heart rate may be communicated to the performer, for example
through a visual display. A heart beat may be detected using
threshold values to detect the presence of a QRS complex.
[0081] In an example, analog data from the ECG sensor may be
continuously fed in to the processing unit at a fixed rated, for
example at 16 Khz. Occurrences of the QRS complex in such a signal
may be detected whenever the signal crosses a certain threshold
value. Implementations of QRS detection software would be known by
persons skilled in the art.
[0082] In some aspects, to eliminate transient data from being
collected by the processing unit, the performer may be given a few
moments to place the electrodes on the patient. This may simplify
the software for recognizing when the electrodes have been placed
and a proper ECG signal is being received. In some aspects, the
device may be able to recognize proper placement of the electrodes
or a proper ECG signal, so that a fixed time delay to allow for
placing of the electrodes may be not necessary.
Other Sensors
[0083] Other sensors may be included in the CPR assist device. One
possible sensor is an ultrasonic sensor, which may be useable as a
position sensor. This sensor may emit a high frequency ultrasonic
pulse with an attenuation and reflection time that can be measured.
The ultrasonic reflectance changes as the density of tissue changes
from soft tissue to bone. Using this data, the correct position of
the performer's hands can be determined, and the performer may be
instructed or guided to accurately position his or her hands over
the patient's sternum.
[0084] Another type of sensor may be a separate sensor for
compression angle. As described previously with regards to the
accelerometer, a compression angle sensor may be implemented using
an accelerometer. Another possible implementation of a compression
angle sensor is using a tilt sensor. A tilt sensor may include a
simple switch that activates when an arm on the sensor is lifted to
a certain angle, or when a sliding mechanism slides down when
lifted to a certain angle and completes an electrical connection.
In the case of the CPR assist glove, such a sensor may be embedded
in the wrist portion to monitor the angle of compression.
Compression angle may be one element to be considered in performing
proper CPR. Currently established CPR guidelines direct the CPR
performer's hands to be locked together and the arms to be
perpendicular to the victim's chest. The proper compression angle
may help to achieve maximum transfer of force. The proper
compression angle may also reduce strain and exhaustion for the CPR
performer.
[0085] Yet another type of sensor may be a body type sensor. By
body type is meant the size, fat-to-muscle ratio, body mass index,
or any other common measurement of body shape or size known in the
art. The body type sensor may use ultrasonic or impedance sensors
to determine the patient's body type. An ultrasonic sensor may
determine the chest depth of the patent by determining the distance
from the sensor on the CPR assist device to the ground below the
patient. An impedance sensor may determine the body fat ratio of a
patient by measuring the patient's body impedance between two
electrodes. Other methods and sensors for determining body type may
also be used. Alternatively or in addition, the CPR assist device
may allow the performer to manually select the patient's body type.
By having information on the patient's body type, the CPR assist
device may provide more suitable CPR instructions to the performer
(e.g., deeper compression depth for a large patient or shallower
compression depth for a smaller patient). Thus, the CPR assist
device may be adaptable for any body size from infant to large
adult.
[0086] Other physiological sensors are possible, including oximetry
sensors which measure oxygen levels in the patient's blood, and
body temperature sensors. As an example, an oximetry sensor may
measure oxygenation of the patient's blood by transmitting light of
two different wavelengths (e.g., red and infrared) through the
patient's skin. Light reflected from the patient may be detected by
the sensor, and oxygenation of the blood may be determined based on
the relative reflectance and absorbance of the two wavelengths.
Information on the oxygenation of the patient's blood may be
analyzed to determine whether the patient requires artificial
respiration, and the CPR assist device may provide feedback to the
CPR performer accordingly. The oximetry sensor may also be used to
determine the patient's heart rate instead of using the ECG sensor,
based on sensing the pulsatile component of blood flow in the
patient.
