U.S. patent application number 12/833976 was filed with the patent office on 2010-10-28 for method and apparatus for providing rechargeable power in data monitoring and management systems.
This patent application is currently assigned to Abbott Diabetes Care Inc.. Invention is credited to Martin J. Fennell, Christopher V. Reggiardo.
Application Number | 20100274108 12/833976 |
Document ID | / |
Family ID | 37902745 |
Filed Date | 2010-10-28 |
United States Patent
Application |
20100274108 |
Kind Code |
A1 |
Reggiardo; Christopher V. ;
et al. |
October 28, 2010 |
Method and Apparatus for Providing Rechargeable Power in Data
Monitoring and Management Systems
Abstract
Method and apparatus for providing a disposable power supply
source integrated into the housing of the transmitter unit mount
that is placed on the skin of the patient, and configured to
receive the transmitter unit is disclosed. The transmitter unit
mount is configured to be disposable with the analyte sensor so
that power supply providing power to the transmitter unit is also
replaced. The transmitter unit may include a rechargeable battery
that is recharged by the power supply unit of the transmitter unit
mount when the transmitter is mounted to the transmitter unit
mount. Other energy store configurations including single large
capacitor (supercap) or a capacitor and DC/DC converter
configurations are disclosed.
Inventors: |
Reggiardo; Christopher V.;
(Castro Valley, CA) ; Fennell; Martin J.;
(Concord, CA) |
Correspondence
Address: |
JACKSON & CO., LLP
6114 LA SALLE AVENUE, #507
OAKLAND
CA
94611-2802
US
|
Assignee: |
Abbott Diabetes Care Inc.
Alameda
CA
|
Family ID: |
37902745 |
Appl. No.: |
12/833976 |
Filed: |
July 10, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11240273 |
Sep 30, 2005 |
7756561 |
|
|
12833976 |
|
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Current U.S.
Class: |
600/309 ; 307/43;
320/103 |
Current CPC
Class: |
A61B 5/14532 20130101;
A61B 5/0002 20130101; A61B 5/14546 20130101; A61B 2560/0209
20130101 |
Class at
Publication: |
600/309 ; 307/43;
320/103 |
International
Class: |
A61B 5/145 20060101
A61B005/145; H02J 1/00 20060101 H02J001/00 |
Claims
1. An apparatus comprising: a transmitter including an analog front
end, a processor, a first power supply configured to provide an
operational voltage level to the analog front end, and a single
large capacitor, wherein the first power supply is coupled to a
boost circuit, and wherein the single large capacitor is coupled in
parallel with the first power supply; and a transmitter mount
configured to receive the transmitter and including a second power
supply configured to provide a supply voltage level to the first
power supply of the transmitter to charge the first power supply of
the transmitter when the transmitter is received by the transmitter
mount; wherein the boost circuit is configured to convert the
supply voltage level received from the second power supply to the
operational voltage level and wherein the single large capacitor is
configured to store the operational voltage.
2. The apparatus of claim 1 wherein the second power supply has a
high current capacity relative to that of the first power
supply.
3. The apparatus of claim 1 further comprising a replaceable sensor
configured to electrically couple with the analog front end of the
transmitter.
4. The apparatus of claim 3 wherein the second power supply of the
transmitter mount is configured to be replaced upon replacement of
the sensor.
5. The apparatus of claim 3 wherein the sensor includes a
transcutaneous insertion portion adapted for transcutaneous
positioning under a skin surface of a patient.
6. The apparatus of claim 5 wherein the sensor is an analyte sensor
configured to generate multiple analyte-related signals and wherein
the transmitter is configured to transmit one or more signals
corresponding to a respective one or more of the multiple
analyte-related signals.
7. The apparatus of claim 1 wherein the first power supply is a
rechargeable battery.
8. The apparatus of claim 1 wherein the second power supply is a
replaceable battery.
9. The apparatus of claim 1 wherein the first power supply is a
rechargeable battery, and further, wherein the second power supply
is a replaceable battery.
10. An apparatus comprising: a transmitter including an analog
front end, a processor and an internal power supply configured to
provide a first operational voltage level to the analog front end,
the internal power supply including a rechargeable battery coupled
to a power circuit including a first DC/DC converter operatively
coupled to a first capacitor, a second DC/DC converter operatively
coupled to a second capacitor, and a third DC/DC converter
operatively coupled to a third capacitor; and a transmitter mount
configured to receive the transmitter and including a replaceable
power supply configured to provide a supply voltage level to the
internal power supply of the transmitter to charge the rechargeable
battery of the transmitter when the transmitter is received by the
transmitter mount; wherein the first DC/DC converter is configured
to convert the supply voltage level received from the replaceable
power supply to the first operational voltage level and wherein the
first capacitor is configured to store the first operational
voltage; wherein the second DC/DC converter is configured to
convert the first operational voltage to a predetermined voltage
level and wherein the second capacitor is configured to store the
predetermined voltage level; and wherein the third DC/DC converter
is configured to convert the predetermined voltage level to a
second operational voltage level that is provided to the processor
when the processor is performing an RF transmission.
