Patent Description:
Embodiments of the subject matter described herein relate generally to medical devices, and more particularly, embodiments of the subject matter relate to managing transitions into fluid infusion device operating modes.

Infusion pump devices and systems are relatively well known in the medical arts, for use in delivering or dispensing an agent, such as insulin or another prescribed medication, to a patient. A typical infusion pump includes a pump drive system which typically includes a small motor and drive train components that convert rotational motor motion to a translational displacement of a plunger (or stopper) in a reservoir that delivers medication from the reservoir to the body of a user via a fluid path created between the reservoir and the body of a user. Use of infusion pump therapy has been increasing, especially for delivering insulin for diabetics.

Continuous insulin infusion provides greater control of a diabetic's condition, and hence, control schemes are being developed that allow insulin infusion pumps to monitor and regulate a user's blood glucose level in a substantially continuous and autonomous manner. For example, an insulin infusion pump may operate in a closed-loop operating mode overnight while a user is sleeping to regulate the user's glucose level to a target glucose level. In practice, multiple different operating modes for providing continuous insulin infusion may be supported by an infusion pump. However, care must be taken when transitioning between operating modes to avoid potentially compromising a user's condition and ensure compliance with applicable regulatory requirements.

Additionally, in some situations, one or more preconditions must be satisfied before entering to a particular operating mode is allowed. When preconditions are not satisfied, entry into the operating mode may be denied, which may frustrate a user who would like to operate the infusion pump in that particular operating mode at that particular moment in time. Additionally, after entering a particular operating mode, various conditions may be encountered while operating the infusion pump in that operating mode that result in generation of alerts, which could be disruptive or distracting to the user. Thus, it is desirable to provide multiple different operating modes that facilitate greater and more customizable control over the user's physiological condition without degrading the user experience. [ 5a] <CIT> describes a pump system operating in a normal mode when a calculated predicted blood glucose is at or above a lower threshold level and is also at or below an upper threshold level. The document also describes a low glucose recovery mode when a future low blood glucose event has been predicted. The document also describes a comparison of a calculated blood glucose prediction to a threshold level to determine whether the infusion pump system should continue in the low blood glucose recover mode or whether the infusion pump system should exit from the low blood glucose recovery mode to return to the normal mode.

The invention is defined by claims <NUM> and <NUM> and preferred embodiments are defined by the dependent claims. Infusion devices, systems and related methods of operation in accordance with various operating modes are provided. One exemplary method involves operating an infusion device to deliver fluid to a user in accordance with a first operating mode of a plurality of operating modes, obtaining operational information pertaining to the first operating mode, and obtaining clinical information pertaining to the user. The method continues by determining a destination operating mode of the plurality of operating modes based at least in part on the operational information and the clinical information, and operating the infusion device to deliver the fluid in accordance with the destination operating mode in a manner that is influenced by at least a portion of the operational information pertaining to the first operating mode.

Another embodiment of an infusion device includes a data storage element to maintain operational information pertaining to a first operating mode of a plurality of operating modes and clinical information pertaining to a user, a motor operable to deliver fluid influencing a physiological condition to a body of the user, and a control system coupled to the motor and the data storage element. The control system operates the motor to deliver the fluid in accordance with the first operating mode, determines a destination operating mode of the plurality of operating modes based at least in part on the operational information and the clinical information, and operates the infusion device to deliver the fluid in accordance with the destination operating mode in a manner that is influenced by at least a portion of the operational information pertaining to the first operating mode.

In yet another embodiment, a method of operating an infusion device operable to deliver insulin to a user involves operating the infusion device to deliver the insulin in accordance with a first operating mode of a plurality of operating modes, obtaining operational information pertaining to the first operating mode, and obtaining one or more glucose values for the user. In response to an indication to terminate the first operating mode, the method continues by determining a set of one or more possible operating modes from the plurality of operating modes based at least in part on the one or more glucose values and the operational information. The method selects a destination operating mode from the set of one or more possible operating modes and operates the infusion device to deliver the insulin in accordance with the destination operating mode in a manner that is influenced by at least a portion of the operational information pertaining to the first operating mode.

The invention also provides an infusion device for a medicinal fluid, the device including: a motor operable to deliver the fluid in response to commands; a management system coupled to the motor for generating said commands; wherein the management system includes: a plurality of control modules each configured to generate said commands in accordance with a different respective operating mode; a supervisory module connected to each of the control modules and configured to monitor the status of the control modules, and to receive a mode transition signal; a command multiplexer connected to each of the control modules, to the motor, and to the supervisory module and configured to direct the said commands from a selected one of the control modules to the motor, in accordance with a selection signal from the supervisory module; the supervisory module being further configured to change the selection signal, upon receipt of the mode transition signal thereby causing the command multiplexer to direct the commands from a different selected one of the control modules to the motor.

The infusion device may further include a user interface and the mode transition signal may be generated by a user manipulating the user interface. The management system may be configured to generate the mode transition signal in response to a predetermined maximum operation time limit being reached by a control module that is generating the commands being sent to the motor. In addition, or instead, the management system may be configured to generate the mode transition signal in response to a unreliability being detected in a control module that is generating the commands being sent to the motor. The supervisory module maybe configured to inhibit the selection on receipt of the mode transition signal, of a control module in which an unreliability has been detected.

The said status may include a prediction of future commands that would be directed to the motor if a respective control module were selected, and the supervisory module may be configured to inhibit the selection on receipt of the mode transition signal, of a control module where the future commands would result in one or more of transgression of a pre-specified maximum suspension time, transgression of a pre-specified maximum delivery limit, and failure to meet a pre-specified minimum delivery threshold.

The operating modes may be selected from a list comprising open-loop mode, closed-loop mode, LGS mode in which a basal rate of delivery of the medicinal fluid is provided while a physiological analyte level that is controlled by the medicinal fluid is above a threshold and suspended while it is not, and PLGM mode in which a basal rate of delivery of the medicinal fluid is provided while a predicted level of the physiological analyte that is controlled by the medicinal fluid is above a threshold and suspended while it is not. The medicinal fluid may be insulin.

A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures, which may be illustrated for simplicity and clarity and are not necessarily drawn to scale.

While the subject matter described herein can be implemented in any electronic device that includes a motor, exemplary embodiments described below are implemented in the form of medical devices, such as portable electronic medical devices. Although many different applications are possible, the following description focuses on a fluid infusion device (or infusion pump) as part of an infusion system deployment. For the sake of brevity, conventional techniques related to infusion system operation, insulin pump and/or infusion set operation, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail here. Examples of infusion pumps may be of the type described in, but not limited to, <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>.

Described herein is a fluid infusion devices including a motor that is operable to linearly displace a plunger (or stopper) of a reservoir provided within the fluid infusion device to deliver a dosage of fluid, such as insulin, to the body of a user. However, as the invention relates to the operation of the infusion device and the structure necessary for that operation detail of any mechanical structures for conveying or propelling the fluid is given as an example only. Dosage commands that govern operation of the motor, i.e. the device responsible for directly or indirectly imparting motion to the fluid, may be generated in an automated manner in accordance with the delivery control scheme associated with a particular operating mode. The fluid infusion device may be operated in any one of a number of operating modes and be able to switch between the modes. Examples of operating modes are closed-loop, predictive, and open-loop. The device typically contains algorithms which when executed implement respective ones of the operating modes. In that case switching modes involves switching from one algorithm to another. In a closed-loop operating mode, for example, the dosage commands are generated based on a difference between a current (or most recent) measurement of a physiological condition in the body of the user (e.g., an interstitial fluid glucose level in the case of diabetes management by infusion of insulin) and a target (or reference) value for that physiological condition. In a predictive operating mode, the dosage commands may be influenced by a predicted value (or anticipated measurement) for that physiological condition in the body of the user at some point in the future. Conversely, in an open-loop operating mode, the dosage commands may be configured to implement a predetermined delivery rate. Such rate may be substantially independent of the current or predicted measurements of the physiological condition of the user.

As described in greater detail below primarily in the context of <FIG>, in exemplary embodiments, transitions between operating modes implemented by the infusion device are also supervised or otherwise managed to maintain satisfactory control of the user's physiological condition and ensure compliance with applicable delivery control rules. The delivery control rules may be dictated by regulatory requirements, manufacturer requirements, device settings, user preferences, or the like. In this regard, the destination operating mode is initialized using operational information pertaining to the current operation of the infusion device in the initial operating mode being transitioned from to provide a relatively seamless transition between operating modes. In exemplary embodiments, before transitioning to the destination operating mode, information pertaining to the operating mode currently being implemented is obtained. The operational information characterizes the current instance of the current operating mode and may include, for example, delivery or suspension information (e.g., whether or not delivery was suspended at any time, the duration delivery was suspended, and the like), the values of any active timers (e.g., the duration of a current instance of delivery suspension, the duration of a current refractory period, and the like), alert information (e.g., whether or not any alerts where generated, and information identifying what types of alerts were generated or the root cause) and information indicating why the current instance of the current operating mode is being exited. At least a portion of the operational information is provided to the destination operating mode upon the transition from the previous operating mode, with the operation of the infusion device in accordance with the destination operating mode being influenced by that operational information. For example, the destination operating mode may be initialized with the same timer values or counter values from the preceding operating mode to ensure that no time constraints or other applicable maximum limits are violated by the destination operating mode.

