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`US 20080281179Al
`
`c19) United States
`c12) Patent Application Publication
`Fennell et al.
`
`c10) Pub. No.: US 2008/0281179 Al
`Nov. 13, 2008
`(43) Pub. Date:
`
`(54) ANALYTE MONITORING SYSTEM AND
`METHODS
`
`(75)
`
`Inventors:
`
`Martin J. Fennell, Concord, CA
`(US); Lei He, Moraga, CA (US);
`Mark K. Sloan, Redwood City, CA
`(US)
`
`Correspondence Address:
`JACKSON & CO., LLP
`6114 LA SALLE AVENUE, #507
`OAKLAND, CA 94611-2802 (US)
`
`(73) Assignee:
`
`Abbott Diabetes Care, Inc.,
`Alameda, CA (US)
`
`(21) Appl. No.:
`
`12/117,694
`
`(22) Filed:
`
`May 8, 2008
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/916,773, filed on May
`8, 2007.
`
`Publication Classification
`
`(51)
`
`Int. Cl.
`A61B 51145
`(2006.01)
`G06F 1100
`(2006.01)
`(52) U.S. Cl. .......................... 600/347; 713/300; 600/345
`
`(57)
`
`ABSTRACT
`
`Methods and systems for providing data communication in
`medical systems are disclosed.
`
`301
`
`'
`
`TEST STRIP
`INTERFACE
`
`302 ~ - -----
`
`RF RECEIVER
`
`FROM
`TRANSMITTER 102
`
`-._ 307
`
`~ 309
`
`SERIAL
`COMMUNICATION
`SECTION
`
`TO
`DATA PROCESSING
`TERMINAL 105
`
`PROCESSING
`&STORAGE
`
`POWER
`CONVERSION
`AND
`MONITORING
`SECTION
`
`OUTPUT/DISPLAY
`
`310
`
`POWER
`SUPPLY
`
`· __ ..• - 308
`
`306
`
`304
`
`I\
`
`305
`
`CLOCK
`
`104
`
`Page 1 of 27
`
`

`

`Patent Application Publication
`
`Nov. 13, 2008 Sheet 1 of 14
`
`US 2008/0281179 Al
`
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`Page 2 of 27
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`

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`FIGURE 2
`
`102
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`207
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`
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`
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`
`j
`
`◄
`
`SECTION
`
`MEASUREMENT
`TEMPERATURE
`
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`
`203-
`
`202
`
`214
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`To Receiver 104
`
`►
`
`I
`
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`
`PROCESSOR
`
`206
`
`SECTION
`
`....-----+I COMMUNICATION
`
`SERIAL
`
`205
`
`204
`
`CIRCUIT
`
`LEAK DETECTION
`
`INTERFACE
`
`ANALOG
`
`209
`
`201-----
`
`211
`
`Page 3 of 27
`
`

`

`Patent Application Publication
`
`Nov. 13, 2008 Sheet 3 of 14
`
`US 2008/0281179 Al
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`Page 4 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 4 of 14
`
`US 2008/0281179 Al
`
`START
`
`1,
`INITIALIZE COUNTER:
`T=0
`- 410
`
`~
`
`~
`
`1,
`RETRIEVE ROLLING DATA
`ATT
`- 420
`
`1,
`RETRIEVE TIME SENSITIVE
`DATA
`- 430
`
`1,
`GENERATE DATA PACKET FOR
`TRANSMISSION
`- 440
`
`1,
`INCREMENT T = T + 1
`- 450
`
`FIGURE 4
`
`Page 5 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 5 of 14
`
`US 2008/0281179 Al
`
`START
`
`H
`RECEIVE DATA PACKET - 510
`
`H
`PARSE RECEIVED DATA
`PACKET INTO ROLLING DATA
`AND TIME SENSITIVE DATA
`- 520
`
`H
`STORE PARSED DATA
`- 530
`
`H
`
`END
`
`FIGURE 5
`
`Page 6 of 27
`
`