11. The apparatus of claim 10 wherein the second operation voltage
level and the first operational voltage level are different.
12. The apparatus of claim 10 wherein the second DC/DC converter
uses voltage stored in at least one of the first capacitor and the
rechargeable battery to convert the first operational voltage to
the predetermined voltage level.
13. The apparatus of claim 10 wherein the first operational voltage
level is greater than the supply voltage level.
14. The apparatus of claim 13 wherein the first operational voltage
level is about twice as great as the supply voltage level.
15. The apparatus of claim 10 wherein the predetermined voltage
level is greater than the first operational voltage level.
16. The apparatus of claim 15 wherein the predetermined voltage
level is about 10 times as great as the first operational voltage
level.
17. The apparatus of claim 10 wherein the second operational
voltage level is less than the predetermined voltage level.
18. The apparatus of claim 10 further comprising a replaceable
sensor configured to electrically couple with the analog front end
of the transmitter.
19. The apparatus of claim 18 wherein the replaceable power supply
of the transmitter mount is configured to be replaced upon
replacement of the sensor.
20. The apparatus of claim 18 wherein the sensor includes a
transcutaneous insertion portion adapted for transcutaneous
positioning under a skin surface of a patient.
21. The apparatus of claim 20 wherein the sensor is an analyte
sensor configured to generate multiple analyte-related signals and
wherein the transmitter is configured to transmit one or more
signals corresponding to a respective one or more of the multiple
analyte-related signals.
Description
RELATED MATTER
[0001] The present application is a continuation of U.S. patent
application Ser. No. 11/240,273 filed Sep. 30, 2005, entitled
"Method and Apparatus for Providing Rechargeable Power in Data
Monitoring and Management Systems", the disclosure of which is
incorporated herein by reference for all purposes.
BACKGROUND
[0002] Analayte, e.g., glucose, monitoring systems including
continuous and discrete monitoring systems generally include a
small, lightweight battery powered and microprocessor controlled
system which is configured to detect signals proportional to the
corresponding measured glucose levels using an electrometer, and RF
signals to transmit the collected data. One aspect of certain
glucose monitoring systems include a transcutaneous or subcutaneous
analyte sensor configuration which is, for example, partially
mounted on the skin of a subject whose glucose level is to be
monitored. The sensor cell may use a two or three-electrode (work,
reference and counter electrodes) configuration driven by a
controlled potential (potentiostat) analog circuit connected
through a contact system.
[0003] The analyte sensor may be configured so that a portion
thereof is placed under the skin of the patient so as to detect the
analyte levels of the patient, and another portion or segment of
the analyte sensor is in communication with the transmitter unit.
The transmitter unit is configured to transmit the analyte levels
detected by the sensor over a wireless communication link such as
an RF (radio frequency) communication link. To transmit signals,
the transmitter unit requires a power supply such as a battery.
Generally, batteries have a limited life span and require periodic
replacement. More specifically, depending on the power consumption
of the transmitter unit, the power supply in the transmitter unit
may require frequent replacement, or the transmitter unit may
require replacement (e.g, disposable power supply such as
disposable battery).
[0004] This may be cumbersome and inconvenient to the patient.
Moreover, in continuous glucose monitoring systems, when the
transmitter unit fails to transmit the glucose data from the sensor
due to power failure, the patient may be approaching a critical
physiological state such as hyperglycemia or hypoglycemia with
little warning or knowledge. This could potentially be fatal to the
patient.
[0005] At the same time, however, it may be undesirable to limit
the functions of the transmitter so as to reduce the power
consumption in order to prolong the battery life of the
transmitter. For example, the transmitter unit may be configured to
transmit less periodically or frequently to save battery
power--this may in turn potentially result in inaccurate
determination of monitored glucose levels as the detected levels
are not sufficiently close together to provide a comprehensive
result of the continuous monitoring.
[0006] Moreover, increasing the battery size may prolong the
operating life of the transmitter unit, but would result in a more
physically cumbersome design, and would add extra weight to be
carried by the patient which is generally undesirable.
[0007] In view of the foregoing, it would be desirable to have an
approach to provide a rechargeable power supply for the transmitter
unit in the data monitoring and management system such that the
compact, lightweight configuration of the transmitter unit worn by
the patient can be maintained. Moreover, in view of the foregoing,
it would be desirable to have various options for the power supply
and/or a rechargeable power supply for the transmitter unit in the
data monitoring and management systems.