[0087] The CPR assist device may also have a sensor to allow the
device to turn on automatically when a CPR performer wears the
device. This may be a capacitive sensor connected to the on-switch
that is able to determine whether the device is being worn. This
may simplify use of the device by forgoing the need to activate the
device, and may speed up the CPR process. An example of a
capacitive sensor suitable for this application is the QProx
QT100.TM. one-touch sensor. The sensor is capable of sensing the
change in capacitance from a nearby electrode. In the case of a CPR
assist glove, this sensor may be implemented by embedding an
electrode material (e.g., thin and flexible indium tin oxide) into
the inside of the glove. When the CPR performer's hand is inserted
into the glove, the hand changes the capacitance from the
electrode, which is sensed by the capacitive sensor. The capacitive
sensor may be able to detect changes through materials, for example
if the performer is wearing a latex glove. The turn-on feature of
the capacitive sensor may be fail-safe, that is if the capacitive
sensor deactivates in error, the CPR assist device may not
automatically turn off, and a manual deactivation may be required
after the device is activated. Other methods and sensors for
triggering automatic activation of the device may be used.
[0088] The sensors have been described as collecting relevant CPR
data. However, the sensors may also be used to detect the
occurrence of an event. By "event" is meant a specific step or
stage in the CPR procedure. For example, the device may detect when
the CPR performer is ready to initiate chest compressions by using
a compression angle sensor to determine when the performer's arms
are at the correct angle (e.g., perpendicular to the patient's
chest), or the device may detect when the performer's hands are on
the patient's chest using pressure sensors. Different feedback for
each step in CPR may be provided to the performer based on the
detection of such events.
Processing Unit
[0089] The processing unit may contain the instructions for data
acquisition and analysis of a sensed parameter. Furthermore, the
processing unit may send out instructions and/or data to the other
components, such as the sensors and the feedback component.
[0090] The processing unit may be able to handle analog data, which
may be desirable in cases where some sensor data are analog. In
some aspects, the processing unit may have available analog to
digital converting inputs. The processing unit may also have the
ability to time the duration of certain events. When calculating
pulse width, such as in the case of the accelerometer, or heart
rate, such as in the case of the ECG sensor, a timer in the
processing unit may be used in the data acquisition process. The
computations being performed on incoming data are typically not
mathematically rigorous, and consequently, an 8-bit microcontroller
with floating point arithmetic may be sufficient for use as the
processing unit. Where data may be transmitted or received, the
processing unit may be capable of transmitting and receiving data.
Such transmission and reception may be wired or may be carried out
wirelessly, and the processing unit may be selected to enable such
functions. The processing unit may allow the direct transmission of
asynchronous data from the transmitting board to a host receiving
station or other separate computing device. In some aspects, the
processing unit may send and receive data to a separate
transmission/reception module that coordinates this
communication.
[0091] In an example, the processing unit may be a microcontroller
such as the ATMEGA32 AVR 8 bit RISC processor, the ATMEGA128
processor from Atmel, or the MSP430 series microcontrollers from
Texas Instruments. In these example processing units, the
integration of timers and analog to digital converters on the
controller may allow for data collection and analysis with few
external components. Analog signals may be connected directly to
port pins and digital signals may be timed with any of the three
onboard timers.
[0092] The processing unit may also have a long-term memory
component. This memory may be used for storage of CPR parameters
for later download and analysis. In this way, the processing unit
may be used as a "blackbox" for recording medical and CPR data
during resuscitation or training. In the example processing units
described above, the microcontrollers may include SRAM and/or
EEPROM useable for this purpose. The memory component may also be
separate from the processing unit, for example as a removable Flash
memory. The memory may also be external, for example as a removable
memory card or a micro SD card. Having a removable memory may make
it easier for data gathered during a CPR session to be downloaded
for analysis.
[0093] In some aspects, the processing unit may enable the user to
download updated software and various simulation models into the
CPR assist device. This may allow the device to be adaptable to
performing CPR in different situations or on different types of
patients. The processing unit may have a data port to enable wired
downloading, or downloading may be done wirelessly.
[0094] In some aspects, the processing unit may be programmable by
connecting the device to a separate computing device. In some
aspects, the processing unit may only be programmable by the
manufacturer, so that average performers cannot accidentally change
the operation of the CPR assist device.
Power Source
[0095] The CPR assist device may be adapted to be connected to a
power source. The CPR assist device may include its own power
source contained in the wearable article, which may increase the
ease of use of the device. This power source may be in the form of
a battery or a rechargeable cell. In other embodiments, the CPR
assist device may include a power source connector that is to be
connected to an external power source, such as a wall socket or an
external battery. This may be suitable where the CPR assist device
is part of a larger emergency kit. The CPR device may also be
adapted to be connected to a power supply in a base unit, which in
turn may be connected to an external power source.
