CN115426946A

CN115426946A - Analyte sensor quality metrics and related therapeutic actions for automated therapeutic delivery systems

Info

Publication number: CN115426946A
Application number: CN202180029980.6A
Authority: CN
Inventors: L·林特尔; A·坎贝尔; D·索科洛夫斯基; N·帕里克; M·米勒
Original assignee: Medtronic Minimed Inc
Current assignee: Medtronic Minimed Inc
Priority date: 2020-04-23
Filing date: 2021-01-26
Publication date: 2022-12-02
Also published as: WO2021216155A1; EP4138656A1

Abstract

A method of controlling operation of a medical device that regulates delivery of a fluid medicament to a user is disclosed. The method obtains a current sensor-generated value indicative of a physiological characteristic of the user and is produced in response to operation of a continuous analyte sensor apparatus. The method continues by: calculating a sensor quality metric indicative of reliability and trustworthiness of the current sensor-generated value; adjusting a therapy action of the medical device in response to the calculated sensor quality metric to configure a quality-specific mode of operation of the medical device; manage generation of a user alert at the medical device in response to the calculated sensor quality metric; and adjusting delivery of the fluid medicant from the medical device in accordance with the current sensor-generated value and the mass-specific mode of operation of the medical device.

Description

Analyte sensor quality metrics and related therapeutic actions for automated therapeutic delivery systems

Technical Field

Embodiments of the subject matter described herein relate generally to systems for delivering a therapeutic (e.g., a drug) to a user. More particularly, the subject matter described herein relates to user interface and quality check features of an insulin infusion system that obtain glucose readings from a continuous glucose sensor.

Background

Medical treatment delivery systems, such as fluid infusion pump devices, for delivering or dispensing a medicament, such as insulin or another prescribed medication, to a patient are relatively well known in the medical arts. A typical infusion pump includes a pump drive system that generally includes a small motor and drive train components that convert rotational motor motion into translational displacement of a plunger (or stopper) in a fluid reservoir that delivers medication from the reservoir to the body of the patient via a fluid path formed between the reservoir and the body of the patient. The use of infusion pump therapy has increased, particularly for delivering insulin to diabetic patients.

Control schemes have been developed to allow insulin infusion pumps to monitor and regulate blood glucose levels in patients in a substantially continuous and autonomous manner. In addition to changes in the individual insulin response and potentially other factors of a patient, changes in the patient's daily activities (e.g., exercise, carbohydrate consumption, etc.) complicate managing the diabetic patient's blood glucose levels. Some control schemes may attempt to proactively account for daily activity to minimize glucose excursions. At the same time, the patient may manually initiate delivery of insulin (e.g., a meal bolus or correction bolus) prior to or concurrently with a meal to prevent the patient's blood glucose level from peaking or fluctuating that might otherwise result from the impending consumption of carbohydrates and response time of the control scheme.

Disclosure of Invention

A method of controlling operation of a medical device that regulates delivery of a fluid medication to a user is disclosed herein. One embodiment of the method involves: receiving a meter-generated value indicative of a physiological characteristic of a user, the meter-generated value being generated in response to operation of the analyte meter device; and obtaining a sensor-generated value indicative of a physiological characteristic of the user, the sensor-generated value being generated in response to operation of a continuous analyte sensor apparatus different from the analyte meter apparatus. When an active meter generated value is available, operating the medical device in a first mode to display the active meter generated value on a user monitoring screen of the medical device and a therapy delivery control screen of the medical device, and operating the medical device in the first mode to calculate a dose of the therapy for delivery based on the active meter generated value. When valid meter-generated values are not available and a current sensor-generated value of the sensor-generated values meets the first quality criteria, operating the medical device in the second mode to display the current sensor-generated value on the user monitoring screen and the therapy delivery control screen, and calculating a dose of the therapy for delivery based on the current sensor-generated value. When the valid meter-generated value is not available and the current sensor-generated value satisfies the second quality criterion but does not satisfy the first quality criterion, operating the medical device in a third mode to display the current sensor-generated value on the user monitoring screen, refraining from displaying the current sensor-generated value on the therapy delivery control screen, and refraining from using the current sensor-generated value to calculate a dose of the therapy for delivery.

A medical device that regulates delivery of a medication to a user is also disclosed herein. One embodiment of the medical device comprises: a drive system; at least one processor device that regulates operation of the drive system to deliver fluid medication from the medical device; a display device; and at least one memory element associated with the at least one processor device and storing processor-executable instructions that are configurable to be executed by the at least one processor device to perform a method of controlling operation of the medical device. One embodiment of the method involves: receiving a meter-generated value indicative of a physiological characteristic of a user, the meter-generated value being generated in response to operation of the analyte meter device; and obtaining a sensor-generated value indicative of a physiological characteristic of the user, the sensor-generated value being generated in response to operation of a continuous analyte sensor apparatus different from the analyte meter apparatus. When the meter-generated value is available, operating the medical device in a first mode to display an effective meter-generated value on the display device on the user monitoring screen and the therapy delivery control screen, and calculating a dose of the therapy for delivery based on the effective meter-generated value. When the meter-generated value is not available and a current sensor-generated value of the sensor-generated values meets the first quality criteria, operating the medical device in a second mode to display the current sensor-generated value on a user monitoring screen and a therapy delivery control screen on the display device, and calculating a dose of the therapy for delivery based on the current sensor-generated value. When a valid meter-generated value is not available and the current sensor-generated value satisfies the second quality criteria but does not satisfy the first quality criteria, operating the medical device in a third mode to display the current sensor-generated value on the display device on the user monitoring screen, to inhibit display of the current sensor-generated value on the therapy delivery control screen, and to inhibit use of the current sensor-generated value to calculate a dose of the therapy for delivery.

Also disclosed herein is a non-transitory computer-readable storage medium comprising program instructions stored thereon, wherein the program instructions are configured to be capable of causing at least one processor device to perform a method involving: receiving a meter-generated value indicative of a physiological characteristic of a user, the meter-generated value being generated in response to operation of the analyte meter device; and obtaining a sensor-generated value indicative of a physiological characteristic of the user, the sensor-generated value being generated in response to operation of a continuous analyte sensor apparatus different from the analyte meter apparatus. When an active meter generated value is available, the method operates the medical device in a first mode to display the active meter generated value on a user monitoring screen of the medical device and a therapy delivery control screen of the medical device, and operates the medical device in a first mode to calculate a dose of the therapy for delivery based on the active meter generated value. When an effective meter-generated value is not available and the current sensor-generated value satisfies the first quality criteria, the method operates the medical device in a second mode to display the current sensor-generated value on the user monitoring screen and the therapy delivery control screen, and operates the medical device in the second mode to calculate a dose of the therapy for delivery based on the current sensor-generated value rather than the meter-generated value. When the valid meter-generated value is not available and the current sensor-generated value satisfies the second quality criterion but does not satisfy the first quality criterion, the method operates the medical device in a third mode to display the current sensor-generated value on the user monitoring screen, operates the medical device in the third mode to inhibit display of the current sensor-generated value on the therapy delivery control screen, and operates the medical device to inhibit use of the current sensor-generated value to calculate a dose of the therapy for delivery.

Also disclosed herein is a method of controlling operation of a medical device that regulates delivery of a fluid medicant to a user, the method involving: obtaining a current sensor-generated value indicative of a physiological characteristic of the user, the current sensor-generated value being generated in response to operation of the continuous analyte sensor apparatus; calculating a sensor quality metric indicative of reliability and trustworthiness of the current sensor-generated value; adjusting a therapy action of the medical device in response to the calculated sensor quality metric to configure a quality-specific mode of operation of the medical device; manage generation of a user alert at a medical device in response to the calculated sensor quality metric; and adjusting delivery of the fluid medicant from the medical device according to the current sensor-generated value and the mass-specific mode of operation of the medical device.

A medical device that regulates delivery of a medication to a user is also disclosed herein. The medical device includes: a drive system; at least one processor device that regulates operation of the drive system to deliver fluid medication from the medical device; a user interface; and at least one memory element associated with the at least one processor device and storing processor-executable instructions that are configurable to be executed by the at least one processor device to perform a method of controlling operation of the medical device. One embodiment of the method involves: obtaining current sensor-generated values indicative of a physiological characteristic of the user, the current sensor-generated values being generated in response to operation of the continuous analyte sensor apparatus; receiving or calculating a sensor quality metric indicative of reliability and trustworthiness of a current sensor-generated value; adjusting a therapeutic action of the medical device in response to the calculated sensor quality metric to configure a quality-specific mode of operation of the medical device; manage generation of a user alert at a user interface in response to the calculated sensor quality metric; and adjusting delivery of the fluid drug from the medical device according to the current sensor-generated value and the mass-specific operating mode of the medical device.

Also disclosed herein is a method of assessing the quality of operation of a continuous analyte sensor apparatus. One embodiment of the method involves: obtaining a current sensor-generated value indicative of a physiological characteristic of the user, the current sensor-generated value being generated in response to operation of the continuous analyte sensor apparatus; calculating a sensor quality metric indicative of reliability and trustworthiness of the current sensor-generated value, wherein the calculation is based on information generated by or derived from the continuous analyte sensor apparatus; and formatting the sensor quality metric to be compatible with the fluid drug delivery device such that a therapeutic action of the fluid drug delivery device is adjusted in response to the calculated sensor quality metric and such that an aggressiveness of the fluid drug therapy provided by the fluid drug delivery device is proportional to a quality of the current sensor-generated value as indicated by the calculated sensor quality metric.

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

Drawings

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.

Fig. 1 depicts an exemplary embodiment of an infusion system;

fig. 2 depicts a plan view of an exemplary embodiment of a fluid infusion device suitable for use in the infusion system of fig. 1;

FIG. 3 is an exploded perspective view of the fluid infusion device of FIG. 2;

FIG. 4 is a cross-sectional view of the fluid infusion device of FIGS. 2-3 as viewed along line 4-4 in FIG. 3 when assembled with a reservoir inserted into the infusion device;

fig. 5 is a block diagram of an exemplary infusion system suitable for use with a fluid infusion device in one or more embodiments;

fig. 6 is a block diagram of an exemplary pump control system suitable for use in the infusion device in the infusion system of fig. 5 in one or more embodiments;

fig. 7 is a block diagram of a closed-loop control system that may be implemented or otherwise supported by the pump control system in the fluid infusion device of fig. 5-6 in one or more exemplary embodiments;

FIG. 8 is a block diagram of an exemplary patient monitoring system;

FIG. 9 is a flow chart illustrating an exemplary embodiment of a process for operating a medical device, such as an insulin infusion device;

FIG. 10 is a flow chart illustrating operation of the insulin infusion device in a first mode;

FIG. 11 is a schematic diagram of a user monitoring screen on an insulin infusion device with a meter generating Blood Glucose (BG) values displayed thereon;

FIG. 12 is a schematic diagram of a therapy delivery control screen on an insulin infusion device with BG values displayed thereon;

FIG. 13 is a flow chart showing operation of the insulin infusion device in a second mode;

FIG. 14 is a schematic diagram of a user monitoring screen on an insulin infusion device with a sensor generated glucose (SG) value displayed thereon;

FIG. 15 is a schematic diagram of a treatment delivery control screen on an insulin infusion device with SG values displayed thereon;

FIG. 16 is a flow chart showing operation of the insulin infusion device in the third mode;

FIG. 17 is a schematic diagram of a treatment delivery control screen on an insulin infusion device with neither BG nor SG values displayed thereon;

FIG. 18 is a flow diagram illustrating an exemplary embodiment of a method of controlling the operation of a medical device to adjust a therapeutic action based on sensor quality;

FIG. 19 is a block diagram illustrating the generation of a sensor quality metric according to an exemplary embodiment; and

fig. 20 is a flowchart illustrating the operation of an insulin infusion device according to an exemplary embodiment.

Detailed Description

The following detailed description is merely illustrative in nature and is not intended to limit the subject matter or the embodiments of the application or the application and uses of such embodiments. As used herein, the word "exemplary" means "serving as an example, instance, or illustration. Any specific implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

Exemplary embodiments of the subject matter described herein are implemented in connection with a medical device, such as a portable electronic medical device. Although many different applications are possible, the following description focuses on embodiments that incorporate an insulin infusion device (or insulin pump) as part of the deployment of an infusion system. For the sake of brevity, conventional techniques related to infusion system operation, insulin pump and/or infusor operation, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Examples of infusion pumps may be of the type described in, but not limited to, the following U.S. patents: 4,562,751, 4,685,903, 5,080,653, 5,505,709, 5,097,122, 6,485,465, 6,554,798, 6,558,320, 6,558,351, 6,641,533, 6,659,980, 6,752,787, 6,817,990, 6,932,584 and 7,621,893; each of these patents is incorporated herein by reference.

Generally, fluid infusion devices incorporate a motor or other actuation means operable to displace a plunger (or stopper) of a fluid reservoir provided in the fluid infusion device to deliver a dose of fluid medicament, such as insulin, to the body of a user. Dosage commands governing operation of the motor may be generated in an automated manner according to a delivery control scheme associated with a particular mode of operation, and dosage commands may be generated in a manner that is influenced by current (or recent) measurements of physiological conditions of the body of the user. For example, in a closed loop or automatic mode of operation, a dose command may be generated based on the difference between a current (or most recent) measurement of interstitial fluid glucose level in the user's body and a target (or reference) glucose set point value. In this regard, the infusion rate may vary with fluctuations in the difference between the current measurement and the target measurement. For purposes of illustration, the present subject matter is described herein in the context of an infusion fluid being insulin for regulating glucose levels of a user (or patient); however, it should be understood that many other fluids may be administered by infusion, and the subject matter described herein is not necessarily limited to use with insulin.

An insulin infusion pump may operate in an automatic mode, wherein basal insulin is delivered at a rate that is automatically adjusted for the user. In controlling the delivery of basal insulin in this manner, the pump may also control the delivery of a correction bolus to account for glucose rise trends due to meals, stress, hormonal fluctuations, and the like. The correction bolus amount should ideally be accurately calculated and administered to maintain the user's blood glucose within a desired range. In particular, the automatically generated and delivered correction bolus should safely manage and maintain the user's blood glucose level above a defined hypoglycemic threshold level.

Turning now to fig. 1, an exemplary embodiment of an infusion system 100 includes, but is not limited to, a fluid infusion device (or infusion pump) 102, a sensing arrangement 104, a Command Control Device (CCD) 106, and a computer 108. The components of the infusion system 100 may be implemented using different platforms, designs, and configurations, and the embodiment shown in fig. 1 is not exhaustive or limiting. In some embodiments, as illustrated in fig. 1, the infusion device 102 and the sensing arrangement 104 are fixed at desired locations on the body of the user (or patient). In this regard, the location at which the infusion device 102 and the sensing arrangement 104 in fig. 1 are secured to the body of the user is provided merely as a representative, non-limiting example. The elements of the infusion system 100 may be similar to those described in U.S. patent No. 8,674,288, the subject matter of which is hereby incorporated by reference in its entirety.