SUMMARY OF THE INVENTION
[0008] In view of the foregoing, in accordance with the various
embodiments of the present invention, there is provided a method
and apparatus for providing a disposable power supply source
integrated into the housing of the transmitter unit mount that is
placed on the skin of the patient, and configured to receive or
"mate" with the transmitter unit. The transmitter unit mount is
configured to be disposable with the analyte sensor, such that with
each replacement of the analyte sensor (for example, every three or
five days), the power supply providing power to the transmitter
unit is also replaced.
[0009] In a further embodiment of the present invention, the
transmitter unit may further be configured to include a
rechargeable battery such that when the transmitter unit is mounted
to the transmitter unit mount (that includes a separate disposable
power supply), the power supply unit of the transmitter unit mount
is configured to charge the rechargeable power supply of the
transmitter unit. In this manner, the transmitter unit may be
configured to maintain the communication link with the
corresponding receiver unit during the period when the patient is
replacing the analyte sensor (along with the transmitter unit
mount).
[0010] Yet in a further embodiment of the present invention, the
transmitter may be configured to include a series of capacitor
combinations (and/or in conjunction with other circuitry including
a corresponding series of DC/DC converters) configured to store
charge so as to provide power to the transmitter. In one
embodiment, the capacitor may include a single large capacitor
(supercap) as energy store to provide power to the transmitter in
the data monitoring and management system.
[0011] These and other objects, features and advantages of the
present invention will become more fully apparent from the
following detailed description of the embodiments, the appended
claims and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a block diagram of a data monitoring and
management system for practicing one embodiment of the present
invention;
[0013] FIG. 2 is a block diagram of the transmitter of the data
monitoring and management system shown in FIG. 1 in accordance with
one embodiment of the present invention;
[0014] FIG. 3 illustrates a cross sectional view of the transmitter
and transmitter mount configuration for providing power to the
transmitter in the data monitoring and management system in
accordance with one embodiment of the present invention;
[0015] FIG. 4 is a circuit diagram of the energy storage approach
for providing power to the transmitter in the data monitoring and
management system in accordance with one embodiment of the present
invention; and
[0016] FIG. 5 illustrates another energy storage approach for
providing power to the transmitter in the data monitoring and
management system in accordance with another embodiment of the
present invention.
DETAILED DESCRIPTION
[0017] FIG. 1 illustrates a data monitoring and management system
such as, for example, an analyte (e.g., glucose) monitoring system
100 in accordance with one embodiment of the present invention. The
subject invention is further described primarily with respect to a
glucose monitoring system for convenience and such description is
in no way intended to limit the scope of the invention. It is to be
understood that the analyte monitoring system may be configured to
monitor a variety of analytes, e.g., lactate, and the like.
[0018] Indeed, analytes that may be monitored include, for example,
acetyl choline, amylase, bilirubin, cholesterol, chorionic
gonadotropin, creatine kinase (e.g., CK-MB), creatine, DNA,
fructosamine, glucose, glutamine, growth hormones, hormones,
ketones, lactate, peroxide, prostate-specific antigen, prothrombin,
RNA, thyroid stimulating hormone, and troponin. The concentration
of drugs, such as, for example, antibiotics (e.g., gentamicin,
vancomycin, and the like), digitoxin, digoxin, drugs of abuse,
theophylline, and warfarin, may also be monitored.
[0019] The glucose monitoring system 100 includes a sensor 101, a
transmitter 102 coupled to the sensor 101, and a receiver 104 which
is configured to communicate with the transmitter 102 via a
communication link 103. The receiver 104 may be further configured
to transmit data to a data processing terminal 105 for evaluating
the data received by the receiver 104. Moreover, the data
processing terminal in one embodiment may be configured to receive
data directly from the transmitter 102 via a communication link 106
which may optionally be configured for bi-directional
communication.
[0020] Only one sensor 101, transmitter 102, communication link
103, receiver 104, and data processing terminal 105 are shown in
the embodiment of the glucose monitoring system 100 illustrated in
FIG. 1. However, it will be appreciated by one of ordinary skill in
the art that the glucose monitoring system 100 may include one or
more sensor 101, transmitter 102, communication link 103, receiver
104, and data processing terminal 105, where each receiver 104 is
uniquely synchronized with a respective transmitter 102. Moreover,
within the scope of the present invention, the glucose monitoring
system 100 may be a continuous monitoring system, or
semi-continuous, or a discrete monitoring system.
[0021] In one embodiment of the present invention, the sensor 101
is physically positioned in or on the body of a user whose glucose
level is being monitored. The sensor 101 may be configured to
continuously sample the glucose level of the user and convert the
sampled glucose level into a corresponding data signal for
transmission by the transmitter 102. In one embodiment, the
transmitter 102 is mounted on the sensor 101 so that both devices
are positioned on the user's body. The transmitter 102 performs
data processing such as filtering and encoding on data signals,
each of which corresponds to a sampled glucose level of the user,
for transmission to the receiver 104 via the communication link
103.
