U.S. patent application number 12/959311 was filed with the patent office on 2011-03-24 for method and system for providing basal profile modification in analyte monitoring and management systems.
This patent application is currently assigned to Abdott Diabetes Care Inc.. Invention is credited to Gary Hayter, Mark K. Sloan.
Application Number | 20110071372 12/959311 |
Document ID | / |
Family ID | 38004718 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110071372 |
Kind Code |
A1 |
Sloan; Mark K. ; et
al. |
March 24, 2011 |
Method and System for Providing Basal Profile Modification in
Analyte Monitoring and Management Systems
Abstract
Method and system for providing basal profile modification in
insulin therapy for use with infusion devices includes periodically
monitoring the analyte levels of a patient for a predetermined
period of time in order to determine, based on the monitored
analyte levels, an appropriate modification factor to be
incorporated into the underlying basal profile which was running at
the time the periodic monitoring of the analyte levels were
performed.
Inventors: |
Sloan; Mark K.; (Hayward,
CA) ; Hayter; Gary; (Oakland, CA) |
Assignee: |
Abdott Diabetes Care Inc.
Alameda
CA
|
Family ID: |
38004718 |
Appl. No.: |
12/959311 |
Filed: |
December 2, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12833975 |
Jul 10, 2010 |
|
|
|
12959311 |
|
|
|
|
11267724 |
Nov 4, 2005 |
7766829 |
|
|
12833975 |
|
|
|
|
Current U.S.
Class: |
600/310 |
Current CPC
Class: |
A61B 5/4839 20130101;
G16H 10/40 20180101; A61B 5/14532 20130101; A61M 2205/3303
20130101; A61M 5/1723 20130101; G16H 40/67 20180101; A61M 2230/201
20130101; G16H 10/60 20180101; G06F 19/00 20130101; A61B 2560/0223
20130101; G16H 20/17 20180101; A61M 2205/52 20130101 |
Class at
Publication: |
600/310 |
International
Class: |
A61B 5/145 20060101
A61B005/145 |
Claims
1. (canceled)
2. A system for providing information associated with a titration
of a medicament in a host, comprising: a continuous analyte sensor
configured to detect a first signal associated with a medicament
concentration in vivo in a host; and a communication device
comprising an input module configured to receive titration
parameters, and a processor module configured to process the first
signal and the titration parameters to obtain titration information
associated with a titration of the medicament, wherein the
communication device is configured to output the titration
information.
3. The system of claim 2, wherein the titration parameters comprise
at least one parameter selected from the group consisting of
medicament identity information, a target medicament concentration,
a medicament concentration limit, a toxic medicament concentration,
a medicament delivery rate, a medicament delivery time, host data,
and medicament effect information.
4. The system of claim 3, wherein the processor module is
configured to provide an alarm when the medicament concentration is
substantially within a predetermined percentage of the medicament
concentration limit.
5. The system of claim 2, wherein the titration information
comprises at least one member selected from the group consisting of
a current medicament concentration, a predicted medicament
concentration, a change in medicament concentration, an
acceleration of medicament concentration, a relationship of
medicament concentration and a medicament concentration limit, rate
of change information, a clearance rate, and a correlation between
a medicament concentration and a medicament effect experienced by
the host.
6. The system of claim 2, wherein the information comprises at
least one member selected from the group consisting of a therapy
recommendation and a therapy instruction.
7. The system of claim 2, wherein the input module is further
configured to receive a second signal associated with an effect of
the medicament, and wherein the processor module is further
configured to process the first signal, the second signal and the
titration parameters to obtain the titration information.
8. The system of claim 7, further comprising a secondary medical
device.
9. The system of claim 8, wherein the secondary medical device
comprises at least one device selected from the group consisting of
a secondary analyte sensor and a patient monitor, wherein the
secondary medical device is configured to detect a second signal
associated with an effect of a delivered medicament.
10. The system of claim 9, wherein the effect of the delivered
medicament is associated with a change in a host physical
attribute.
11. The system of claim 2, wherein the communication device is
configured to output the titration information to a secondary
medical device.
12. The system of claim 11, wherein the secondary medical device
comprises a medicament delivery device.
13. The system of claim 11, wherein the secondary medical device is
configured to monitor an attribute of the host.
14. The system of claim 2, wherein the processor module is
configured to determine an optimal dose of the medicament.
15. The system of claim 2, wherein the communication device
comprises a user interface configured to perform at least one of
outputting the titration information and receiving titration
parameters.
16. A system for continuous ambulatory drug testing, comprising: an
ambulatory host monitor comprising a continuous sensor configured
to detect a signal associated with a presence of a drug in vivo in
a host, a location module configured to provide a location of the
continuous sensor, and a first processor module configured to
process the signal to obtain drug information; and a transmitter
configured to transmit the drug information.
17. The system of claim 16, further comprising a communication
device located remotely from the ambulatory host monitor, wherein
the communication device is configured to receive the drug
information and the location, and to process the drug information
and the location to obtain drug-monitoring information, and wherein
the communication device is configured to output the
drug-monitoring information.