In the illustrated embodiment of fig. 1, the infusion device 102 is designed as a portable medical device adapted to infuse fluids, liquids, gels or other medicaments into the body of a user. In an exemplary embodiment, the infused fluid is insulin, but many other fluids may be administered by infusion, such as, but not limited to, HIV drugs, drugs to treat pulmonary hypertension, iron-chelating drugs, analgesics, anti-cancer therapeutic drugs, vitamins, hormones, and the like. In some embodiments, the fluid may include nutritional supplements, dyes, tracking media, saline media, hydration media, and the like.

The sensing arrangement 104 generally represents a component of the infusion system 100 configured to sense, detect, measure, or otherwise quantify a condition of a user, and may include a sensor, monitor, or the like for providing data indicative of the condition sensed, detected, measured, or otherwise monitored by the sensing arrangement. In this regard, the sensing arrangement 104 may include electronics and enzymes that are responsive to a biological condition of the user, such as blood glucose levels, etc., and provide data indicative of the blood glucose level to the infusion device 102, the CCD 106, and/or the computer 108. For example, the infusion device 102, the CCD 106, and/or the computer 108 may include a display for presenting information or data (e.g., a current glucose level of the user, a plot or chart of the user's glucose level versus time, a device status indicator, an alarm message, etc.) to the user based on the sensor data received from the sensing arrangement 104. In other embodiments, the infusion device 102, the CCD 106, and/or the computer 108 may contain electronics and software configured to analyze the sensor data and operate the infusion device 102 to deliver fluid to the body of the user based on the sensor data and/or a pre-programmed delivery routine. Thus, in an exemplary embodiment, one or more of the infusion device 102, the sensing arrangement 104, the CCD 106, and/or the computer 108 includes a transmitter, receiver, and/or other transceiver electronics that allow communication with other components of the infusion system 100 such that the sensing arrangement 104 can transmit sensor data or monitor data to one or more of the infusion device 102, the CCD 106, and/or the computer 108.

Still referring to fig. 1, in various embodiments, the sensing arrangement 104 may be secured to or embedded in the body of the user at a location remote from where the infusion device 102 is secured to the body of the user. In various other embodiments, the sensing arrangement 104 may be incorporated within the infusion device 102. In other embodiments, the sensing arrangement 104 may be separate and apart from the infusion device 102, and may be part of the CCD 106, for example. In such embodiments, the sensing device 104 may be configured to receive a biological sample, analyte, or the like to measure a condition of the user.

In some embodiments, the CCD 106 and/or the computer 108 may include electronics and other components configured to perform processing, deliver daily doses, and control the infusion device 102 in a manner that is influenced by sensor data measured by and/or received from the sensing arrangement 104. By including control functions in the CCD 106 and/or the computer 108, the infusion device 102 may be made with more simplified electronics. However, in other embodiments, the infusion device 102 may include all control functions and may operate without the CCD 106 and/or the computer 108. In various embodiments, the CCD 106 may be a portable electronic device. Additionally, in various embodiments, the infusion device 102 and/or the sensing arrangement 104 may be configured to transmit data to the CCD 106 and/or the computer 108 for display or processing of the data by the CCD 106 and/or the computer 108.

In some embodiments, the CCD 106 and/or the computer 108 may provide information to the user that facilitates subsequent use of the infusion device 102 by the user. For example, the CCD 106 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 106 may provide information to the infusion device 102 to autonomously control the rate or dosage of medication administered into the body of the user. In some embodiments, the sensing device 104 may be integrated into the CCD 106. Such embodiments may allow a user to monitor a condition by, for example, providing a sample of his or her blood to the sensing device 104 to assess his or her condition. In some embodiments, the sensing arrangement 104 and the CCD 106 may be used to determine a glucose level in the blood and/or body fluid of the user without the use or need of a wired or cable connection between the infusion device 102 and the sensing arrangement 104 and/or the CCD 106.

In some embodiments, the sensing arrangement 104 and/or the infusion device 102 are cooperatively configured to deliver fluid to a user using a closed loop system. Examples of sensing devices and/or infusion pumps utilizing closed loop systems may be found in, but are not limited to, the following U.S. patents: 6,088,608, 6,119,028, 6,589,229, 6,740,072, 6,827,702, 7,323,142, and 7,402,153, or U.S. patent application publication 2014/0066889, all of which are incorporated by reference herein in their entirety. In such embodiments, the sensing arrangement 104 is configured to sense or measure a condition of the user, such as blood glucose level or the like. The infusion device 102 is configured to deliver fluid in response to a condition sensed by the sensing arrangement 104. In turn, the sensing arrangement 104 continues to sense or otherwise quantify the current condition of the user, thereby allowing the infusion device 102 to continuously deliver fluid responsive to the condition currently (or most recently) sensed by the sensing arrangement 104 indefinitely. In some embodiments, the sensing arrangement 104 and/or the infusion device 102 may be configured to utilize the closed loop system only during a portion of the day, for example only when the user is asleep or awake.

Fig. 2-4 illustrate one exemplary embodiment of a fluid infusion device 200 (or alternatively, an infusion pump) suitable for use in an infusion system, such as the infusion device 102 in the infusion system 100 of fig. 1. The fluid infusion device 200 is a portable medical device designed to be carried or worn by a patient (or user), and the fluid infusion device 200 may utilize any number of conventional features, components, elements, and characteristics of existing fluid infusion devices, such as some of the features, components, elements, and/or characteristics described in U.S. Pat. nos. 6,485,465 and 7,621,893. It should be understood that fig. 2-4 illustrate some aspects of the infusion device 200 in a simplified manner; in some embodiments, the infusion device 200 may include additional elements, features, or components not shown or described in detail herein.

As best shown in fig. 2-3, the illustrated embodiment of the fluid infusion device 200 includes a housing 202 adapted to receive a reservoir 205 containing a fluid. An opening 220 in the housing 202 accommodates a fitting 223 (or cap) for the reservoir 205, where the fitting 223 is configured to mate or otherwise interface with a tubing 221 of an infusion set 225 to provide a fluid path to/from the body of a user. In this manner, fluid communication is established from the interior of reservoir 205 to the user through tube 221. The illustrated fluid infusion device 200 includes a human-machine interface (HMI) 230 (or user interface) that includes

elements

232, 234 that can be manipulated by a user to administer a bolus of fluid (e.g., insulin), change therapy settings, change user preferences, select display features, and the like. The infusion device also includes a display device 226, such as a Liquid Crystal Display (LCD) or another suitable display device, which may be used to present various types of information or data to the user, such as, but not limited to: the current glucose level of the patient; time; a graph or chart of glucose levels versus time for the patient; device status indicators, and the like.

The housing 202 is formed of a substantially rigid material having a hollow interior 214 adapted to allow the electronics assembly 204, the slide member (or sled) 206, the drive system 208, the sensor assembly 210, and the drive system cover member 212 to be disposed therein in addition to the reservoir 205, wherein the contents of the housing 202 are surrounded by a housing cover member 216. The opening 220, the slider 206, and the drive system 208 are coaxially aligned in an axial direction (indicated by arrow 218), whereby the drive system 208 facilitates linear displacement of the slider 206 in the axial direction 218 to dispense fluid from the reservoir 205 (after the reservoir 205 has been inserted into the opening 220), wherein the sensor assembly 210 is configured to measure an axial force (e.g., a force aligned with the axial direction 218) exerted on the sensor assembly 210 in response to operating the drive system 208 to displace the slider 206. In various embodiments, the sensor component 210 may be used to detect one or more of the following: slow, prevent, or otherwise reduce an obstruction in the fluid path of fluid delivery from the reservoir 205 to the body of the user; when the reservoir 205 is empty; when the slide 206 is properly seated with the reservoir 205; when a fluid dose has been delivered; when the infusion device 200 is subjected to shock or vibration; when the infusion device 200 requires maintenance.

Depending on the embodiment, the fluid-containing reservoir 205 may be implemented as a syringe, vial, cartridge, bag, or the like. In certain embodiments, the fluid infused is insulin, although many other fluids may be administered by infusion, such as, but not limited to, HIV drugs, drugs to treat pulmonary hypertension, iron-chelating drugs, analgesic drugs, anti-cancer therapies, drugs, vitamins, hormones, and the like. As best shown in fig. 3-4, the reservoir 205 generally includes a reservoir barrel 219 that contains a fluid and is concentrically and/or coaxially aligned (e.g., in the axial direction 218) with the slide 206 when the reservoir 205 is inserted into the infusion device 200. The end of the reservoir 205 proximate the opening 220 may include or otherwise mate with a fitting 223 that secures the reservoir 205 in the housing 202 and prevents displacement of the reservoir 205 in the axial direction 218 relative to the housing 202 after the reservoir 205 is inserted into the housing 202. As described above, the fitting 223 extends from (or through) the opening 220 of the housing 202 and cooperates with the tubing 221 to establish fluid communication from the interior of the reservoir 205 (e.g., the reservoir barrel 219) to the user via the tubing 221 and the infusor 225. The opposite end of the reservoir 205, proximate the slide 206, contains a plunger 217 (or plug) positioned to push fluid along a fluid path through the tube 221 from the interior of the barrel 219 of the reservoir 205 to the user. The slide 206 is configured to mechanically couple or otherwise engage with the plunger 217, thereby becoming seated with the plunger 217 and/or the reservoir 205. When the drive system 208 is operated to displace the slide 206 in the axial direction 218 towards the opening 220 in the housing 202, fluid is forced out of the reservoir 205 through the tube 221.

In the shown implementation of fig. 3-4, the drive system 208 includes a motor assembly 207 and a drive screw 209. The motor assembly 207 includes a motor coupled to a drive train component of the drive system 208 configured to convert rotary motor motion into translational displacement of the slide 206 in the axial direction 218 and thereby engage and displace the plunger 217 of the reservoir 205 in the axial direction 218. In some embodiments, the motor assembly 207 may also be powered to translate the slide 206 in an opposite direction (e.g., a direction opposite to direction 218) to retract and/or detach from the reservoir 205 to allow replacement of the reservoir 205. In an exemplary embodiment, the motor assembly 207 includes a brushless DC (BLDC) motor having one or more permanent magnets mounted, attached, 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 motors may be implemented as solenoid motors, AC motors, stepper motors, piezoelectric tracked drives, shape memory actuator drives, electrochemical gas cells, thermally driven gas cells, bimetallic actuators, and the like. The drive train components may include one or more lead screws, cams, pawls, jacks, pulleys, pawl, clamps, gears, nuts, slides, bearings, levers, beams, dogs, plungers, sliders, brackets, rails, bearings, supports, bellows, covers, diaphragms, bags, heaters, and the like. In this regard, although the illustrated embodiment of the infusion pump uses coaxially aligned drive trains, the motor may be offset or otherwise arranged in a non-coaxial manner with respect to the longitudinal axis of the reservoir 205.

As best shown in fig. 4, the drive screw 209 mates with threads 402 inside the slide 206. When the motor assembly 207 is powered and operated, the drive screw 209 rotates and forces the slide 206 to translate in the axial direction 218. In an exemplary embodiment, the infusion device 200 includes a sleeve 211 to prevent the slider 206 from rotating when the drive screw 209 of the drive system 208 is rotated. Thus, rotation of the drive screw 209 causes the slide 206 to extend or retract relative to the drive motor assembly 207. When the fluid infusion device is assembled and operable, the slide 206 contacts the plunger 217 to engage the reservoir 205 and control the delivery of fluid from the infusion device 200. In an exemplary embodiment, a shoulder portion 215 of the slider 206 contacts or otherwise engages the plunger 217 to displace the plunger 217 in the axial direction 218. In an alternative embodiment, the slide 206 may include a threaded tip 213 that is removably engageable with internal threads 404 on the plunger 217 of the reservoir 205, as described in detail in U.S. Pat. nos. 6,248,093 and 6,485,465, which are incorporated herein by reference.

As shown in fig. 3, the electronics assembly 204 includes control electronics 224 coupled to a display device 226, wherein the housing 202 includes a transparent window portion 228 aligned with the display device 226 to allow the display device 226 to be viewed by a user when the electronics assembly 204 is disposed within the interior 214 of the housing 202. The control electronics 224 generally represent hardware, firmware, processing logic, and/or software (or a combination thereof) configured to control the operation of the motor assembly 207 and/or the drive system 208, as described in greater detail below in the context of fig. 5. The control electronics 224 are also suitably configured and designed to support various user interface, input/output, and display features of the fluid infusion device 200. Whether such functionality is implemented as hardware, firmware, state machine, or software depends upon the particular application and design constraints imposed on the embodiment. Such functionality may be implemented in a manner that is similar to those described herein for each particular application, but such implementation-specific decisions should not be interpreted as limiting or restrictive. In an exemplary embodiment, the control electronics 224 includes one or more programmable controllers that may be programmed to control the operation of the infusion device 200.

The motor assembly 207 includes one or more electrical leads 236 adapted to electrically couple to the electronics assembly 204 to establish communication between the control electronics 224 and the motor assembly 207. In response to command signals from the control electronics 224 for operating a motor driver (e.g., a power converter) to regulate the amount of power supplied to the motor from the power source, the motor actuates the drive train components of the drive system 208 to displace the slide 206 in the axial direction 218 to force fluid out of the reservoir 205 along the fluid path (including the tube 221 and the infuser), thereby administering a dose of fluid contained in the reservoir 205 into the body of the user. Preferably, the power source is implemented as one or more batteries contained within the housing 202. Alternatively, the power source may be a solar panel, a capacitor, an AC or DC power source provided through a power cord, or the like. In some embodiments, the control electronics 224 may operate the motors of the motor assembly 207 and/or the drive system 208 in a step-wise manner, typically on an intermittent basis; separate precise doses of fluid are administered to the user according to the programmed delivery profile.