In exemplary embodiments, before transitioning into a destination operating mode, clinical status information pertaining to the physiological condition of the user is also obtained. As described above, the clinical information may include, for example, recent or historical sensor measurement values of the physiological condition of the user, reference measurement values of the physiological condition of the user, sensor calibration history for the user, and the like. In one or more embodiments, the destination operating mode is automatically determined based at least in part on portions of the clinical information and the operational information for the current operating mode along with the device settings or user preferences establishing a hierarchical order for the operating modes. In this regard, the clinical information and/or the operational information may be used to identify and exclude operating modes that are likely to violate any applicable constraints or requirements upon entry, with the hierarchical information for the operating modes being used to select the most preferable operating mode from among the remaining potential operating modes.

Turning now to <FIG>, one exemplary embodiment of an infusion system <NUM> includes, without limitation, a fluid infusion device (or infusion pump) <NUM>, a sensing arrangement <NUM>, a command control device (CCD) <NUM>, and a computer <NUM>. The components of an infusion system <NUM> may be realized using different platforms, designs, and configurations, and the embodiment shown in <FIG> is not exhaustive or limiting. In practice, the infusion device <NUM> and the sensing arrangement <NUM> are secured at desired locations on the body of a user (or patient), as illustrated in <FIG>. In this regard, the locations at which the infusion device <NUM> and the sensing arrangement <NUM> are secured to the body of the user in <FIG> are provided only as a representative, non-limiting, example. The elements of the infusion system <NUM> may be similar to those described in <CIT>.

In the illustrated embodiment of <FIG>, the infusion device <NUM> is designed as a portable medical device suitable for infusing a fluid, a liquid, a gel, or other agent into the body of a user. In exemplary embodiments, the infused fluid is insulin, although many other fluids may be administered through infusion such as, but not limited to, HIV drugs, drugs to treat pulmonary hypertension, iron chelation drugs, pain medications, anti-cancer treatments, medications, vitamins, hormones, or the like. In some embodiments, the fluid may include a nutritional supplement, a dye, a tracing medium, a saline medium, a hydration medium, or the like.

The sensing arrangement <NUM> generally represents the components of the infusion system <NUM> configured to sense, detect, measure or otherwise quantify a condition of the user, and may include a sensor, a monitor, or the like, for providing data indicative of the condition that is sensed, detected, measured or otherwise monitored by the sensing arrangement. In this regard, the sensing arrangement <NUM> may include electronics and enzymes reactive to a biological condition, such as a blood glucose level, or the like, of the user, and provide data indicative of the blood glucose level to the infusion device <NUM>, the CCD <NUM> and/or the computer <NUM>. For example, the infusion device <NUM>, the CCD <NUM> and/or the computer <NUM> may include a display for presenting information or data to the user based on the sensor data received from the sensing arrangement <NUM>, such as, for example, a current glucose level of the user, a graph or chart of the user's glucose level versus time, device status indicators, alert messages, or the like. In other embodiments, the infusion device <NUM>, the CCD <NUM> and/or the computer <NUM> may include electronics and software that are configured to analyze sensor data and operate the infusion device <NUM> to deliver fluid to the body of the user based on the sensor data and/or preprogrammed delivery routines. Thus, in exemplary embodiments, one or more of the infusion device <NUM>, the sensing arrangement <NUM>, the CCD <NUM>, and/or the computer <NUM> includes a transmitter, a receiver, and/or other transceiver electronics that allow for communication with other components of the infusion system <NUM>, so that the sensing arrangement <NUM> may transmit sensor data or monitor data to one or more of the infusion device <NUM>, the CCD <NUM> and/or the computer <NUM>.

Still referring to <FIG>, in various embodiments, the sensing arrangement <NUM> may be secured to the body of the user or embedded in the body of the user at a location that is remote from the location at which the infusion device <NUM> is secured to the body of the user. In various other embodiments, the sensing arrangement <NUM> may be incorporated within the infusion device <NUM>. In other embodiments, the sensing arrangement <NUM> may be separate and apart from the infusion device <NUM>, and may be, for example, part of the CCD <NUM>. In such embodiments, the sensing arrangement <NUM> may be configured to receive a biological sample, analyte, or the like, to measure a condition of the user.

As described above, in some embodiments, the CCD <NUM> and/or the computer <NUM> may include electronics and other components configured to perform processing, delivery routine storage, and to control the infusion device <NUM> in a manner that is influenced by sensor data measured by and/or received from the sensing arrangement <NUM>. By including control functions in the CCD <NUM> and/or the computer <NUM>, the infusion device <NUM> may be made with more simplified electronics. However, in other embodiments, the infusion device <NUM> may include all control functions, and may operate without the CCD <NUM> and/or the computer <NUM>. In various embodiments, the CCD <NUM> may be a portable electronic device. In addition, in various embodiments, the infusion device <NUM> and/or the sensing arrangement <NUM> may be configured to transmit data to the CCD <NUM> and/or the computer <NUM> for display or processing of the data by the CCD <NUM> and/or the computer <NUM>.

In some embodiments, the CCD <NUM> and/or the computer <NUM> may provide information to the user that facilitates the user's subsequent use of the infusion device <NUM>. For example, the CCD <NUM> may provide information to the user to allow the user to determine the rate or dose of medication to be administered into the user's body. In other embodiments, the CCD <NUM> may provide information to the infusion device <NUM> to autonomously control the rate or dose of medication administered into the body of the user. In some embodiments, the sensing arrangement <NUM> may be integrated into the CCD <NUM>. Such embodiments may allow the user to monitor a condition by providing, for example, a sample of his or her blood to the sensing arrangement <NUM> to assess his or her condition. In some embodiments, the sensing arrangement <NUM> and the CCD <NUM> may be used for determining glucose levels in the blood and/or body fluids of the user without the use of, or necessity of, a wire or cable connection between the infusion device <NUM> and the sensing arrangement <NUM> and/or the CCD <NUM>.

In some embodiments, the sensing arrangement <NUM> and/or the infusion device <NUM> are cooperatively configured to utilize a closed-loop system for delivering fluid to the user. Examples of sensing devices and/or infusion pumps utilizing closed-loop systems may be found at, but are not limited to, the following <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>. In such embodiments, the sensing arrangement <NUM> is configured to sense or measure a condition of the user, such as, blood glucose level or the like. The infusion device <NUM> is configured to deliver fluid in response to the condition sensed by the sensing arrangement <NUM>. In turn, the sensing arrangement <NUM> continues to sense or otherwise quantify a current condition of the user, thereby allowing the infusion device <NUM> to deliver fluid continuously in response to the condition currently (or most recently) sensed by the sensing arrangement <NUM> indefinitely. In some embodiments, the sensing arrangement <NUM> and/or the infusion device <NUM> may be configured to utilize the closed-loop system only for a portion of the day, for example only when the user is asleep or awake.

<FIG> depict one exemplary embodiment of a fluid infusion device <NUM> (or alternatively, infusion pump) suitable for use in an infusion system, such as, for example, as infusion device <NUM> in the infusion system <NUM> of <FIG>. The fluid infusion device <NUM> is a portable medical device designed to be carried or worn by a patient (or user), and the fluid infusion device <NUM> may leverage any number of conventional features, components, elements, and characteristics of existing fluid infusion devices, such as, for example, some of the features, components, elements, and/or characteristics described in <CIT> and <CIT>. It should be appreciated that <FIG> depict some aspects of the infusion device <NUM> in a simplified manner; in practice, the infusion device <NUM> could include additional elements, features, or components that are not shown or described in detail herein.

As best illustrated in <FIG>, the illustrated embodiment of the fluid infusion device <NUM> includes a housing <NUM> adapted to receive a fluid-containing reservoir <NUM>. An opening <NUM> in the housing <NUM> accommodates a fitting <NUM> (or cap) for the reservoir <NUM>, with the fitting <NUM> being configured to mate or otherwise interface with tubing <NUM> of an infusion set <NUM> that provides a fluid path to/from the body of the user. In this manner, fluid communication from the interior of the reservoir <NUM> to the user is established via the tubing <NUM>. The illustrated fluid infusion device <NUM> includes a human-machine interface (HMI) <NUM> (or user interface) that includes elements <NUM>, <NUM> that can be manipulated by the user to administer a bolus of fluid (e.g., insulin), to change therapy settings, to change user preferences, to select display features, and the like. The infusion device also includes a display element <NUM>, such as a liquid crystal display (LCD) or another suitable display element, that can be used to present various types of information or data to the user, such as, without limitation: the current glucose level of the patient; the time; a graph or chart of the patient's glucose level versus time; device status indicators; etc..

The housing <NUM> is formed from a substantially rigid material having a hollow interior <NUM> adapted to allow an electronics assembly <NUM>, a sliding member (or slide) <NUM>, a drive system <NUM>, a sensor assembly <NUM>, and a drive system capping member <NUM> to be disposed therein in addition to the reservoir <NUM>, with the contents of the housing <NUM> being enclosed by a housing capping member <NUM>. The opening <NUM>, the slide <NUM>, and the drive system <NUM> are coaxially aligned in an axial direction (indicated by arrow <NUM>), whereby the drive system <NUM> facilitates linear displacement of the slide <NUM> in the axial direction <NUM> to dispense fluid from the reservoir <NUM> (after the reservoir <NUM> has been inserted into opening <NUM>), with the sensor assembly <NUM> being configured to measure axial forces (e.g., forces aligned with the axial direction <NUM>) exerted on the sensor assembly <NUM> responsive to operating the drive system <NUM> to displace the slide <NUM>. In various embodiments, the sensor assembly <NUM> may be utilized to detect one or more of the following: an occlusion in a fluid path that slows, prevents, or otherwise degrades fluid delivery from the reservoir <NUM> to a user's body; when the reservoir <NUM> is empty; when the slide <NUM> is properly seated with the reservoir <NUM>; when a fluid dose has been delivered; when the infusion pump <NUM> is subjected to shock or vibration; when the infusion pump <NUM> requires maintenance.