`

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`
`FIGURE 6
`
`Comparator
`Power Voltage
`
`Ultra Low
`
`22
`
`GRD
`
`R2
`
`_L
`
`Capacitor
`
`Storage
`
`rattery
`
`21
`
`623----....,_ • Electronic Switch
`
`Rl
`
`>
`
`I
`
`CNTR
`
`I
`
`Receiver (OOK)
`Close Proximity
`
`(FSK)
`
`Rf Transmitter
`
`CPU
`
`24
`
`R
`E
`T
`N
`u
`0
`C
`
`to Frequency
`Sensor Current
`
`WRK
`
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`
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`
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`
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`
`R
`0
`s
`N
`E
`s
`
`Page 7 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 7 of 14
`
`US 2008/0281179 Al
`
`START
`
`,,
`RETRIEVE A CLOSE
`PROXIMITY COMMAND FOR
`TRANSMISSION
`- 710
`
`,,
`ESTABLISH TRANSMISSION
`RANGE
`-720
`
`TRANSMIT THE CLOSE
`PROXIMITY COMMAND WHILE
`WITHIN THE ESTABLISHED
`TRANSMISSION RANGE
`- 730
`,,
`RECEIVE PACKET IN
`RESPONSE TO THE CLOSE
`PROXIMITY COMMAND
`- 740
`
`,,
`GENERA TE A KEY BASED ON
`THE RECEIVED PACKET
`- 750
`
`,,
`END
`
`FIGURE 7
`
`Page 8 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 8 of 14
`
`US 2008/0281179 Al
`
`START
`
`',
`DETECT CONNECTION TO
`SENSOR
`- 810
`
`V
`EXIT POWER DOWN MODE
`- 820
`
`,,
`RECEIVE AND PROCESS
`SENSOR SIGNAL
`- 830
`
`',
`TRANSMIT PROCESSED
`SENSOR SIGNAL
`- 840
`
`V
`
`END
`
`FIGURE 8
`
`Page 9 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 9 of 14
`
`US 2008/0281179 Al
`
`START
`
`u
`DETECT SENSOR REMOVAL
`- 910
`
`u
`GENERATE STATUS SIGNAL
`- 920
`
`u
`TRANSMIT GENERATED
`STATUS SIGNAL
`- 930
`
`u
`ENTER POWER DOWN MODE
`- 940
`
`u
`
`END
`
`FIGURE 9
`
`Page 10 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 10 of 14
`
`US 2008/0281179 Al
`
`START
`
`,,
`
`RECEIVE SENSOR INTIATE
`COMMAND
`- 1010
`
`,,
`
`RETRIEVE AND TRANSMIT
`IDENTIFICATION
`INFORMATION
`-1020
`
`,,
`
`RECEIVE COMMUNICATION
`KEY
`- 1030
`
`,,
`TRANSMIT SENSOR RELATED
`DATA WITH KEY
`-1040
`
`,,
`
`END
`
`FIGURE 10
`
`Page 11 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 11 of 14
`
`US 2008/0281179 Al
`
`START
`
`,,
`TRANSMIT SENSOR INTIATE
`COMMAND
`- 1110
`
`,,
`RECEIVE TRANSMITTER
`IDENTIFICATION
`INFORMATION
`- 1120
`
`,,
`GENERATE AND TRANSMIT
`COMMUNICATION KEY
`- 1130
`
`,,
`
`END
`
`FIGURE 11
`
`Page 12 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 12 of 14
`
`US 2008/0281179 Al
`
`START
`
`, ..
`DETECT PERIODIC DATA
`TRANSMISSION
`- 1210
`
`, ..
`INCREMENT A COUNT FOR
`EACH DETECTED DATA
`TRANSMISSION
`- 1220
`
`, ..
`PERIODICALLY TRANSMIT THE
`COUNT
`- 1230
`
`, ..
`STORE THE COUNT
`- 1240
`
`'r
`
`END
`
`FIGURE 12
`
`Page 13 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 13 of 14
`
`US 2008/0281179 Al
`
`START
`
`RECEIVE A CLOSE PROXIMITY
`COMMAND
`- 1310
`
`u
`DETERMINE COMMUNICATION
`STATUS
`- 1320
`
`u
`MODIFY THE
`COMMUNICATION STATUS
`BASED ON THE RECEIVED
`COMMAND
`- 1330
`
`',
`END
`
`FIGURE 13
`
`Page 14 of 27
`
`