[0022] In one embodiment, the glucose monitoring system 100 is
configured as a one-way RF communication path from the transmitter
102 to the receiver 104. In such embodiment, the transmitter 102
transmits the sampled data signals received from the sensor 101
without acknowledgement from the receiver 104 that the transmitted
sampled data signals have been received. For example, the
transmitter 102 may be configured to transmit the encoded sampled
data signals at a fixed rate (e.g., at one minute intervals) after
the completion of the initial power on procedure. Likewise, the
receiver 104 may be configured to detect such transmitted encoded
sampled data signals at predetermined time intervals.
Alternatively, the glucose monitoring system 100 may be configured
with a bi-directional RF (or otherwise) communication between the
transmitter 102 and the receiver 104.
[0023] Additionally, in one aspect, the receiver 104 may include
two sections. The first section is an analog interface section that
is configured to communicate with the transmitter 102 via the
communication link 103. In one embodiment, the analog interface
section may include an RF receiver and an antenna for receiving and
amplifying the data signals from the transmitter 102, which are
thereafter, demodulated with a local oscillator and filtered
through a band-pass filter. The second section of the receiver 104
is a data processing section which is configured to process the
data signals received from the transmitter 102 such as by
performing data decoding, error detection and correction, data
clock generation, and data bit recovery.
[0024] In operation, upon completing the power-on procedure, the
receiver 104 is configured to detect the presence of the
transmitter 102 within its range based on, for example, the
strength of the detected data signals received from the transmitter
102 or a predetermined transmitter identification information. Upon
successful synchronization with the corresponding transmitter 102,
the receiver 104 is configured to begin receiving from the
transmitter 102 data signals corresponding to the user's detected
glucose level. More specifically, the receiver 104 in one
embodiment is configured to perform synchronized time hopping with
the corresponding synchronized transmitter 102 via the
communication link 103 to obtain the user's detected glucose
level.
[0025] Referring again to FIG. 1, the data processing terminal 105
may include a personal computer, a portable computer such as a
laptop or a handheld device (e.g., personal digital assistants
(PDAs)), and the like, each of which may be configured for data
communication with the receiver via a wired or a wireless
connection. Additionally, the data processing terminal 105 may
further be connected to a data network (not shown) for storing,
retrieving and updating data corresponding to the detected glucose
level of the user.
[0026] Within the scope of the present invention, the data
processing terminal 105 may include an infusion device such as an
insulin infusion pump or the like, which may be configured to
administer insulin to patients, and which may be configured to
communicate with the receiver unit 104 for receiving, among others,
the measured glucose level. Alternatively, the receiver unit 104
may be configured to integrate an infusion device therein so that
the receiver unit 104 is configured to administer insulin therapy
to patients, for example, for administering and modifying basal
profiles, as well as for determining appropriate boluses for
administration based on, among others, the detected glucose levels
received from the transmitter 102.
[0027] Additionally, the transmitter 102, the receiver 104 and the
data processing terminal 105 may each be configured for
bi-directional wireless communication such that each of the
transmitter 102, the receiver 104 and the data processing terminal
105 may be configured to communicate (that is, transmit data to and
receive data from) with each other via the wireless communication
link 103. More specifically, the data processing terminal 105 may
in one embodiment be configured to receive data directly from the
transmitter 102 via the communication link 106, where the
communication link 106, as described above, may be configured for
bi-directional communication. In this embodiment, the data
processing terminal 105 which may include an insulin pump, may be
configured to receive the glucose signals from the transmitter 102,
and thus, incorporate the functions of the receiver 104 including
data processing for managing the patient's insulin therapy and
glucose monitoring. In one embodiment, the communication link 103
may include one or more of an RF communication protocol, an
infrared communication protocol, a Bluetooth enabled communication
protocol, an 802.11x wireless communication protocol, or an
equivalent wireless communication protocol which would allow
secure, wireless communication of several units (for example, per
HIPPA requirements) while avoiding potential data collision and
interference.
[0028] FIG. 2 is a block diagram of the transmitter of the data
monitoring and detection system shown in FIG. 1 in accordance with
one embodiment of the present invention. Referring to the Figure,
the transmitter 102 in one embodiment includes an analog interface
201 configured to communicate with the sensor 101 (FIG. 1), a user
input 202, and a temperature measurement section 203, each of which
is operatively coupled to a transmitter processor 204 such as a
central processing unit (CPU). As can be seen from FIG. 2, there
are provided four contacts, three of which are electrodes--work
electrode (W) 210, guard contact (G) 211, reference electrode (R)
212, and counter electrode (C) 213, each operatively coupled to the
analog interface 201 of the transmitter 102 for connection to the
sensor unit 101 (FIG. 1). In one embodiment, each of the work
electrode (W) 210, guard contact (G) 211, reference electrode (R)
212, and counter electrode (C) 213 may be made using a conductive
material that is either printed or etched, for example, such as
carbon which may be printed, or metal foil (e.g., gold) which may
be etched.
