U.S. patent application number 10/423567 was filed with the patent office on 2005-03-10 for reconfigurable defibrillator battery module and method.
Invention is credited to Kavounas, Gregory T..
Application Number | 20050052154 10/423567 |
Document ID | / |
Family ID | 34228288 |
Filed Date | 2005-03-10 |
United States Patent
Application |
20050052154 |
Kind Code |
A1 |
Kavounas, Gregory T. |
March 10, 2005 |
RECONFIGURABLE DEFIBRILLATOR BATTERY MODULE AND METHOD
Abstract
Methods and apparatus are provided for portable medical devices
such as defibrillators having different charging and operating
voltages. The apparatus comprises a connection for receiving DC
input voltage VIN, an energy storage device (e.g., a capacitor), a
battery having at least two cells therein coupled to the connection
and the capacitor, and switches to selectively reconfigure the
battery cells so as to: (i) charge from VIN, and (ii) discharge to
the capacitor at VOUT>VIN. The method comprises charging the
battery from VIN while its cells are arranged substantially in
parallel, then reconfiguring the switches to arrange some of the
charged cells substantially in series to give VOUT>VIN, and then
charging the capacitor therefrom. The cells are thereafter
reconfigured back to the parallel arrangement ready to be recharged
from VIN. Isolation switches are conveniently provided to isolate
the battery from VIN while charging the capacitor.
Inventors: |
Kavounas, Gregory T.;
(Kirkland, WA) |
Correspondence
Address: |
INGRASSIA FISHER & LORENZ, P.C.
7150 E. CAMELBACK, STE. 325
SCOTTSDALE
AZ
85251
US
|
Family ID: |
34228288 |
Appl. No.: |
10/423567 |
Filed: |
April 24, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60409948 |
Sep 11, 2002 |
|
|
|
Current U.S.
Class: |
320/116 |
Current CPC
Class: |
H02J 7/345 20130101;
H02J 7/0024 20130101 |
Class at
Publication: |
320/116 |
International
Class: |
H02J 007/00 |
Claims
1. A medical device, comprising: a connection adapted to receive
input energy of a first voltage; an energy storage device; a
battery module coupled to the connection and the energy storage
device and having at least two battery cells therein; and a
reconfiguration switch for selectively coupling the at least two
battery cells to charge from the first voltage and discharge to the
energy storage device at a second voltage larger than the first
voltage.
2. The medical device of claim 1, wherein the two cells are coupled
in parallel to charge from the first voltage and coupled in series
to discharge to the energy storage device.
3. The medical device of claim 1, further comprising a line
operated AC to DC converter for providing the first voltage.
4. The medical device of claim 1 farther comprising an isolation
switch between the connection and the battery module, for coupling
and uncoupling the battery module to the first voltage.
5. The medical device of claim 4 wherein the isolation switch is
responsive to an isolation signal, and the reconfiguration switch
is responsive to a reconfiguration signal.
6. The medical device of claim 4 wherein the isolation switch and
the reconfiguration switch are responsive to, except for polarity,
substantially the same signal.
7. The medical device of claim 1, further comprising: (i) an input
energy source for providing the first voltage, the input energy
source comprising a primary battery coupled to the connection, and
(ii) an isolation switch coupled between the connection and the
battery module, wherein the primary battery charges the battery
module selectively depending on a state of the isolation
switch.
8. The medical device of claim 7 wherein the isolation switch is
responsive to an isolation signal and the reconfiguration switch is
responsive to a reconfiguration signal.
9. The medical device of claim 7 wherein the isolation switch and
the reconfiguration switch are responsive to, except for polarity,
substantially the same signal.
10. The medical device of claim 7, further comprising at least a
second isolation switch coupled between the connection and the
battery module, and wherein the primary battery includes at least
two primary battery cells, each able to charge a corresponding one
of the battery cells of the battery module through one of the at
least two isolation switches.
11. The medical device of claim 10 wherein the at least two primary
batty cells are electrically isolated from one another.
12. A defibrillator comprising: a power source connection, a
capacitor, and a reconfigurable battery module charged from the
power source connection dug a first cycle and charging the
capacitor during a second cycle, wherein the battery module
includes a plurality of secondary cells and a plurality of
reconfiguration switches placing interconnections of the secondary
cells in a first configuration during the first cycle and in a
second configuration during the second cycle.