[0096] In some aspects where the CPR assist device is powered by
rechargeable batteries, the device may be plugged directly into a
wall, a computer, a car jack, or a similar power source to be
charged. The device may have low power consumption and the
batteries may be designed to last long periods of time. In some
aspects, if battery level is low, an audible and/or visual (e.g., a
light) signal may be emitted to warn the performer.
[0097] Using a smaller battery may enhance wearability or ease of
use of the CPR assist device. In an example, a one-cell lithium
polymer battery may be used, which provides small battery size and
high energy density. A DC/DC converter boost may be used to
increase the nominal voltage of the battery to a desired operating
voltage for the device. Other possible power supplies may be
adapted to the device, as would be known to a person skilled in the
art.
Feedback Component
[0098] The feedback component may provide the performer with raw
data from the sensors or processed data from the processing unit.
This feedback may be provided to the performer in a variety of
ways, such as visual, audio or tactile. In some aspects, the
feedback component of the CPR assist device may provide the
performer with visual feedback. FIG. 11 shows two examples of
visual feedback that may be provided to the performer. In screen
50, the performer may be instructed to place his or her hand in
position to check for a patient's pulse, to determine if CPR is
necessary. In screen 52, the performer may be instructed to
position his or her hands over the patient's sternum at the start
of the CPR procedure.
[0099] Feedback data may be displayed on a screen, such as an LCD
screen directly embedded into the CPR assist device. There may be
more than one feedback component on the device (e.g., two screens
or a screen and an audio tone), which may provide different
feedback information to the CPR performer, or may allow the
performer to receive the same information in different forms. The
feedback component may be provided in a separate base unit to be
used with the device. In some aspects, the data is transmitted to a
separate computing device, such as a personal computer or a
portable wireless device for display. This transmission may be done
wirelessly or may be wired.
[0100] In an example, a 40.times.2 character LCD display may be
used to display output information. The specific model for this
example may be TM402CDAU6. The display may be tethered to the CPR
assist device rather than being embedded in the device. This may be
desirable, for example, where the device is in the form of a glove
and the display is a large LCD screen that would not fit
comfortably on the glove.
[0101] A graphical LCD with color support may be used in some
aspects. A graphical LCD may allow for display of pictures, which
may provide visual CPR instructions. Also, such an LCD may be able
to display the ECG signal in its entirety, rather than text-based
information. The LCD display may be capable of providing color
displays and/or text displays. Other suitable display devices would
be known to a person skilled in the art.
[0102] In some aspects, feedback may be provided using a separate
computing device, such as a laptop, a personal computer, portable
device, or a base unit. A computer may provide a larger viewing
screen, ample processing power and storage and may aid in data
analysis and transmission. A computer software package may be used
on the computer to interact with the CPR assist device. Such a
software package may be used for independent training of a single
CPR performer, or for training a group of performers. The software
package may be capable of receiving and/or analyzing data from
multiple CPR assist devices at one time.
[0103] In some aspects, an audible feedback may be provided. This
feedback may be in the form of voice commands so that the performer
does not have to read the display. The audio feedback may include a
piezo element that emits a sound every time a compression should be
performed. This sound may enable the performer to maintain an
efficient and accurate rhythm. Methods of providing rhythmic
feedback may include any means of generating a tone, for example a
tone generator, a buzzer, or a piezo element.
[0104] The audio feedback may also be in the form of audio
instructions which may be in addition to or in place of visual
instructions to the performer. Audible cues such as "Compress
Faster" or "Compress Deeper" may be provided in real-time to guide
the performer through the CPR procedure. Such audio feedback may be
conveyed via a speaker (e.g., a magnetic speaker or a piezo
speaker) and possibly an amplifier on the CPR assist device. The
speaker and/or amplifier may be thin so that it is not cumbersome,
which may be desirable where these components are provided on the
device. Specific audio cues may be stored in the processing unit in
the form of audio files.