Referring to fig. 2-4, as described above, the user interface 230 includes HMI elements such as buttons 232 and directional keys 234 formed on a graphical keypad overlay 231 overlaying a keypad assembly 233 that includes features corresponding to the buttons 232, directional keys 234, or other user interface entries indicated by the graphical keypad overlay 231. When assembled, the keypad assembly 233 is coupled to the control electronics 224, thereby allowing the user to manipulate the

HMI elements

232, 234 to interact with the control electronics 224 and control operation of the infusion device 200, e.g., 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, etc. In this regard, the control electronics 224 maintains and/or provides information regarding program parameters, delivery profiles, pump operation, alarms, warnings, status, etc. to the display device 226, which may be adjusted using the

HMI elements

232, 234. In various embodiments, the

HMI elements

232, 234 may be implemented as physical objects (e.g., buttons, knobs, joysticks, etc.) or virtual objects (e.g., graphical user interface elements using touch-sensing and/or proximity-sensing technologies). For example, in some embodiments, the display device 226 may be implemented as a touch screen or touch sensitive display, and in such embodiments, the features and/or functionality of the

HMI elements

232, 234 may be integrated into the display device 226 and the HMI 230 may not be present. In some embodiments, the electronics assembly 204 may further include an alert generation element coupled to the control electronics 224 and suitably configured to generate one or more types of feedback, such as, but not limited to: auditory feedback; visual feedback; tactile (physical) feedback, and the like.

Referring to fig. 3-4, in accordance with one or more implementations, the sensor assembly 210 includes a back plate structure 250 and a loading element 260. The loading element 260 is disposed between the capping member 212 and a beam structure 270 that includes one or more beams having sensing elements disposed thereon that are affected by a compressive force applied to the sensor assembly 210 that deflects the one or more beams, as described in more detail in U.S. patent No. 8,474,332, which is incorporated herein by reference. In an exemplary embodiment, the backplate structure 250 is attached, adhered, mounted, or otherwise mechanically coupled to the bottom surface 238 of the drive system 208 such that the backplate structure 250 resides between the bottom surface 238 of the drive system 208 and the housing cover member 216. The drive system cover member 212 is contoured to accommodate and match the bottom of the sensor assembly 210 and the drive system 208. The drive system cover member 212 may be attached to the interior of the housing 202 to prevent displacement of the sensor assembly 210 in a direction opposite the direction of force provided by the drive system 208 (e.g., a direction opposite direction 218). Thus, the sensor assembly 210 is positioned between the motor assemblies 207 and secured by the cover member 212, which prevents displacement of the sensor assembly 210 in a downward direction opposite the direction of the arrow representing the axial direction 218, such that the sensor assembly 210 is subjected to a counteracting compressive force when the drive system 208 and/or the motor assembly 207 is operated to displace the slide 206 in the axial direction 218 opposite the fluid pressure in the reservoir 205. Under normal operating conditions, the compressive force applied to the sensor assembly 210 is related to the fluid pressure in the reservoir 205. As shown, the electrical leads 240 are adapted to electrically couple the sensing elements of the sensor assembly 210 to the electronics assembly 204 to establish communication with the control electronics 224, wherein the control electronics 224 are configured to measure, receive, or otherwise obtain electrical signals from the sensing elements of the sensor assembly 210 indicative of the force applied by the drive system 208 in the axial direction 218.

Fig. 5 depicts an exemplary embodiment of an infusion system 500 suitable for use with an infusion device 502, such as any of the

infusion devices

102, 200 described above. The infusion system 500 is capable of controlling or otherwise adjusting a physiological condition within the body 501 of a patient to a desired (or target) value, or otherwise maintaining the condition within a range of acceptable values, in an automated or autonomous manner. In one or more exemplary embodiments, the regulated condition is sensed, detected, measured, or otherwise quantified by a sensing arrangement 504 (e.g., a blood glucose sensing arrangement 504) communicatively coupled to the infusion device 502. It should be noted, however, that in alternative embodiments, the condition being regulated by the infusion system 500 may be correlated to the measurements obtained by the sensing arrangement 504. That is, for clarity and illustration purposes, the present subject matter may be described herein in the context of the sensing arrangement 504 being implemented as a glucose sensing arrangement that senses, detects, measures, or otherwise quantifies a patient's glucose level, which is regulated in the body 501 of the patient by the infusion system 500.

In an exemplary embodiment, the sensing arrangement 504 includes one or more interstitial glucose sensing elements that generate or otherwise output an electrical signal (alternatively referred to herein as a measurement signal) having a signal characteristic that correlates to, is affected by, or is otherwise indicative of a relative interstitial fluid glucose level in the patient's body 501. The output electrical signal is filtered or otherwise processed to obtain a measurement indicative of the patient's interstitial fluid glucose level. In an exemplary embodiment, a blood glucose meter 530 (e.g., a fingertip device) is used to directly sense, detect, measure, or otherwise quantify blood glucose in the body 501 of the user. In this regard, the blood glucose meter 530 outputs or otherwise provides a measured blood glucose value that may be used as a reference measurement for calibrating the sensing arrangement 504 and converting a measurement value indicative of the patient's interstitial fluid glucose level into a corresponding calibrated blood glucose value. For purposes of illustration, the calibrated blood glucose value calculated based on the electrical signal output by the one or more sensing elements of the sensing arrangement 504 may alternatively be referred to herein as a sensor glucose value, a sensed glucose value, or a variant thereof.

In an exemplary embodiment, the infusion system 500 further includes one or more

additional sensing devices

506, 508 configured to sense, detect, measure, or otherwise quantify a characteristic of the patient's body 501 indicative of a condition in the patient's body 501. In this regard, in addition to the glucose sensing arrangement 504, one or more secondary sensing arrangements 506 may be worn, carried, or otherwise associated with the patient's body 501 to measure patient (or patient activity) characteristics or conditions that may affect the patient's blood glucose level or insulin sensitivity. For example, a heart rate sensing device 506 may be worn on or otherwise associated with the patient's body 501 to sense, detect, measure, or otherwise quantify the patient's heart rate, which in turn may indicate motion (and its intensity) that may affect the patient's glucose level or insulin response in the body 501. In yet another embodiment, another invasive, interstitial or subcutaneous sensing device 506 may be inserted into the patient's body 501 to obtain measurements of another physiological condition that may indicate motion (and its intensity), such as a lactate sensor, a ketone sensor, or the like. Depending on the embodiment, the one or more secondary sensing apparatus 506 may be implemented as a separate component worn by the patient, or alternatively, the one or more secondary sensing apparatus 506 may be integrated with the infusion device 502 or the glucose sensing apparatus 504.

The illustrated infusion system 500 also includes an acceleration sensing device 508 (or accelerometer) that may be worn on or otherwise associated with the patient's body 501 to sense, detect, measure or otherwise quantify acceleration of the patient's body 501, which in turn may indicate movement or some other condition of the body 501 that may affect the patient's insulin response. While the acceleration sensing arrangement 508 is shown in fig. 5 as being integrated into the infusion device 502, in alternative embodiments, the acceleration sensing arrangement 508 may be integrated with another

sensing arrangement

504, 506 on the patient's body 501, or the acceleration sensing arrangement 508 may be implemented as a separate, stand-alone component worn by the patient.

In the illustrated embodiment, the pump control system 520 generally represents the electronics and other components of the infusion device 502 that control the operation of the fluid infusion device 502 in a manner that is influenced by a sensed glucose value indicative of a current glucose level in the body 501 of the patient according to a desired infusion delivery program. For example, to support the closed-loop operating mode, the pump control system 520 maintains, receives, or otherwise obtains a target or commanded glucose value, and automatically generates or otherwise determines a dosage command for operating an actuation device, such as the motor 532, to displace the plunger 517 and deliver insulin to the patient's body 501 based on the difference between the sensed glucose value and the target glucose value. In other operating modes, the pump control system 520 may generate or otherwise determine a dosage command configured to maintain the sensed glucose value below an upper glucose limit, above a lower glucose limit, or other value within a desired range of glucose values. In some embodiments, the infusion device 502 can store or otherwise maintain the target value, one or more upper and/or lower glucose limits, one or more insulin delivery limits, and/or one or more other glucose thresholds in a data storage element accessible to the pump control system 520. As described in more detail, in one or more exemplary embodiments, the pump control system 520 automatically adjusts or adapts one or more parameters or other control information used to generate commands for operating the motor 532 in a manner that accounts for possible changes in the patient's glucose level or insulin response caused by meals, exercise, or other activities.

Still referring to fig. 5, the target glucose value and other threshold glucose values utilized by the pump control system 520 may be received from an external component (e.g., the CCD 106 and/or the computing device 108) or may be input by the patient via a user interface element 540 associated with the infusion device 502. In some embodiments, the one or more user interface elements 540 associated with the infusion device 502 generally include at least one input user interface element, such as a button, keypad, keyboard, knob, joystick, mouse, touch panel, touch screen, microphone, or another audio input device, and/or the like. Further, the one or more user interface elements 540 include at least one output user interface element, such as a display device (e.g., a light emitting diode, etc.), a display device (e.g., a liquid crystal display, etc.), a speaker or another audio output device, a haptic feedback device, or the like, for providing notifications or other information to the patient. It should be noted that although fig. 5 depicts the one or more user interface elements 540 as being separate from the infusion device 502, in some embodiments, the one or more user interface elements 540 may be integrated with the infusion device 502. Further, in some embodiments, one or more user interface elements 540 are integrated with the sensing arrangement 504 in addition to and/or in lieu of one or more user interface elements 540 being integrated with the infusion device 502. The patient may manipulate one or more user interface elements 540 as needed to operate the infusion device 502 to deliver a correction bolus, adjust target values and/or thresholds, modify a delivery control scheme or operating mode, etc.

Still referring to fig. 5, in the illustrated embodiment, the infusion device 502 includes a motor control module 512 coupled to a motor 532 (e.g., motor assembly 207) that is operable to displace a plunger 517 (e.g., plunger 217) in a reservoir (e.g., reservoir 205) and provide a desired amount of fluid to the body 501 of the patient. In this regard, displacement of the plunger 517 causes a fluid, such as insulin, capable of affecting a physiological condition of the patient to be delivered to the patient's body 501 via a fluid delivery path (e.g., via the tubing 221 of the infuser 225). The motor driver module 514 is coupled between the energy source 518 and the motor 532. The motor control module 512 is coupled to the motor driver module 514, and the motor control module 512 generates or otherwise provides command signals that operate the motor driver module 514 to provide current (or power) from the energy source 518 to the motor 532 to displace the plunger 517 in response to receiving a dosage command from the pump control system 520 indicating a desired amount of fluid to be delivered.

In an exemplary embodiment, the energy source 518 is implemented as a battery housed within the infusion device 502 (e.g., within the housing 202) that provides Direct Current (DC) power. In this regard, the motor driver module 514 generally represents a combination of circuitry, hardware, and/or other electrical components configured to convert or otherwise transform DC power provided by the energy source 518 into alternating current signals applied to the stator windings of the motor 532 that cause currents to flow through respective phases of the stator windings that generate stator magnetic fields and rotate the rotor of the motor 532. The motor control module 512 is configured to receive or otherwise obtain a commanded dosage from the pump control system 520, convert the commanded dosage to a commanded translational displacement of the plunger 517, and command, signal, or otherwise operate the motor driver module 514 such that rotation of the rotor of the motor 532 produces an amount of the commanded translational displacement of the plunger 517. For example, the motor control module 512 may determine the amount of rotation of the rotor required to produce a translational displacement of the plunger 517 that achieves the commanded dose received from the pump control system 520. Based on the current rotational position (or orientation) of the rotor relative to the stator, as indicated by the output of the rotor sensing device 516, the motor control module 512 determines the appropriate sequence of alternating current signals to be applied to the stator windings for the respective phases of rotation that should rotate the rotor from its current position (or orientation) by the determined amount of rotation. In embodiments where the motor 532 is implemented as a BLDC motor, the alternating electrical signals commutate the phases of the stator windings at the appropriate orientation of the rotor poles relative to the stator and in the appropriate sequence to provide a rotating stator magnetic field that rotates the rotor in the desired direction. The motor control module 512 then operates the motor driver module 514 to apply the determined alternating current electrical signal (e.g., command signal) to the stator windings of the motor 532 to achieve the desired delivery of fluid to the patient.

When the motor control module 512 is operating the motor driver module 514, current flows from the energy source 518 through the stator windings of the motor 532 to generate a stator magnetic field that interacts with the rotor magnetic field. In some embodiments, after the motor control module 512 operates the motor driver module 514 and/or the motor 532 to achieve the commanded dose, the motor control module 512 stops operating the motor driver module 514 and/or the motor 532 until a subsequent dose command is received. In this regard, the motor driver module 514 and the motor 532 enter an idle state during which the motor driver module 514 is effective to disconnect or decouple the stator windings of the motor 532 from the energy source 518. In other words, when the motor 532 is idle, current does not flow from the energy source 518 through the stator windings of the motor 532, and therefore the motor 532 does not consume power from the energy source 518 in the idle state, thereby improving efficiency.

Depending on the embodiment, the motor control module 512 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 an exemplary embodiment, the motor control module 512 includes or otherwise accesses a data storage element or memory, including any kind of Random Access Memory (RAM), read Only Memory (ROM), flash memory, registers, hard disk, a removable disk, magnetic or optical mass storage, or any other short-term or long-term storage medium or other non-transitory computer-readable medium capable of storing programming instructions executed by the motor control module 512. When read and executed by the motor control module 512, the computer-executable programming instructions cause the motor control module 512 to perform or otherwise support the tasks, operations, functions, and processes described herein.

It should be understood that fig. 5 is a simplified representation of an infusion device 502 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 504 may be implemented by or otherwise integrated into the pump control system 520, or vice versa. Similarly, in some embodiments, the features and/or functionality of the motor control module 512 may be implemented by or otherwise integrated into the pump control system 520 or vice versa. Further, the features and/or functions of the pump control system 520 may be implemented by the control electronics 224 located in the fluid infusion device 502, while in alternative embodiments, the pump control system 520 may be implemented by a remote computing device that is physically distinct and/or separate from the infusion device 502 (e.g., the CCD 106 or the computing device 108).

Fig. 6 illustrates an exemplary embodiment of a pump control system 600 suitable for use as the pump control system 520 of fig. 5, according to one or more embodiments. The pump control system 600 shown includes, but is not limited to, a pump control module 602, a communication interface 604, and a data storage element (or memory) 606. The pump control module 602 is coupled to the communication interface 604 and the memory 606, and the pump control module 602 is suitably configured to support the operations, tasks, and/or processes described herein. In various embodiments, the pump control module 602 is also coupled to one or more user interface elements (e.g., user interfaces 230, 540) to receive user input (e.g., a target glucose value or other glucose threshold) and provide notifications, alerts, or other therapy information to the patient.