`

`Patent Application Publication Nov. 13, 2008 Sheet 14 of 14
`
`US 2008/0281179 Al
`
`START
`
`f
`
`l
`
`,,
`
`RECEIVE SENSOR COUNTER
`INFORMATION
`- 1410
`
`,
`RETRIEVE STORED SENSOR
`COUNTER INFORMATION
`-1420
`
`,,
`
`COMPARE THE RECEIVED
`SENSOR COUNTER
`INFORMATION WITH THE
`RETRIEVED SENSOR COUNTER
`INFORMATION
`-1430
`
`,,
`
`GENERATE AND OUTPUT
`SIGNAL BASED ON THE
`COMPARISON
`-1440
`
`END
`
`f
`
`l
`
`FIGURE 14
`
`Page 15 of 27
`
`

`

`US 2008/0281179 Al
`
`Nov. 13, 2008
`
`1
`
`ANALYTE MONITORING SYSTEM AND
`METHODS
`
`the following detailed description of the embodiments, the
`appended claims and the accompanying drawings.
`
`RELATED APPLICATION
`
`[0001] The present application claims priority under 35
`U.S.C. § 119( e) to U.S. provisional application No. 60/916,
`773 filed May 8, 2007, entitled "Analyte Monitoring System
`and Methods", the disclosure of which is incorporated herein
`by reference for all purposes.
`
`BACKGROUND
`
`[000_2] Analyte, e._g., glucose monitoring systems including
`~ontmuous and discrete monitoring systems generally
`mclude a small, lightweight battery powered and micropro(cid:173)
`cessor c_ontrolled system which is configured to detect signals
`proport10nal to the corresponding measured glucose levels
`using an electrometer. RF signals may be used to transmit the
`collected data. One aspect of certain analyte monitoring sys(cid:173)
`tems include a transcutaneous or subcutaneous analyte sensor
`c_onfiguration which is, for example, at least partially posi(cid:173)
`tioned through the skin layer of a subject whose analyte level
`is to be monitored. The sensor may use a two or three-elec(cid:173)
`trode (work, reference and counter electrodes) configuration
`driven by a controlled potential (potentiostat) analog circuit
`connected through a contact system.
`[0003] An analyte sensor may be configured so that a por(cid:173)
`tion thereof is placed under the skin of the patient so as to
`contact analyte of the patient, and another portion or segment
`of the analyte sensor may be in communication with the
`transmitter unit. The transmitter unit may be configured to
`transmit the analyte levels detected by the sensor over a
`wireless communication link such as an RF (radio frequency)
`communication link to a receiver/monitor unit. The receiver/
`monitor unit may perform data analysis, among other func(cid:173)
`tions, on the received analyte levels to generate information
`pertaining to the monitored analyte levels.
`[0004] Transmission of control or command data over
`wireless communication link is often constrained to occur
`within a substantially short time duration. In turn, the time
`const~aint in data communication imposes limits on the type
`and size of data that may be transmitted during the transmis(cid:173)
`sion time period.
`[0005]
`In view of the foregoing, it would be desirable to
`have a method and apparatus for optimizing the RF commu(cid:173)
`nication link between two or more communication devices
`for example, in a medical communication system.
`'
`
`SUMMARY
`
`[0006] Devices and methods for analyte monitoring, e.g.,
`glucose monitoring, are provided. Embodiments include
`transmitting information from a first location to a second
`e.g., using a telemetry system such as RF telemetry. System~
`h~rein include continuous analyte monitoring systems and
`discrete analyte monitoring system.
`[0007]
`In one embodiment, a method including detecting