[0105] Other types of feedback may be implemented, such as tactile
feedback (e.g., a small vibration), which may be used to control
the rate of compression. The CPR assist device may also have a
combination of different feedback types to provide a wider range of
information to the performer. Other types of feedback may be given
to the user (e.g., if the compression depth is to shallow or deep,
or if too much or too little force is being used), and this
feedback may be visual, audio, or tactile. The type of feedback may
be different depending on the information being conveyed, and the
feedback type may be selectable by the performer.
Wireless Transmission
[0106] In some aspects, the CPR assist device may be capable of
transmitting data wirelessly. The CPR assist device may also be
capable of receiving data or instructions wirelessly from a
separate computing device.
[0107] In some aspects, a separate computing device is used, which
may be a separate base unit dedicated to the CPR assist device. The
separate computing device may receive data from the CPR assist
device, and may contain a visual display, such as a graphic LCD,
that may be used to display instructions and data relevant to CPR.
To facilitate the link between the transmitting and receiving ends,
a wireless link may be established, or the transmission and
reception may be done by wired means.
[0108] In an example, the transmitter/receiver set being used may
be the TX-433 series from Linx Technologies. These transmitters can
transmit over a long distance (e.g., up to 3000 feet) and at
reasonably high speeds (e.g., 10 kbps). No external components may
be required for this transmitter and receiver, which may further
decrease board size. The transmitter may be connected to an
antenna, such as a 1/4 whip antenna or a low profile ceramic
antenna, to further enhance the quality of the wireless link. The
antenna may be kept small so as to minimize the overall size of the
system. The transmitter may be connected directly to the processing
unit so that asynchronous serial data can be fed directly into the
transmitter module.
[0109] A protocol for transmission of data from the device may be a
standard wireless RF protocol. The Bluetooth protocol or other
suitable short-range wireless protocol may be suitable for
transmission of data. The Bluetooth protocol may be desirable since
it would allow communication between the CPR assist device and
other wireless devices using this protocol, such as cellular
telephones, personal digital assistants, data phones, or similar
devices.
[0110] In some aspects, most of the data analysis may occur at a
separate computing device such as a dedicated base unit. This may
minimize the number of components (and hence board size) on the CPR
assist device. The separate computing device may contain a
processing unit for carrying out data analysis, and may also have a
speaker module for voice commands, a visual display for display of
data and instructions, and an external memory (e.g., an SD card or
a Compact Flash card) for data storage and retrieval. This memory
may be used to log the events of a CPR training session, test, or
real life medical emergency. The data may also be sent directly
from the CPR assist device to a separate computing device. This
data may later be downloaded and analyzed to assess the performer's
technique during the CPR event. Software may be available for
personal computing systems so that the CPR assist device may be run
on a standard home computer instead of a specialized base unit.
Software Algorithm
[0111] The CPR assist device implements a software algorithm in the
processing unit to assist the performer in performing CPR. This
algorithm guides the performer in performing CPR, and may be based
on medically established guidelines for performing CPR. An example
of an established guideline for performing CPR is as follows:
[0112] 1. Call 911
[0113] 2. Check the victim for unresponsiveness. If there is no
response, Call 911 and return to the victim. In most locations the
emergency dispatcher can assist the CPR performer with CPR
instructions
[0114] 3. Administer Breaths
[0115] 4. Tilt the head back and listen for breathing. If not
breathing normally, the performer should pinch nose and cover the
mouth with his or her own and blow until the patient's chest rises.
Give 2 breaths. Each breath should take 1 second
[0116] 5. Chest Compressions
[0117] 6. If the victim is still not breathing normally, coughing
or moving, begin chest compressions. Push down on the chest 4 to 5
cm 30 times right between the nipples. Pump at the rate of 100
pumps per minute, faster than once per second.
[0118] In an example, the software algorithm instructs the
performer to carry out a CPR procedure as follows:
[0119] 1. Attempt to get the patient's pulse and instruct performer
to check if the patient is breathing.
[0120] 2. If the patient's heart rate is detected and/or the
patient is breathing, instruct the performer that CPR is not
required.
[0121] 3. If the patient's heart rate is not detected and the
patient is not breathing, instruct the performer to begin
compressions.
[0122] 4. As compressions occur, compression force and compression
depth data is gathered via the respective sensors on the CPR assist
device. Force data may be displayed as visual feedback to the
performer as compressions are given.