Depending on the embodiment, the fluid-containing reservoir <NUM> may be realized as a syringe, a vial, a cartridge, a bag, or the like. In certain embodiments, the infused fluid is insulin, although many other fluids may be administered through infusion such as, but not limited to, HIV drugs, drugs to treat pulmonary hypertension, iron chelation drugs, pain medications, anti-cancer treatments, medications, vitamins, hormones, or the like. As best illustrated in <FIG>, the reservoir <NUM> typically includes a reservoir barrel <NUM> that contains the fluid and is concentrically and/or coaxially aligned with the slide <NUM> (e.g., in the axial direction <NUM>) when the reservoir <NUM> is inserted into the infusion pump <NUM>. The end of the reservoir <NUM> proximate the opening <NUM> may include or otherwise mate with the fitting <NUM>, which secures the reservoir <NUM> in the housing <NUM> and prevents displacement of the reservoir <NUM> in the axial direction <NUM> with respect to the housing <NUM> after the reservoir <NUM> is inserted into the housing <NUM>. As described above, the fitting <NUM> extends from (or through) the opening <NUM> of the housing <NUM> and mates with tubing <NUM> to establish fluid communication from the interior of the reservoir <NUM> (e.g., reservoir barrel <NUM>) to the user via the tubing <NUM> and infusion set <NUM>. The opposing end of the reservoir <NUM> proximate the slide <NUM> includes a plunger <NUM> (or stopper) positioned to push fluid from inside the barrel <NUM> of the reservoir <NUM> along a fluid path through tubing <NUM> to a user. The slide <NUM> is configured to mechanically couple or otherwise engage with the plunger <NUM>, thereby becoming seated with the plunger <NUM> and/or reservoir <NUM>. Fluid is forced from the reservoir <NUM> via tubing <NUM> as the drive system <NUM> is operated to displace the slide <NUM> in the axial direction <NUM> toward the opening <NUM> in the housing <NUM>.

In the illustrated embodiment of <FIG>, the drive system <NUM> includes a motor assembly <NUM> and a drive screw <NUM>. The motor assembly <NUM> includes a motor that is coupled to drive train components of the drive system <NUM> that are configured to convert rotational motor motion to a translational displacement of the slide <NUM> in the axial direction <NUM>, and thereby engaging and displacing the plunger <NUM> of the reservoir <NUM> in the axial direction <NUM>. In some embodiments, the motor assembly <NUM> may also be powered to translate the slide <NUM> in the opposing direction (e.g., the direction opposite direction <NUM>) to retract and/or detach from the reservoir <NUM> to allow the reservoir <NUM> to be replaced. In exemplary embodiments, the motor assembly <NUM> includes a brushless DC (BLDC) motor having one or more permanent magnets mounted, affixed, or otherwise disposed on its rotor. However, the subject matter described herein is not necessarily limited to use with BLDC motors, and in alternative embodiments, the motor may be realized as a solenoid motor, an AC motor, a stepper motor, a piezoelectric caterpillar drive, a shape memory actuator drive, an electrochemical gas cell, a thermally driven gas cell, a bimetallic actuator, or the like. The drive train components may comprise one or more lead screws, cams, ratchets, jacks, pulleys, pawls, clamps, gears, nuts, slides, bearings, levers, beams, stoppers, plungers, sliders, brackets, guides, bearings, supports, bellows, caps, diaphragms, bags, heaters, or the like. In this regard, although the illustrated embodiment of the infusion pump utilizes a coaxially aligned drive train, the motor could be arranged in an offset or otherwise non-coaxial manner, relative to the longitudinal axis of the reservoir <NUM>.

As best shown in <FIG>, the drive screw <NUM> mates with threads <NUM> internal to the slide <NUM>. When the motor assembly <NUM> is powered and operated, the drive screw <NUM> rotates, and the slide <NUM> is forced to translate in the axial direction <NUM>. In an exemplary embodiment, the infusion pump <NUM> includes a sleeve <NUM> to prevent the slide <NUM> from rotating when the drive screw <NUM> of the drive system <NUM> rotates. Thus, rotation of the drive screw <NUM> causes the slide <NUM> to extend or retract relative to the drive motor assembly <NUM>. When the fluid infusion device is assembled and operational, the slide <NUM> contacts the plunger <NUM> to engage the reservoir <NUM> and control delivery of fluid from the infusion pump <NUM>. In an exemplary embodiment, the shoulder portion <NUM> of the slide <NUM> contacts or otherwise engages the plunger <NUM> to displace the plunger <NUM> in the axial direction <NUM>. In alternative embodiments, the slide <NUM> may include a threaded tip <NUM> capable of being detachably engaged with internal threads <NUM> on the plunger <NUM> of the reservoir <NUM>, as described in detail in <CIT> and <CIT>.

As illustrated in <FIG>, the electronics assembly <NUM> includes control electronics <NUM> coupled to the display element <NUM>, with the housing <NUM> including a transparent window portion <NUM> that is aligned with the display element <NUM> to allow the display <NUM> to be viewed by the user when the electronics assembly <NUM> is disposed within the interior <NUM> of the housing <NUM>. The control electronics <NUM> generally represent the hardware, firmware, processing logic and/or software (or combinations thereof) configured to control operation of the motor assembly <NUM> and/or drive system <NUM>, as described in greater detail below in the context of <FIG>. Whether such functionality is implemented as hardware, firmware, a state machine, or software depends upon the particular application and design constraints imposed on the embodiment. Those familiar with the concepts described here may implement such functionality in a suitable manner for each particular application, but such implementation decisions should not be interpreted as being restrictive or limiting. In an exemplary embodiment, the control electronics <NUM> includes one or more programmable controllers that may be programmed to control operation of the infusion pump <NUM>.

The motor assembly <NUM> includes one or more electrical leads <NUM> adapted to be electrically coupled to the electronics assembly <NUM> to establish communication between the control electronics <NUM> and the motor assembly <NUM>. In response to command signals from the control electronics <NUM> that operate a motor driver (e.g., a power converter) to regulate the amount of power supplied to the motor from a power supply, the motor actuates the drive train components of the drive system <NUM> to displace the slide <NUM> in the axial direction <NUM> to force fluid from the reservoir <NUM> along a fluid path (including tubing <NUM> and an infusion set), thereby administering doses of the fluid contained in the reservoir <NUM> into the user's body. Preferably, the power supply is realized one or more batteries contained within the housing <NUM>. Alternatively, the power supply may be a solar panel, capacitor, AC or DC power supplied through a power cord, or the like. In some embodiments, the control electronics <NUM> may operate the motor of the motor assembly <NUM> and/or drive system <NUM> in a stepwise manner, typically on an intermittent basis; to administer discrete precise doses of the fluid to the user according to programmed delivery profiles.

Referring to <FIG>, as described above, the user interface <NUM> includes HMI elements, such as buttons <NUM> and a directional pad <NUM>, that are formed on a graphic keypad overlay <NUM> that overlies a keypad assembly <NUM>, which includes features corresponding to the buttons <NUM>, directional pad <NUM> or other user interface items indicated by the graphic keypad overlay <NUM>. When assembled, the keypad assembly <NUM> is coupled to the control electronics <NUM>, thereby allowing the HMI elements <NUM>, <NUM> to be manipulated by the user to interact with the control electronics <NUM> and control operation of the infusion pump <NUM>, for example, to administer a bolus of insulin, to change therapy settings, to change user preferences, to select display features, to set or disable alarms and reminders, and the like. In this regard, the control electronics <NUM> maintains and/or provides information to the display <NUM> regarding program parameters, delivery profiles, pump operation, alarms, warnings, statuses, or the like, which may be adjusted using the HMI elements <NUM>, <NUM>. In various embodiments, the HMI elements <NUM>, <NUM> may be realized as physical objects (e.g., buttons, knobs, joysticks, and the like) or virtual objects (e.g., using touch-sensing and/or proximity-sensing technologies). For example, in some embodiments, the display <NUM> may be realized as a touch screen or touch-sensitive display, and in such embodiments, the features and/or functionality of the HMI elements <NUM>, <NUM> may be integrated into the display <NUM> and the HMI <NUM> may not be present. In some embodiments, the electronics assembly <NUM> may also include alert generating elements coupled to the control electronics <NUM> and suitably configured to generate one or more types of feedback, such as, without limitation: audible feedback; visual feedback; haptic (physical) feedback; or the like.

Referring to <FIG>, in accordance with one or more embodiments, the sensor assembly <NUM> includes a back plate structure <NUM> and a loading element <NUM>. The loading element <NUM> is disposed between the capping member <NUM> and a beam structure <NUM> that includes one or more beams having sensing elements disposed thereon that are influenced by compressive force applied to the sensor assembly <NUM> that deflects the one or more beams, as described in greater detail in <CIT>. In exemplary embodiments, the back plate structure <NUM> is affixed, adhered, mounted, or otherwise mechanically coupled to the bottom surface <NUM> of the drive system <NUM> such that the back plate structure <NUM> resides between the bottom surface <NUM> of the drive system <NUM> and the housing cap <NUM>. The drive system capping member <NUM> is contoured to accommodate and conform to the bottom of the sensor assembly <NUM> and the drive system <NUM>. The drive system capping member <NUM> may be affixed to the interior of the housing <NUM> to prevent displacement of the sensor assembly <NUM> in the direction opposite the direction of force provided by the drive system <NUM> (e.g., the direction opposite direction <NUM>). Thus, the sensor assembly <NUM> is positioned between the motor assembly <NUM> and secured by the capping member <NUM>, which prevents displacement of the sensor assembly <NUM> in a downward direction opposite the direction of arrow <NUM>, such that the sensor assembly <NUM> is subjected to a reactionary compressive force when the drive system <NUM> and/or motor assembly <NUM> is operated to displace the slide <NUM> in the axial direction <NUM> in opposition to the fluid pressure in the reservoir <NUM>. Under normal operating conditions, the compressive force applied to the sensor assembly <NUM> is correlated with the fluid pressure in the reservoir <NUM>. As shown, electrical leads <NUM> are adapted to electrically couple the sensing elements of the sensor assembly <NUM> to the electronics assembly <NUM> to establish communication to the control electronics <NUM>, wherein the control electronics <NUM> are configured to measure, receive, or otherwise obtain electrical signals from the sensing elements of the sensor assembly <NUM> that are indicative of the force applied by the drive system <NUM> in the axial direction <NUM>.