18. The system of claim 17, wherein the drug-monitoring information
comprises at least one of an instruction and a recommendation.
19. The system of claim 16, wherein the first processor module is
configured to provide an alarm when the signal is below a
programmed level.
20. The system of claim 16, wherein the drug is a drug of abuse and
wherein drug information comprises information associated with a
presence of the drug of abuse in the host.
21. The system of claim 16, wherein the drug is a medicament and
the drug information comprises information associated with a
presence of the medicament in the host.
22. The system of claim 16, further comprising a secondary device
configured to operably connect with the ambulatory host monitor,
wherein the ambulatory host monitor is further configured to
provide drug information to the secondary device, and wherein the
secondary device is configured to perform at least one of providing
an alert and deactivating a machine.
23. The system of claim 16, wherein the continuous sensor is a
transcutaneous continuous sensor.
24. A system for continuously monitoring a hormone level,
comprising: a continuous hormone sensor configured to detect a
signal associated with a hormone concentration in vivo in a host;
and a communication device comprising a processor module configured
to process the signal to provide hormone information, wherein the
communication device is configured to output the hormone
information in real time.
25. The system of claim 24, wherein communication device is further
configured to store the hormone information over time, and wherein
the processor module is further configured to process the stored
hormone information and the real-time hormone information to
provide diagnostic information.
26. An analyte sensor for monitoring nutritional status in a host,
comprising: a first sensing portion configured to measure a first
signal associated with a glucose concentration in a host; a second
sensing portion configured to measure a second signal associated
with an analyte concentration in the host; and a processor module
configured to process the first signal and the second signal to
obtain nutrition information in vivo.
27. The device of claim 26, wherein the first sensing portion is
configured and arranged to measure the first signal using at least
one detection method selected from electrochemical detection,
physical detection, optical detection, or combinations thereof.
28. The device of claim 26, wherein the second sensing portion is
configured and arranged to measure the second signal using at least
one detection method selected from electrochemical detection,
physical detection, optical detection, or combinations thereof.
29. The device of claim 26, further comprising an output module
configured to output the nutrition information.
30. The device of claim 29, wherein the nutrition information
comprises at least one member selected from the group consisting of
the analyte concentration, a change in analyte concentration, a
rate of change in analyte concentration, a peak analyte
concentration, a lowest analyte concentration, a correlation
between the glucose concentration and the analyte concentration,
nutrition status, and an alarm.
Description
RELATED APPLICATION
[0001] The present application is a continuation of U.S. patent
application Ser. No. 12/833,975 filed Jul. 10, 2010, which is a
continuation of U.S. patent application Ser. No. 11/267,724 filed
Nov. 4, 2005, now U.S. Pat. No. 7,766,829, the disclosures of each
of which are incorporated herein by reference for all purposes.
BACKGROUND
[0002] The present invention relates to analyte monitoring systems
and health management systems. More specifically, the present
invention relates to method and system for providing basal profile
modification in analyte monitoring systems to improve insulin
therapy in diabetic patients.
[0003] In data communication systems such as continuous,
semi-continuous or discrete analyte monitoring systems for insulin
therapy, analyte levels of a patient are monitored and/or measured,
and the measured analyte levels are used for treatment. For
example, real time values of measured analyte levels of a patient
would allow for a more robust and accurate diabetes treatment.
Moreover, a profile of a series of measured analyte levels of a
diabetic patient can provide valuable information regarding the
fluctuations and variations of the analyte levels in a diabetic
patient. In turn, this type of information would be invaluable in
establishing a suitable insulin therapy regimen.
[0004] Many diabetic patients that use an infusion device such as
an infusion pump generally have a preset or pre-established basal
profiles which are programmed or stored into the infusion device by
the patient's physician or the patient herself. Indeed, based on
several factors such as insulin sensitivity, the patient's
physiology and other variable factors that effect the patient's
analyte levels, the physician may tailor the basal profiles of the
patient to be programmed into the infusion device such that the
patient's analyte level is maintained within an acceptable range,
and thus the patient is not going to experience hyperglycemia or
hypoglycemia.
[0005] While physicians attempt to best determine the most suitable
basal profiles for each diabetic patient using the infusion device,
it is often difficult to attain the most suitable profiles to
ensure the safe operating range of the infusion device while
providing the patient with the most suitable level of insulin at
all times when the patient is wearing and operating the infusion
device.
[0006] Often, diabetics who use infusion pumps run basal profiles
to maintain a steady level of insulin and also, supplement with
additional boluses administered typically with the same infusion
pumps. Various devices exist that enable the determination of the
appropriate bolus to supplement the basal profiles. For example,
prior to the ingestion of a large quantity of carbohydrates, the
patient is able to calculate a carbohydrate bolus and administer
the same with the infusion pump so that the intake of the
carbohydrates does not adversely impact the patient's physiology.
While bolus supplements are useful and critical to a well managed
insulin therapy regimen, it does not address the underlying concern
related to the basal profiles that the infusion devices are
programmed to administer.