[0123] 5. After administering a predetermined number of
compressions, the average compression depth may be displayed. The
performer may be instructed to give two breaths and check the
patient's pulse via a ECG sensor.
[0124] 6. If the patient's heart rate is detected, return to step
2, otherwise return to step 3.
[0125] The CPR assist device may communicate with a separate
computing device that may also carry out analysis of a sensed
parameter, or may store data from the device for later retrieval
and/or analysis.
[0126] The CPR assist device may be adaptable to specific emergency
scenarios. Software related to specific emergencies may be easily
downloaded into the device. Such download may be done by a wired
connection or wirelessly. Provision and downloading of new software
may be limited to certain authorities, to prevent tampering.
Depending on the specific situation, the device may instruct the
performer on the proper protocol for that event. For example, the
instruction set in the case of a drowning may be different then the
instruction set in the case of a heart attack or the protocol for
an infant may differ from that for an adult.
[0127] Furthermore, in training mode, various simulations may be
run while using the CPR assist device. These simulations may
provide CPR training for a multitude of unique situations. In some
embodiments, the device may include a link to a computing device in
which a simulation can be run. The device may transmit to the
computing device over a wireless link, such as via radiofrequency
(RF), Bluetooth or any other means of communication without wires.
Such training may take place over a communication network, such as
the Internet, to allow for online independent learning.
[0128] Simulations may be real life scenarios with real life
variables and the device may measure whether the individual being
trained is responding correctly. These simulations may be software
based and graphically oriented. As CPR guidelines are updated, the
CPR assist device may also be updated to reflect changes. A
programming interface may be provided in the device to enable
download and installation of new guidelines, simulations, and/or
instructions. Such downloading may take place over a communication
network, such as the Internet.
Base Unit
[0129] In some aspects, the CPR assist device may be provided as
part of a system, which includes the CPR assist device and a base
unit. The base unit may be in the form of a container for the CPR
assist device. In some aspects, the base unit may be suitable for
defibrillation, such as a defibrillator. As shown in FIG. 12, the
base unit 80 may communicate with the device 82 wirelessly, and
this communication may be facilitated by transmission/receiver
modules 84, 86 as shown or by antennae (not shown) included on the
base unit and/or the device. Such transmission/receiver modules or
antennae may also allow the system to establish a communication
link with medical authorities. For example, the base unit may be
capable of establishing a landline communication link with 911. In
another example, the base unit may be capable of establishing a
wireless cellular link with 911. The communication as described
above may also be by wired means.
[0130] The system may also be equipped with a positioning system
such as a Global Positioning System (GPS) so the location of a CPR
emergency may be communicated to a medical authority. This
communication may take place automatically when the system is
activated for performing CPR. In the case where the base unit is
not intended to be moved, the location of the system may be fixed
and this fixed location may be communicated to a medical authority.
The location may also be communicated verbally by the CPR
performer, for example through a microphone provided on the device
or the base unit.
[0131] In some aspects, the feedback component may be provided on
the base unit in addition to or alternative to being on the device.
This may be in the form of an audio speaker on the base unit or a
larger visual display on the base unit. Where the base unit is a
container, the feedback component may be a visual display on the
cover. The container may also include a processing unit in addition
to or as an alternative to the processing unit on the device. The
processing unit provided on the container may be larger and provide
greater processor power than the processing unit on the device. The
base unit may also provide a power source for the device. The
feedback component and/or the processing unit in the base unit may
perform the same tasks as discussed above in relation to the same
components being provided on the CPR assist device. By providing
some or all of the feedback components on the base unit instead of
on the CPR assist device, the battery life of the power supply on
the device may be extended.
[0132] The base unit may be useable for defibrillation. For
example, the base unit may include defibrillator pads or be part of
a defibrillator. In this case, the instructions and feedback
provided by the system may include instructions for the CPR
performer to also perform defibrillation on the patient.
[0133] The base unit may be fixed in location or may be mobile.
Where the base unit is fixed in location, the CPR assist device is
mobile and removable from the base unit, and the device may be free
of connections to the base unit, to increase the ease of use of the
device. Where the base unit is mobile, it may be mounted or
connected to an external power source when not in use, for charging
a rechargeable power supply in the system. The base unit may be
easily portable so it can be brought to the patient's location.