`an electrical connection with an analyte sensor, and activating
`a data processing device to receive one or more analyte
`related signals from the analyte sensor, is disclosed, as well as
`devices and systems for the same.
`[0008] These and other objects, features and advantages of
`the present invention will become more fully apparent from
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`[0009] FIG. 1 illustrates a block diagram of a data monitor(cid:173)
`ing and management system for practicing one or more
`embodiments of the present invention;
`[0010] 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;
`[0011] FIG. 3 is a block diagram of the receiver/monitor
`unit of the data monitoring and management system shown in
`~IG. ~ in accordance with one embodiment of the present
`mvent10n;
`[0012] FIG. 4 is a flowchart illustrating data packet proce(cid:173)
`dure including rolling data for transmission in accordance
`with one embodiment of the present invention;
`[0013] FIG. 5 is a flowchart illustrating data processing of
`the received data packet including the rolling data in accor(cid:173)
`dance with one embodiment of the present invention;
`[0014] FIG. 6 is a block diagram illustrating the sensor unit
`and the transmitter unit of the data monitoring and manage(cid:173)
`ment system of FIG. 1 in accordance with one embodiment of
`the present invention;
`[0015] FIG. 7 is a flowchart illustrating data communica(cid:173)
`tion using close proximity commands in the data monitoring
`and management system of FIG. 1 in accordance with one
`embodiment of the present invention;
`[0016] FIG. 8 is a flowchart illustrating sensor insertion
`detection routine in the data monitoring and management
`system of FIG. 1 in accordance with one embodiment of the
`present invention;
`[0017] FIG. 9 is a flowchart illustrating sensor removal
`detection routine in the data monitoring and management
`system of FIG. 1 in accordance with one embodiment of the
`present invention;
`[0018] FIG. 10 is a flowchart illustrating the pairing or
`synchronization routine in the data monitoring and manage(cid:173)
`ment system of FIG. 1 in accordance with one embodiment of
`the present invention;
`[0019] FIG. 11 is a flowchart illustrating the pairing or
`synchronization routine in the data monitoring and manage(cid:173)
`ment system of FIG. 1 in accordance with another embodi(cid:173)
`ment of the present invention;
`[0020] FIG. 12 is a flowchart illustrating the power supply
`determination in the data monitoring and management sys(cid:173)
`tem of FIG. 1 in accordance with one embodiment of the
`present invention;
`[0021] FIG. 13 is a flowchart illustrating close proximity
`command for RF communication control in the data moni(cid:173)
`toring and management system of FIG. 1 in accordance with
`one embodiment of the present invention; and
`[0022] FIG. 14 is a flowchart illustrating analyte sensor
`identification routine in accordance with one embodiment of
`the present invention.
`
`DETAILED DESCRIPTION
`
`[0023] As summarized above and as described in further
`detail below, in accordance with the various embodiments of
`the present invention, there is provided a method and system
`for det~cti~g an electrical connection with an analyte sensor,
`and act1vatmg a data processing device to receive one or more
`analyte related signals from the analyte sensor.
`
`Page 16 of 27
`
`