[0007] In view of the foregoing, it would be desirable to have a
method and system for providing basal profile modification for
diabetic patients so as to comprehend each patient's unique
physiology as well as response to insulin intake. More
specifically, it would be desirable to modify basal profiles such
that as the use of the infusion device progresses, the patient's
basal profiles may be tailored to be more suitable for that
patient
SUMMARY OF THE INVENTION
[0008] In accordance with the various embodiments of the present
invention, there is provided a method and system for analyte
monitoring and management configured to monitor the levels of a
patient's analyte over a predetermined period of time, and based on
the monitored analyte levels, determine one or more patterns in the
analyte levels for the given period of time, and to provide a
recommendation for modification to the basal profiles under which a
medication delivery system such as an infusion pump is
operating.
[0009] For example, in one embodiment, the analyte monitoring and
management system of the present invention will be configured to
monitor the analyte levels of a patient over a predetermined time
period (for example, 1 day, 3 days, or 7 days), and during which,
the patient is using an infusion device such as an insulin pump
administering insulin based on a predetermined one or more basal
profiles. Upon conclusion of the analyte level monitoring during
the predetermined time period, the collected data are analyzed and,
considered in conjunction with the underlying basal profiles under
which the patient was infusing insulin during that same
predetermined time period, used to determine a suitable
modification to the basal profiles, if any, to improve the insulin
therapy of the patient.
[0010] In this manner, a robust health management system may be
provided which may be configured in one embodiment to monitor the
analyte levels of a patient over a period of time and to recommend
or suggest a modification to the existing or current basal profiles
based on the collected and analyzed analyte levels taken in
conjunction with the underlying basal profiles under which the
infusion device was running during the time period of analyte level
monitoring. Within the scope of the present invention, the
monitored time period may vary depending upon the patient's need,
the underlying basal profiles, the condition of the patient and the
like, such that the patient may alter or modify the running basal
profiles prior to its completion based on the monitored and
analyzed analyte levels so as to provide a more effective insulin
therapy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a block diagram of a data monitoring and
management system for practicing one embodiment of the present
invention;
[0012] FIG. 2 is a block diagram of the transmitter unit of the
data monitoring and management system shown in FIG. 1 in accordance
with one embodiment of the present invention;
[0013] FIG. 3 is a flowchart illustrating the process for
monitoring analyte levels and determining modification to a current
basal profile in accordance with one embodiment of the present
invention; and
[0014] FIGS. 4A-4C illustrate a current basal profile, a monitored
analyte level profile, and a modified basal profile recommendation
respectively, in accordance with one embodiment of the present
invention.
DETAILED DESCRIPTION
[0015] FIG. 1 illustrates a data monitoring and management system
such as, for example, an analyte (e.g., glucose) monitoring and
management system 100 in accordance with one embodiment of the
present invention. The subject invention is further described
primarily with respect to an analyte monitoring and management
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.
[0016] 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.
[0017] The analyte monitoring and management system 100 includes a
sensor 101, a transmitter unit 102 coupled to the sensor 101, and a
receiver unit 104 which is configured to communicate with the
transmitter unit 102 via a communication link 103. The receiver
unit 104 may be further configured to transmit data to a data
processing terminal 105 for evaluating the data received by the
receiver unit 104. Moreover, the data processing terminal in one
embodiment may be configured to receive data directly from the
transmitter unit 102 via a communication link 106 which may
optionally be configured for bi-directional communication.
[0018] Only one sensor 101, transmitter unit 102, communication
link 103, receiver unit 104, and data processing terminal 105 are
shown in the embodiment of the analyte monitoring and management
system 100 illustrated in FIG. 1. However, it will be appreciated
by one of ordinary skill in the art that the analyte monitoring and
management system 100 may include one or more sensor 101,
transmitter unit 102, communication link 103, receiver unit 104,
and data processing terminal 105, where each receiver unit 104 is
uniquely synchronized with a respective transmitter unit 102.
Moreover, within the scope of the present invention, the sensor 101
may include a subcutaneous analyte sensor, a transcutaneous analyte
sensor, an implantable analyte sensor, or a noninvasive analyte
sensor such as a transdermal patch or an optical sensor (for
example, infrared sensor).
[0019] Moreover, within the scope of the present invention, the
analyte monitoring system 100 may be a continuous monitoring
system, or semi-continuous, or a discrete monitoring system.
Additionally, within the scope of the present invention, the sensor
101 may include a subcutaneous analyte sensor or an implantable
analyte sensor which is configured to be substantially wholly
implanted in a patient.
[0020] In one embodiment of the present invention, the sensor 101
is physically positioned in or on the body of a user whose analyte
level is being monitored. The sensor 101 may be configured to
continuously sample the analyte level of the user and convert the
sampled analyte level into a corresponding data signal for
transmission by the transmitter unit 102. In one embodiment, the
transmitter unit 102 is mounted on the sensor 101 so that both
devices are positioned on the user's body. The transmitter unit 102
performs data processing such as filtering and encoding on data
signals, each of which corresponds to a monitored analyte level of
the user, for transmission to the receiver unit 104 via the
communication link 103.