<FIG> depicts an exemplary embodiment of a control system <NUM> suitable for use with an infusion device <NUM>, such as the infusion device <NUM> in <FIG> or the infusion device <NUM> of <FIG>. The control system <NUM> is configured to control or otherwise regulate a physiological condition in the body <NUM> of a user. In one or more exemplary embodiments, the condition being regulated is sensed, detected, measured or otherwise quantified by a sensing arrangement <NUM> (e.g., sensing arrangement <NUM>) communicatively coupled to the infusion device <NUM>. However, it should be noted that in alternative embodiments, the condition being regulated by the control system <NUM> may be correlative to the measured values obtained by the sensing arrangement <NUM>. That said, for clarity and purposes of explanation, the subject matter may be described herein in the context of the sensing arrangement <NUM> being realized as a glucose sensing arrangement that senses, detects, measures or otherwise quantifies the user's glucose level, which is being regulated in the body <NUM> of the user by the control system <NUM>.

In exemplary embodiments, the sensing arrangement <NUM> includes one or more interstitial glucose sensing elements that generate or otherwise output electrical signals having a signal characteristic that is correlative to, influenced by, or otherwise indicative of the relative interstitial fluid glucose level in the body <NUM> of the user. The output electrical signals are filtered or otherwise processed to obtain a measurement value indicative of the user's interstitial fluid glucose level. In exemplary embodiments, a blood glucose meter <NUM>, such as a finger stick device, is utilized to directly sense, detect, measure or otherwise quantify the blood glucose in the body <NUM> of the user. In this regard, the blood glucose meter <NUM> outputs or otherwise provides a measured blood glucose value that may be utilized as a reference measurement for calibrating the sensing arrangement <NUM> and converting a measurement value indicative of the user's interstitial fluid glucose level into a corresponding calibrated blood glucose measurement value. For purposes of explanation, sensor glucose value, sensed glucose value, or variants thereof should be understood to encompass any glucose value indicative of a current glucose level in the body of the user that is based on the electrical signals output by the sensing element(s) of the sensing arrangement <NUM>.

The pump control system <NUM> generally represents the electronics and other components of the infusion device <NUM> that control operation of the fluid infusion device <NUM> according to a desired infusion delivery program in a manner that may be influenced by the sensed glucose value indicative of a current glucose level in the body <NUM> of the user. The particular operating mode being implemented by the pump control system <NUM> influences the generated dosage commands for operating the motor <NUM> to displace the plunger <NUM> and deliver insulin to the body <NUM> of the user. For example, in a closed-loop (CL) operating mode, the pump control system <NUM> generates or otherwise determines dosage commands for operating the motor <NUM> based on the difference between a sensed glucose value and the target (or commanded) glucose value to regulate the sensed glucose value to the target. In other operating modes, the pump control system <NUM> may generate or otherwise determine dosage commands configured to maintain the sensed glucose value below an upper glucose limit, above a lower glucose limit, or otherwise within a desired range of glucose values. For example, in a predictive low glucose management (PLGM) operating mode, the pump control system <NUM> calculates or otherwise determines a predicted glucose value based on the currently sensed glucose value, and generates dosage commands configured to provide a basal infusion rate when the predicted glucose value is greater than a predictive suspend threshold and automatically suspends delivery (e.g., by providing dosage commands equal to zero) when the predicted glucose value is less than the predictive suspend threshold. In a low glucose suspend (LGS) operating mode, the pump control system <NUM> generates dosage commands configured to provide a basal infusion rate when the sensed glucose value is greater than a suspend threshold (which may be different from the predictive suspend threshold) and automatically suspends delivery when the sensed glucose value is less than the suspend threshold. In an open-loop (OL) operating mode, the pump control system <NUM> generates dosage commands configured to provide a predetermined open-loop basal infusion rate independent of the sensed glucose value. In practice, the infusion device <NUM> may store or otherwise maintain the target value, suspension threshold values, and/or other glucose threshold value(s) in a data storage element accessible to the pump control system <NUM>.

The target glucose value and other threshold values may be received from an external component (e.g., CCD <NUM> and/or computing device <NUM>) or be input by a user via a user interface element <NUM> associated with the infusion device <NUM>. In practice, the one or more user interface element(s) <NUM> associated with the infusion device <NUM> typically include at least one input user interface element, such as, for example, a button, a keypad, a keyboard, a knob, a joystick, a mouse, a touch panel, a touchscreen, a microphone or another audio input device, and/or the like. Additionally, the one or more user interface element(s) <NUM> include at least one output user interface element, such as, for example, a display element (e.g., a light-emitting diode or the like), a display device (e.g., a liquid crystal display or the like), a speaker or another audio output device, a haptic feedback device, or the like, for providing notifications or other information to the user. It should be noted that although <FIG> depicts the user interface element(s) <NUM> as being separate from the infusion device <NUM>, in practice, one or more of the user interface element(s) <NUM> may be integrated with the infusion device <NUM>. Furthermore, in some embodiments, one or more user interface element(s) <NUM> are integrated with the sensing arrangement <NUM> in addition to and/or in alternative to the user interface element(s) <NUM> integrated with the infusion device <NUM>. The user interface element(s) <NUM> may be manipulated by the user to operate the infusion device <NUM> to deliver correction boluses, adjust target and/or threshold values, modify the delivery control scheme or operating mode, and the like, as desired.

In exemplary embodiments, the pump control system <NUM> includes or otherwise accesses a data storage element, memory, or other non-transitory computer-readable medium capable of storing programming instructions for execution by the pump control system <NUM>. The computer-executable programming instructions, when read and executed, cause the pump control system <NUM> to determine dosage commands in accordance with a particular operating mode and perform various additional tasks, operations, functions, and processes described herein in the context of <FIG>-<NUM>.

Still referring to <FIG>, in the illustrated embodiment, the infusion device <NUM> includes a motor control module <NUM> coupled to a motor <NUM> (e.g., motor assembly <NUM>) that is operable to displace a plunger <NUM> (e.g., plunger <NUM>) in a reservoir (e.g., reservoir <NUM>) and provide a desired amount of fluid to the body <NUM> of a user. In this regard, displacement of the plunger <NUM> results in the delivery of a fluid that is capable of influencing the condition in the body <NUM> of the user to the body <NUM> of the user via a fluid delivery path (e.g., via tubing <NUM> of an infusion set <NUM>). A motor driver module <NUM> is coupled between an energy source <NUM> and the motor <NUM>. The motor control module <NUM> is coupled to the motor driver module <NUM>, and the motor control module <NUM> generates or otherwise provides command signals that operate the motor driver module <NUM> to provide current (or power) from the energy source <NUM> to the motor <NUM> to displace the plunger <NUM> in response to receiving, from a pump control system <NUM>, a dosage command indicative of the desired amount of fluid to be delivered.

In exemplary embodiments, the energy source <NUM> is realized as a battery housed within the infusion device <NUM> (e.g., within housing <NUM>) that provides direct current (DC) power. In this regard, the motor driver module <NUM> generally represents the combination of circuitry, hardware and/or other electrical components configured to convert or otherwise transfer DC power provided by the energy source <NUM> into alternating electrical signals applied to respective phases of the stator windings of the motor <NUM> that result in current flowing through the stator windings that generates a stator magnetic field and causes the rotor of the motor <NUM> to rotate. The motor control module <NUM> is configured to receive or otherwise obtain a commanded dosage from the pump control system <NUM>, convert the commanded dosage to a commanded translational displacement of the plunger <NUM>, and command, signal, or otherwise operate the motor driver module <NUM> to cause the rotor of the motor <NUM> to rotate by an amount that produces the commanded translational displacement of the plunger <NUM>. For example, the motor control module <NUM> may determine an amount of rotation of the rotor required to produce translational displacement of the plunger <NUM> that achieves the commanded dosage received from the pump control system <NUM>. Based on the current rotational position (or orientation) of the rotor with respect to the stator that is indicated by the output of the rotor sensing arrangement <NUM>, the motor control module <NUM> determines the appropriate sequence of alternating electrical signals to be applied to the respective phases of the stator windings that should rotate the rotor by the determined amount of rotation from its current position (or orientation). In embodiments where the motor <NUM> is realized as a BLDC motor, the alternating electrical signals commutate the respective phases of the stator windings at the appropriate orientation of the rotor magnetic poles with respect to the stator and in the appropriate order to provide a rotating stator magnetic field that rotates the rotor in the desired direction. Thereafter, the motor control module <NUM> operates the motor driver module <NUM> to apply the determined alternating electrical signals (e.g., the command signals) to the stator windings of the motor <NUM> to achieve the desired delivery of fluid to the user.