The communication interface 604 generally represents hardware, circuitry, logic, firmware, and/or other components of the pump control system 600 that are coupled to the pump control module 602 and configured to support communication between the pump control system 600 and the

various sensing devices

504, 506, 508. In this regard, the communication interface 604 may include or otherwise be coupled to one or more transceiver modules capable of supporting wireless communication between the

pump control system

520, 600 and the

sensing device

504, 506, 508. For example, the communication interface 604 may be used to receive sensor measurements or other measurement data from each of the

sensing devices

504, 506, 508 in the infusion system 500. In other embodiments, the communication interface 604 may be configured to support wired communication to/from one or

more sensing devices

504, 506, 508. In various embodiments, the communication interface 604 may also support communication with another electronic device (e.g., the CCD 106 and/or the computer 108) in the infusion system (e.g., to upload sensor measurements to a server or other computing device, to receive control information from a server or other computing device, etc.).

The pump control module 602 generally represents the hardware, circuitry, logic, firmware, and/or other components of the pump control system 600 that are coupled to the communication interface 604 and configured to determine dosage commands for operating the motor 532 to deliver fluid to the body 501 and perform various additional tasks, operations, functions, and/or operations described herein based on measurement data received from the

sensing devices

504, 506, 508. For example, in an exemplary embodiment, the pump control module 602 implements or otherwise executes a command generation application 610 that supports one or more autonomous operating modes and calculates or otherwise determines dosage commands for operating the motor 532 of the infusion device 502 in the autonomous operating mode based at least in part on current measurements of the condition of the patient's body 501. For example, in the closed-loop operating mode, the command generation application 610 may determine a dosage command for operating the motor 532 to deliver insulin to the patient's body 501 to adjust the patient's blood glucose level to the target reference glucose value based at least in part on the current glucose measurement value most recently received from the sensing arrangement 504. In addition, command generation application 610 may generate dosage commands for boluses that are manually initiated or otherwise directed by the patient via user interface elements.

In an exemplary embodiment, the pump control module 602 also implements or otherwise executes a personalization application 608 cooperatively configured to interact with the command generation application 610 to support adjusting dosage commands or control information indicating the manner in which dosage commands are generated in a personalized, patient-specific manner. In this regard, in some embodiments, based on the correlation between the current or most recent measurement data and the current operational context relative to historical data associated with the patient, the personalization application 608 may adjust or otherwise modify the values of one or more parameters utilized by the command generation application 610 in determining the dosage command, for example, by modifying the parameter values at the registers referenced by the command generation application 610 or locations in the memory 606. In still other embodiments, the personalization application 608 may predict meals or other events or activities that the patient may be engaged in, and output or otherwise provide an indication of the predicted patient behavior for confirmation or modification by the patient, which in turn may be utilized to adjust the manner in which the dosage commands are generated in order to adjust glucose in a manner that accounts for patient behavior in a personalized manner.

Still referring to fig. 6, depending on the embodiment, the pump control module 602 may be implemented or realized with at least one general purpose processor device, microprocessor, controller, microcontroller, state machine, content addressable memory, application specific integrated circuit, 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 602, or in any practical combination thereof. In an exemplary embodiment, the pump control module 602 contains or otherwise accesses a data storage element or memory 606, which may be implemented using any kind of non-transitory computer readable medium capable of storing programming instructions for execution by the pump control module 602. When read and executed by the pump control module 602, the computer-executable programming instructions cause the pump control module 602 to implement or otherwise generate the applications 608, 610 and perform the tasks, operations, functions, and processes described herein.

It should be understood that fig. 6 is a simplified representation of a pump control system 600 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 512 may be implemented by or otherwise integrated into the pump control system 600 and/or the pump control module 602, such as by the command generation application 610 converting the dose commands into corresponding motor commands, in which case there may be no separate motor control module 512 in embodiments of the infusion device 502.

Fig. 7 illustrates an exemplary closed-loop control system 700 that may be implemented by the

pump control system

520, 600 to provide a closed-loop mode of operation that autonomously adjusts a condition in a patient's body to a reference (or target) value. In this regard, the control system 700 may be used to regulate the delivery of insulin to the patient during an automated basal insulin delivery operation. It should be understood that fig. 7 is a simplified representation of a control system 700 for purposes of illustration and is not intended to limit the subject matter described herein in any way.

In an exemplary embodiment, the control system 700 receives or otherwise obtains a target glucose value at an input 702. In some embodiments, the target glucose value may be stored or otherwise maintained by the infusion device 502 (e.g., in the memory 606), however, in some alternative embodiments, the target value may be received from an external component (e.g., the CCD 106 and/or the computer 108). In one or more embodiments, the target glucose value may be 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 base rate and a patient-specific daily insulin demand that are determined based on historical delivery information (e.g., the amount of insulin delivered over the previous 24 hours) over a previous time interval. The control system 700 also receives or otherwise obtains a current glucose measurement value (e.g., a most recently obtained sensor glucose value) from the sensing arrangement 504 at an input 704. The illustrated control system 700 implements or otherwise provides proportional-integral-derivative (PID) control to determine or otherwise generate a delivery command for operating the motor 532 based at least in part on a difference between a target glucose value and a 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 adjusts the measured value to a desired value. PID control parameters are applied to the difference between the target glucose level at input 702 and the glucose level measured at input 704 to generate or otherwise determine a dosage (or delivery) command provided at output 730. Based on the delivery command, the motor control module 512 operates the motor 532 to deliver insulin to the patient's body to affect the patient's glucose level and thereby reduce the difference between the subsequently measured glucose level and the target glucose level.

The illustrated control system 700 includes or otherwise implements a summation block 706 configured to determine a difference between a target value obtained at the input 702 and a measured value obtained from the sensing arrangement 504 at the input 704, e.g., by subtracting the target value from the measured value. The output of the summation block 706 represents the difference between the measured value and the target value, which is then provided to each of the proportional, integral, and differential term paths. The proportional term path includes a gain block 720 that multiplies the difference by a proportional gain factor KP to obtain a proportional term. The integral term path includes an integral block 708 that integrates the difference value and a gain block 722 that multiplies the integrated difference value by an integral gain factor KI to obtain an integral term. The derivative term path includes a derivative block 710 that determines the derivative of the difference and a gain block 724 that multiplies the derivative of the difference by a derivative gain factor KD to obtain a derivative term. The proportional, integral, and derivative terms are then added or otherwise combined to obtain a delivery command at output 730 for operating the motor. Various implementation details related to closed-loop PID control and determination of gain coefficients are described in more detail in U.S. patent 7,402,153, which is incorporated herein by reference.

In one or more exemplary embodiments, the PID gain coefficients are patient-specific and are dynamically calculated or otherwise determined prior to entering the closed-loop operating mode based on historical insulin delivery information (e.g., amount and/or timing of previous doses, historical correction bolus information, etc.), historical sensor measurements, historical reference blood glucose measurements, user-reported or user-entered events (e.g., meals, exercise, etc.), and the like. In this regard, one or more patient-specific control parameters (e.g., insulin sensitivity coefficient, daily insulin demand, insulin limits, reference basal rate, reference fasting glucose, active insulin action duration, time constant for drug effect, etc.) may be used to compensate for, correct, or otherwise adjust the PID gain coefficients to account for various operating conditions experienced and/or exhibited by the infusion device 502. The PID gain coefficients may be maintained by a memory 606 accessible to the pump control module 602. In this regard, the memory 606 may contain a plurality of registers associated with control parameters for PID control. For example, a first parameter register may store a target glucose value and be accessed by or otherwise coupled to the summing block 706 at input 702, and similarly, a second parameter register accessed by the proportional gain block 720 may store a proportional gain coefficient, a third parameter register accessed by the integral gain block 722 may store an integral gain coefficient, and a fourth parameter register accessed by the derivative gain block 724 may store a derivative gain coefficient.

In one or more exemplary embodiments, one or more parameters of the closed-loop control system 700 are automatically adjusted or adapted in a personalized manner to account for potential changes in the patient's glucose level or insulin sensitivity due to meals, exercise, or other events or activities. For example, in one or more embodiments, the target glucose value may be decreased prior to predicting a meal event to effect an increase in the rate of insulin infusion in order to effectively pre-bolus a meal and thereby reduce the likelihood of postprandial hyperglycemia. Additionally or alternatively, time constants or gain coefficients associated with one or more paths of the closed-loop control system 700 may be adjusted to tune responsiveness to deviations between measured glucose values and target glucose values. For example, based on the particular type of meal being consumed or the particular time of day the meal is consumed, the time constant associated with micro block 710 or the micro entry path may be adjusted to make the closed loop control more or less aggressive in response to an increase in the patient's glucose level based on the patient's historical blood glucose response to the particular meal type.

Fig. 8 shows an exemplary embodiment of a patient monitoring system 800. The patient monitoring system 800 includes a medical device 802 communicatively coupled to a sensing element 804 that is inserted into or worn by a patient to obtain measurement data indicative of a physiological condition in the patient's body, such as a sensed glucose level. The medical device 802 is communicatively coupled to the client device 806 via a communication network 810, wherein the client device 806 is communicatively coupled to a remote device 814 via another communication network 812. In this regard, the client device 806 may serve as an intermediary for uploading or otherwise providing measurement data from the medical device 802 to the remote device 814. It should be understood that fig. 8 shows a simplified representation of a patient monitoring system 800 for purposes of illustration, and is not intended to limit the subject matter described herein in any way.

In an exemplary embodiment, the client device 806 is implemented as a mobile phone, smartphone, tablet computer, or other similar mobile electronic device; however, in other embodiments, client device 806 may be implemented as any kind of electronic device capable of communicating with medical device 802 via network 810, such as a laptop or notebook computer, a desktop computer, or the like. In an exemplary embodiment, the network 810 is implemented as a bluetooth network, a ZigBee network, or another suitable personal area network. That is, in other embodiments, network 810 may be implemented as a wireless ad hoc network, a Wireless Local Area Network (WLAN), or a Local Area Network (LAN). The client device 806 includes or is coupled to a display device (such as a monitor, screen, or another conventional electronic display) that is capable of graphically presenting data and/or information related to a physiological condition of a patient. Client device 806 also includes or is otherwise associated with a user input device (such as a keyboard, mouse, touch screen, etc.) that is capable of receiving input data and/or other information from a user of client device 806.

In an exemplary embodiment, a user (such as a patient, a doctor of the patient, or another healthcare provider) manipulates a client device 806 to execute a client application 808 that supports communications with the medical device 802 via a network 810. In this regard, the client application 808 supports establishing a communication session with the medical device 802 over the network 810 and receiving data and/or information from the medical device 802 via the communication session. Medical device 802 may similarly execute or otherwise implement a corresponding application or process that supports establishing a communication session with client application 808. Client application 808 generally represents a software module or another feature generated or otherwise implemented by client device 806 to support the processes described herein. Thus, the client device 806 typically includes a processing system and data storage elements (or memory) capable of storing programming instructions for execution by the processing system that, when read and executed, cause the processing system to create, generate, or otherwise facilitate the client application 808 and perform or otherwise support the processes, tasks, operations, and/or functions described herein. Depending on the embodiment, the processing system may be implemented using any suitable processing system and/or device, such as one or more processor devices, central Processing Units (CPUs), controllers, microprocessors, microcontrollers, processing cores configured to support the operations of the processing system described herein, and/or other hardware computing resources. Similarly, the data storage elements or memories may be implemented as Random Access Memory (RAM), read Only Memory (ROM), flash memory, magnetic or optical mass storage, or any other suitable non-transitory short-term or long-term data storage or other computer-readable medium, and/or any suitable combination thereof.

In one or more embodiments, the client device 806 and the medical device 802 establish an association (or pairing) with each other over the network 810 to enable subsequent establishment of a peer-to-peer or peer-to-peer communication session between the medical device 802 and the client device 806 via the network 810. For example, according to one embodiment, the network 810 is implemented as a bluetooth network, wherein the medical device 802 and the client device 806 are paired with each other (e.g., by obtaining and storing network identification information for each other) by performing a discovery process or other suitable pairing process. The pairing information obtained during the discovery process allows either the medical device 802 or the client device 806 to initiate establishment of a secure communication session via the network 810.

In one or more exemplary embodiments, client application 808 is further configured to store or otherwise maintain an address and/or other identifying information for remote device 814 on second network 812. In this regard, the second network 812 may be physically and/or logically distinct from the network 810, such as the internet, a cellular network, a Wide Area Network (WAN), and so forth. The remote device 814 generally represents a server or other computing device configured to receive and analyze or otherwise monitor measurement data, event log data, and possibly other information obtained for a patient associated with the medical device 802. In an exemplary embodiment, remote device 814 is coupled to a database 816 that is configured to store or otherwise maintain data associated with individual patients. In some embodiments, the remote device 814 may reside at a physically different and/or separate location from the medical device 802 and the client device 806, such as at a facility owned and/or operated by or otherwise affiliated with the manufacturer of the medical device 802. For purposes of explanation, but not limitation, remote device 814 may alternatively be referred to herein as a server.

Still referring to fig. 8, sensing element 804 generally represents a component of patient monitoring system 800 configured to generate, produce, or otherwise output one or more electrical signals indicative of a physiological condition sensed, measured, or otherwise quantified by sensing element 804. In this regard, the physiological condition of the patient will affect the characteristics of the electrical signal output by the sensing element 804 such that the characteristics of the output signal correspond to or are otherwise related to the physiological condition to which the sensing element 804 is sensitive. In an exemplary embodiment, the sensing element 804 is implemented as an interstitial glucose sensing element inserted at a location on the patient's body that generates an output electrical signal having a current (or voltage) associated therewith that is correlated with an interstitial fluid glucose level that is sensed or otherwise measured in the patient's body by the sensing element 804.

The medical device 802 generally represents a component of the patient monitoring system 800 that is communicatively coupled to an output of the sensing element 804 to receive or otherwise obtain measurement data samples (e.g., measured glucose and characteristic impedance values) from the sensing element 804, store or otherwise maintain the measurement data samples, and upload or otherwise transmit the measurement data to the remote device 814 or server via the client device 806. In one or more embodiments, the medical device 802 is implemented as an

infusion device

102, 200, 502 configured to deliver a fluid, such as insulin, to the body of a patient. That is, in other embodiments, the medical device 802 may be a separate sensing or monitoring device that is separate and independent from the infusion device (e.g., sensing arrangement 104, 504). It should be noted that although fig. 8 depicts the medical device 802 and the sensing element 804 as separate components, in some embodiments, the medical device 802 and the sensing element 804 may be integrated or otherwise combined to provide a unitary device that may be worn by a patient.