[0021] In one embodiment, the analyte monitoring system 100 is
configured as a one-way RF communication path from the transmitter
unit 102 to the receiver unit 104. In such embodiment, the
transmitter unit 102 transmits the sampled data signals received
from the sensor 101 without acknowledgement from the receiver unit
104 that the transmitted sampled data signals have been received.
For example, the transmitter unit 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 unit 104 may be configured to
detect such transmitted encoded sampled data signals at
predetermined time intervals. Alternatively, the analyte monitoring
system 100 may be configured with a bi-directional RF (or
otherwise) communication between the transmitter unit 102 and the
receiver unit 104.
[0022] Additionally, in one aspect, the receiver unit 104 may
include two sections. The first section is an analog interface
section that is configured to communicate with the transmitter unit
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 unit
102, which are thereafter, demodulated with a local oscillator and
filtered through a band-pass filter. The second section of the
receiver unit 104 is a data processing section which is configured
to process the data signals received from the transmitter unit 102
such as by performing data decoding, error detection and
correction, data clock generation, and data bit recovery.
[0023] In operation, upon completing the power-on procedure, the
receiver unit 104 is configured to detect the presence of the
transmitter unit 102 within its range based on, for example, the
strength of the detected data signals received from the transmitter
unit 102 or a predetermined transmitter identification information.
Upon successful synchronization with the corresponding transmitter
unit 102, the receiver unit 104 is configured to begin receiving
from the transmitter unit 102 data signals corresponding to the
user's detected analyte level. More specifically, the receiver unit
104 in one embodiment is configured to perform synchronized time
hopping with the corresponding synchronized transmitter unit 102
via the communication link 103 to obtain the user's detected
analyte level.
[0024] Referring again to FIG. 1, the data processing terminal 105
in one embodiment may be configured to include a medication
delivery unit such as an infusion device including, for example, an
insulin pump, and which may be operatively coupled to the receiver
unit 104. In such an embodiment, the medication delivery unit 105
may be configured to administer a predetermined or calculated
insulin dosage based on the information received from the receiver
unit 104. For example, as discussed in further detail below, the
medication delivery unit 105 in one embodiment may be configured to
deliver insulin based on pre-programmed basal profiles to diabetic
patients, as well as to determine and/or administer one or more
suitable bolus levels (e.g., carbohydrate bolus, and correction
bolus).
[0025] Referring again to FIG. 1, the receiver unit 104 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 receiver unit 104 may further be connected to a data network
(not shown) for storing, retrieving and updating data corresponding
to the monitored analyte levels of the patient.
[0026] Furthermore, in one embodiment of the present invention, the
receiver unit 104 or the data processing terminal 105, or both the
receiver unit 104 and the data processing terminal 105 may be
configured to incorporate a glucose strip meter so as to be
configured to include, for example, a test strip port for receiving
a glucose test strip. In this embodiment of the present invention,
the receiver unit 104 and the data processing terminal 105 may be
configured to perform analysis upon the sample from the glucose
test strip so as to determine the glucose level from the test
strip. One example of such strip meter is Freestyle.RTM. glucose
meters commercially available from the assignee of the present
invention, Abbott Diabetes Care Inc. of Alameda Calif.
[0027] Furthermore, 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 analyte levels
received from the transmitter unit 102.
[0028] Additionally, the transmitter unit 102, the receiver unit
104 and the data processing terminal 105 may each be configured for
bi-directional wireless communication such that each of the
transmitter unit 102, the receiver unit 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 unit 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 analyte signals from the
transmitter unit 102, and thus, incorporate the functions of the
receiver 104 including data processing for managing the patient's
insulin therapy and analyte monitoring.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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 analyte 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.
[0037] 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 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.
[0038] Additional detailed description of the continuous analyte
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.
[0039] FIG. 3 is a flowchart illustrating the process for
monitoring analyte levels and determining modification to a current
basal profile in accordance with one embodiment of the present
invention. Referring to FIG. 3, at step 301, the analyte levels
such as the patient's analyte level is monitored for a
predetermined period of time, and at step 302, the monitored
analyte levels is stored in a data storage unit (for example, in
one or more memory devices of the receiver unit 104 and/or the data
processing terminal 105 (FIG. 1)). Thereafter, at step 303, patient
specific parameters are retrieved from the data processing terminal
105 and/or the receiver unit 104, as well as the current basal
profile(s) which the patient is implementing to operate the
infusion device for insulin delivery during the time period of the
analyte monitoring discussed above.
[0040] In one embodiment, patient specific parameters may include
the type of insulin currently being infused into the patient, the
patient's insulin sensitivity, insulin resistance level, level of
insulin on board, the specific time period of the analyte
monitoring, including the activities performed by the patient
during that time period, or any other factors and variables that
may have an impact upon the effectiveness of insulin therapy for
the patient.