When the motor control module <NUM> is operating the motor driver module <NUM>, current flows from the energy source <NUM> through the stator windings of the motor <NUM> to produce a stator magnetic field that interacts with the rotor magnetic field. In some embodiments, after the motor control module <NUM> operates the motor driver module <NUM> and/or motor <NUM> to achieve the commanded dosage, the motor control module <NUM> ceases operating the motor driver module <NUM> and/or motor <NUM> until a subsequent dosage command is received. In this regard, the motor driver module <NUM> and the motor <NUM> enter an idle state during which the motor driver module <NUM> effectively disconnects or isolates the stator windings of the motor <NUM> from the energy source <NUM>. In other words, current does not flow from the energy source <NUM> through the stator windings of the motor <NUM> when the motor <NUM> is idle, and thus, the motor <NUM> does not consume power from the energy source <NUM> in the idle state, thereby improving efficiency.

Depending on the embodiment, the motor control module <NUM> may be implemented or realized with a general purpose processor, a microprocessor, a controller, a microcontroller, a state machine, a content addressable memory, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. Furthermore, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by the motor control module <NUM>, or in any practical combination thereof. In exemplary embodiments, the motor control module <NUM> includes or otherwise accesses a data storage element or memory, including any sort of random access memory (RAM), read only memory (ROM), flash memory, registers, hard disks, removable disks, magnetic or optical mass storage, or any other short or long term storage media or other non-transitory computer-readable medium, which is capable of storing programming instructions for execution by the motor control module <NUM>. The computer-executable programming instructions, when read and executed by the motor control module <NUM>, cause the motor control module <NUM> to perform the tasks, operations, functions, and processes described herein.

It should be appreciated that <FIG> is a simplified representation of the infusion device <NUM> for purposes of explanation and is not intended to limit the subject matter described herein in any way. In this regard, depending on the embodiment, some features and/or functionality of the sensing arrangement <NUM> may be implemented by or otherwise integrated into the pump control system <NUM>, or vice versa. Similarly, in practice, the features and/or functionality of the motor control module <NUM> may be implemented by or otherwise integrated into the pump control system <NUM>, or vice versa. Furthermore, the features and/or functionality of the pump control system <NUM> may be implemented by control electronics <NUM> located in the fluid infusion device <NUM>, while in alternative embodiments, the pump control system <NUM> may be implemented by a remote computing device that is physically distinct and/or separate from the infusion device <NUM>, such as, for example, the CCD <NUM> or the computing device <NUM>.

<FIG> depicts an exemplary embodiment of a pump control system <NUM> suitable for use as the pump control system <NUM> in <FIG> in accordance with one or more embodiments. The illustrated pump control system <NUM> includes, without limitation, a pump control module <NUM>, a communications interface <NUM>, and a data storage element (or memory) <NUM>. The pump control module <NUM> is coupled to the communications interface <NUM> and the memory <NUM>, and the pump control module <NUM> is suitably configured to support the operations, tasks, and/or processes described herein. In exemplary embodiments, the pump control module <NUM> is also coupled to one or more user interface elements <NUM> (e.g., user interface <NUM>, <NUM>) for receiving bolus or other delivery instructions and providing notifications or other information to the user. Although <FIG> depicts the user interface element <NUM> as being integrated with the pump control system <NUM> (e.g., as part of the infusion device <NUM>, <NUM>), in various alternative embodiments, the user interface element <NUM> may be integrated with the sensing arrangement <NUM> or another element of an infusion system <NUM> (e.g., the computer <NUM> or CCD <NUM>).

Referring to <FIG> and with reference to <FIG>, the communications interface <NUM> generally represents the hardware, circuitry, logic, firmware and/or other components of the pump control system <NUM> that are coupled to the pump control module <NUM> and configured to support communications between the pump control system <NUM> and the sensing arrangement <NUM>. In this regard, the communications interface <NUM> may include or otherwise be coupled to one or more transceiver modules capable of supporting wireless communications between the pump control system <NUM>, <NUM> and the sensing arrangement <NUM> or another electronic device <NUM>, <NUM> in an infusion system <NUM>. In other embodiments, the communications interface <NUM> may be configured to support wired communications to/from the sensing arrangement <NUM>.

The pump control module <NUM> generally represents the hardware, circuitry, logic, firmware and/or other component of the pump control system <NUM> that is coupled to the communications interface <NUM> and configured to determine dosage commands for operating the motor <NUM> to deliver fluid to the body <NUM> based on data received from the sensing arrangement <NUM> and perform various additional tasks, operations, functions and/or operations described herein. For example, in exemplary embodiments, pump control module <NUM> implements or otherwise executes a command generation module <NUM> that automatically calculates or otherwise determines a dosage command for operating the motor <NUM> of the infusion device <NUM> in accordance with a particular operating mode. In exemplary embodiments described herein, the command generation module <NUM> supports multiple different operating modes having different delivery control schemes associated therewith. Additionally, the command generation module <NUM> may generate dosage commands for delivering boluses that are manually-initiated or otherwise instructed by a user via a user interface element <NUM>. The illustrated pump control module <NUM> also implements or otherwise executes a diagnostics module <NUM> that generates or otherwise provides user notifications or alerts via a user interface element <NUM>.

Still referring to <FIG>, depending on the embodiment, the pump control module <NUM> may be implemented or realized with a general purpose processor, a microprocessor, a controller, a microcontroller, a state machine, a content addressable memory, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this regard, the steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in firmware, in a software module executed by the pump control module <NUM>, or in any practical combination thereof. In exemplary embodiments, the pump control module <NUM> includes or otherwise accesses the data storage element or memory <NUM>, which may be realized using any sort of non-transitory computer-readable medium capable of storing programming instructions for execution by the pump control module <NUM>. The computer-executable programming instructions, when read and executed by the pump control module <NUM>, cause the pump control module <NUM> to perform the tasks, operations, functions, and processes described in greater detail below.

It should be understood that <FIG> is a simplified representation of a pump control system <NUM> for purposes of explanation and is not intended to limit the subject matter described herein in any way. For example, in some embodiments, the features and/or functionality of the motor control module <NUM> may be implemented by or otherwise integrated into the pump control system <NUM> and/or the pump control module <NUM>, for example, by the command generation module <NUM> converting the dosage command into a corresponding motor command, in which case, the separate motor control module <NUM> may be absent from an embodiment of the infusion device <NUM>.

<FIG> depicts an exemplary closed-loop control system <NUM> that may be implemented by a pump control system <NUM>, <NUM> to regulate a condition in the body of a user to a desired (or target) value. It should be appreciated that <FIG> is a simplified representation of the control system <NUM> for purposes of explanation and is not intended to limit the subject matter described herein in any way.

In exemplary embodiments, the control system <NUM> receives or otherwise obtains a target glucose value at input <NUM>. In some embodiments, the target glucose value may be stored or otherwise maintained by the infusion device <NUM> (e.g., in memory <NUM>), however, in some alternative embodiments, the target value may be received from an external component (e.g., CCD <NUM> and/or computer <NUM>). In one or more embodiments, the target glucose value may be dynamically calculated or otherwise determined prior to entering the closed-loop operating mode based on one or more patient-specific control parameters. For example, the target blood glucose value may be calculated based at least in part on a patient-specific reference basal rate and a patient-specific daily insulin requirement, which are determined based on historical delivery information over a preceding interval of time (e.g., the amount of insulin delivered over the preceding <NUM> hours). The control system <NUM> also receives or otherwise obtains a current glucose measurement value from the sensing arrangement <NUM> at input <NUM>. The illustrated control system <NUM> implements or otherwise provides proportional-integral-derivative (PID) control to determine or otherwise generate delivery commands for operating the motor <NUM> based at least in part on the difference between the target glucose value and the current glucose measurement value. In this regard, the PID control attempts to minimize the difference between the measured value and the target value, and thereby regulates the measured value to the desired value. PID control parameters are applied to the difference between the target glucose level at input <NUM> and the measured glucose level at input <NUM> to generate or otherwise determine a dosage (or delivery) command provided at output <NUM>. Based on that delivery command, the motor control module <NUM> operates the motor <NUM> to deliver insulin to the body of the user to influence the user's glucose level, and thereby reduce the difference between a subsequently measured glucose level and the target glucose level.

The illustrated control system <NUM> includes or otherwise implements a summation block <NUM> configured to determine a difference between the target value obtained at input <NUM> and the measured value obtained from the sensing arrangement <NUM> at input <NUM>, for example, by subtracting the target value from the measured value. The output of the summation block <NUM> represents the difference between the measured and target values, which is then provided to each of a proportional term path, an integral term path, and a derivative term path. The proportional term path includes a gain block <NUM> that multiplies the difference by a proportional gain coefficient, KP, to obtain the proportional term. The integral term path includes an integration block <NUM> that integrates the difference and a gain block <NUM> that multiplies the integrated difference by an integral gain coefficient, KI, to obtain the integral term. The derivative term path includes a derivative block <NUM> that determines the derivative of the difference and a gain block <NUM> that multiplies the derivative of the difference by a derivative gain coefficient, KD, to obtain the derivative term. The proportional term, the integral term, and the derivative term are then added or otherwise combined to obtain a delivery command that is utilized to operate the motor at output <NUM>. Various implementation details pertaining to closed-loop PID control and determine gain coefficients are described in greater detail in <CIT>.

In one or more exemplary embodiments, the PID gain coefficients are user-specific (or patient-specific) and dynamically calculated or otherwise determined prior to entering the closed-loop operating mode based on historical insulin delivery information (e.g., amounts and/or timings of previous dosages, historical correction bolus information, or the like), historical sensor measurement values, historical reference blood glucose measurement values, user-reported or user-input events (e.g., meals, exercise, and the like), and the like. In this regard, one or more patient-specific control parameters (e.g., an insulin sensitivity factor, a daily insulin requirement, an insulin limit, a reference basal rate, a reference fasting glucose, an active insulin action duration, pharmodynamical time constants, or the like) may be utilized to compensate, correct, or otherwise adjust the PID gain coefficients to account for various operating conditions experienced and/or exhibited by the infusion device <NUM>. The PID gain coefficients may be maintained by the memory <NUM> accessible to the pump control module <NUM>. In this regard, the memory <NUM> may include a plurality of registers associated with the control parameters for the PID control. For example, a first parameter register may store the target glucose value and be accessed by or otherwise coupled to the summation block <NUM> at input <NUM>, and similarly, a second parameter register accessed by the proportional gain block <NUM> may store the proportional gain coefficient, a third parameter register accessed by the integration gain block <NUM> may store the integration gain coefficient, and a fourth parameter register accessed by the derivative gain block <NUM> may store the derivative gain coefficient.