In the exemplary embodiment, medical device 802 includes a control module 822, a data storage element 824 (or memory), and a communication interface 826. Control module 822 generally represents hardware, circuitry, logic, firmware, and/or one or more other components of medical device 802 that are coupled to sensing element 804 to receive electrical signals output by sensing element 804 and to perform or otherwise support various additional tasks, operations, functions, and/or processes described herein. Depending on the embodiment, the control module 822 may be implemented or realized with a general purpose processor device, a microprocessor device, 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 some embodiments, the control module 822 includes an analog-to-digital converter (ADC) or another similar sampling device that will sample or otherwise convert the output electrical signal received from the sensing element 804 into a corresponding digital measurement data value. In other embodiments, the sensing element 804 may incorporate an ADC and output a digital measurement.

Communication interface 826 generally represents the hardware, circuitry, logic, firmware, and/or other components of medical device 802 that are coupled to control module 822 to output/transmit data and/or information from/to medical device 802 to/from client device 806. For example, communication interface 826 may include or otherwise be coupled to one or more transceiver modules capable of supporting wireless communication between medical device 802 and client device 806. In an exemplary embodiment, communication interface 826 is implemented as a bluetooth transceiver or adapter configured to support Bluetooth Low Energy (BLE) communication.

In an exemplary embodiment, remote device 814 receives measurement data values associated with a particular patient (e.g., sensor glucose measurements, acceleration measurements, etc.) obtained using sensing element 804 from client device 806, and remote device 814 stores or otherwise maintains historical measurement data in database 816 associated with the patient (e.g., using one or more unique patient identifiers). Additionally, remote device 814 may also receive meal data or other event log data from or via client device 806, which may be input or otherwise provided by the patient (e.g., via client application 808), and store or otherwise maintain historical meal data and other historical event or activity data associated with the patient in database 816. In this regard, meal data includes, for example, a time or timestamp associated with a particular meal event, a meal type or other information indicative of the composition or nutritional characteristics of the meal, and an indication of the size associated with the meal. In an exemplary embodiment, the remote device 814 also receives historical fluid delivery data corresponding to a basal or bolus dose of fluid delivered to the patient by the

infusion device

102, 200, 502. For example, the client application 808 may communicate with the

infusion device

102, 200, 502 to obtain the insulin delivery dose and corresponding timestamp from the

infusion device

102, 200, 502 and then upload the insulin delivery data to the remote device 814 for storage associated with a particular patient. Remote device 814 may also receive geolocation data and possibly other contextual data associated with

devices

802, 806 from client device 806 and/or client application 808, and store or otherwise maintain historical operational contextual data associated with a particular patient. In this regard, one or more of the

devices

802, 806 may include a Global Positioning System (GPS) receiver, or similar module, component, or circuitry capable of outputting or otherwise providing data characterizing the geographic location of the

respective device

802, 806 in real-time.

The historical patient data may be analyzed by one or more of the remote device 814, the client device 806, and/or the medical device 802 to change or adjust the operation of the

infusion device

102, 200, 502 to affect fluid delivery in a personalized manner. For example, historical meal data and corresponding measurement data or other contextual data for a patient may be analyzed to predict a future time at which the patient may consume the next meal, a likelihood of a future meal event within a particular time period, a likely size or amount of carbohydrates associated with a future meal, a likely type or nutritional composition of a future meal, and so forth. Further, historical measurement data of the patient's postprandial period after a historical dining event may be analyzed to model or otherwise characterize the patient's predicted size and type of glycemic response to meals of the current context (e.g., time of day, day of week, geo-location, etc.). One or more aspects of the

infusion device

102, 200, 502 controlling or regulating insulin delivery may then be modified or adjusted to proactively account for the patient's likely meal activity and glycemic response.

In one or more exemplary embodiments, remote device 814 utilizes machine learning to determine which combination of historical sensor glucose measurement data, historical delivery data, historical auxiliary measurement data (e.g., historical acceleration measurement data, historical heart rate measurement data, etc.), historical event log data, historical geo-location data, and other historical or background data correlates with or predicts the occurrence of a particular event, activity, or metric for a particular patient, and then determines a corresponding equation, function, or model for calculating a parameter value of interest based on the set of input variables. Thus, the model can characterize or map a particular combination of one or more of current (or recent) sensor glucose measurement data, auxiliary measurement data, delivery data, geographic location, patient behavior or activity, or the like, to a value representing a current probability or likelihood of a particular event or activity or a current value of a parameter of interest. It should be noted that the subset of input variables predicted or associated with a particular patient may differ from other patients, as the physiological response of each patient may differ from other populations. Furthermore, the relative weights applied to the respective variables of the prediction subset may also be different from other patients who may have a common prediction subset, based on different correlations between particular input variables and historical data for that particular patient. It should be noted that remote device 814 may utilize any number of different machine learning techniques to determine which input variables predict a patient of current interest, such as artificial neural networks, genetic programming, support vector machines, bayesian networks, probabilistic machine learning models or other bayesian techniques, fuzzy logic, heuristically derived combinations, or the like.

Medical devices of the type described herein may generate a variety of user interface display screens that support different functions and features. For example, an insulin infusion device may generate a main screen that functions as a patient status or monitoring screen, a settings/preferences screen, a bolus delivery control screen, and the like. These and other display screens may present different information, status data, notifications, patient data (e.g., glucose data), and/or other information to a user in any desired arrangement or format.

Non-assisted insulin delivery requires the provision of a Sensor Glucose (SG) value for bolus dose estimation. The SG value should only be presented to the user if it is accurate, reliable, or otherwise trusted. The user may instead choose to use Blood Glucose (BG) values from a linked glucose meter device (e.g., a glucose meter device in wireless or wired communication with the medical device). Assuming that there are two input sources for the treatment and that only one source can be used, the insulin infusion device is suitably configured to clearly indicate which glucose source is being used. To this end, the exemplary embodiments described herein are controlled in an appropriate manner to avoid using the current SG value for bolus estimation when the quality or reliability of the SG value is determined to be not high enough. Exemplary embodiments also safely distinguish SG from BG for bolus estimation and presentation to the user.

The method of operation described in more detail below is governed by certain rules when dealing with BG and SG values. For example, when a BG value is provided to the system, the value is displayed on the bolus delivery control screen until the BG value expires (e.g., after a specified period of time, such as 12 minutes). A unique and visually distinguishable icon is used to indicate that the displayed value is a BG value. If the user fails to make a bolus delivery selection within a predetermined time period (e.g., 12 minutes or any other time period), the bolus delivery function will timeout.

According to another operational rule, when the system trusts the SG value and there is no recent BG input, the bolus delivery control screen includes the current SG value with a corresponding icon in a manner that is visually distinguishable from the displayed BG value. The SG value displayed in the bolus delivery interface cannot be modified via the user interface of the insulin infusion device.

According to another operating rule, if there is a sudden peak in the SG reading that cannot be attributed to carbohydrate intake or other physiological processes (e.g., SG increases at a rate above a predetermined threshold), the current SG value is assumed to be temporarily inapplicable to non-adjuvant therapy. In this case, no alarm is required, but the SG value is not presented on the bolus delivery control screen, and the SG value is not used to calculate the bolus estimate.

Thus, the insulin infusion device supports a user interface associated with a full non-bolus estimation. When the current SG value is a stable/trusted value, it is visually displayed in the bolus delivery control screen. Otherwise, the SG value is removed from the bolus delivery control screen without generating a user alert. If the user wishes to administer a manual bolus, the user can provide a BG value for bolus estimation. The display screen and user interface features are designed to clearly distinguish SG values from BG values. This avoids user confusion and potential bolus estimation errors.

Fig. 9 is a flow diagram illustrating an exemplary embodiment of a process 900 for operating a medical device that regulates the delivery of a fluid medicant to a user. The process 900 may be performed by an insulin infusion device of the type described above or any other medical device. The process 900 receives a meter generated value indicative of a physiological characteristic of a user, wherein the generated value is produced in response to operation of an analyte meter device. For the exemplary implementations described herein, the medical device is an insulin infusion device, the fluid medication is insulin, the physiological characteristic of interest is blood glucose, and the meter-generated value is a BG value obtained from a blood glucose meter device (e.g., a BG fingertip device) that generates BG measurements from a blood sample taken from a user. Thus, an exemplary embodiment of process 900 receives BG values (e.g., once a day, once every 12 hours, or as frequently as desired by the user) either directly from a linked BG meter or via manual data entry by the user or caregiver at the insulin infusion device (task 902). The insulin infusion device assumes that the most recently received BG measurements (whether user input or received directly from the BG meter device) are accurate and authentic.

The process 900 also obtains sensor-generated values indicative of the same physiological characteristic of the user, where the sensor-generated values are produced in response to operation of the continuous analyte sensor apparatus. For the exemplary insulin infusion device implementations described herein, the sensor-generated value is an SG value obtained from (or calculated from) sensor data obtained from a continuous glucose monitor or sensor worn by the user. Accordingly, an exemplary embodiment of process 900 obtains the SG value periodically, e.g., every five minutes, every ten minutes, or any other desired time period (task 904). In some embodiments,

tasks

902 and 904 are performed independently of each other. For example, task 904 may be performed more frequently than task 902, or

tasks

902 and 904 may be performed in any order, in succession, or simultaneously.

The process 900 determines how BG values and/or SG values are used for display purposes as well as therapeutic dosing and delivery purposes. To do so, an exemplary embodiment of process 900 checks for the presence of a valid BG value (e.g., a valid meter generated value) (query task 906). For this particular implementation, the current BG value is considered "valid" until it expires after an expiration time period. The expiration period may vary from one embodiment to another. For this particular example, the effective lifetime of the BG value is only 12 minutes; the expired BG value is not used. Thus, if process 900 determines that a valid BG value is available ("YES" branch of query task 906), the device is controlled to operate in a first mode in an appropriate manner, e.g., as described in further detail below in connection with FIG. 10 (task 908). According to embodiments described herein, when a valid meter is available to generate BG values, the device operates in the first mode regardless of the availability of the sensor to generate SG values, and regardless of the quality, accuracy, or confidence (if one is available) of the current SG value.

Fig. 10 is a flow chart illustrating operation of the insulin infusion device in the first mode. The first mode operational process 1000 depicted in fig. 10 may be performed at task 908 of process 900.

In this example, it is assumed that the "new" BG value is accurate and trustworthy. Accordingly, process 1000 displays the valid BG value on the user monitor screen of the device (task 1002). When the BG value remains valid, it remains displayed on the user monitor screen. Once the BG value expires or is otherwise deemed invalid, it is removed from the user monitoring screen (e.g., ceases to be displayed within the user monitoring screen). In some embodiments, the user monitoring screen is a main screen of the insulin infusion device, and the main screen may include additional information, such as other patient data, status indicators, and the like, if desired. In this regard, fig. 11 is a schematic diagram of a user monitoring screen 1100 on an insulin infusion device with current and active meter generated BG values 1102 displayed thereon. The BG value 1102 may be displayed along with a "BG" tab 1104 to explicitly indicate that the displayed value is indeed a BG value (rather than a SG value). Further, the process 1000 displays BG values using a visually distinguishable characteristic, which may also be used to display a "BG" label 1104 and units (mg/dL) used to display BG values. For example, any one or more of the following visually distinguishable characteristics may be used to display BG values: color; designing a font; font size; font properties such as bold, italics, or outline; animation, such as a blinking display or a moving display; filling patterns or patches; a level of transparency; and an accompanying icon (such as a drop of blood).

Referring back to fig. 10, process 1000 also displays the effective BG value on the device's therapy delivery control screen (task 1004). When the BG value remains active, it remains displayed on the therapy delivery control screen. Once the BG value expires or is otherwise deemed invalid, it is removed from the therapy delivery control screen. For this particular embodiment, the therapy delivery control screen is an insulin bolus delivery control screen of the insulin infusion device, and the bolus delivery control screen may include additional information related to the estimated bolus dosage and operation of the bolus delivery function. In this regard, fig. 12 is a schematic diagram of a therapy delivery control screen 1200 on an insulin infusion device with current and effective BG values 1202 displayed thereon. BG values 1202 may be displayed along with a "BG" tab 1204 to explicitly indicate that the displayed value is indeed a BG value (rather than a SG value). Further, BG values 1202 may be displayed along with a visually distinguishable and contextually relevant icon 1206 to further indicate that the displayed value is a BG value rather than a SG value. For this example, the icon 1206 resembles a drop of blood, and the color of the icon 1206 is red.

Notably, the process 1000 displays the BG value 1202 using the same (or substantially similar) visually distinguishable characteristic used to display the BG value 1102 on the user monitoring screen 1100. This same visually distinguishable characteristic may also be used to display a "BG" label 1204 and to display units of BG values (mg/dL). Using the same visually distinguishable characteristic for BG values on different user interface screens or features makes it easy for a user to interpret and identify the source of the displayed glucose measurement. While this description focuses on user monitoring screens and treatment delivery control screens, consistent visual characteristics ("look and feel" aspects) may be used across any number of display screens generated by the device.

Referring back to fig. 10, process 1000 disables display of any SG values on the user monitor screen and the therapy delivery control screen (task 1006). In this regard, if a valid BG value is available, the device relies on this measurement, whether or not a current and accurate SG value is also available. Thus, preventing the display of an available SG value under these conditions is intuitive for the user and not confusing.

Process 1000 continues by calculating a dose of the therapeutic for delivery (if needed) based on the active meter generated BG values (task 1008). For this example, an insulin bolus is calculated at task 1008 and the calculated bolus amount is displayed on the therapy delivery control screen. In this regard, therapy delivery control screen 1200 shown in fig. 12 includes a calculated insulin bolus of 0.8 units. Thus, the effective BG value is used as an input or parameter for the purpose of estimating an appropriate insulin bolus to maintain the blood glucose level of the user within a desired target range.

In some embodiments, the calculated bolus amount may be applied automatically or manually. For example, if the auto-delivery mode is supported and activated, a bolus may be automatically delivered. Accordingly, during operation in the first mode, process 1000 enables the automatic therapy delivery functionality of the device (task 1010). Thus, if the user is unable to manually administer the calculated bolus amount, the automatic delivery function will take appropriate action to deliver the bolus in a timely manner. To this end, process 1000 may automatically control operation of the device to adjust delivery of the fluid medicant (insulin) from the device according to the calculated therapeutic dose (task 1012).

Returning to the description of fig. 9 and process 900, if a valid BG value is not available ("no" branch of query task 906), process 900 checks the current SG value to determine a measure of quality. Any suitable method may be used to determine or calculate the quality of the current SG value. For example, the current SG value may be compared to historical SG measurements, historical BG measurements, most recent BG values, and the like. Additionally or alternatively, the quality of the current SG value may be determined using a "self-diagnostic" technique that takes into account the age of the continuous glucose sensor, SG measurement trends, electrical noise in the raw sensor signal, and the like. According to certain embodiments, the process 900 determines the quality of the SG measurements using the methods described in more detail below.