[0041] Referring to FIG. 3, after retrieving the patient specific
parameters and the current basal profile(s) that the patient is
implementing in the infusion device at step 303, at step 304, the
monitored analyte levels are retrieved and, based on one or more
patterns from the analyte levels monitored and factoring in the
current basal profile(s), a recommendation or modification to the
current basal profile(s) is determined. Thereafter, the
recommendation or modification to the current basal profiles(s)
determined at step 304 is provided to the patient visually on a
display or audibly, or a combination of visual and audio output,
such that the patient may be able to decide whether the
modification to the current basal profile(s) is appropriate or
suitable to the patient.
[0042] While the modification to the basal profile(s) is discussed
above as output to the patient, within the scope of the present
invention, the basal profile modification determined in accordance
with one embodiment of the present invention may be provided to a
health care provider so as to determine suitability of the
modification to the current basal profile in view of the monitored
analyte levels. Furthermore, in an alternate embodiment, the
determined modification to the current basal profile may be
provided to both the patient and the health care provider so that
the patient is able to make an informed decision as to whether the
recommended modification to the current basal profile is suitable
for the patient in improving insulin therapy to better manage
diabetes.
[0043] Within the scope of the present invention, the modification
to the current basal profile may include several factors that are
considered including, for example, the current basal profile as a
function of the time period during which insulin infusion takes
place and analyte levels are monitored, the level of the analyte
monitored as a function of time, patient specific parameters
discussed above including, for example, patient's activities during
the monitored time period, patient's diet, insulin sensitivity,
level of insulin on board, and the insulin type, and the frequency
of bolus dosing during the time period of the analyte level
monitoring (for example, the number of correction bolus dosing,
and/or carbohydrate dosing).
[0044] In this manner, in one embodiment of the present invention,
the modification to the current basal profile(s) may be achieved
for one or more specific goals for the patient's diabetes
management, including for example, elimination of extreme glucose
excursions, automating or semi-automating routine or regular bolus
dosing, and adjustment to the mean glucose value.
[0045] For example, to effectively eliminate extreme glucose
excursions, the modification to the current basal profiles may be
configured to provide recommendation to modify to reduce extreme
levels, so that unless the monitored glucose level exceeds a
predetermined threshold level (e.g, 200 mg/dL), modification to the
current basal profile is not recommended. In the case of automating
regular bolus dosing, based on the monitored analyte levels, a
regular correction bolus dosing during the current basal profile
implementation may be converted into a modification to the current
basal profile so that the patient may effectively be rid of the
need to implement routine correction type bolus dosing.
Additionally, with the collected data from the continuously
monitored analyte levels, the current basal profile may be modified
to adjust the mean target glucose value even in the case where
extreme excursions of glucose levels do not occur.
[0046] Within the scope of the present invention, the current basal
profile modification may be performed at different times during the
time that the patient is using an infusion device. For example, the
patient may perform the current basal profile modification
procedure discussed above on a daily basis if, for example, glucose
excursions are anticipated on a regular basis. Alternatively, the
current basal profile modification procedure may be performed each
time a bolus is administered.
[0047] Moreover, within the scope of the present invention, when a
pattern of glucose excursions is detected over several days (for
example, 48 or 72 hours), the analyte monitoring and management
system 100 (FIG. 1) may be configured to continue analyte level
monitoring to determine whether a pattern exists in the frequency
and/or level of the glucose excursions. In such a case, it is
possible to modify the current basal profile modification procedure
to correct for such patterns in the monitored analyte levels such
that the modification to the current basal profile may address such
excursions.
[0048] In a further embodiment, the loop gain setting may be
configured to determine the appropriate level of modification to
the current basal profiles for a given glucose excursion pattern
detected based on the monitored analyte levels. While several
iterations may be necessary for low loop gain to reach the optimal
modification level of the current basal profile, a conservative and
less aggressive modification may be recommended in such cases. For
medium loop gain, when critically controlled, the determined
recommendation for modification to the current basal profile may be
reached based on one iteration, but with the potential for an
increased risk for overshoot and thereby resulting in
over-compensation. Notwithstanding, the loop gain setting may be
trained into the analyte monitoring and management system 100 so
that by starting with a low loop gain and then learning the loop
responses to reach the optimal loop gain, the desired modification
to the current basal profile may be determined and provided to the
patient.
[0049] FIGS. 4A-4C illustrate a current basal profile, a monitored
analyte level profile, and a modified basal profile recommendation
respectively, in accordance with one embodiment of the present
invention. Referring to FIG. 4A, a profile of the glucose level as
a function of time is shown for a current basal profile programmed
into the infusion device of the patient. FIG. 4B illustrates a
profile of the glucose levels as a function of time for the same
time period during which the basal profile shown in FIG. 4A is
administered to the patient. Finally, FIG. 4C illustrates a profile
of glucose level as a function of time which factors in the patient
parameters including the monitored glucose levels of the patient,
to provide a modification to the current basal profile so as to
improve the patient's insulin therapy.