[0029] Further shown in FIG. 2 are a transmitter serial
communication section 205 and an RF transmitter 206, each of which
is also operatively coupled to the transmitter processor 204.
Moreover, a power supply 207 such as a battery is also provided in
the transmitter 102 to provide the necessary power for the
transmitter 102. Additionally, as can be seen from the Figure,
clock 208 is provided to, among others, supply real time
information to the transmitter processor 204.
[0030] In one embodiment, a unidirectional input path is
established from the sensor 101 (FIG. 1) and/or manufacturing and
testing equipment to the analog interface 201 of the transmitter
102, while a unidirectional output is established from the output
of the RF transmitter 206 of the transmitter 102 for transmission
to the receiver 104. In this manner, a data path is shown in FIG. 2
between the aforementioned unidirectional input and output via a
dedicated link 209 from the analog interface 201 to serial
communication section 205, thereafter to the processor 204, and
then to the RF transmitter 206. As such, in one embodiment, via the
data path described above, the transmitter 102 is configured to
transmit to the receiver 104 (FIG. 1), via the communication link
103 (FIG. 1), processed and encoded data signals received from the
sensor 101 (FIG. 1). Additionally, the unidirectional communication
data path between the analog interface 201 and the RF transmitter
206 discussed above allows for the configuration of the transmitter
102 for operation upon completion of the manufacturing process as
well as for direct communication for diagnostic and testing
purposes.
[0031] As discussed above, the transmitter processor 204 is
configured to transmit control signals to the various sections of
the transmitter 102 during the operation of the transmitter 102. In
one embodiment, the transmitter processor 204 also includes a
memory (not shown) for storing data such as the identification
information for the transmitter 102, as well as the data signals
received from the sensor 101. The stored information may be
retrieved and processed for transmission to the receiver 104 under
the control of the transmitter processor 204. Furthermore, the
power supply 207 may include a commercially available battery.
[0032] The transmitter 102 is also configured such that the power
supply section 207 is capable of providing power to the transmitter
for a minimum of about three months of continuous operation after
having been stored for about eighteen months in a low-power
(non-operating) mode. In one embodiment, this may be achieved by
the transmitter processor 204 operating in low power modes in the
non-operating state, for example, drawing no more than
approximately 1 .mu.A of current. Indeed, in one embodiment, the
final step during the manufacturing process of the transmitter 102
may place the transmitter 102 in the lower power, non-operating
state (i.e., post-manufacture sleep mode). In this manner, the
shelf life of the transmitter 102 may be significantly improved.
Moreover, as shown in FIG. 2, while the power supply unit 207 is
shown as coupled to the processor 204, and as such, the processor
204 is configured to provide control of the power supply unit 207,
it should be noted that within the scope of the present invention,
the power supply unit 207 is configured to provide the necessary
power to each of the components of the transmitter unit 102 shown
in FIG. 2.
[0033] Referring back to FIG. 2, the power supply section 207 of
the transmitter 102 in one embodiment may include a rechargeable
battery unit that may be recharged by a separate power supply
recharging unit so that the transmitter 102 may be powered for a
longer period of usage time. Moreover, in one embodiment, the
transmitter 102 may be configured without a battery in the power
supply section 207, in which case the transmitter 102 may be
configured to receive power from an external power supply source
(for example, a battery) as discussed in further detail below.
[0034] Referring yet again to FIG. 2, the temperature measurement
section 203 of the transmitter 102 is configured to monitor the
temperature of the skin near the sensor insertion site. The
temperature reading is used to adjust the glucose readings obtained
from the analog interface 201. The RF transmitter 206 of the
transmitter 102 may be configured for operation in the frequency
band of 315 MHz to 322 MHz, for example, in the United States.
Further, in one embodiment, the RF transmitter 206 is configured to
modulate the carrier frequency by performing Frequency Shift Keying
and Manchester encoding. In one embodiment, the data transmission
rate is 19,200 symbols per second, with a minimum transmission
range for communication with the receiver 104.
[0035] Referring yet again to FIG. 2, also shown is a leak
detection circuit 214 coupled to the guard electrode (G) 211 and
the processor 204 in the transmitter 102 (FIG. 1) of the data
monitoring and management system 100. The leak detection circuit
214 in accordance with one embodiment of the present invention may
be configured to detect leakage current in the sensor 101 to
determine whether the measured sensor data are corrupt or whether
the measured data from the sensor 101 is accurate.