13. The defibrillator of claim 12, wherein the first configuration
couples the secondary cells in parallel and the second
configuration couples at least some of the secondary cells in
series.
14. The defibrillator of claim 12, in which the power source is a
DC battery module.
15. The defibrillator of claim 12, in which the first and second
configurations are different.
16. The defibrillator of claim 12 wherein the plurality of
reconfiguration switches comprises first reconfiguration switches
that couple the secondary cells in substantially parallel
arrangement and second reconfiguration switches that couple at
least some of the secondary switches in substantially series
arrangement.
17. The defibrillator of claim 16, wherein the first and second
reconfiguration switches operate in opposite phases.
18. A method comprising: charging a battery module of a medical
device while cells of the module are in a first interconnection
configuration; then adjusting switches of the medical device to
place the cells in a second interconnection configuration; and then
charging a capacitor of the medical device.
19. The method of claim 18, in which the battery module is charged
from a power source, and further comprising opening an isolation
switch before charging the capacitor to temporarily isolate the
capacitor from the power source.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/409,948, filed Sep. 11, 2002.
[0002] Commonly assigned U.S. patent application Ser. No.
10/035,297 filed Oct. 26, 2001 may be found to be related.
TECHNICAL FIELD OF THE INVENTION
[0003] The present invention generally relates to battery power
sources for portable medical equipment, and more particularly to
power sources for medical devices such as defibrillators and other
equipment having different charging and operating voltages.
BACKGROUND OF THE INVENTION
[0004] Battery operated devices find diverse applications ranging
from small and simple children's toys to sophisticated laptop
computers and large electric powered vehicles. Batteries are also
used in medical devices, such as manual, automatic or semiautomatic
defibrillators. Defibrillators and other medical devices may be
external or implanted in the body. Automatic and semiautomatic
external defibrillators are referred to by the abbreviation "AED"
or "AEDs". External defibrillators are described in U.S. Pat. No.
5,803,927 to Cameron et al., and in European Patent Application EP
0 757 912 A2 to Olson et al. Battery arrangements for use in AEDs
and other portable equipment are described in U.S. Pat. No,
5,314,451 to Mulier, in U.S. patent No. U.S. Pat. No. 6,441,582 to
Powers, in U.S. Pat. No. 6,268,709 to Lee et al., in U.S. Pat. No.
5,741,305 to Vincent et al., in U.S. Pat. No. 6,157,531 to Breyen
et al, in U.S. Patent Application Publication No. US 2002/0138103
to Mulhauser, in European Patent Application EP 1 093 829 A1 to
Muffoletto et al., and in International (PCT) Patent Application
No. WO 96/22811 (PCT/US96/00763) to Kroll et al.
[0005] The battery of a medical device is typically provided in a
module. The module is typically a collection of battery cells. Each
battery cell is provided in a housing, out of which emerge two
electrical contacts. One of the contacts is coupled to an anode
plate and the other to a cathode plate inside the battery cell. An
electrolyte between the anode and the cathode plates permits them
to interact chemically. The anode and the cathode have different
tendencies to gain or lose electrons. This difference in electron
affinity is harnessed in a chemical reaction to accomplish useful
work. The amount of work or energy available depends on the
magnitude of the electron affinity difference and quantity of the
anode and cathode materials available for the chemical reaction.
The difference in affinity is a function of the battery chemistry
of the battery cell.
[0006] FIG. 1 shows typical prior art battery module 10 with
terminals 12, 13 (FIG. 1 is a reproduction of FIG. 2B of U.S. Pat.
No. 6,441,582 B1). Module 10 has M branches with N cells 14 in each
branch. The total output voltage VT of module 10 appearing between
terminals 12, 13 is N*V, where V is the voltage of each cell 14.
There is a current blocking device 16 connected in series with each
of the M parallel strings to prevent a reverse current or charging
condition from another parallel string in battery module 10.
Current blocking device 16 can be a diode with the anode connected
to the positive side of the string being protected and the cathode
connected to positive output 13.