Turning now to <FIG>, in accordance with one or more embodiments, a management system <NUM> manages transitions between operating modes supported by an infusion device. In one or more exemplary embodiments described herein, the management system <NUM> is implemented by a pump control system <NUM>, <NUM> and/or pump control module <NUM>. In this regard, the various modules <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be subcomponents of the pump control module <NUM> or the command generation module <NUM>. For example, in one embodiment, the command generation module <NUM> includes or otherwise implements the management system <NUM>. The illustrated system <NUM> includes a plurality of operating mode control modules <NUM>, <NUM>, <NUM>, <NUM> along with a supervisory control module <NUM> that manages transitions between the respective operating modes. In the illustrated embodiment, the supervisory control module <NUM> operates a command multiplexer <NUM>, which is coupled to the motor control module <NUM> to output a dosage command from the selected operating mode control module <NUM>, <NUM>, <NUM>, <NUM> corresponding to the operating mode currently being implemented by the infusion device <NUM>.

The closed-loop control module <NUM> generally represents the components of the pump control system <NUM>, <NUM> that are configured to support the closed-loop operating mode. In this regard, the closed-loop control module <NUM> may implement the closed-loop control system <NUM> of <FIG> and generate a dosage command based on a difference between the current (or most recent) measurement of the user's interstitial fluid glucose level and a target (or reference) interstitial fluid glucose value.

The predictive low glucose control module <NUM> generally represents the components of the pump control system <NUM>, <NUM> that are configured to support a PLGM operating mode. As described above, the PLGM control module <NUM> generates dosage commands to provide a basal infusion rate when a predicted glucose value is greater than a predictive suspend threshold and automatically suspends delivery (or generates dosage commands equal to zero) when the predicted glucose value is less than the predictive suspend threshold.

The low glucose control module <NUM> generally represents the components of the pump control system <NUM>, <NUM> that are configured to support a LGS operating mode. As described above, the LGS control module <NUM> by generates dosage commands to provide a basal infusion rate when the current (or most recent) measurement of the user's interstitial fluid glucose level is greater than a suspend threshold and automatically suspends delivery when the current measurement value is less than the suspend threshold.

The open-loop control module <NUM> generally represents the components of the pump control system <NUM>, <NUM> that are configured to support an open-loop operating mode. In this regard, the open-loop control module <NUM> generates dosage commands configured to provide a predetermined open-loop basal infusion rate.

In the illustrated embodiment, the command multiplexer <NUM> is coupled to the outputs of the respective control modules <NUM>, <NUM>, <NUM>, <NUM> to selectively output the dosage command from one of the modules <NUM>, <NUM>, <NUM>, <NUM> to the motor control module <NUM> in response to a selection signal from the supervisory control module <NUM>. In this regard, the selection signal identifies the operating mode that is currently being implemented by the infusion device <NUM>, <NUM>, <NUM>. The supervisory control module <NUM> generally represents the components of the pump control system <NUM>, <NUM> that are coupled to the control modules <NUM>, <NUM>, <NUM>, <NUM> and configured to support the operating mode transition process <NUM> and perform the tasks, operations, functions, and processes described herein managing transitions between operating modes associated with the respective control modules <NUM>, <NUM>, <NUM>, <NUM>.

It should be appreciated that <FIG> is a simplified representation of the management system <NUM> for purposes of explanation and is not intended to limit the subject matter described herein in any way. In this regard, depending on the embodiment, any number of operating mode control modules may be present to support any number of operating modes. In some embodiments, the features and/or functionality of the command multiplexer <NUM> may be implemented by or otherwise integrated into the supervisory control module <NUM>. Furthermore, while in some embodiments the features and/or functionality of the management system <NUM> are implemented by control electronics <NUM> located in the fluid infusion device <NUM>, <NUM>, in alternative embodiments, various aspects of the management system <NUM> may be implemented by a remote computing device that is physically distinct and/or separate from the infusion device <NUM>, <NUM>, such as, for example, the CCD <NUM> or the computing device <NUM>.

<FIG> depicts an exemplary operating mode transition process <NUM> suitable for implementation by a control system associated with a fluid infusion device to manage transitions between operating modes supported by the device. Various tasks performed in connection with the operating mode transition process <NUM> may be performed by hardware, firmware, software executed by processing circuitry, or any combination thereof. For illustrative purposes, the following description refers to elements mentioned above in connection with <FIG>. In practice, portions of the operating mode transition process <NUM> may be performed by different elements of the control system <NUM>, such as, for example, the infusion device <NUM>, the pump control system <NUM>, <NUM>, the diagnostics module <NUM>, the command generation module <NUM>, the management system <NUM>, the supervisory control module <NUM> and/or the command multiplexer <NUM>. It should be appreciated that the operating mode transition process <NUM> may include any number of additional or alternative tasks, the tasks need not be performed in the illustrated order and/or the tasks may be performed concurrently, and/or the operating mode transition process <NUM> may be incorporated into a more comprehensive procedure or process having additional functionality not described in detail herein. Moreover, one or more of the tasks shown and described in the context of <FIG> could be omitted from a practical embodiment of the operating mode transition process <NUM> as long as the intended overall functionality remains intact.

Referring to <FIG>, and with continued reference to <FIG>, the operating mode transition process <NUM> initializes or otherwise begins in response to detecting or otherwise identifying a desire to exit a particular operating mode. For example, the operating mode transition process <NUM> may be initiated in response to a user manipulating the user interface <NUM>, <NUM> to indicate a desire to exit one operating mode and enter another operating mode. In other embodiments, the operating mode transition process <NUM> may be initiated in response to a particular operating mode automatically determining it should be exited and providing a corresponding indication to the supervisory module <NUM>. For example, a maximum time limit may be imposed for one or more of the control modules <NUM>, <NUM>, <NUM>, <NUM>, with the respective control module <NUM>, <NUM>, <NUM>, <NUM> implementing a timer and automatically notifying the supervisory control module <NUM> when the maximum time limit has been reached. Alternatively, the supervisory control module <NUM> may implement the appropriate timers and identify when the maximum time limit for a particular operating mode has been reached. Additionally, in some embodiments, one or more of the control modules <NUM>, <NUM>, <NUM>, <NUM> may be configured to continually monitor or analyze its performance and detect or otherwise identify that its operating mode should be terminated when its performance appears to be unreliable. For example, the closed-loop control module <NUM> may automatically identify that the closed-loop operating mode should exit when one or more of the closed-loop control parameters appears to be invalid or unreliable, when measurement values from the sensing arrangement <NUM> appear to be invalid or unreliable, or the like.

In response to detecting or otherwise identifying a desire to exit a particular operating mode, the operating mode transition process <NUM> receives or otherwise obtains operational information pertaining to the operating mode being exited along with clinical information pertaining to the physiological condition of the user (tasks <NUM>, <NUM>). In this regard, the supervisory module <NUM> obtains operational information from the control module <NUM>, <NUM>, <NUM>, <NUM> associated with the operating mode currently being implemented. The operational information includes timer values (e.g., a delivery suspend time, a refractory period time, and the like), delivery status (e.g., whether or not delivery has been suspended), alert or event information (e.g., hypoglycemic events or alerts, hyperglycemic events or alerts, and the like), the reason the operating mode is terminating (e.g., manually-initiated, timeout, invalid control parameters and/or invalid measurement values, an anomalous condition, or the like), and other information characterizing the current instance of the operating mode. In exemplary embodiments, the supervisory module <NUM> obtains clinical information for the user, such as, for example, recent sensor glucose measurement values, predicted glucose measurement values, blood glucose reference measurement values, sensor calibration data, other historical data, and the like, from memory <NUM>.

Using the operational information and the clinical information, the mode transition process <NUM> identifies or otherwise determines the available operating modes for the transition destination (task <NUM>). In this regard, the supervisory module <NUM> utilizes the clinical information in conjunction with the operational information to identify which other operating modes are viable destinations for the transition while excluding any operating modes that are likely to violate one or more applicable constraints or otherwise are not likely to be viable. In this manner, the mode transition process <NUM> increases the likelihood that the destination operating mode will not result in violations of applicable delivery control rules, constraints, limits, or the like. The mode transition process <NUM> also reduces the likelihood that the destination operating mode will generate alerts that could degrade the user experience, and reduces the likelihood that the destination operating mode will automatically terminate or exit after being activated.

For example, in one or more embodiments, a maximum suspension time limit may be imposed on the infusion device <NUM> across all operating modes, with the supervisory module <NUM> excluding operating modes that would likely result in the minimum suspension time being violated based on the current suspend duration for the initial operating mode and the current or predicted glucose values for the user. For example, if transitioning from a closed-loop operating mode that has been suspending delivery for a period of time, and the user's predicted glucose value indicates the PLGM operating mode will likely suspend delivery for an additional amount of time such that the sum of the current suspend duration for the closed-loop operating mode and the expected suspend duration for the PLGM operating mode exceeds the maximum suspension time, the supervisory module <NUM> may exclude the PLGM operating mode from consideration as a possible destination operating mode.