[0036] Additional detailed description of the continuous glucose
monitoring system, its various components including the functional
descriptions of the transmitter are provided in U.S. Pat. No.
6,175,752 issued Jan. 16, 2001 entitled "Analyte Monitoring Device
and Methods of Use", and in application Ser. No. 10/745,878 filed
Dec. 26, 2003 entitled "Continuous Glucose Monitoring System and
Methods of Use", each assigned to the Assignee of the present
application, and the disclosures of each of which are incorporated
herein by reference for all purposes.
[0037] FIG. 3 illustrates a cross sectional view of the transmitter
and transmitter mount configuration for providing power to the
transmitter in the data monitoring and management system in
accordance with one embodiment of the present invention. Referring
to the Figure, there is shown a transmitter unit mount 302 which is
placed on the skin 301 of the patient, and configured to receive a
portion of the sensor 101, and the other end portion of the sensor
is inserted, e.g., subcutaneously, under the patient's skin 301.
Referring to FIG. 3, the transmitter unit mount 302 is configured
to receive or "mate" with the transmitter 102 so that the
transmitter 102 is in electrical contact with the sensor 101 that
extends from the patient's skin 301 at the sensor contact 304. In
one embodiment and as discussed above, the sensor contact 304 may
be configured to operatively couple the analog interface unit 201
of the transmitter 102 with the sensor electrodes and contacts
(working electrode 210, guard trace 211, reference electrode 212,
and counter electrode 213).
[0038] While not shown in the Figure, the transmitter unit mount
302 in one embodiment is firmly affixable onto the patient's skin
301 by an adhesive layer on the surface of the transmitter unit
mount 302 that is in contact with the patient's skin 301. In this
manner, the patient's movement of the body does not substantially
affect the position of the transmitter unit mount 302, and thus the
sensor 101 in contact with the transmitter 102. Referring back to
FIG. 3, also shown is a power supply 303 (such as, for example, a
battery) mounted to the transmitter unit mount 302. In one
embodiment, the power supply 303 is positioned to establish
electrical contact with the transmitter 102 at the power supply
contact 305, when the transmitter is mounted onto the transmitter
unit mount 302.
[0039] More specifically, in this configuration, the internal power
supply 207 (FIG. 2) and/or other components of the transmitter 102
are coupled to the external power supply 303 via the power supply
contact 305. In this manner, when the transmitter 102 is mounted to
the transmitter unit mount 302, the internal power supply 207 of
the transmitter 102 is configured to receive power from the
external power supply 303, and thus may be configured to transmit
sensor data received from the sensor 101.
[0040] Within the scope of the present invention, the external
power supply 303 mounted to the transmitter unit mount 302 may
include a disposable battery, or a printed battery which may be
printed onto the surface of the transmitter unit mount 302 on the
surface where the transmitter 102 is configured to physically
contact the transmitter unit mount 302.
[0041] In a further embodiment, as discussed above, the internal
power supply 207 of the transmitter 102 may include a rechargeable
battery which may be configured to receive power to recharge from
the external power supply 303 mounted to the transmitter unit mount
302, when the transmitter 102 is mounted to the transmitter unit
mount 302. In this manner, the external power supply 303 may be
configured to provide power to recharge the internal power supply
207 of the transmitter 102, and further, to provide power to the
transmitter 102.
[0042] Within the scope of the present invention, the rechargeable
internal power supply 207 in the transmitter 102 and the external
power supply 303 mounted on the transmitter unit mount 302 may
include one or more of alkaline, nickel metal hydride, lithium,
nickel cadmium, lithium hydride, polymer batteries, polymorphic
heavy ion salts, bi-metallic interstitial lattice ionic crystals or
ferromagnetic materials. Furthermore, in one embodiment, the
external power supply 303 may be mounted or coupled to the
transmitter unit mount 302 by one of insert molding, welding,
casting or printing.
[0043] In the manner described above, in accordance with one
embodiment of the present invention, a transmitter unit mount 302
may be configured to integrate a power supply 303, such as a
battery, that is disposable, so that when the transmitter 102 is
mounted, power is provided to the transmitter 102. When the
transmitter 102 is dismounted from the transmitter unit mount 302,
then the transmitter 102 may be powered off and the transmitter
unit mount 302 and the power supply 303 are discarded. The
transmitter 102 in one embodiment may also be configured to enter a
low power sleep state powered by the remaining charge in the power
supply 207.
[0044] In one embodiment, the power supply 303 which includes
disposable batteries can be very small since it is a disposable
battery which is to be replaced with each sensor 101 replacement,
and thus does not require a large capacity (thus allowing the size
of the battery to be small). One example of such disposable battery
as power supply 303 is a silver oxide battery.