[0007] The prior art suffers from a number of disadvantages and
limitations. For example, with the arrangement shown in FIG. 1, all
cells in module 10 are coupled together. This creates design
constraints, especially when it is desired to minimize degradation
or failure of the module due to failure of one or more of
individual cells 14. Another limitation of the prior art is that
the input voltage needed to charge the battery array must generally
be equal or greater than the output or operating voltage of the
battery array. This creates significant difficulties when the
application requires large output or operating voltages.
[0008] Accordingly, it is desirable to provide an improved means
and method for portable power supplies for medical devices,
especially battery operated medical devices such as defibrillators.
In addition, it is desirable to provide an arrangement wherein the
charging voltage and operating voltage need not be in fixed
relationship, and especially where the charging voltage can be less
than the operating or output voltage. Still further, it is
desirable that the battery arrangement be programmable and
reconfigurable with respect to the interconnection of individual
cells. Furthermore, other desirable features and characteristics of
the present invention will become apparent from the subsequent
detailed description and the appended claims, taken in conjunction
with the accompanying drawings and the foregoing technical field
and background.
BRIEF SUMMARY OF THE INVENTION
[0009] Methods and apparatus are provided for portable medical
devices such as defibrillators having different charging and
operating voltages. The apparatus comprises a connection for
receiving DC input of a first voltage (VIN), an energy storage
device such as a capacitor, a secondary battery having at least two
cells therein coupled to the connection and the energy storage
device, and reconfiguration switches selectively coupling the
battery cells so as to: (i) charge from the first voltage VIN and
(ii) discharge to the energy storage device at a second voltage
VOUT>VIN.
[0010] The method comprises charging the secondary battery from VIN
while the cells are arranged substantially in parallel, then
reconfiguring the switches to arrange the charged cells at least
partly in series to give VOUT>VIN, and then charging the
capacitor therefrom. The cells are then conveniently reconfigured
back to the parallel arrangement ready to be recharged from VIN.
Isolation switches are conveniently provided to isolate the battery
from VIN while charging the energy storage device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and
[0012] FIG. 1 is a simplified electrical circuit diagram of battery
cells forming a battery module according to the prior art;
[0013] FIG. 2 is a simplified electrical schematic block diagram of
a defibrillator according to a first embodiment the present
invention;
[0014] FIGS. 3A and 3B show timing relationships between an
isolation signal (1S) and a reconfiguration signal (RS) of battery
modules according to different embodiments of the present
invention;
[0015] FIG. 4 is a simplified electrical schematic block diagram of
a defibrillator according to a further embodiment the present
invention;
[0016] FIG. 5 shows a simplified schematic electrical circuit of a
portion of a defibrillator according to the present invention,
showing further details;
[0017] FIG. 6A shows a simplified schematic electrical circuit of a
rechargeable battery module portion of a defibrillator, according
to a further embodiment of the present invention and in an
unconfigured state;
[0018] FIG. 6B shows the circuit of FIG. 6A when configured for
being charged;
[0019] FIG. 6C shows the circuit of FIG. 6A when reconfigured for
providing an output to a further charging circuit; and
[0020] FIG. 7 is a flowchart illustrating a method for providing a
rechargeable medical device according to the present invention.
DETAILED DESCRIPTION
[0021] The following detailed description is merely exemplary in
nature, and is not intended to limit the invention or the
application and uses of the invention. Furthermore, there is no
intention to be bound by any expressed or implied theory presented
in the preceding technical field, background, brief summary or the
following detailed description. The present invention provides for
reconfiguring connections of cells of a battery module adapted to
provide power to medical devices, such as for example
defibrillators and AEDs. While the invention is described in the
context of a defibrillator, but this is merely for convenience of
explanation and not intended to be limiting. As used herein, the
word defibrillator(s) and the abbreviation AED(s) are intended to
include other medical devices having different battery charging and
operating voltage requirements.
[0022] FIG. 2 is a simplified electrical schematic block diagram of
defibrillator 100 according to a first embodiment the present
invention. Defibrillator 100 includes AC to DC converter or adapter
110 that conveniently receives power from AC source 90 via leads
92, 94. Adapter 110 converts the incoming AC power to DC power.