As another example, a maximum insulin delivery limit over a particular timeframe (e.g., the preceding <NUM> hours) may be imposed, with the supervisory module <NUM> excluding operating modes that would likely result in the maximum insulin delivery limit being delivered based on the amount of insulin delivered for the initial operating mode and the current or predicted glucose values for the user. For example, if the difference between current and/or predicted glucose values for the user and the target glucose value for the closed-loop operating mode indicates that the closed-loop operating mode is likely to result in an amount of fluid delivery that would cause a maximum insulin delivery limit to be violated, the supervisory module <NUM> may exclude the closed-loop operating mode from consideration as a possible destination operating mode. In lieu of the closed-loop operating mode, in some embodiments, if the mode transition process <NUM> is initiated in response to the maximum insulin delivery limit being reached during implementation of a current operating mode, a safe basal delivery mode (or hybrid closed-loop delivery mode) may be identified as a possible destination operating mode. The safe basal delivery mode may be realized as a hybrid closed-loop operating mode that configured to maintain a delivery rate that does not violate either the maximum insulin delivery limit or a minimum insulin delivery limit independent of the current or predicted measurements of the user's glucose. In this regard, the safe basal delivery mode may impose a maximum delivery rate that is less than or equal to the maximum insulin delivery limit divided by its applicable timeframe and impose a minimum delivery rate that is greater than the minimum insulin delivery limit divided by its applicable timeframe. Thus, the delivery commands generated in the safe basal delivery mode based on the difference between the current sensor glucose measurement value and the target glucose measurement value are bounded such that they will not violate applicable delivery limits.

Similarly, the supervisory module <NUM> may exclude operating modes that would likely result in the minimum insulin delivery limit being violated based on the amount of insulin delivered for the initial operating mode and the current or predicted glucose values for the user. For example, if the difference between current and/or predicted glucose values for the user and the target glucose value indicates the closed-loop operating mode is unlikely to deliver fluid for an amount of time that would cause the minimum insulin delivery limit to be violated, the supervisory module <NUM> may exclude the closed-loop operating mode from consideration as a possible destination operating mode. In some embodiments, if the mode transition process <NUM> is initiated in response to the minimum insulin delivery limit being reached during implementation of a current operating mode, a safe basal delivery mode may be identified as a possible destination operating mode in lieu of the closed-loop operating mode.

The supervisory module <NUM> excludes operating modes that utilize sensor glucose measurement values based on sensor health information. In this regard, recent sensor glucose measurement values or historical calibration information for the sensing arrangement <NUM> indicating that the sensing arrangement <NUM> may not be viable for the particular operating mode. In this regard, if the previous sensor glucose measurement values or historical calibration information indicates the sensing arrangement <NUM> is unhealthy or may require recalibration or replacement, the supervisory module <NUM> prevents entry of operating modes that would otherwise be relying potentially unreliable sensor measurement values. For example, the supervisory module <NUM> may exclude the closed-loop operating mode from consideration as a possible destination operating mode if a difference between the current sensor glucose measurement value and a predicted glucose value is greater than a threshold value, a calibration factor for the sensing arrangement <NUM> has expired, communications with the sensing arrangement <NUM> have been interrupted, a difference between the current calibration factor and the preceding calibration factor is greater than a threshold amount (e.g., a difference of more than <NUM>%), or a difference between reference blood glucose measurement value and the corresponding sensor measurement value used for the current calibration factor is greater than a threshold amount (e.g., the sensor measurement value is more than <NUM>% greater than or less than the reference blood glucose measurement value). In other embodiments, an operating mode that utilizes sensor glucose measurement values may be excluded when a duration of time that has elapsed since the most recent calibration exceeds a threshold value.

In one exemplary embodiment, a desired maximum number of alerts over a particular timeframe (e.g., the preceding <NUM> hours) could be designated by the user, with the supervisory module <NUM> excluding operating modes that would likely result in that maximum number of alerts being exceeded. For example, the operational information obtained by the supervisory module <NUM> may include a current number of user notifications or alerts that have been generated by the current operating mode (e.g., by the respective control module <NUM>, <NUM>, <NUM>, <NUM> implementing a corresponding counter). The supervisory module <NUM> may determine an expected number of user notifications or alerts to be generated by a particular operating mode based on the current and/or predicted glucose values for the user, and exclude that operating mode from the set of possible destination operating modes when the sum of the expected number of alerts and the current number of alerts exceeds the maximum number chosen by the user.

In one or more embodiments, the supervisory module <NUM> excludes operating modes based on the status of user notifications previously generated by the infusion device <NUM>. For example, if a user notification has been generated that indicates the user should recalibrate or replace the sensing arrangement <NUM>, and the user has not responded to the user notification by recalibrating or replacing the sensing arrangement <NUM> within a threshold amount of time (e.g., <NUM> minutes), the supervisory module <NUM> may exclude the closed-loop operating mode or other operating modes that rely on the sensing arrangement <NUM> from consideration as possible destination modes until the user responds to the notification.

Still referring to <FIG>, after identifying the available operating modes for a potential transition destination, the mode transition process <NUM> continues by identifying or otherwise selecting a destination operating mode from among the group of available operating modes (task <NUM>). In exemplary embodiments, the supervisory module <NUM> automatically selects the available operating mode to that is most preferable or most highly ranked based on device settings or user preferences maintained in memory <NUM>. In this regard, the user may manipulate a user interface <NUM>, <NUM> to establish a hierarchical ordering of the operating modes in the user's order of preference, with the hierarchical information being stored in the memory <NUM> along with other user preferences. For example, the user may identify the closed-loop operating mode as the most preferred operating mode, followed by the PLGM operating mode as the next most preferred operating mode, the LGS operating mode as the next most preferred operating mode, and the open-loop operating mode as the least preferred operating mode. In other embodiments, default settings for the infusion device <NUM>, <NUM>, <NUM> may specify a default hierarchical order of operating modes. It should be appreciated, however, that the subject matter described herein is not limited to any particular type of selection criteria used to identify the most preferable operating mode from among the available operating modes.

After selecting the destination operating mode, the mode transition process <NUM> continues by identifying or otherwise determining the types or subset of operational information pertaining to the current operating mode to be provided to the destination operating mode and providing that identified operational information to the destination operating mode (tasks <NUM>, <NUM>). In this regard, the supervisory module <NUM> passes at least a portion of the operational information obtained from the current operating mode control module <NUM>, <NUM>, <NUM>, <NUM> to the destination module <NUM>, <NUM>, <NUM>, <NUM> such that the implementation of the destination operating mode does not violate any delivery rules, constraints, limits, or the like. For example, the supervisory module <NUM> may obtain the current refractory period timer value, the current suspend duration timer value, or the like, from the control module <NUM>, <NUM>, <NUM>, <NUM> corresponding to the current operating mode and provide those values to the control module <NUM>, <NUM>, <NUM>, <NUM> corresponding to the destination operating mode to ensure that the destination operating mode does not violate a minimum refractory time period between suspending delivery, a maximum suspend duration, a minimum suspend duration, or the like. Additionally, the supervisory module <NUM> may provide the exit reason for the current operating mode, the current delivery status, information about alerts or events that occurred during the current operating mode, active insulin estimates, sensor health status and/or calibration information, and/or other historical delivery information to the destination operating mode control module <NUM>, <NUM>, <NUM>, <NUM>. The destination operating mode generates dosage commands in accordance with the operational information received from the preceding operating mode to provide a relatively seamless transition among operating modes.

Referring again to <FIG>, the mode transition process <NUM> continues by providing, to the infusion device motor control module, the dosage (or delivery) commands generated by the destination operating mode in accordance with the provided operational information (task <NUM>). In this regard, the supervisory module <NUM> signals, commands or otherwise operates the command multiplexer <NUM> to output dosage commands generated by the destination operating mode control module <NUM>, <NUM>, <NUM>, <NUM> and cease outputting dosage commands from the previously-active operating mode. For example, to transition from the closed-loop operating mode to the PLGM operating mode, the supervisory module <NUM> signals, commands or otherwise operates the command multiplexer <NUM> to output dosage commands generated by the PLGM control module <NUM> instead of the closed-loop control module <NUM>. Additionally, in some embodiments, the supervisory module <NUM> may assert or otherwise provide interrupt signals that indicate, to the respective control modules <NUM>, <NUM>, <NUM>, <NUM>, whether or not the respective control module <NUM>, <NUM>, <NUM>, <NUM> should generate dosage commands. For example, the supervisory module <NUM> may deactivate the closed-loop control module <NUM> (e.g., by providing a logical high interrupt signal to the closed-loop control module <NUM>) and activate the PLGM control module <NUM> (e.g., by providing a logical low interrupt signal to the PLGM control module <NUM>) while maintaining the other control modules <NUM>, <NUM> deactivated.

Referring to <FIG>, in accordance with one embodiment, when transitioning from the closed-loop operating mode to the PLGM operating mode, the supervisory module <NUM> obtains information identifying the exit reason (e.g., manual or auto), the amount of time delivery has been suspended in the preceding sixty minutes, and the current value of the closed-loop refractory timer from the closed-loop control module <NUM>. In some embodiments, the supervisory module <NUM> calculates the refractory time based on the amount of continuous delivery commands that precede the transition. The supervisory module <NUM> provides the obtained values and information to the PLGM control module <NUM>, and thereafter, the PLGM control module <NUM> generates dosage commands in accordance with the operational information from the closed-loop control module <NUM>.