Although the quality of the SG measurements can be expressed in any suitable manner, exemplary embodiments of process 900 consider "high quality" SG measurements to be the best quality (e.g., above a high quality threshold) and thus suitable for glucose monitoring, therapeutic dose calculation, and controlling delivery of therapeutics. The process 900 considers a "monitored quality" SG measurement to be suitable only for glucose monitoring, where a monitored quality SG measurement is less desirable than a high quality SG measurement, but still suitable for certain non-treatment related functions (e.g., below a high quality threshold and above a low quality threshold). If the quality of the SG measurement is deemed less than the monitored quality (e.g., below a low quality threshold), the SG value is neither displayed nor used for treatment-related functions.

If process 900 determines that the current SG value meets a "high quality" criterion, e.g., a quality above a high quality threshold ("YES" branch of query task 910), the device is controlled to operate in the second mode in an appropriate manner (task 912). According to embodiments described herein, the device operates in the second mode when active meter generated BG values are not available and when the current sensor generated SG value is determined to be of high quality.

Fig. 13 is a flow chart illustrating operation of the insulin infusion device in the second mode. The second mode of operation process 1300 depicted in fig. 13 may be performed at task 912 of process 900. The second mode depends on the currently available high quality SG value. Accordingly, process 1300 displays the current SG value on the user monitor screen of the device (task 1302). The SG value remains displayed on the user monitor screen until it is refreshed. Fig. 14 is a schematic diagram of a user monitoring screen 1400 on the insulin infusion device with a current SG value 1402 displayed thereon. SG value 1402 can be displayed with an "SG" tab (not shown) to explicitly indicate that the displayed value is indeed an SG value (rather than a BG value). The example shown in fig. 14 displays a glucose trend arrow 1404 near the displayed SG value 1402 to indicate whether the user's blood glucose level is increasing or decreasing (e.g., as compared to a previous glucose level measurement). Further, the process 1300 displays the SG value 1402 using a visually distinguishable characteristic, which can also be used to display the "SG" label, the trend arrow 1404, and units of SG value (mg/dL). The embodiments described herein use color as a visually distinguishable characteristic. However, in some embodiments, any one or more of the following characteristics may be used to display the SG value: color; designing a font; font size; font properties such as bold, italics, or outline; animation, such as a blinking display or a moving display; filling patterns or patches; a level of transparency; and an accompanying icon. Notably, the SG values and BG values are displayed using different visually distinguishable characteristics so that a user can quickly and easily observe whether the displayed measurement is a BG value or an SG value. For example, BG values and related information may appear in white or yellow fonts, while SG values and related information may appear in a distinctly contrasting color, such as blue, cyan, or violet.

Referring back to fig. 13, process 1300 also displays the current SG value on the device's therapy delivery control screen (task 1304). The SG value remains displayed on the therapy delivery control screen until it is refreshed and cannot be modified via the device's user interface. Fig. 15 is a schematic diagram of a therapy delivery control screen 1500 on an insulin infusion device, on which a current (and high quality) SG value 1502 is displayed. The SG value 1502 may be displayed with the "SG" label 1504 to clearly indicate that the displayed value is indeed an SG value (and not a BG value). Additionally, the SG value 1502 can be displayed with a visually distinguishable and contextually relevant icon 1506 to further indicate that the displayed value is an SG value rather than a BG value. For this example, the icon 1506 is similar to a graph or signal waveform, and the color of the icon 1506 matches the color of the displayed SG value 1502.

Notably, the process 1300 displays the SG value 1502 using the same (or substantially similar) visually distinguishable characteristic for displaying the SG value 1402 on the user monitoring screen 1400. This same visually distinguishable characteristic may also be used to display the "SG" label 1504 and to display the units of SG value (mg/dL). Using the same visually distinguishable characteristic for SG values on different user interface screens or features makes it easy for a user to interpret and identify the source of the displayed glucose measurement. Although this description focuses on user monitoring screens and therapeutic delivery control screens, consistent visual characteristics ("look and feel" aspects) may be used across any number of display screens generated by the device.

Referring back to fig. 13, process 1300 inhibits the display of any BG values on the user monitor screen and the therapy delivery control screen (task 1306). In this regard, if valid BG values are not available, the device only considers the current (e.g., most recent) and accurate SG values for display purposes.

Process 1300 continues by calculating a therapeutic dose for delivery (if needed) based on the high quality sensor generated SG values (task 1308). For this example, an insulin bolus is calculated at task 1308, and the calculated bolus amount is displayed on the therapy delivery control screen. In this regard, therapy delivery control screen 1500 shown in fig. 15 includes a calculated insulin bolus of 0.8 units. Thus, a high quality SG value is used as an input or parameter for the purpose of estimating an appropriate insulin bolus to maintain the user's blood glucose level within a desired target range.

In some examples, the calculated bolus amount may be manually administered or automatically delivered if an automatic delivery mode is supported and activated. Accordingly, during operation in the second mode, process 1300 enables the automatic therapy delivery functionality of the device (task 1310). Thus, if the user is unable to manually administer the calculated bolus amount, the automatic delivery function will take appropriate action to deliver the bolus in a timely manner. To this end, process 1300 may automatically control operation of the device to adjust delivery of the fluid drug (insulin) from the device according to the calculated therapeutic dose (task 1312).

Returning to the description of fig. 9 and process 900, if the current SG value does not meet the "high quality" criteria (the "no" branch of query task 910), but meets the "monitor quality" criteria (the "yes" branch of query task 914), then the device is controlled in an appropriate manner to operate in the third mode (task 916). According to embodiments described herein, the device operates in the third mode when an active meter-generated BG value is not available, and when the current sensor-generated SG value is determined to be of sufficient quality for user monitoring purposes but may not be suitable for use in calculating a therapeutic dose.

Fig. 16 is a flow chart illustrating operation of the insulin infusion device in the third mode. The third mode operational procedure 1600 depicted in fig. 16 may be performed at task 916 of procedure 900. The third mode depends on the currently available monitoring quality SG value. Accordingly, process 1600 displays the current SG value on the user monitor screen of the device (task 1602). The SG value remains displayed on the user monitor screen until it is refreshed. The above description of the user monitoring screen 1400 (see fig. 14) also applies to this scenario, as the monitoring quality SG value is displayed in a similar manner, with the same visually distinguishable characteristics previously described in connection with the exemplary display shown in fig. 14.

While operating in the third mode, the device disables display of the current SG value on the therapy delivery control screen (task 1604). In addition, process 1600 prohibits the display of any BG values on the therapy delivery control screen (task 1606). Instead, the device is operated to display an appropriate message, notification, or indication on the therapy delivery control screen, where the displayed content indicates that no suitable measurements of the physiological characteristics of the user are available. For this particular example, process 1600 displays a message such as "no glucose" or "no available glucose" on the therapy delivery control screen (task 1608). Fig. 17 is a schematic diagram of a therapy delivery control screen 1700 on an insulin infusion device with neither BG nor SG values displayed thereon. Instead, therapy delivery control screen 1700 includes a "no glucose" message or field 1702 that lets the user know that no appropriate glucose measurement is available for calculating the estimated bolus. Thus, treatment delivery control screen 1700 indicates a bolus amount of 0.0 units under these conditions.

Referring back to fig. 16, process 1600 prohibits calculating a therapeutic dose for delivery using the current SG value (task 1610). While the monitored quality SG value is suitable for use as a general indicator of the user's glucose level, the process 1600 assumes that it may not be suitable for calculating an accurate insulin bolus amount. Accordingly, process 1600 operates the device in the third mode to disable the automatic treatment delivery functionality (task 1612). For the embodiments described herein, task 1612 ensures that a correction bolus of insulin is not administered when the insulin infusion device is operating in the third mode.

Process 1600 may continue by prompting the user to obtain a new meter-generated BG value (task 1614), which may be used to update the user monitoring screen and the therapy delivery control screen. In addition, the new BG value may be used to calculate an estimated bolus and reactivate the automatic therapy delivery function. Additionally or alternatively, the process 1600 can generate reminders, messages, or notifications to prompt the user to check the integrity of the sensor device, recalibrate the sensor device, replace the sensor device with a new unit, and the like.

Referring again to fig. 9, if process 900 determines that the current SG value does not meet the specified "quality of monitoring" criteria ("no" branch of query task 914), process 900 generates an appropriate alert, message, or notification that some form of corrective action needs to be taken (task 918). For example, the device may generate an alert to remind the user to take one or more of the following actions: obtaining/inputting a new BG value; checking the integrity of the currently deployed sensor device; recalibrating the currently deployed sensor device; checking a data communication function of a currently deployed sensor device; replacing the sensor device with a new unit; and so on.

The process 900 is performed in a continuous manner in anticipation of updating BG and/or SG values over time. The dashed lines in fig. 9 indicate how the process 900 is repeated as necessary to receive and process new BG and SG values.

Automatic insulin infusion systems that use feedback from a Continuous Glucose Monitor (CGM) to adjust the insulin dosage need to implement safety functions to mitigate the risk of over-delivery and hypoglycemia under certain glucose sensor conditions. These mitigation measures may employ one or more of the following technical components: (1) Detection and ranking of CGM measurement quality for automated insulin dosing; (2) A set of treatment adjustments applicable to each sensor quality level; (3) A set of system alerts or other User Interface (UI) notifications that guide the user to take appropriate action when needed. Examples of insulin infusion systems that utilize sensor quality metrics to adjust therapy delivery modes are described above.

Sensor quality-high quality CGM/sensor measurements are required to achieve the full advantages of an automatic insulin infusion system control and basal and bolus insulin delivery. Known factors that may affect sensor accuracy may be used to determine the sensor quality metric. Examples of such factors include, but are not limited to: (1) Age of the sensor with a known correlation to measurement accuracy; (2) Measurement noise in the CGM electronics and/or raw sensor signal; (3) The sensor measurements that cannot be attributed to natural physiological conditions suddenly rise or fall sharply.

According to an exemplary embodiment, the sensor quality metric may be mapped to a scale (e.g., a scale of 1 to 10, or low/medium/high values) that provides different quality levels that may be used to adjust the treatment. The determination of a particular level should be associated with a potential risk of providing automated treatment because the underlying conditions result in a desired level of sensor error. For example, for purposes of this specification, transient measurement noise may result in a moderate CGM measurement error, and thus it may correspond to a "moderate" sensor quality metric, while a sudden, discontinuous jump or drop in CGM measurement may correspond to a "low" sensor quality metric.

The sensor quality metric may also depend on the characteristics of the historical CGM values in the time series. For example, the previous CGM value of the moving time window may be analyzed and compared to the current value. As another example, an average of historical CGM values obtained at or near the same day can be analyzed and compared to the current value (obtained on the day of analysis). Thus, if a sufficient number of historical values are not available, the condition itself may result in a conservative sensor quality rating until sufficient historical values are recorded.

Therapy adjustment-once the sensor quality metric is determined, adjustments may need to be made to the control algorithm or method governing automatic insulin infusion to mitigate the risk of insulin delivery overdose or underdose. In some embodiments, the particular type of adjustment depends on the design of the automated infusion algorithm.

For example, consider an automatic infusion algorithm that uses CGM measurements to make real-time adjustments to basal insulin and provides an additional bolus of insulin during a rapid glucose rise. Further, the algorithm incorporates a safe backup delivery mode that provides a constant basal rate when CGM measurements are not available. In such a system, the treatment adjustments may be made for:

case 1: "high" CGM/sensor quality metric-algorithm can use its full authorization for basal and bolus insulin based on CGM measurements.

Case 2: "intermediate" CGM/sensor quality metric-CGM is only allowed to be used to determine basal insulin delivery, but to stop or otherwise limit the delivery of bolus insulin.

Case 3: "low" CGM/sensor quality metric-CGM is ignored altogether and restored to safe backup delivery mode until sensor quality is restored.

The three cases listed above are representative examples of a hypothetical automatic insulin infusion system. Different algorithm designs will require adjustments of the treatment that match the dosage rules of the algorithm and/or other factors.

System alerts and notifications-system alerts and notifications represent another component that helps manage risk while balancing treatment effectiveness and user burden. It would be desirable to maintain acceptable therapy without burdening the user with system alarms. However, in some cases, it is desirable to raise an alarm to further mitigate the risks associated with poor CGM quality or to guide the user to take the action required to restore the optimal treatment.

For example, it is known that certain CGM quality conditions are transient in nature and are generally recoverable without any intervention. In this case, it may be appropriate for the system to make the treatment adjustments without notifying the user. However, if the CGM quality is not completely restored after a specified period of time, a condition for notifying the user may be included.

As another example, it can be known that different CGM quality conditions require calibration that is restored using external blood glucose measurements. In this case, it would be appropriate to alert the user that CGM calibration is required once this condition occurs.

As described above, the scale of the sensor quality metric may be changed in any desired manner. According to an example embodiment, the sensor quality metric may be "unknown" or "uncertain", or it may indicate a low, medium or high sensor quality. Table 1 indicates all of the sensor quality metrics for this implementation, as well as their associated treatment actions and system alarms.

Table 1: sensor quality and corresponding motion

Fig. 18 is a flow diagram illustrating an exemplary embodiment of a process 1800 for controlling the operation of a medical device to adjust a therapeutic action based on sensor quality. The process 1800 obtains a current sensor-generated value indicative of a physiological characteristic of the user, where the value is produced in response to operation of the continuous analyte sensor apparatus. Embodiments presented herein relate to an insulin infusion system including or cooperating with a continuous glucose sensor, wherein the physiological characteristic is glucose level.

The process 1800 obtains the current SG value from the CGM sensor device (task 1802). Process 1800 calculates, receives, or otherwise obtains a sensor quality metric for the CGM sensor device, where the sensor quality metric indicates the accuracy, reliability, and/or trustworthiness of the current sensor generating the SG value (task 1804). According to certain embodiments, the sensor quality metric is calculated by the CGM sensor device, which communicates the calculated sensor quality metric to one or more target devices as needed (e.g., the calculated sensor quality metric may be transmitted from the CGM sensor device to an insulin infusion device, a glucose monitoring device, a mobile device running a suitably configured mobile app, etc.). Alternatively or in addition, the sensor quality metric can be calculated by one or more devices other than the CGM sensor device based on the raw sensor signals or information generated at the CGM sensor device. For example, the CGM sensor device may provide its electrical output (such as a current value or voltage) to the insulin infusion device, which then calculates a sensor quality metric based on the provided electrical output value.