Adapter 110 may have one pair of DC outputs, e.g., outputs 107,
108, or multiple pairs of DC outputs (not shown).
[0023] Defibrillator 100 includes rechargeable secondary battery
module 130. Module 130 contains at least two battery cells 131,
133. Importantly, secondary battery module 130 also includes
reconfiguration switch 135 coupling the at least two battery cells
131, 133 in various arrangements. Reconfiguration switch 135 is
preferably responsive to a reconfiguration signal RS provided via
lead 137. Battery cells 131, 133 and reconfiguration switch 135 are
shown only generally in FIG. 2 and their arrangement and
interconnection are described in more detail later. In general,
many battery cells and multiple reconfiguration switches can be
used in module 130 and cells 131, 133 and switch 135 are intended
to be generally representative thereof.
[0024] Defibrillator 100 further includes energy storage component
122, which may include at least one capacitor. When defibrillator
100 is operated, energy storage component 122 supplies an
electrical charge to electrodes 112 and 114 via leads 121, 123 as
is known in the art. In defibrillators, such charge is often
applied to human or animal bodies using electrodes 112, 114 to
restart or stabilize cardiac functions. Defibrillator 100
additionally desirably includes charging circuit 126 coupled
between secondary battery module 130 and energy storage component
122. Circuit 126 receives energy (charge) from module 130 vial
leads 111, 113 and supplies energy to storage component 122 (e.g.,
a capacitor) via leads 115, 117. Circuit 126 conveniently controls
how much of the energy (charge) available in battery module 130 is
transferred to energy storage component 122.
[0025] The function of reconfiguration switch 135 is to rearrange
connections of individual battery cells 131, 133, etc., of
secondary battery module 130 so that a first set of connections is
provided for battery cells 131, 133, etc., while module 130 is
being charged, and a second set of connections is provided for
battery cells 131, 133, etc., while module 130 is supplying energy
to charging circuit 126 via leads 111, 113. As will be subsequently
explained, the at least two cells 131, 133 can be connected in
series or in parallel or a combination thereof, as may be desired
to provide different output voltages to energy storage device 122
and electrodes 112, 114.
[0026] Optional isolation switch 165 is preferably provided in
leads 107, 109 between adapter or converter 110 and secondary
battery module 130. In the case of FIG. 2, secondary battery module
130 is charged from line power source 90 through AC/CD converter
110, but other power supply embodiments can also be used (see for
example FIGS. 4-6). The function of isolation switch 165 is to
isolate secondary battery module 130 from its power source when
secondary battery module 130 is reconfigured to a different state.
Isolation switch 165 is desirably responsive to isolation signal IS
provided via lead 167.
[0027] FIGS. 3A and 3B show timing relationships between isolation
signal IS and reconfiguration signal RS for defibrillator battery
modules according to different embodiments of the present
invention. FIGS. 3A and 3B show two possible relationships between
isolation signal IS and reconfiguration signal RS. In FIG. 3A,
signal IS is activated at time t1 and signal RS is activated at
time t2>t1. Signal RS remains activated until time t3>t2 when
it is shut off. Signal IS remains activated until time t4>t3
when it is then deactivated. In FIG. 3B the IS and RS are activated
substantially at time t5 and deactivated substantially at time
t6>t5. In FIG. 3B, IS and RS may be the same signal and the
designations of IS or RS is interchangeable.
[0028] Secondary battery module 130 of FIG. 2 can receive energy
(charge) from power source 110 during time span 300 up to time t1
in FIG. 3A or during time span 310 up to time t5 in FIG. 3B (and
after time t4 and t6), and give energy (charge) to charging circuit
126 and energy storage component 122 during time span 320 from t2
to t3 in FIG. 3A and during time span 330 from t5 to t6 in FIG. 3B.
Either arrangement is useful. Persons of skill in the art will
understand that the relative timing, overlap and polarity of the IS
and RS signals will depend upon the exact circuit configuration
used. What is important is that the isolation and reconfiguration
switches operate in such a way that the cells of secondary battery
module 130 or equivalent are not short-circuited during the
reconfiguration process.