For example, the PLGM control module <NUM> may set its refractory timer to the value of the closed-loop refractory timer and maintain delivery until the total refractory time exceeds the minimum refractory time period before suspending delivery. Thus, even if the user's predicted glucose level is below the predictive suspend threshold, the PLGM control module <NUM> may continue providing dosage commands that result in a basal rate of infusion until the value of the PLGM refractory timer is greater than or equal to the minimum refractory time period. In some embodiments, the PLGM control module <NUM> may utilize the exit reason to determine whether to continue providing dosage commands until the value of the PLGM refractory timer is greater than or equal to the minimum refractory time period. For example, if the exit reason is manual (e.g., the user manually transitioned the infusion device <NUM> to the PLGM mode), the PLGM control module <NUM> may provide dosage commands until the minimum refractory time period is observed, however, if the exit reason is automatic, the PLGM control module <NUM> may suspend dosage commands before the minimum refractory time period is observed and reset the PLGM refractory timer as appropriate.

In some embodiments, the sensor health status and/or calibration information, estimated active insulin information, and/or other operational information from the closed-loop operating mode may be utilized in conjunction with the exit reason when determining whether to observe the minimum refractory time period in the PLGM operating mode. For example, the PLGM control module <NUM> may allow dosage commands to be suspended only if the sensing arrangement <NUM> was calibrated less than a threshold amount of time before the transition (e.g., within the last hour) and the estimated active insulin is greater than a safe threshold value, which may be manually set by a user or a default value maintained by the infusion device <NUM>. Thus, the minimum refractory time period may still be observed for an automatic transition if the sensing arrangement <NUM> was not calibrated recently or the estimated active insulin is too low. Conversely, the PLGM control module <NUM> may automatically suspend delivery when the refractory time from the closed-loop control module <NUM> is less than the minimum refractory time period in response to determining the active insulin estimate from the closed-loop control module <NUM> is greater than the threshold value.

Similarly, if delivery is currently being suspended, the PLGM control module <NUM> may set its delivery suspend timer to the value of the closed-loop suspend timer (e.g., the amount of time delivery has been suspended in the preceding sixty minutes). Thus, even if the user's predicted glucose level is below the predictive suspend threshold, the PLGM control module <NUM> may begin providing dosage commands once the value of the PLGM delivery suspend timer is greater than the maximum suspension time period. Additionally, in some embodiments, the exit reason may be utilized by the PLGM control module <NUM> to determine whether to suspend delivery or resume delivery, either independently or in conjunction with the sensor health status and/or calibration information, estimated active insulin information, and/or other operational information, in a similar manner as described above. For example, if the sensing arrangement <NUM> was calibrated less than a threshold amount of time before the transition (e.g., within the last hour) and the estimated active insulin is less than a threshold value, the PLGM control module <NUM> may resume providing dosage commands even though the maximum suspension time period may not have been met.

When transitioning from the closed-loop operating mode to the LGS operating mode, the supervisory module <NUM> obtains information identifying the exit reason (e.g., manual or auto), the amount of time delivery has been suspended in the preceding sixty minutes, and the current value of the closed-loop refractory timer from the closed-loop control module <NUM> and provides the obtained values and information to the LGS control module <NUM> for generating dosage commands in accordance therewith, in a similar manner as described above for transitions to the PLGM operating mode.

In another example embodiment, when transitioning from the closed-loop operating mode to the open-loop operating mode, the supervisory module <NUM> may only provide the refractory timer values from the closed-loop control module <NUM> to the open-loop control module <NUM>. In such an embodiment, the open-loop control module <NUM> provides dosage commands that result in an open-loop basal rate of infusion while dynamically updating the refractory timer value for a subsequent transition to another operating mode. In this regard, the refractory timer value is updated so that if the infusion device <NUM> subsequently transitions from the open-loop operating mode to another operating mode where delivery could be suspended, the minimum refractory period is still observed by the control module <NUM>, <NUM>, <NUM> associated with that subsequent operating mode before delivery is suspended. In other embodiments, in lieu of providing the refractory time information to the open-loop control module <NUM>, the supervisory module <NUM> may independently manage and dynamically update the refractory time information, and subsequently provide the refractory time information to another destination control module <NUM>, <NUM>, <NUM> when transitioning from the open-loop operating mode. Similarly, in some embodiments, the supervisory module <NUM> may provide suspension information to the open-loop control module <NUM> (e.g., the amount of time delivery was suspended over a preceding time interval) for dynamically updating the suspension time information to ensure any maximum suspension limits are still observed by a control module <NUM>, <NUM>, <NUM> associated with that subsequent operating mode. Alternatively, the supervisory module <NUM> may also independently manage and dynamically update the refractory time information, and subsequently provide the refractory time information to a destination control module <NUM>, <NUM>, <NUM> when transitioning from the open-loop operating mode.

In other exemplary embodiments, when transitioning from the PLGM operating mode or the LGS operating mode to the closed-loop operating mode, the supervisory module <NUM> obtains information identifying the exit reason (e.g., manual or auto) and the current value of the respective refractory timer from the respective control module <NUM>, <NUM> and provides the obtained values and information to the closed-loop control module <NUM>. In this regard, the closed-loop control module <NUM> sets its refractory timer to the value of the refractory timer of the respective control module <NUM>, <NUM> and may maintain delivery until the total refractory time exceeds the minimum refractory time period before suspending delivery. In other embodiments, the closed-loop control module <NUM> may suspend delivery even though the total refractory time is less than the minimum refractory time period. For example, the closed-loop control module <NUM> may obtain sensor calibration information from the preceding operating mode and determine whether a duration of time that has elapsed since the most recent calibration exceeds a threshold value corresponding to the reliable lifetime of a calibration factor for purposes of the closed-loop mode. When the duration of time that has elapsed since the most recent calibration exceeds the threshold value, the closed-loop control module <NUM> may generate a notification via the user interface <NUM> that prompts the user to obtain a new blood glucose reference measurement value for recalibrating the sensing arrangement <NUM> upon transitioning to the closed-loop mode. In response to the user manipulating the blood glucose meter <NUM> to obtain a new blood glucose reference measurement value, and the new blood glucose reference measurement value indicates delivery should be suspended, the closed-loop control module <NUM> may suspend delivery even though the total refractory time does not exceed the minimum refractory time period. Alternatively, in the absence of a new blood glucose reference measurement value that indicates delivery should be suspended, the closed-loop control module <NUM> may generate dosage commands to provide a minimum basal rate of infusion while the closed-loop refractory timer value is less than the minimum refractory time period even though the user's current glucoses measurement value may be less than the target glucose value for the closed-loop control system.

In yet other exemplary embodiments, when transitioning from the open-loop operating mode to another operating mode, the supervisory module <NUM> obtains information identifying the exit reason (e.g., manual or auto) and the current value of the refractory timer from the open-loop module <NUM> and provides the obtained value to the particular destination operating mode control module <NUM>, <NUM>, <NUM>. In this regard, when transitioning from the open-loop operating mode, the destination operating mode control module <NUM>, <NUM>, <NUM> sets its refractory timer to the value provided by the supervisory module <NUM> to maintain delivery until the total refractory time exceeds the minimum refractory time period before allowing delivery to be suspended.

It will be appreciated that in practice there are numerous different types of information that may be exchanged among control modules <NUM>, <NUM>, <NUM>, <NUM> to achieve a desired manner of transitioning and comply with the particular constraints, rules, and/or limits for a particular application. Accordingly, the above examples are provided merely to aid in understanding of the subject matter and are not intended to be limiting.

To briefly summarize, the subject matter described herein facilitates transitioning between operating modes in a manner that enhances the user experience (e.g., by enabling the user to proactively increase viability of a desired operating mode and/or excluding operating modes that are likely to generate alerts from possible destinations for automatic transitions) and ensures compliance with applicable delivery control rules and other constraints (e.g., by excluding operating modes that are otherwise likely to result in a violation and transferring timer and/or counter values across operating modes).

For the sake of brevity, conventional techniques related to glucose sensing and/or monitoring, closed-loop glucose control, predictive glucose management, sensor calibration and/or compensation, and other functional aspects of the subject matter may not be described in detail herein. In addition, certain terminology may also be used in the herein for the purpose of reference only, and thus is not intended to be limiting. For example, terms such as "first", "second", and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. The foregoing description may also refer to elements or nodes or features being "connected" or "coupled" together. As used herein, unless expressly stated otherwise, "coupled" means that one element/node/feature is directly or indirectly joined to (or directly or indirectly communicates with) another element/node/feature, and not necessarily mechanically.

Claim 1:
An infusion device (<NUM>,<NUM>) comprising a reservoir (<NUM>) for fluid to be infused into a patient and a control system (<NUM>) , the control system being configured to operate the infusion device
to deliver the fluid in an automated manner in accordance with a first operating mode of a plurality of different operating modes, each operating mode of the plurality of different operating modes generating commands for delivering the fluid to the user in an automated manner in accordance with a different delivery control scheme associated therewith;
to obtain operational information pertaining to the operating of the infusion device in accordance with the first operating mode;
to obtain clinical information pertaining to the user;
to determine a destination operating mode of the plurality of different operating modes based at least in part on the operational information and the clinical information;
to transition operation of the infusion device from the first operating mode to the destination operating mode, wherein the destination operating mode is initialized using at least a portion of the operational information pertaining to the operating of the infusion device in accordance with the first operating mode; and
to operate the infusion device to deliver the fluid in accordance with the destination operating mode in a manner that is influenced by the portion of the operational information pertaining to the first operating mode
characterized in that
the portion of the operational information includes sensor health information; and
to determine the destination operating mode comprises:
to identify a set of one or more possible operating modes of the plurality of different operating modes by excluding an operating mode of the plurality of different operating modes based on the sensor health information; and
to select the destination operating mode from the set, wherein sensor health information is indicative that the sensing arrangement, which is communicatively coupled with the infusion device, is not viable for particular operating modes.