`

`US 2008/0281179 Al
`
`Nov. 13, 2008
`
`2
`
`[0024] FIG. 1 illustrates a data monitoring and manage(cid:173)
`ment system such as, for example, 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 under(cid:173)
`stood that the analyte monitoring system may be configured
`to monitor a variety of analytes, e.g., lactate, and the like.
`[0025] Analytes that may be monitored include, for
`example, acetyl choline, amylase, bilirubin, cholesterol,
`chorionic gonadotropin, creatinekinase (e.g., CK-MB), cre(cid:173)
`atine, DNA, fructosamine, glucose, glutamine, growth hor(cid:173)
`mones, hormones, ketones, lactate, peroxide, prostate-spe(cid:173)
`cific 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. More than one analyte may
`be monitored by a single system, e.g. a single analyte sensor.
`[0026] The analyte monitoring system 100 includes a sen(cid:173)
`sor unit 101, a transmitter unit 102 coupleable to the sensor
`unit 101, and a primary receiver unit 104 which is configured
`to communicate with the transmitter unit 102 via a bi-direc(cid:173)
`tional communication link 103. The primary receiverunit 104
`may be further configured to transmit data to a data process(cid:173)
`ing terminal 105 for evaluating the data received by the pri(cid:173)
`mary receiver unit 104. Moreover, the data processing termi(cid:173)
`nal 105 in one embodiment may be configured to receive data
`directly from the transmitter unit 102 via a communication
`link which may optionally be configured for bi-directional
`communication. Accordingly, transmitter unit 102 and/or
`receiver unit 104 may include a transceiver.
`[0027] Also shown in FIG. 1 is an optional secondary
`receiver unit 106 which is operatively coupled to the commu(cid:173)
`nication link and configured to receive data transmitted from
`the transmitter unit 102. Moreover, as shown in the Figure, the
`secondary receiver unit 106 is configured to communicate
`with the primary receiver unit 104 as well as the data process(cid:173)
`ing terminal 105. Indeed, the secondary receiver unit 106 may
`be configured for bi-directional wireless communication with
`each or one of the primary receiver unit 104 and the data
`processing terminal 105. As discussed in further detail below,
`in one embodiment of the present invention, the secondary
`receiver unit 106 may be configured to include a limited
`number of functions and features as compared with the pri(cid:173)
`mary receiver unit 104. As such, the secondary receiver unit
`106 may be configured substantially in a smaller compact
`housing or embodied in a device such as a wrist watch, pager,
`mobile phone, PDA, for example. Alternatively, the second(cid:173)
`ary receiver unit 106 may be configured with the same or
`substantially similar functionality as the primary receiver unit
`104. The receiver unit may be configured to be used in con(cid:173)
`junction with a docking cradle unit, for example for one or
`more of the following or other functions: placement by bed(cid:173)
`side, for re-charging, for data management, for night time
`monitoring, and/or bi-directional communication device.
`[0028]
`In one aspect sensor unit 101 may include two or
`more sensors, each configured to communicate with trans(cid:173)
`mitter unit 102. Furthermore, while only one, transmitter unit
`102, communication link 103, and data processing terminal
`105 are shown in the embodiment of the analyte monitoring
`system 100 illustrated in FIG. 1. However, it will be appreci(cid:173)
`ated by one of ordinary skill in the art that the analyte moni-
`
`taring system 100 may include one or more sensors, multiple
`transmitter units 102, communication links 103, and data
`processing terminals 105. 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. In a multi-component environ(cid:173)
`ment, each device is configured to be uniquely identified by
`each of the other devices in the system so that communication
`conflict is readily resolved between the various components
`within the analyte monitoring system 100.
`[0029]
`In one embodiment of the present invention, the
`sensor unit 101 is physically positioned in or on the body of a
`user whose analyte level is being monitored. The sensor unit
`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 certain embodiments, the transmitter unit 102
`may be physically coupled to the sensor unit 101 so that both
`devices are integrated in a single housing and positioned on
`the user's body. The transmitter unit 102 may perform data
`processing such as filtering and encoding on data signals
`and/or other functions, each of which corresponds to a
`sampled analyte level of the user, and in any event transmitter
`unit 102 transmits analyte information to the primary receiver
`unit 104 via the communication link 103.
`[0030]
`In one embodiment, the analyte monitoring system