[0050] Indeed, in one embodiment of the present invention, it can
be seen that the analyte level monitoring and detecting patterns in
the monitored analyte levels during the time period that the
patient is using an infusion device such as an insulin pump running
a pre-programmed basal profile, provides contemporaneous patient
response of the infused insulin based on the current basal profile,
and thus, it is possible to improve the insulin therapy.
[0051] By way of an example, in the case that the patient desired
to eliminate or substantially reduce the occurrences of high
glucose extremes or excursions, it is determined whether there is a
consistent pattern of high glucose levels versus time of day of
such occurrence based on the monitored glucose levels. An example
of such monitored levels is shown in the Table 1 below:
TABLE-US-00001 TABLE 1 High Glucose Excursions 00:00 00:30 01:00
01:30 23:30 Day 1 (0-24 hr) 1 1 Day 2 (24-48 hr) 1 1 1 Day 3 (48-72
hr) 1 1 1 Sum 2 1 3 2 0
where over a 72 hour period post calibration of the sensor 101
(FIG. 1), the monitored data is reviewed to determine if the
monitored glucose level exceeds a predetermined threshold level.
Each occurrence of when the glucose level exceeds a predetermined
threshold level is shown with a "1" in Table 1 above.
[0052] For each column shown in Table 1 where the sum of the data
entry equals "3", and the sum of the adjacent columns is equal to
or greater than "1", the analyte monitoring and management system
100 in one embodiment may be configured to recommend an increase to
the current basal profile for that time slot or period during the
72 hour period.
[0053] More specifically, using a conventional bolus calculation
mechanism, a correction bolus may be determined based on the
detection of the high glucose level. Thereafter, rather than
implementing the calculated correction bolus, the modification to
the current basal profile may be determined based on the following
relationship:
Modification=K*Calculated Correction Bolus/30 minutes (1)
where K is a loop gain value determined by the patient's health
care provider, and is typically less than 1 for over dampened
control, and further, where the 30 minutes is a scaling factor for
the Modification determination.
[0054] After the calculation, the determined Modification from the
equation (1) above is provided to the patient to either accept and
implement, storage for further analysis or modification, or
reject.
[0055] In one embodiment, the Modification determination based on
relationship described in the equation (1) above may include
glucose rate or higher derivative information, or alternatively,
may also include an integral factor. In a further embodiment, the
determination may also factor in the glucose profile variation.
Other potentially relevant factors also include the physiological
dynamics and/or sensor/monitor dynamics, as well as the patient's
insulin infusions, caloric intake, exercise, etc.
[0056] As another example, in the case where correction bolus
dosing may be replaced with modification to the current basal
profiles based on the monitored analyte levels, a consistent
pattern in the monitored analyte levels of bolus delivery versus
time of day is determined. Table 2 below shows one example of such
pattern:
TABLE-US-00002 TABLE 2 Bolus Replacement 00:00 00:30 01:00 01:30
23:30 Day 1 (0-24 hr) 1 1 Day 2 (24-48 hr) 1 1 1 Day 3 (48-72 hr) 1
1 1 Sum 2 1 3 2 0
[0057] Referring to Table 2 and in conjunction with equation (1)
discussed above, the administration of bolus doses is reviewed and
if, for example, there were three bolus deliveries (each shown in
Table 2 with a "1" entry) within 30 minutes of the same time of day
period, then an increase in the insulin level for same time period
may be proposed to the current basal profile using equation (1) to
determine the level of modification to the current basal
profile.
[0058] In the case of addressing the occurrence of low extremes of
glucose levels, similar determinations as above may be performed
given the monitored analyte levels for the desired time period and
data reviewed for detection of patterns in the monitored analyte
levels associated with the occurrences of low extremes. For
example, Table 3 below provides data for a three day period
illustrating patterns associated with the occurrences of low
extremes.
TABLE-US-00003 TABLE 3 Low Extremes Pattern 00:00 00:30 01:00 01:30
23:30 Day 1 (0-24 hr) 1 1 Day 2 (24-48 hr) 1 1 1 Day 3 (48-72 hr) 1
1 1 Sum 2 1 3 2 0
where the "1" entry in a particular column illustrates the
occurrence of the measured glucose level that is below a
predetermined low threshold level.
[0059] Again, in conjunction with equation (1) above, a
modification to the current basal profile may be determined and
provided to the patient. More specifically, where over a 72 hour
period post calibration of the sensor 101 (FIG. 1), the monitored
data is reviewed to determine if the monitored glucose level falls
below the predetermined low threshold level, each such is shown
with a "1" in Table 3 above.
[0060] For each column shown in Table 3 where the sum of the data
entry equals "3", and the sum of the adjacent columns is equal to
or greater than "1", the analyte monitoring and management system
100 in one embodiment may be configured to recommend a modification
to the current basal profile for that time slot or period during
the 72 hour period based on the relationship set forth in equation
(1). The user or patient may then be provided with the modification
to the current basal profile which may be accepted for
implementation, stored for further analysis or modification, or
rejected by the patient.