[0029] FIG. 4 is a simplified electrical schematic block diagram of
defibrillator or AED 400 according to a further embodiment the
present invention. Referring now to FIG. 4, defibrillator 400 has
many components analogous to those of defibrillator 100. Like
components are identified by the same reference numbers in the
various figures. Accordingly, a description of such similar
components is omitted here and incorporated by reference to FIG. 2.
Defibrillator 400 of FIG. 4 differs from defibrillator 100 of FIG.
2 through use of primary battery module 420 and receptacle 410
instead of AC power source 90 and AC/DC converter 110. Primary
battery module 420, also referred to as a "charging pack" is
inserted in receptacle 410 to provide primary power to charge
defibrillator 400, instead of power sources 90, 110 of
defibrillator 100 of FIG. 2. Module 420 can be conveniently of the
type illustrated by battery module 10 of FIG. 1. When module 420 is
inserted in receptacle 410, it becomes electrically coupled to
rechargeable secondary battery module 130 via isolation switch
165.
[0030] FIG. 5 illustrates simplified electrical circuit 500 of a
portion of a defibrillator according to the present invention,
showing further details. Referring to FIG. 5, circuit 500
illustrates how components 420, 165, and 130 of the general
embodiment of FIG. 4 provide the desired functions. Primary module
420' of FIG. 5 is analogous to module 420 of FIG. 4 and includes
two primary battery cells 522, 524. While only two primary battery
cells 522, 524 are shown in FIG. 5, persons of skill in the art
will understand based on the description herein that is by way of
example and not of limitation. Any number of cells equal or greater
than two cells can also be used in module 420, 420'. In the circuit
of FIG. 5, cells 522, 524 are not directly connected. They are
electrically isolated by transistor switches 565A, 565B, but that
is not necessary for practicing the present invention. Either
arrangement is useful.
[0031] Secondary module 130' of FIG. 5 is analogous to secondary
module 130 of FIGS. 2, 4 and includes two secondary cells 532, 534,
analogous to cells 131, 133 of FIGS. 2, 4. While only two cells
532, 534 are shown in circuit 500, this is by way of example and
not of limitation. Larger numbers can also be used. Cells 532, 534
are selectively electrically isolated from each other by transistor
switch 535. Transistor switch 535 thus implements reconfiguration
switch 135, and is controlled by signal RS. In other words,
reconfiguration signal RS controls the interconnections of
secondary cells 532, 534. More than one reconfiguration switch may
be used, wherein opening or closing thereof is provided by one or
more reconfigurations signals to alter the interconnections of
secondary cells 532, 534, etc.
[0032] Secondary module 130' is conveniently electrically isolated
from primary module 420' by transistor switches 565A, 565B.
Transistor switches 565A, 565B implement the function of isolation
switch 165 of FIGS. 2, 4 controlled by signal IS. In circuit 500,
two isolation switches 565A, 565B are conveniently used, both
controlled by signal IS, that is, there is isolation switch 565A
for battery cell 522 and isolation switch 565B for battery cell 524
of primary power source 420'. Using separate isolation switches to
isolate each cell of primary power source 420' is convenient but
not necessary, and one or more of the primary cells need not be
isolated or they may be isolated in groups. In addition,
sub-circuit 580 receives a single control signal input CTL and
outputs isolation signal IS and reconfiguration signal RS. Signals
IS and RS conveniently have the same timing, that is, the timing
configuration shown in FIG. 3B, but are of opposite polarity in
circuit 500 than in FIG. 3B to suit the drive requirements of
transistors 565A, 565B and 535. Persons of skill in the art will
understand that the polarity and timing of the IS and RS signals
produced by module 580 should be such that transistors 565A-B and
535 act in opposite phase, that is, when transistors 565A-B are ON,
transistor 535 is generally OFF and vice versa. The use of
individual isolation switches 565A-B conveniently permits the IS
and RS signals to have substantially the same timing, that is,
corresponding to FIG. 3B. The polarity of the IS, RS signals
depends on the connections and type of transistors employed.
[0033] An advantage of the present invention is in shipping. Module
400, 500 and their associated primary batteries 420, 420' will have
a lower voltage, since cells 131, 133; 522, 524 are not connected
in series while shipping. This may facilitate meeting regulatory
requirements for shipping.