Process 1800 continues by adjusting a therapeutic action of the insulin infusion device in response to the sensor quality metric to configure a quality-specific operating mode of the insulin infusion device (task 1806), as described in more detail below with reference to fig. 20. Thus, therapy-related functions, features, and/or operations of the medical device (insulin infusion device) are changed based on the calculated sensor quality metric (e.g., high quality, medium quality, low quality, etc.). As shown in table 1, conservative or aggressive insulin therapy options may be enabled/disabled in a sustained manner depending on the current state of the sensor quality metric. Further, process 1800 manages generation of a user alert at the medical device in response to the calculated sensor quality metric (task 1808). In this regard, the process 1800 controls the insulin infusion device (and/or other user device) to generate, disable, or otherwise adjust a user alert based on the current state of the sensor quality metric. In some embodiments, task 1808 manages the alert by generating a user alert when the calculated sensor quality metric satisfies the specified alert generation criteria, and disabling the user alert when the calculated sensor quality metric does not satisfy the specified alert generation criteria. Alarm generation criteria may be specified to reduce unwanted or annoying alarms, warnings, and notifications. For example, if the sensor quality metric is "good" than a low value, the alert generation criteria may disable a user alert. As another example, the alert generation criteria may allow a user to alert if the sensor quality metric is low, or if the system determines that the sensor is at the end of its life or has lost communication with the medical device. This provides a better user experience, reducing nuisance alerts and alarming notifications.

Process 1800 continues by adjusting delivery of fluid medication (e.g., insulin) from the medical device according to the current SG value and according to the mass-specific operating mode of the medical device (task 1810). In other words, the delivery of fluid medication is controlled in response to a current sensor quality metric that determines the quality specific mode of operation to be used, which results in an adjustment to certain therapeutic actions (see table 1). For this particular implementation, task 1810 adjusts the therapy action of the insulin infusion device such that the aggressiveness of the insulin delivery therapy is proportional to the quality of the current SG value as indicated by the calculated sensor quality metric, as described in more detail below with reference to fig. 20. Any desired method or algorithm driven by the value of the sensor quality metric may be used to adjust, control or regulate the therapeutic action in different ways depending on the particular application and type of medical device. Process 1800 may be repeated in an ongoing manner to take into account updated SG values and their corresponding sensor quality metrics for adjusting therapy actions over time.

Fig. 19 is a block diagram illustrating generation of a sensor quality metric according to an example embodiment. Fig. 19 depicts sensor quality calculation logic 1900 that calculates a sensor quality metric 1902 from one or more data inputs. Sensor quality calculation logic 1900 may reside and execute at: a CGM sensor device; an insulin infusion device; a user monitoring device; a mobile device; a smart device or appliance; a cloud-based system, device or service; an in-vehicle computing system or device; a tablet, desktop, or laptop computer; and so on. Although not always required, the exemplary embodiments presented herein calculate a sensor quality metric 1902 solely from information, data, or signals generated by or derived from the continuous analyte sensor apparatus. In other words, the data input to sensor quality calculation logic 1900 is generated by the sensor device or derived/calculated from data generated by the sensor device, and sensor quality calculation logic 1900 does not process information from an external calibration device or information from an auxiliary device to obtain sensor quality metric 1902. In this regard, a continuous analyte sensor apparatus may generate its own sensor quality metric 1902 in an "isolated" and self-diagnostic manner, without relying on any additional information obtained from another apparatus or system. Alternatively, the continuous analyte sensor apparatus may provide information generated or calculated internally to a compatible target apparatus, which then uses only the information obtained from the sensor apparatus to calculate the sensor quality metric 1902.

In some examples, the data input utilized by sensor quality calculation logic 1900 may be selected to suit the needs and requirements of a particular medical device system, intended application, and/or particular embodiment. The example shown in fig. 19 handles at least the following data inputs: sensor age data 1904; raw sensor signal values 1906; and/or historical sensor-generated values 1908 generated in response to operation of the continuous analyte sensor apparatus. As described above, these three data inputs are generated by the sensor device or derived from information/data generated by the sensor device.

The sensor age data 1904 indicates a chronological age, operational life or "run time" of the sensor device, an amount of time since deployment of the sensor device, and the like. In this regard, the sensor age data 1904 may be based on the date/time of manufacture, the date/time of initial deployment on the user's body, the date/time after initialization or warm-up of the sensor device after deployment, and so forth. Preferred implementations base the age of the sensor device on the time immediately after initialization or warm-up of the deployed sensor device, which may be determined or flagged by the sensor device in certain implementations. The sensor device may keep track of its age and update the sensor age data 1904 in a continuous manner over time. Alternatively or in addition, the sensor device may flag and report an initial date/time (after warming up) to enable the target device to keep track of sensor age and update sensor age data over time 1904.

The raw sensor signal values 1906 correspond to the raw signal output of the continuous analyte sensor apparatus that is produced when the sensor apparatus is monitoring a physiological characteristic of interest. In certain embodiments, the raw sensor signal values 1906 are current and/or voltage measurements. For the continuous glucose sensor example described herein, the raw sensor signal value 1906 is a current reading sometimes referred to as an "ISIG" value. The raw sensor signal values 1906 are processed or converted to monitored analyte levels, such as blood glucose values. To this end, the sensor generation values 1908 shown in fig. 19 represent available sensor values derived, calculated, or converted from the raw sensor signal values 1906. The methods described herein take into account a plurality of historical sensor generation values 1908 required to generate a sensor quality metric 1902 associated with a current sensor value.

In certain embodiments, sensor quality calculation logic 1900 calculates sensor quality metric 1902 based on: sensor age data 1904; measurement noise of the raw signal output of the continuous analyte sensor apparatus; and a change in the sensor-generated value 1908 that cannot be attributed to the user's natural physiological condition. Sensor age data 1904 is considered because the accuracy of newly deployed sensor devices typically fluctuates for a short period of time immediately after an initialization or warm-up period. Measurement noise in the raw sensor signal values 1906 can be caused by various conditions, such as physical movement of the sensor device, displacement of the embedded sensor element, sudden unpredictable physiological changes, infiltration of water or other substances at the sensor site, and the like. The raw sensor signal value 1906 is typically relatively stable over a "long" period of time, such as five minutes. However, if the sensor quality calculation logic 1900 detects a high variation (measurement noise) in the raw sensor signal values 1906, the corresponding sensor measurement may be designated as low quality. Similarly, if the sensor-generated values 1908 exhibit measurements that do not correspond to sharp changes, peaks, or unrealistic in normal physiological changes or conditions, the sensor quality computation logic 1900 may label those sensor values as low quality or ignore them.

Sensor quality calculation logic 1900 may consider any input data items, alone or in any combination, to generate sensor quality metric 1902. As previously described, the sensor quality metric 1902 may be expressed in any desired format using any desired range, scale, or domain. For the exemplary embodiment presented herein, the sensor quality metric 1902 is calculated as a number between 0 and 10 (inclusive), but only four available metric values are mapped to the quality states indicated in table 1: indeterminate; low; performing the following steps; and high. In other embodiments, more or less than four mass states may be utilized. Sensor quality metrics 1902 are generated and formatted in a suitable manner compatible with the fluid drug delivery device such that a therapeutic action of the fluid drug delivery device is adjusted in response to the calculated sensor quality metrics.

Sensor quality calculation logic 1900 performs a method of evaluating the quality of operation of a continuous analyte sensor apparatus, where sensor quality metric 1902 is used as an indication of quality. Sensor quality metric 1902 may be used to adjust, control, or adjust certain functions or features of an associated medical device that regulates the delivery of a therapeutic to a patient. In this regard, fig. 20 is a flowchart illustrating operation of an insulin infusion device in accordance with an exemplary embodiment of sensor mass calculation logic 1900 (process 2000). The following description of the process 2000 assumes that the insulin infusion device receives or generates a sensor quality metric having a corresponding SG value, as described above. Thus, the illustrated implementation of process 2000 begins by processing the current value of the sensor quality metric (task 2002). For this particular implementation, process 2000 checks whether the sensor quality metric indicates indeterminate quality (query task 2004), high quality (query task 2012), medium quality (query task 2020), or low quality (query task 2028).

When the sensor quality metric indicates indeterminate quality (the "yes" branch of query task 2004), process 2000 adjusts certain therapeutic actions of the insulin infusion device to configure the operating mode appropriate for the indeterminate quality state. More specifically, when the sensor quality metric indicates an indeterminate quality, process 2000 enables automatic basal insulin delivery by the insulin infusion device (task 2006), disables the automatic bolus delivery function of the insulin infusion device (task 2008), and inhibits generation of any user alerts related to current sensor-generated values having the indeterminate quality (task 2010). Under the assumption that the sensor quality metric will be determined in the near future, the adjustment of the therapeutic for that particular mode of operation is appropriate. Thus, no user alert is generated, but the automatic bolus delivery function is temporarily disabled.

When the sensor quality metric indicates high quality, for example, the sensor quality metric is greater than or equal to a high threshold, such as 7 (the "yes" branch of query task 2012), the process 2000 adjusts certain therapeutic actions of the insulin infusion device to configure an appropriate high quality operating mode. More specifically, when the sensor quality metric indicates high quality, the process 2000 enables automatic basal insulin delivery by the insulin infusion device (task 2014), enables the automatic bolus delivery function (task 2016), and disables generation of any user alerts related to current sensor-generated values having high quality (task 2018). The adjustment of the treatment to this high quality mode of operation is appropriate under the assumption that the sensor device is operating in a normal and accurate manner. To this end, no user alert is generated and both automatic basal delivery and automatic bolus delivery remain activated and enabled.

When the sensor quality metric indicates a medium quality, e.g., the sensor quality metric is between a low threshold (such as 3) and a high threshold (such as 7) ("yes" branch of query task 2020), the process 2000 adjusts certain therapeutic actions of the insulin infusion device to configure the appropriate medium quality mode of operation. More specifically, when the sensor quality metric indicates a medium quality, process 2000 enables automatic basal insulin delivery by the insulin infusion device (task 2022), enables limited automatic bolus delivery functionality (task 2024), and disables generation of any user alerts related to current sensor-generated values having a medium quality (task 2026). The adjustment of the therapy for this medium quality mode of operation is appropriate under the assumption that the sensor device is operating in a manner that is still capable of supporting the modified automatic bolus delivery function. Thus, no user alert is generated and automatic basal delivery remains activated. However, the automatic bolus delivery function is modified to be less aggressive than usual. For example, the amount of insulin delivered by the automatic bolus delivery function may be limited or capped by some amount, or the bolus amount, which may be calculated from the current SG value, may be reduced by some percentage as a safety factor. As another example, when the sensor quality metric indicates medium quality, the insulin infusion device may be controlled in a manner that sets an upper limit on the current SG value in order to calculate and administer an automatic bolus. According to certain embodiments, when the sensor quality metric indicates medium quality, the maximum SG value is used for bolus calculation purposes (e.g., 250 mg/dL) -if the current SG value is higher than the maximum allowed SG value, the actual SG value is ignored for automatic bolus calculation purposes. This approach reduces the likelihood of delivering too much insulin when reliability or quality of the continuous glucose sensor device may be problematic.

When the sensor quality metric indicates a low quality, e.g., the sensor quality metric is less than or equal to a low threshold, such as 3 (the "yes" branch of query task 2028), process 2000 adjusts certain therapeutic actions of the insulin infusion device to configure the appropriate low quality mode of operation. More specifically, when the sensor quality metric indicates low quality, process 2000 enables a safe basal insulin delivery mode of the insulin infusion device (task 2030), disables the automatic bolus delivery function (task 2032), and generates a user alert to prompt the user to take corrective action, such as obtaining new blood glucose values for sensor calibration (task 2034). Therapeutic adjustments to this low quality mode of operation result in conservative insulin therapy. To this end, the user's normal basal insulin delivery profile may be adjusted to be generally less aggressive, or the basal delivery profile may be adjusted to provide only a flat profile of basal insulin basal amounts over time. In addition, automatic bolus delivery is suspended until the sensor quality metric improves.

As described above, a low aggressiveness of fluid medication therapy is provided when the sensor quality metric is low (e.g., at or below a low threshold), a medium aggressiveness is provided when the sensor quality metric is medium (e.g., between a low threshold and a high threshold), and a high aggressiveness is provided when the sensor quality metric is high (e.g., at or above a high threshold). Depending on the implementation, more or less than three levels of aggressiveness may be supported.

If the sensor quality metric indicates a quality that is worse than low, or indicates an error value, process 2000 may generate an appropriate alert, message, or notification that an investigation is needed, corrective action is taken, etc. (task 2036). For example, an insulin infusion device may generate an audible alarm and display a message that requires the user to check the integrity of the sensor device, recalibrate the sensor device, replace the sensor device, and the like.

Iterations of process 2000 may be performed frequently in a continuous manner as needed. In some embodiments, process 2000 is performed for each new SG value (and its corresponding sensor quality metric).

Techniques and technologies may be described herein in terms of functional and/or logical block components, and with reference to symbolic representations of operations, processing tasks, and functions that may be performed by various computing components or devices. Such operations, tasks, and functions are sometimes referred to as being computer-executed, computerized, software-implemented, or computer-implemented. It should be appreciated that the various block components shown in the figures may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, an embodiment of a system or component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices.

When implemented in software, firmware, or other forms of executable program instructions, the various elements of the system described herein are essentially the code segments or instructions that perform the various tasks. In certain embodiments, the programs or code segments are stored in a tangible processor-readable medium, which may include any medium that can store or transfer information. Examples of non-transitory and processor-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, and hard disks, among others.

The various tasks performed in connection with the processes described herein may be performed by software, hardware, firmware, or any combination thereof. It should be appreciated that the described processes may include any number of additional or alternative tasks, the tasks shown in the flowchart representation need not be performed in the illustrated order, and the described processes may be incorporated into a more comprehensive procedure or process having additional functionality not described in detail herein. Furthermore, one or more of the tasks shown may be omitted from the described implementation of the process, as long as the intended overall functionality remains intact.

While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, including known equivalents and foreseeable equivalents at the time of filing this patent application.

Various aspects of the disclosure may be described in the following clauses:

1. a method of controlling operation of a medical device that regulates delivery of a fluid medicant to a user, the method comprising:

receiving a meter-generated value indicative of a physiological characteristic of the user, the meter-generated value being generated in response to operation of an analyte meter device;

obtaining a sensor-generated value indicative of the physiological characteristic of the user, the sensor-generated value being produced in response to operation of a continuous analyte sensor device distinct from the analyte meter device.