[0061] In the case of reducing the mean glucose level using the
analyte monitoring and management system 100 in one embodiment of
the present invention, again, consistent patterns in the monitored
analyte levels over a predetermined time period is analyzed and
detected as a function of time of day of the analyte level
monitoring. Table 4 below shows an example of such pattern:
TABLE-US-00004 TABLE 4 Mean Glucose Level 00:00 00:30 01:00 01:30
23:30 Day 1 (0-24 hr) 1 1 Day 2 (24-48 hr) 1 1 1 Day 3 (48-72 hr) 1
1 1 Sum 2 1 3 2 0
where, an entry of a "1" in Table 4 above illustrates a detected
glucose level of greater than a predetermined level (e.g., 120)
during the three day period based on the data from the sensor 101
(FIG. 1).
[0062] Again, similar to the determinations above, if the sum of
any column in Table 4 is equal to three, and the sum of the
adjacent columns is greater than or equal to one, then a decrease
in the current basal profile for that particular time slot is
recommended based on the relationship set forth above in equation
(1).
[0063] In a further embodiment, a 24 hour profile may be determined
based on time-of-day averages over a predetermined number of days.
The correction factor may then be based on maintaining the
time-of-day averages within a predetermined target range value.
Within the scope of the present invention, the various approaches
and implementations for correction calculation and/or basal profile
modification recommendation may be combined or implemented
individually, depending upon the patient's physiology and the
criteria for drug therapy such as insulin therapy.
[0064] In accordance with the various embodiments of the present
invention, additional or alternative approaches to the
determination of the modification to the basal profile may include,
for example, (1) modifying the basal rate by a constant value, (2)
changing the basal rate by a constant percentage of the current
basal profile rate, (3) changing the basal rate in proportion to
the magnitude of the error, or (4) changing the basal rate in
proportion to the magnitude of the error, compensating for the loop
gain factor based on the affects of the previous basal rate
modifications/adjustments. Each of these approaches within the
scope of the present invention is described in further detail
below.
[0065] In the first embodiment described above, the basal rate is
configured for modification by a constant amount. For example, the
modification is described by the following equation (2):
Modification=sign(measured-target)*U (2)
where U is a constant value in insulin units, and is applied to the
difference between the target glucose and measured glucose
levels.
[0066] Moreover, the "sign(measured-target)" relationship holds the
following: [0067] if (measured-target)=0, then 0 [0068] else if
(measured-target)>0, then +1 [0069] else if
(measured-target)<0, then -1
[0070] For example, in the equation (2) above, the constant value U
may be 0.1 units of insulin/hour. This may be a configurable value.
Indeed, for the case where U is 0.1 units, if the measured glucose
level is 140, while the target glucose level is 100, then the
Modification to the basal rate would result in +1*0.1 equaling 0.1
units/hour.
[0071] In this manner, in one embodiment, a simple and effective
basal rate modification approach is provided and which does not
require knowledge of the patient's physiology, is simple to
implement, and does not provide resolution issues. On the other
hand, for safely values of the constant factor U, several
iterations or corrections may be needed to reach the desired
results.
[0072] In another embodiment, the basal rate may be modified by a
constant percentage of the current rate. In this case, the
following equation (3) holds:
Modification=sign(measured-target)*K*U (3)
where K=constant percentage, 0<=K<=1, and U=current basal
rate (in units of insulin).
[0073] For example, where the constant percentage K is 0.1 and with
the current basal rate U of 2.0 units/hour, and for example, the
measured and target glucose levels at 140 and 100, respectively,
the basal rate Modification in accordance with the equation (3)
equals +1*0.1*2.0=0.2 units/hour. In this manner, in one
embodiment, a simple and effective way to implement basal rate
modification is provided, and which does not require the knowledge
of the user's physiology. For safe values of the constant
percentage K, several iterations may be needed to reach the desired
level of basal rate modification, and resolution issues may
potentially arise.
[0074] In a further embodiment of the present invention, the
modification to the basal rate may be determined by changing the
basal rate proportional to the magnitude of the error. In this
case, the following equation (4) holds:
Modification=(measured-target)*K*P (4)
where K is the loop gain factor, and for example, K<1 for
dampened control, K=1 for critical control, K>1 for over
control, and further, where P is the patient's physiological
response to insulin (insulin sensitivity).
[0075] For example, in the case where the loop gain factor K is
0.75, the patient's insulin sensitivity P is 0.02 units/mg/dL, and
where the measured and target glucose levels are 140 and 100,
respectively, the Modification to the basal rate in accordance to
equation (4) is determined to be (140-100)*0.75*0.02=0.6
units/hour. This approach requires prior determination of the
patient's insulin sensitivity, and may likely require less
iterations or corrective routines to reach the desired level of
basal rate modification for effective treatment.