[0034] FIG. 6A shows simplified schematic electrical circuit 600 of
an unconfigured rechargeable battery module portion of an AED or
defibrillator (e.g., of defibrillator 100 or 400 of FIGS. 2, 4),
according to a further embodiment of the present invention. FIG. 6B
shows version 601 of circuit 600 of FIG. 6A when configured for
being charged by VIN and FIG. 6C shows version 602 of circuit 600
of FIG. 6A when reconfigured for providing an output voltage VOUT
via terminals 636, 638 to a further circuit, e.g., to charging
circuit 126 and energy storage module 122 of FIGS. 2, 4 via leads
111, 113 and 115, 117 respectively. In order to avoid unnecessarily
cluttering the drawings and obscure details thereof, signal leads
for actuating switches 632, 634, 665 have been omitted from FIGS.
6A-C. Persons of skill in the art will understand how to provide
such signal leads to control the operation of switches 632, 634,
665 in the manner described herein.
[0035] Referring now to FIGS. 6A-B, power source 620 is provided to
supply energy to circuit 600, 601 during a first charging cycle.
Power source 620 is analogous to power sources 90, 110 of FIG. 2
and/or 420 of FIG. 4. Circuit 600-602 includes secondary battery
module 630 analogous to secondary battery module 130 of FIGS. 2-4.
Secondary battery module 630 includes individual battery cells
630-1, 630-2, 630-3, . . . 630-N, corresponding to cells 131, 133
of FIGS. 2, 4, and reconfiguration switches 632, 634 corresponding
switch 135 of FIGS. 2, 4. While only three individual battery cells
630-1, 630-2, 630-3 are shown in secondary module 630, this is
merely for convenience of explanation and not intended to be
limiting. Any number of cells 630-1 to 630-N can be included. The
choice depends upon the output voltage VOUT desired from secondary
battery module 630. Reconfiguration switches 632, 634 and isolation
switches 665 of circuits 600, 601, 602 are analogous to and
illustrate how reconfiguration switches 135 and isolation switches
165 of FIGS. 2, 4 can be implemented. To obtain higher values of
VOUT from circuits 600-602, additional units 639 containing a
battery cell and associated reconfiguration switches are
cascaded.
[0036] During a first charging cycle, secondary battery module 630
is conveniently configured as in circuit 601 of FIG. 6B with
individual battery cells 630-1 . . . 630-N in parallel. Isolation
switches 665 and reconfiguration switches 632 are closed and
reconfiguration switches 634 are open. Module 630 is charged from
power source 620 and isolated from outputs 636, 638 coupled to
subsequent circuits 126, 122. The voltage required to charge module
630 during the first charging cycle is determined by the charging
voltage V of individual cells 630-1 . . . 630-N. Thus, for the
configuration illustrated in FIGS. 6A-B, the charging voltage
during the first charging cycle can be as small as voltage V of a
single cell. During the first charging cycle, module 630 is
receiving energy (charge) from power source 620 (see FIGS.
3A-B).
[0037] During a second charging cycle, secondary battery module 630
is conveniently configured as in circuit 602 of FIG. 6C with
individual battery cells 630-1 . . . 630-N substantially in series.
Isolation switches 665 and reconfiguration switches 632 are open
and reconfiguration switches 634 are closed. Module 630 is coupled
via outputs 636, 638 to charging circuit 126 and energy storage
module 122 (see FIGS. 2, 4). During the second charging cycle,
module 630 charges energy storage module 122 (e.g., a capacitor)
via charging circuit 126. During the second charging cycle, module
630 is giving energy (charge) to subsequent components 126, 122 of
FIGS. 2, 4 (see also FIGS. 3A-B).
[0038] Persons of skill in the art will understand based on the
explanation herein that reconfiguration switches 632 and 634 in
FIGS. 6A-C generally act in opposite phase, that is: (i) as shown
in circuit 601 of FIG. 6B, when switches 632 are closed then
switches 634 are open, and (ii) as shown in circuit 602 in FIG. 6C,
when switches 634 are closed then switches 632 are open. Thus, the
RS signals that cause reconfiguration from circuit 601 to circuit
602 should be presented in appropriate polarity and timing to
accomplish the proper closing and opening of switches 632, 634,
preferably without overlap. Switches 632 and 634 should not be
closed at the same time since this could short circuit one or more
of battery cells 630-1 . . . 630-N. This can be conveniently
accomplished for example, by using normally closed devices for
switches 632 and normally open devices for switches 634.