[0045] Within the scope of the present invention, there is also
provided an embodiment which includes a second rechargeable battery
integrated with the transmitter 102 so that the transmitter 102 may
be configured to maintain the RF communication link with the
receiver 104 and/or the data processing terminal 105. In this
embodiment, as discussed above, when the transmitter 102 is mounted
to the transmitter mount unit 302, the internal power supply 207 of
the transmitter 102 is configured to recharge from the energy
powered by the external power supply 303 of the transmitter unit
mount 302.
[0046] FIG. 4 is a circuit diagram of the energy storage approach
for providing power to the transmitter in the data monitoring and
management system in accordance with one embodiment of the present
invention. Referring to the Figure, there is shown the disposable
power supply 401 of the transmitter unit mount 302 which is
configured to be replaced with the replacement of the sensor 101
(FIG. 1). Also, shown is the transmitter 102 including, among
others, the internal power supply 207, which, in one embodiment,
includes a plurality of DC/DC converters 403, 404, 405, each
operatively coupled to a respective capacitors 406, 407, 408. Also
shown in FIG. 4 is a resistor 409 operatively coupled to a
rechargeable battery 402 of the transmitter 102. The rechargeable
battery 402 of the transmitter 102 shown in FIG. 4 in one
embodiment corresponds to the power supply 207 of the transmitter
102 shown in FIG. 2.
[0047] In one embodiment, referring to FIG. 4, when the transmitter
102 is mounted to the transmitter unit mount 302, the power supply
401 of the transmitter unit mount 302 is configured to charge the
rechargeable battery 402 of the transmitter 102. The DC/DC
converter 403 in one embodiment is configured to boost the voltage
signal from power supply 401 (e.g., 1.5 Volts) to the voltage level
needed for the processor 204 of the transmitter 102 to operate (for
example, to 3 Volts). Indeed, as shown in FIG. 4, the voltage level
at the Analog Front End (AFE) of the transmitter 102 can be derived
from the node 410 shown in the Figure.
[0048] Referring back to FIG. 4, in one embodiment, the energy from
capacitor 406 and/or from the rechargeable battery 402 of the
transmitter 102 may be used to charge the capacitor 407 to a
predetermined value (e.g., between a 5 Volt to 35 Volt range) by
the DC/DC converter 404 boosting the voltage level to the
predetermined range from the 3 Volts at node 410. In one
embodiment, both the rechargeable battery 402 and the capacitor
406, or alternatively, the rechargeable battery 402 or the
capacitor 406, may be used to charge the capacitor 407, depending
upon the various system requirements and the design trade-offs. One
example of the capacitor 407 is a Tantalum type capacitor.
[0049] Indeed, increasing the voltage from 3 Volts to 30 Volts, for
example, provides approximately 100 times the energy storage (since
the energy stored in a capacitor is equal to one half of the
product of the capacitance multiplied with the capacitor voltage
squared--i.e., 1/2CV.sup.2). Then, referring again to FIG. 4, the
stored energy in capacitor 407 is converted by the DC/DC converter
405 and filtered by capacitor 408 to a functional voltage level
which the processor 204 of the transmitter 102 may be configured to
utilize for the RF transmission operation (e.g., 3.3 Volts or 5
Volts).
[0050] As pulsed (or peak) current is drawn by the processor 204 in
the transmitter 102, during the RF transmission operations, the
voltage across the capacitor 407 drops from a high value towards
the minimum value for DC/DC converter operation. In other words, in
one embodiment, the capacitor 407 is "trickle charged" at a low
current during periods when the pulse current is not active, and
when the large peak load occurs, the capacitor 407 is configured to
draw charge from the capacitor and not the source.
[0051] In this manner, in one embodiment of the present invention,
the DC/DC converters 404 and 405 and the corresponding capacitors
407 and 408, are configured to draw a small current from the energy
store (e.g., capacitor 406 or the rechargeable battery 402), and to
store energy on capacitor 407 that provides a large peak (pulsed)
current capability to the processor 204 and RF transmitter 206.
This allows low current drive power sources, such as a printed
battery or a low current coin-cell battery to power the transmitter
102 in normal operations. For test and configuration purposes, a
more robust power source such as a bench power supply may be used
to support continuous operation.
[0052] FIG. 5 illustrates another energy storage approach for
providing power to the transmitter in the data monitoring and
management system in accordance with another embodiment of the
present invention. Referring to the Figure, in one embodiment of
the present invention, a single large capacitor (supercap) 501 is
used for energy store in the transmitter 102, as opposed to, for
example, the capacitor 406 shown in the embodiment in FIG. 4.