[0076] In still a further embodiment, the modification to the basal
rate may be determined by the changing the basal rate proportional
to the magnitude of error, and further making adjustment to the
loop gain factor based on the results of the prior basal rate
adjustments. For example, the following equation (5) holds:
with K=f(affect of last adjustment)
Modification=(measured-target)*K*P (5)
where K is loop gain factor, and P is the patient's physiology
response to insulin (insulin sensitivity).
[0077] For example, if the loop gain factor is initially 0.75, then
the determined basal rate modification is the same as in the
embodiment described above in conjunction with equation (4). In the
next iteration, with the measured glucose level still higher than
the target level, the look gain factor is increased. In this case,
for example, with measured glucose level of 110 where the target
level is 100, the new loop gain factor K is determined to be
((first delta)/(first change))*old K=(40/30)*0.75=1.00.
[0078] Having determined the new loop gain factor K, the basal rate
modification is determined by equation (5) as
(110-100)*1.00*0.02=0.2 units/hour. It is to be noted that if the
loop gain factor K did not change between the two iterations
described above, then the basal rate modification in the second
iteration may be relatively smaller, and it can be seen that the
adjustment to the loop gain factor allows faster settling to the
final value. For example, using equation (5) above, the basal rate
modification is determined as:
Modification=(110-100)*0.75*0.02=0.15 units/hour
[0079] In this manner, in one embodiment of the present invention,
the basal rate modification may be configured to self adjust to the
patient's physiology such that it may be more tolerant of
inaccurate input values.
[0080] In this manner, the various embodiments of the present
invention provides a mechanism for diabetic patients to compare the
actual glucose levels during a predetermined time period and to use
that information in addition to the actual basal profile to
recommend a new or modified basal profile to the patient. The
patient will have the option to accept the recommendation, the
accept the recommendation with the modification, or alternatively
to decline the proposed modified basal profile so as to select the
most appropriate basal profile for the patient.
[0081] Moreover, contrasting with real time closed loop insulin
therapy where the insulin infusion is modified at a rate (i.e.,
minutes) much faster than the physiological response times, one
embodiment of the present invention is characterized by a)
corrections to basal profiles that are made over periods (i.e.,
days) which are much longer than physiological response times, and
b) corrections based on repeating diurnal glucose patterns. In this
manner, in one embodiment, the present invention is configured to
identify the patient's glucose levels retrospectively over a
predetermined period of time (for example, over a 24 hour period)
to determine any recommended modification to the existing basal
profiles. In this manner, the recommended modification to the basal
profiles will be a function of the actual measured glucose values
of the patient under the existing basal profiles.
[0082] In the manner described above, in accordance with the
various embodiments of the present invention, the patient and the
doctor or educator may work together to adjust the insulin profile
to the patient's activities. This will require experience and some
trial and error as well. An automated basal profile correction in
accordance with the embodiments of the present invention may
monitor and gather much more information and may incorporate the
knowledge of the physician/educator within the modification
algorithm. Indeed, different objectives can be identified and the
modification algorithms developed to achieve the objectives.
[0083] Accordingly, a method in one embodiment includes monitoring
an analyte level of a patient, retrieving a predetermined
parameter, and determining a modification to an drug therapy
profile based on the monitored analyte level and the predetermined
parameter.
[0084] The analyte includes glucose, and the drug infusion rate may
include a basal profile.
[0085] Further, the predetermined parameter may include one or more
of an insulin sensitivity, a drug infusion rate, and a drug
infusion time period, a time period corresponding to the monitored
analyte level, a time of day associated with the monitored analyte
level, or a loop gain factor.
[0086] Moreover, the monitoring step may include determining the
analyte level of the patient at a predetermined time interval
including one of 5 minutes, 30 minutes, 1 hour, or 2 hours.
[0087] The method in one embodiment may further include the step of
outputting the modification to the drug therapy profile to the
patient.
[0088] Also, the method may additionally include the step of
implementing the modification to the drug therapy profile.
[0089] In a further aspect, the drug therapy profile may include an
insulin infusion profile.
[0090] A system in yet another embodiment of the present invention
includes an analyte monitoring unit, and a processing unit
operatively coupled to the analyte monitoring unit, the processing
unit configured to receive a plurality of monitored analyte levels
of a patient, and to determine a modification to a drug therapy
profile based on the received plurality of monitored analyte
levels.
[0091] The analyte monitoring unit in one embodiment may include a
sensor unit provided in fluid contact with an analyte of a
patient.
[0092] Further, the sensor unit may include a subcutaneous analyte
sensor, a transcutaneous analyte sensor, and a transdermal patch
sensor.
[0093] Moreover, the processing unit may be operatively coupled to
an infusion device.
[0094] In a further aspect, the processing unit may include an
insulin pump.
[0095] Moreover, in still another aspect, the processing unit may
be is configured to determine the modification based on a pattern
in the monitored analyte level, where the pattern may be determined
based on the plurality of monitored analyte levels for a
predetermined time period, and further, where the predetermined
time period may include one of a 12 hour period, or 24 hour
period.
[0096] The system in ye another embodiment may include a display
unit operatively coupled to the processing unit for displaying the
determined modification.
[0097] 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.
* * * * *