[0134] Where the base unit is in the form of a container, it may be
used as a first aid kit container. In addition to the CPR assist
device, the base unit may container other first aid supplies, such
as bandages and antiseptic.
Applications
[0135] The CPR assist device and/or the system may be used in at
least the following scenarios: in simulation-based training of
individuals, in maintaining CPR quality through testing, and in
real life emergencies. These uses will be described in greater
detail below.
[0136] In one example where the CPR assist device is used for
training, the CPR assist device may be worn by the person
performing the CPR or may be placed on a training device, such as a
CPR mannequin. Once the CPR assist device is properly placed, the
performer may proceed to perform CPR unhindered. The CPR assist
device may guide the performer on the proper technique and timing
of the phases of the CPR routine, for example through a display on
the CPR assist device, a separate computing device, the base unit,
or through other feedback means (e.g., audio feedback). In addition
to the instructions being conveyed to the performer, there may also
be provided additional data such as how fast the performer is
performing the compressions, how deep each compression is, what
angle each compression is at, what the heart rate of the patient
is, and how much force is being applied during compression. The
information and the type of feedback presented to the performer may
be selected by the performer, and may depend on the sensors
incorporated into the CPR assist device. After a training session,
the data may be downloaded from the CPR assist device to a separate
computing device or database, to a memory on the base unit, or
stored on a memory in the CPR assist device for further analysis.
The CPR assist device may allow individuals to train themselves or
be trained with minimal supervision.
[0137] The CPR assist device and/or system may be used for online
training as well. A separate computing device or the base unit may
communicate with the device in order to receive quantitative data
in real-time to assess a performer's CPR proficiency. The device or
the base unit may communicate wirelessly (e.g., using Bluetooth) or
through a wired connection (e.g., a USB port) with an external
computing device, which may be connected to a communication
network, such as the Internet. Medical personnel or other suitable
authorities may then access the data online, or an online service
may be used to assess a performer's abilities in CPR and certify
him or her accordingly.
[0138] In the case of testing, an individual may wear the CPR
assist device or put the device on a mannequin and perform a round
of CPR. After completion of a test, the data may be analyzed to
determined if the CPR was corrected performed. This analysis may be
performed by a suitable authority, or by the device or base unit.
In this way, the CPR assist device may provide an objective,
standardized measure of CPR quality. Such testing may take place
over a communication network, such as the Internet. In this case,
data from the CPR assist device may be provided over the
communication network to a suitable authority for analysis, such as
a suitable testing service.
[0139] In the case of real emergencies, the CPR assist device may
be worn by a CPR performer during administration of CPR or may be
put on the patient. The device may guide an individual through each
phase of CPR. Furthermore, data feedback may be provided to the
performer in real-time so that CPR may be performed effectively and
efficiently. The device may be fairly small and portable, so as to
be easily stored in first aid kits, pool houses, homes, community
centers, restaurants, malls or any other location where it may be
needed. In the case where the CPR assist device is in the form of a
glove, it may be no larger than a standard glove and may be taken
on trips, hikes, or carried in a purse or backpack.
[0140] The CPR assist device, when in the form of a wearable glove,
may be useful in conjunction with a defibrillator, and the
defibrillator may be the base unit to be used with the device. It
may provide insulation between the performer and the patient, hence
speeding up the time for defibrillation by allowing measurement of
the patient's heart rhythm without interference while CPR is being
performed. CPR may increase the effectiveness of
defibrillation.
[0141] FIG. 13 illustrates an example of how the CPR assist device
may be used to aid a CPR performer during a CPR procedure.
[0142] At a step 100, the CPR assist device is activated. This may
be an automatic activation triggered by the device being worn,
either by the CPR performer or by the patient. The software may
automatically run and initiate the instructions for performing
CPR.
[0143] At a step 102, the CPR performer is instructed to position
the device for checking the patient's pulse. This instruction may
be conveyed to the CPR performer through the at least one feedback
component, for example a visual feedback and/or an audio feedback.
The device then senses whether there is a heart rate.
[0144] At a step 104, a heart rate is present, so CPR is not
required. This may be conveyed to the performer, and the CPR assist
device may be deactivated.