Alternatively, when semiconductor switches are used, as illustrated
for example in FIG. 5, then the timing and polarity of the RS
signals to switches 632, 634 depend upon the semiconductor device
type used and their switching properties. For example, the RS
signal to switches 632 (hereafter RS(632)) and the RS signal to
switches 634 (hereafter RS(634)) may differ in polarity and
slightly in timing in order to insure that switches 632 and 634 are
not on at the same time. Persons of skill in the art will
understand how to accomplish this. The IS signal used to actuate
isolation switches 665 is usefully (but not necessarily) coincident
with the RS signal to switches 632 since they are desirably closed
and opened together. Alternatively, switches 632 and 665 can be
driven by the IS signal and switches 634 driven by the RS signal.
Then only one RS signal is needed. It is desirable but not
essential that switches 665 and switches 634 not be closed at the
same time since this would couple power supply 620 directly to
output terminals 636, 638, although this is not precluded.
[0039] Methods of the invention are now described. In general, a
method of the invention is to charge a battery module of a medical
device, such as a defibrillator, while cells of the battery module
are in a first interconnection configuration. Then switches of the
medical device are adjusted to place the cells of the battery
module in a second interconnection configuration. Then a capacitor
of the medical device is charged from the reconfigured cells of the
battery module.
[0040] The battery module is charged from a power source.
Optionally and preferably, an isolation switch between the power
source and the battery module is opened before charging the
capacitor, to temporarily isolate the capacitor from the power
source at least during charging. The isolation switch can be
implemented such that it is closed as a part of the first
configuration.
[0041] The first configuration preferably places the cells of the
battery module in substantially parallel arrangement. That is true
whether at the single cell level, or with multi-cell branches
parallel to each other. The second configuration preferably places
the cells of the battery module in substantially serial
arrangement, by coupling the cells (or branches) in series. The
second configuration results in a higher output voltage from the
battery module than the first configuration. In addition, a third
or further configuration may be implemented to give other output
voltages for purposes of a particular design, etc.
[0042] FIG. 7 is a flowchart illustrating method 700 for operating
a defibrillator or AED containing a reconfigurable battery module,
according to the present invention. Method 700 illustrated in the
flowchart of FIG. 7 may be practiced by using the circuits of FIGS.
2, 4-6. For purposes of explanation and not intended to be
limiting, method 700 is described with reference to FIGS. 4 and
6A-C.
[0043] Beginning with START 702, COUPLING step 710 is performed
wherein primary energy source 620 and secondary battery module 630
are coupled together. Primary energy source 620 is analogous to AC
energy source 90 plus AC/DC converter 110 or to primary battery
module 420. Thus step 710 may be performed by inserting primary
battery module 420 in receptacle 410 or by switching on energy
source 90 and AC/DC converter 110, and/or by closing one or more
isolation switches 165, 665. If battery module 420 (or power supply
90, 110) is already connected, then it is only necessary to close
isolation switches 165, 665.
[0044] In first CHARGING step 720, secondary battery module 630 is
charged using, for example, circuit configuration 602 of FIG. 6B.
This first charging step can be from a primary module (e.g., module
420), or from a line source via an AC to DC adapter (e.g., source
90 and converter 110). In subsequent UNCOUPLING step 730, secondary
battery module 130, 630 is uncoupled from primary power module 420,
620. This may be performed by opening one or more isolation
switches 165, 665, which in turn may be actuated by applying one or
more isolation signals IS. In subsequent RECONFIGURING step 740,
cells 630-1 . . . 630-N of secondary module 630 are reconfigured
from a first configuration of parallel connection (see FIG. 6B)
during the first (input) charging cycle to a second configuration
of series connection (see FIG. 6C) for the second (output) charging
cycle. Reconfiguring is performed by opening and/or closing one or
more of reconfiguration switches 632, 634, that is, changing from
the configuration of circuit 601 to the configuration of circuit
602. This opening and closing may be performed by applying one or
more reconfiguration signals RS to reconfiguration switches 632,
634 (see also FIG. 5).