`100 is configured as a one-way RF communication path from
`the transmitter unit 102 to the primary receiver unit 104. In
`such embodiment, the transmitter unit 102 transmits the
`sampled data signals received from the sensor unit 101 with(cid:173)
`out acknowledgement from the primary receiver unit 104 that
`the transmitted sampled data signals have been received. For
`example, the transmitter unit 102 may be configured to trans(cid:173)
`mit 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 primary 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 primary receiver unit 104.
`[0031] Additionally, in one aspect, the primary receiver
`unit 104 may include two sections. The first section is an
`analog interface section that is configured to communicate
`with the transmitterunit 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 primary
`receiver unit 104 is a data processing section which is con(cid:173)
`figured to process the data signals received from the transmit(cid:173)
`ter unit 102 such as by performing data decoding, error detec(cid:173)
`tion and correction, data clock generation, and data bit
`recovery.
`[0032]
`In operation, upon completing the power-on proce(cid:173)
`dure, the primary 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 and/or a predetermined trans(cid:173)
`mitter identification information. Upon successful synchro(cid:173)
`nization with the corresponding transmitter unit 102, the pri(cid:173)
`mary receiver unit 104 is configured to begin receiving from
`the transmitter unit 102 data signals corresponding to the
`
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`Nov. 13, 2008
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`3
`
`user's detected analyte level. More specifically, the primary
`receiver unit 104 in one embodiment is configured to perform
`synchronized time hopping with the corresponding synchro(cid:173)
`nized transmitter unit 102 via the communication link 103 to
`obtain the user's detected analyte level.
`[0033] Referring again to FIG. 1, the data processing ter(cid:173)
`minal 105 may include a personal computer, a portable com(cid:173)
`puter 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 pro(cid:173)
`cessing terminal 105 may further be connected to a data
`network (not shown) for storing, retrieving and updating data
`corresponding to the detected analyte level of the user.
`[0034] Within the scope of the present invention, the data
`processing terminal 105 may include an infusion device such
`as an insulin infusion pump ( external or implantable) 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 mea(cid:173)
`sured analyte level. Alternatively, the receiver unit 104 may
`be configured to integrate or otherwise couple to 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.
`[0035] Additionally, the transmitter unit 102, the primary
`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 primary receiver
`unit 104 and the data processing terminal 105 may be con(cid:173)
`figured 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.
`[0036]
`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 103 includ(cid:173)
`ing data processing for managing the patient's insulin therapy
`and analyte monitoring. In one embodiment, the communi(cid:173)
`cation link 103 may include one or more of an RF communi(cid:173)
`cation protocol, an infrared communication protocol, a Blue(cid:173)
`tooth enabled communication protocol, an 802.1 lx wireless
`communication protocol, or an equivalent wireless commu(cid:173)
`nication protocol which would allow secure, wireless com(cid:173)
`munication of several units (for example, per HIPP A require(cid:173)
`ments) while avoiding potential data collision and
`interference.
`[0037] 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 unit 102 in one
`embodiment includes an analog interface 201 configured to
`communicate with the sensor unit 101 (FIG. 1), a user input
`202, and a temperature detection 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 elec-
`
`trodes-work electrode (W) 210, guard contact (G) 211, ref(cid:173)
`erence electrode (R) 212, and counter electrode (C) 213, each
`operatively coupled to the analog interface 201 of the trans(cid:173)
`mitter unit 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 or ablated, for
`example, such as carbon which may be printed, or a metal
`such as a metal foil ( e.g., gold) or the like, which may be
`etched or ablated or otherwise processed to provide one or
`more electrodes. Fewer or greater electrodes and/or contact
`may be provided in certain embodiments.
`[0038] 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 pro(cid:173)
`cessor 204. Moreover, a power supply 207 such as a battery is
`also provided in the transmitter unit 102 to provide the nec(cid:173)
`essary power for the transmitter unit 102. Additionally, as can