[0145] At a step 106, a heart rate is not detected. This may be
conveyed to the performer, and the performer may be instructed to
carry out CPR on the patient.
[0146] At a step 108, the performer is instructed to place hands
over the patient's sternum in preparation for performing CPR. The
device may provide visual and/or audio feedback to aid the
performer to provide chest compressions at a desired rate. For
example, the device may produce audio beeps at 100 Hz.
[0147] At a step 110, the device detects each chest compression,
for example via a pressure sensor. The device may instruct the
performer to perform a predetermined number of compressions in a
cycle (e.g., 30 compressions). The number of compressions is
recorded, and the rate and depth of each compression is also
measured and recorded. The device may provide the performer with
visual and/or audio feedback about the compressions, for example
there may be a visual display of how many compressions remain in a
cycle. There may also be feedback, for example an audio cue, if the
compressions are too slow or fast, or too deep or shallow. There
may additionally be an audio cue when there is a certain number of
compressions remaining to in the cycle.
[0148] After the predetermined number of compressions have been
completed in a cycle, at a step 112 the performer is provided with
feedback about the average compression depth and rate for the
cycle. This may be through a visual display. The performer is then
instructed to give a predetermined number of breaths (e.g., two
breaths) to the patient to complete the cycle.
[0149] After the completion of breaths, the process returns to step
108 and the performer is instructed to repeat the cycle. This
continues until help arrives (e.g., medical authorities or an
ambulance) or until the patient is resuscitated.
[0150] FIG. 14 illustrates an example of how a CPR assist system
having a CPR assist device and a base unit may be used to aid a CPR
performer in performing CPR.
[0151] At a step 120, the CPR assist device and the base unit is
brought to the patient's location. The CPR assist device may be
contained in the base unit, for example where the CPR assist device
is in the form of a glove and the base unit is a container for the
glove.
[0152] At a step 122, the CPR assist device is activated. This
maybe triggered by the device being worn by the performer or the
patient. This may also be triggered by removing the device from the
base unit. Activation of the device may automatically initiate the
software to being instructions for performing CPR.
[0153] At a step 124, a communication link is established with the
authorities (e.g., to 911). This may be automatically triggered
when the device is activated. The patient's location may be
automatically communicated to the authorities. This may be
communicated automatically by the system (e.g., where the device or
base unit is equipped with a locating system such as GPS) or the
CPR performer may be prompted to communication the location
verbally via a microphone on the device or base unit.
[0154] At a step 126, the performer is guided to perform CPR, as
described above with reference to FIG. 13. The performer may be
provided with feedback in the form of instructions or corrections
where the CPR procedure is incorrect. Such feedback may be provided
through the device and/or the base unit.
[0155] At a step 128, the base unit may be useable for
defibrillation, for example where it is equipped with
defibrillation pads.
[0156] If the base unit is useable for defibrillation, then at a
step 130, the CPR performer is instructed to defibrillate the
patient. The performer may be provided with instructions for
placing defibrillation pads on the patient and may be guided
through how to perform defibrillation. After defibrillation, the
process continues to a step 132.
[0157] If the base unit is not useable for defibrillation, the
process continues directly to step 132. At step 132, the performer
is instructed to continue carrying out CPR on the patient until
help arrives or until the patient is resuscitated.
[0158] As discussed above, the CPR assist device may be adaptable
to different patients and different situations. The sensors have
been discussed as being in certain positions on the CPR assist
device, but these positions may be modified as necessary to obtain
the desired sensing function. The positions of the sensors may be
modified by the CPR performer so as to suit the specific
application, or the sensors may be interchangeable. The analysis
and feedback program in the processing unit may be updated as
necessary. For example, it may be that compressions are more
effective when performed on the patient's abdomen rather than the
chest. The CPR assist device may be updated to provide this
information to the CPR performer.
[0159] The CPR assist device and system is in no way limited to the
specific embodiments described. Any device for the training of
individuals in CPR, testing of individuals in their ability to
perform CPR or for use in emergencies and that is to be wearable by
the performer or the patient is covered by this application. The
scope of this application is not to be limited by the listing of
specific components. Any electrical or computing components may be
used to satisfy the goal of the invention.
* * * * *