[0045] In second CHARGING step 750, the energy now available in
secondary module 130, 630 is used to charge energy storage device
122 (e.g., a capacitor). Because capacitor 122 has been charged
from module 130, 630 while in the second (series) configuration of
circuit 602, the voltage available on capacitor 122 is equal or
close to the series coupled voltage of cells 630-1 . . . 630-N,
that is VOUT=.about.N*V. (The value may be adjusted for voltage
drops across the reconfiguration switches.) This is a much larger
voltage than the primary charging voltage VIN=.about.V used in the
first charging cycle to charge the individual cells of secondary
storage battery module 130, 630. The operator of defibrillator 100,
400 uses the charge on capacitor 122 for defibrillation. In RETURN
RECONFIGURING step 760, secondary storage module 130, 630 is
returned to the first (parallel) configuration by selectively
actuating reconfiguration switches 632, 634 to place cells 630-1 to
630-N back in a parallel configuration. The method then goes back
to START 702 ready to repeat initial step 710.
[0046] The defibrillators, AEDs, circuits, battery modules and the
individual battery cells of the invention may be made in any way
known in the art. Plus the composition and/or construction of the
battery modules and the individual battery cells may be arranged to
result in any voltage, dimension, capacity, or toxicity. A person
skilled in the art will be able to practice the present invention
in view of the description present in this document, which is to be
taken as a whole. Numerous details have been set forth in order to
provide a more thorough understanding of the invention. In other
instances, well-known features or arrangements have not been
described in detail in order not to unnecessarily obscure the
invention.
[0047] While at least one exemplary embodiment has been presented
in the foregoing detailed description, it should be appreciated
that a vast number of variations exist. For example, while the
arrangements illustrated in FIGS. 2-6 show battery cells (e.g.,
630-1 . . . 630-N) of individual voltage V being charged in
parallel (e.g., from input voltage VIN=.about.V) and discharged in
series (e.g., with output voltage VOUT=VT=.about.N*V). But, this is
merely for convenience of explanation and not intended to be
limiting. Persons of skill in the art will appreciate that
reconfiguration switches 632, 634 can be used to provide different
output voltages VOUT in the range V<VOUT<VT by arranging
cells 630-1 . . . 630-N in series-parallel groups. This can be
accomplished, for example, by individually controlling switches
632, 634, rather than having all switches 632 act together and all
switches 634 act together. For example, if those of switches 632
coupling adjacent cells (e.g., 630-1 and 630-2; 630-3 and 630-4;
etc.) are kept closed this arranges the cells in pairs. They can
then be switched in pairs from parallel to series configuration by
deactivating those of switches 632 and activating those switches
634 lying between the pairs, e.g., that switch 634 coupling pairs
630-1, 630-2 and pairs 630-3, 630-4. The output voltage will be
half what would be obtained if all cells were individually switched
from parallel to series configuration. By varying the pairing of
cells, any output voltage from VOUT=.about.V to VOUT=.about.N*V can
be obtained. In addition, cells such as 630-1, while shown as
single cells, can be branches of cells. Each such branch can have
two or more cells. So, while a "parallel" definition is used for
coupling cells in the first configuration, it is equivalently meant
parallel branches of cells.
[0048] It should also be appreciated that the exemplary embodiments
are only examples, and are not intended to limit the scope,
applicability, or configuration of the invention in any way.
Rather, the foregoing detailed description will provide those
skilled in the art with a convenient road map for implementing the
exemplary embodiments. It should be understood that various changes
can be made in the function and arrangement of elements without
departing from the scope of the invention as set forth in the
appended claims and the legal equivalents thereof. The inventor
regards the subject matter of the invention to include all
combinations and sub-combinations of the various elements,
features, functions and/or properties disclosed herein. The
following claims define certain combinations and sub-combinations,
which are regarded as novel and non-obvious. Additional claims for
other combinations and sub-combinations of features, functions,
elements and/or properties may be presented in this or a related
document.
* * * * *