`be seen from the Figure, clock 208 is provided to, among
`others, supply real time information to the transmitter proces(cid:173)
`sor 204.
`[0039]
`In one embodiment, a unidirectional input path is
`established from the sensor unit 101 (FIG. 1) and/or manu(cid:173)
`facturing and testing equipment to the analog interface 201 of
`the transmitter unit 102, while a unidirectional output is
`established from the output of the RF transmitter 206 of the
`transmitter unit 102 for transmission to the primary receiver
`unit 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 embodi(cid:173)
`ment, via the data path described above, the transmitter unit
`102 is configured to transmit to the primary receiver unit 104
`(FIG.1), via the communication link 103 (FIG. 1), processed
`and encoded data signals received from the sensor unit 101
`(FIG. 1). Additionally, the unidirectional communication
`data path between the analog interface 201 and the RF trans(cid:173)
`mitter 206 discussed above allows for the configuration of the
`transmitter unit 102 for operation upon completion of the
`manufacturing process as well as for direct communication
`for diagnostic and testing purposes.
`[0040] As discussed above, the transmitter processor 204 is
`configured to transmit control signals to the various sections
`of the transmitter unit 102 during the operation of the trans(cid:173)
`mitter unit 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 unit 102,
`as well as the data signals received from the sensor unit 101.
`The stored information may be retrieved and processed for
`transmission to the primary receiver unit 104 under the con(cid:173)
`trol of the transmitter processor 204. Furthermore, the power
`supply 207 may include a commercially available battery,
`which may be a rechargeable battery.
`[0041]
`In certain embodiments, the transmitter unit 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, e.g., after
`having been stored for about eighteen months such as stored
`in a low-power (non-operating) mode. In one embodiment,
`this may be achieved by the transmitter processor 204 oper(cid:173)
`ating in low power modes in the non-operating state, for
`example, drawing no more than approximately 1 µA of cur-
`
`Page 18 of 27
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`Nov. 13, 2008
`
`4
`
`rent. Indeed, in one embodiment, a step during the manufac(cid:173)
`turing process of the transmitter unit 102 may place the trans(cid:173)
`mitter unit 102 in the lower power, non-operating state (i.e.,
`post-manufacture sleep mode). In this manner, the shelf life
`of the transmitter unit 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.
`[0042] Referring back to FIG. 2, the power supply section
`207 of the transmitter unit 102 in one embodiment may
`include a rechargeable battery unit that may be recharged by
`a separate power supply recharging unit (for example, pro(cid:173)
`vided in the receiver unit 104) so that the transmitter unit 102
`may be powered for a longer period of usage time. Moreover,
`in one embodiment, the transmitter unit 102 may be config(cid:173)
`ured without a battery in the power supply section 207, in
`which case the transmitter unit 102 may be configured to
`receive power from an external power supply source (for
`example, a battery) as discussed in further detail below.
`[0043] Referring yet again to FIG. 2, the temperature detec(cid:173)
`tion section 203 of the transmitter unit 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. In certain
`embodiments, the RF transmitter 206 of the transmitter unit
`102 may be configured for operation in the frequency band of
`approximately 315 MHz to approximately 322 MHz, for
`example, in the United States. In certain embodiments, the RF
`transmitter 206 of the transmitter unit 102 may be configured
`for operation in the frequency band of approximately 400
`MHz to approximately 470 MHz. Further, in one embodi(cid:173)
`ment, the RF transmitter 206 is configured to modulate the
`carrier frequency by performing Frequency Shift Keying and
`Manchester encoding. In one embodiment, the data transmis(cid:173)
`sion rate is about 19,200 symbols per second, with a mini(cid:173)
`mum transmission range for communication with the primary
`receiver unit 104.
`[0044] 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 unit 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 unit 101 to determine whether the measured sensor
`data are corrupt or whether the measured data from the sensor
`101 is accurate. Describe sensor, calibration (single point),
`etc. Exemplary analyte systems that may be employed are
`described in, for example, U.S. Pat. Nos. 6,134,461, 6,175,
`752, 6,121,611, 6,560,471, 6,746,582, and elsewhere, the
`disclosure of each of which are incorporated by reference for
`all purposes.
`[0045] FIG. 3 is a block diagram of the