Moreover, it can be seen that the power supply 502 (e.g., battery)
of the transmitter 102 shown in FIG. 5 is similar to the power
supply 402 shown in FIG. 4. Further, the boost circuit 503 shown in
FIG. 5 in one embodiment corresponds to the DC/DC converter 403 of
the embodiment shown in FIG. 4.
[0053] Referring back to FIG. 5, the use of the single supercap 501
in parallel with the power supply 502 for energy storage has
advantages in terms of size and cost. Moreover, it should be noted
that the equivalent series resistance (ESR) of the capacitor is an
important design consideration. Indeed, in general, supercaps have
a higher ESR which tends to limit the efficiency and effectiveness
of the supercap design, especially in cases where the working
voltage is greater than 2.5 volts. Moreover, within the scope of
the present invention, the battery 502 may need to have relatively
high current capacity (for example, compared to the rechargeable
battery 402 shown in FIG. 4), due to ESR of the supercap 501.
[0054] In one embodiment, the supercap 501 may be configured to
provide a low internal resistance energy source that allows a large
current to be delivered to the transmitter unit 102. It is
difficult to achieve this directly from a battery. Small batteries
generally cannot deliver a high current, so for a relatively small
and compact size design such as for the design of the transmitter
unit 102, this provides a significant advantage. Also, while at low
temperatures the internal resistance of batteries increase, this
may be mitigated by using a supercap or other type of storage
capacitor connected in parallel with the battery.
[0055] In the manner described above, an apparatus including a data
transmission unit in one embodiment includes a sensor, a
transmitter base including a first power supply, and a transmitter
unit coupled to the transmitter base, the transmitter unit
including a second power supply, the transmitter unit further
configured to establish electrical contact with the sensor, and
further, where the transmitter unit is configured to draw power
from one or more of the first power supply and the second power
supply.
[0056] The sensor may in one embodiment include an analyte sensor
transcutaneously positioned in a patient such that at least a
portion of the analyte sensor is in fluid contact with a biological
fluid of the patient.
[0057] Moreover, the first power supply may include a disposable
battery, such as, for example, a silver oxide battery, and where
the second power supply may include a rechargeable battery
configured to selectively draw power from the first power
supply.
[0058] In a further embodiment, each of the first power supply and
the second power supply may include one of a disposable battery or
a rechargeable battery.
[0059] The transmitter unit in one embodiment may be configured to
transmit one or more signals, where the one or more signals
correspond to a respective one or more signals received from the
sensor, and where the transmitter unit may be configured for
wireless communication or may include a physical connection.
Additionally, the one or more signal received from the sensor
corresponds to one or more analyte levels (for example, glucose
levels) of a patient detected by the sensor.
[0060] An apparatus in a further embodiment of the present
invention includes a sensor transcutaneously positioned in a
patient, a transmitter base including a transmitter base power
supply, a transmitter unit coupled to the transmitter base power
supply of the transmitter base, the transmitter base power supply
of the transmitter base configured to provide power to the
transmitter unit, the transmitter unit further configured to
establish electrical contact with the sensor.
[0061] In one embodiment, the sensor may include an analyte sensor
where least a portion of the analyte sensor is in fluid contact
with a biological fluid of the patient, where the biological fluid
includes one of interstitial fluid, lactate or oxygen.
[0062] Moreover, the apparatus in one embodiment may also include a
receiver unit configured to receive the one or more signals from
the transmitter unit.
[0063] In still a further embodiment, the transmitter base power
supply may include a disposable battery such as for example, a
silver oxide battery.
[0064] Also, the transmitter unit may further include a transmitter
unit power supply disposed substantially within the housing of the
transmitter unit, where the transmitter unit power supply may in
one embodiment include a rechargeable battery, and also, where the
rechargeable battery may be configured to substantially draw power
from the transmitter base power supply.
[0065] An apparatus in still a further embodiment includes a
rechargeable battery, and a transmitter unit coupled to the
rechargeable battery configured to draw power from the rechargeable
battery.
[0066] A method in still another embodiment of the present
invention includes the steps of providing a power supply to a
transmitter mount, operatively coupling a transmitter unit to the
transmitter mount such that the transmitter unit is in electrical
contact with the power supply, operatively coupling a
transcutaneously positioned analyte sensor to the transmitter unit
such that the transmitter unit receives one or more signals
corresponding to one or more analyte levels from the sensor.
[0067] Various other modifications and alterations in the structure
and method of operation of this invention will be apparent to those
skilled in the art without departing from the scope and spirit of
the invention. Although the invention has been described in
connection with specific preferred embodiments, it should be
understood that the invention as claimed should not be unduly
limited to such specific embodiments. It is intended that the
following claims define the scope of the present invention and that
structures and methods within the scope of these claims and their
equivalents be covered thereby.
* * * * *