When an effective meter-generated value is available, operating the medical device in a first mode to display the effective meter-generated value on a user monitoring screen of the medical device and a therapy delivery control screen of the medical device, and operating the medical device in the first mode to calculate a dose of therapy for delivery based on the effective meter-generated value;

when a valid meter-generated value is not available and a current sensor-generated value of the sensor-generated values meets a first quality criterion, operating the medical device in a second mode to display the current sensor-generated value on the user monitoring screen and the therapy delivery control screen, and operating the medical device in the second mode to calculate a dose of therapy for delivery based on the current sensor-generated value; and

when a valid meter-generated value is not available and the current sensor-generated value satisfies a second quality criterion but does not satisfy the first quality criterion, operating the medical device in a third mode to display the current sensor-generated value on the user monitoring screen, operating the medical device in the third mode to inhibit display of the current sensor-generated value on the therapy delivery control screen, and operating the medical device to inhibit use of the current sensor-generated value to calculate a dose of therapy for delivery.

2. The method of clause 1, further comprising:

operating the medical device in the third mode to inhibit display of any meter-generated values on the therapy delivery control screen when valid meter-generated values are not available and the current sensor-generated value satisfies a second quality criterion but does not satisfy the first quality criterion.

3. The method of clause 1, further comprising:

operating the medical device in the third mode to display a message on the therapy delivery control screen indicating that no suitable measurement of the physiological characteristic of the user is available when an effective meter-generated value is not available and the current sensor-generated value satisfies a second quality criterion but does not satisfy the first quality criterion.

4. The method of clause 1, further comprising:

operating the medical device in the first mode to enable an automatic therapy delivery function when a valid meter generation value is available;

operating the medical device in the second mode to enable the automatic therapy delivery function when a valid meter-generated value is not available and the current sensor-generated value satisfies the first quality criteria; and

operating the medical device in the third mode to disable the automatic therapy delivery function when an effective meter-generated value is not available and the current sensor-generated value satisfies the second quality criteria but does not satisfy the first quality criteria.

5. The method of clause 1, further comprising:

operating the medical device in the first mode to display an effective meter-generated value on the user monitoring screen and the therapy delivery control screen using a first visually distinguishable characteristic when the effective meter-generated value is available; and

operating the medical device in the second mode to display the current sensor-generated value on the user monitoring screen and the therapy delivery control screen using a second visually distinguishable characteristic different from the first visually distinguishable characteristic when a valid meter-generated value is not available and the current sensor-generated value satisfies the first quality criteria.

6. The method of clause 1, further comprising:

operating the medical device in the first mode when valid meter generated values are available regardless of the availability of sensor generated values.

7. The method of clause 1, further comprising:

operating the medical device in the third mode to prompt the user to obtain a new meter-generated value when a valid meter-generated value is not available and the current sensor-generated value satisfies the second quality criterion but does not satisfy the first quality criterion.

8. The method of any of clauses 1-7, further comprising:

adjusting delivery of the fluid drug from the medical device according to the calculated therapeutic dose when operating the medical device in the first mode or the second mode.

9. The method of any of clauses 1-8, wherein:

the valid meter generated value is available until it expires after an expiration time period; and

the valid meter generated value is not available after its expiration.

10. A medical device to regulate delivery of a medication to a user, the medical device comprising:

a drive system;

at least one processor device that regulates operation of the drive system to deliver fluid medication from the medical device;

a display device; and

at least one memory element associated with the at least one processor device and storing processor-executable instructions configurable to be executed by the at least one processor device to perform a method of controlling operation of the medical device, the method comprising:

When a meter-generated value is available, operating the medical device in the first mode to display the effective meter-generated value on the display device on a user monitoring screen and a therapy delivery control screen, and operating the medical device in the first mode to calculate a dose of therapy for delivery based on the effective meter-generated value;

when a meter-generated value is not available and a current sensor-generated value of the sensor-generated values satisfies a first quality criterion, operating the medical device in a second mode to display the current sensor-generated value on the display device on the user monitoring screen and the therapy delivery control screen, and operating the medical device in the second mode to calculate a dose of therapy for delivery based on the current sensor-generated value; and

when a valid meter-generated value is not available and the current sensor-generated value satisfies a second quality criterion but does not satisfy the first quality criterion, operating the medical device in a third mode to display the current sensor-generated value on the user monitoring screen on the display device, operating the medical device in the third mode to inhibit display of the current sensor-generated value on the therapy delivery control screen, and operating the medical device to inhibit calculation of a dose of therapy for delivery using the current sensor-generated value.

11. The medical device of clause 10, wherein the method performed by the at least one processor device further comprises:

12. The medical device of clause 10, wherein the method performed by the at least one processor device further comprises:

operating the medical device in the third mode to display a message on the therapy delivery control screen on the display device indicating that no suitable measurement of the physiological characteristic of the user is available when a valid meter-generated value is not available and the current sensor-generated value satisfies a second quality criterion but does not satisfy the first quality criterion.

13. The medical device of clause 10, wherein the method performed by the at least one processor device further comprises:

operating the medical device in the first mode to enable an automatic therapy delivery function when an effective meter generation value is available;

operating the medical device in the second mode to enable the automatic therapy delivery function when an effective meter-generated value is not available and the current sensor-generated value satisfies the first quality criteria; and

14. The medical device of any of clauses 10-13, wherein the method performed by the at least one processor device further comprises:

operating the medical device in the first mode to display an effective meter-generated value on the user monitoring screen and the therapy delivery control screen on the display device using a first visually distinguishable characteristic when the effective meter-generated value is available; and

operating the medical device in the second mode to display the current sensor-generated value on the user monitoring screen and the therapy delivery control screen on the display device using a second visually distinguishable characteristic different from the first visually distinguishable characteristic when a valid meter-generated value is not available and the current sensor-generated value satisfies the first quality criterion.

15. The medical device of clause 10, wherein the method performed by the at least one processor device further comprises:

operating the medical device in the third mode to prompt the user to obtain a new meter generated value when a valid meter generated value is not available and the current sensor generated value meets the second quality criteria but does not meet the first quality criteria.

16. The medical device of clause 10, wherein the method performed by the at least one processor device further comprises:

adjusting delivery of the fluid drug from the medical device according to the therapeutic dose calculated when operating the medical device in the first mode or the second mode.

17. The medical device of any of clauses 10-16, wherein:

the medical device is an insulin infusion device;

the fluid medication comprises insulin; and

the physiological characteristic of the user is blood glucose.

18. The medical device of clause 17, wherein:

the user monitoring screen is a main screen of the insulin infusion device; and

the therapy delivery control screen is an insulin bolus delivery control screen of the insulin infusion device.

19. A non-transitory computer readable storage medium comprising program instructions stored thereon, wherein the program instructions are configured to cause at least one processor device to perform a method comprising:

obtaining a sensor-generated value indicative of the physiological characteristic of the user, the sensor-generated value being produced in response to operation of a continuous analyte sensor device distinct from the analyte meter device;

when an effective meter-generated value is not available and a current sensor-generated value satisfies a first quality criterion, operating the medical device in a second mode to display the current sensor-generated value on the user monitoring screen and the therapy delivery control screen, and operating the medical device in the second mode to calculate a dose of therapy for delivery based on the current sensor-generated value and not a meter-generated value; and

when a valid meter-generated value is not available and the current sensor-generated value satisfies a second quality criterion but does not satisfy the first quality criterion, operating the medical device in a third mode to display the current sensor-generated value on the user-monitoring screen, operating the medical device in the third mode to inhibit display of the current sensor-generated value on the therapy-delivery-control screen, and operating the medical device to inhibit use of the current sensor-generated value to calculate a dose of therapy for delivery.

20. The storage medium of clause 19, wherein the method performed by the at least one processor device further comprises:

operating the medical device in the first mode to enable an automatic therapy delivery function using a therapy dose calculated based on an effective meter-generated value when the effective meter-generated value is available;

when an effective meter-generated value is not available and the current sensor-generated value satisfies the first quality criterion, operating the medical device in the second mode to enable the automatic therapy delivery function using a dose of therapy calculated based on the current sensor-generated value rather than a meter-generated value; and

21. The storage medium of clause 19, wherein the method performed by the at least one processor device further comprises:

when valid meter-generated values are not available and the current sensor-generated values satisfy a second quality criterion but do not satisfy the first quality criterion, operating the medical device in the third mode to disable display of any meter-generated values on the therapy delivery control screen and operating the medical device in the third mode to display a message on the therapy delivery control screen indicating that no suitable measurement of the physiological characteristic of the user is available.

Claims

obtaining a current sensor-generated value indicative of a physiological characteristic of the user, the current sensor-generated value being produced in response to operation of a continuous analyte sensor apparatus;

calculating a sensor quality metric indicative of reliability and trustworthiness of the current sensor-generated value;

adjusting a therapy action of the medical device in response to the calculated sensor quality metric to configure a quality-specific mode of operation of the medical device;

manage generation of a user alert at the medical device in response to the calculated sensor quality metric; and

adjusting delivery of the fluid medicant from the medical device as a function of the current sensor-generated value and the mass-specific mode of operation of the medical device.

2. The method of claim 1, wherein the sensor quality metric is calculated from information generated by or derived from the continuous analyte sensor, particularly wherein the information comprises sensor age data, raw sensor signal values, and historical sensor generation values produced in response to operation of the continuous analyte sensor apparatus.

3. The method of any preceding claim, wherein managing generation of user alerts comprises:

generating a user alert when the calculated sensor quality metric meets alert generation criteria; and

disabling a user alert when the calculated sensor quality metric does not meet the alert generation criteria.

4. The method of any one of the preceding claims, wherein:

calculating, by the continuous analyte sensor apparatus, the sensor quality metric;

obtaining, by the medical device, the current sensor-generated value; and is

The method further comprises the step of transmitting the calculated sensor quality metric from the continuous analyte sensor device to the medical device.

5. The method of any preceding claim, wherein the calculating step calculates the sensor quality metric based on:

sensor age data indicative of an age of the continuous analyte sensor apparatus;

a measurement noise of a raw signal output of the continuous analyte sensor apparatus; and

a change in a sensor-generated value that cannot be attributed to the user's natural physiological condition.

6. The method of any preceding claim, wherein:

the medical device is an insulin infusion device;

the fluid medication comprises insulin;

the physiological characteristic of the user is blood glucose; and is

The continuous analyte sensor apparatus is a continuous glucose sensor apparatus.

7. The method of claim 6, wherein:

when the sensor quality metric indicates an indeterminate quality, the adjusting step enables automatic basal insulin delivery by the insulin infusion device, disables an automatic bolus delivery function of the insulin infusion device, and inhibits generation of any user alerts related to the current sensor-generated value of indeterminate quality;

when the sensor quality metric indicates high quality, the adjusting step enables automatic basal insulin delivery by the insulin infusion device, enables the automatic bolus delivery functionality, and disables generation of any user alerts associated with the current sensor-generated value having high quality;

when the sensor quality metric indicates a medium quality, the adjusting step enables automatic basal insulin delivery by the insulin infusion device, enables limited automatic bolus delivery functionality, and disables generation of any user alert related to the current sensor-generated value having a medium quality; and is

When the sensor quality metric indicates a low quality, the adjusting step enables a safe basal insulin delivery mode of the insulin infusion device, disables the automatic bolus delivery functionality, and generates a user alert to prompt the user to take corrective action.

8. The method of claim 7, wherein the user alert prompts the user to calibrate the continuous glucose sensor apparatus.

9. The method of any of the preceding claims, wherein the adjusting step adjusts the therapeutic action of the medical device such that aggressiveness of fluid medication therapy is proportional to the quality of the current sensor-generated value as indicated by the calculated sensor quality metric.

a drive system (208);

at least one processor device that regulates operation of the drive system (208) to deliver fluid medication from the medical device;

a user interface; and

at least one memory element associated with the at least one processor device, the at least one memory element storing processor-executable instructions configurable to be executed by the at least one processor device to perform a method of controlling operation of the medical device, the method comprising:

receiving or calculating a sensor quality metric indicative of reliability and trustworthiness of the current sensor-generated value;

adjusting a therapeutic action of the medical device in response to the calculated sensor quality metric to configure a quality-specific mode of operation of the medical device;

manage generation of a user alert at the user interface in response to the calculated sensor quality metric; and

adjusting delivery of the fluid drug from the medical device as a function of the current sensor-generated value and the mass-specific operating mode of the medical device.

11. The medical device of claim 10, wherein the medical device receives the sensor quality metric from the continuous analyte sensor device, or wherein the medical device calculates the sensor quality metric only from information generated by or derived from the continuous analyte sensor device, in particular wherein the medical device calculates the sensor quality metric based on:

12. The medical device of any one of claims 10 or 11, wherein:

the medical device is an insulin infusion device;

the fluid medication comprises insulin;

the physiological characteristic of the user is blood glucose; and is provided with

The continuous analyte sensor apparatus is a continuous glucose sensor apparatus,

in particular, the amount of the solvent to be used,

when the sensor quality metric indicates an indeterminate quality, the adjusting step enables automatic basal insulin delivery by the insulin infusion device, disables an automatic bolus delivery function of the insulin infusion device, and inhibits generation of any user alerts related to the current sensor-generated value having an indeterminate quality;

when the sensor quality metric indicates high quality, the adjusting step enables automatic basal insulin delivery by the insulin infusion device, enables the automatic bolus delivery functionality, and disables generation of any user alerts related to the current sensor-generated value having high quality;

when the sensor quality metric indicates a medium quality, the adjusting step enables automatic basal insulin delivery by the insulin infusion device, enables limited automatic bolus delivery functionality, and inhibits generation of any user alerts related to the current sensor-generated value having a medium quality; and is

13. The medical device of any one of claims 10-12, wherein the adjusting step adjusts the therapeutic action of the medical device such that aggressiveness of fluid medication therapy is proportional to the quality of the current sensor-generated value as indicated by the sensor quality metric.

14. A method of assessing the quality of operation of a continuous analyte sensor apparatus, the method comprising:

obtaining a current sensor-generated value indicative of a physiological characteristic of the user, the current sensor-generated value being produced in response to operation of the continuous analyte sensor apparatus;

calculating a sensor quality metric indicative of reliability and trustworthiness of the current sensor-generated value, wherein the calculation is based on information generated by or derived from the continuous analyte sensor device; and

formatting the sensor quality metric to be compatible with a fluid drug delivery device, such that a therapeutic action of the fluid drug delivery device is adjusted in response to the calculated sensor quality metric, and such that an aggressiveness of a fluid drug therapy provided by the fluid drug delivery device is proportional to a quality of the current sensor-generated value as indicated by the calculated sensor quality metric.

15. The method of claim 14, wherein:

the information includes sensor age data indicative of an age of the continuous analyte sensor apparatus, raw sensor output values of the continuous analyte sensor apparatus, and historical sensor-generated values produced in response to operation of the continuous analyte sensor apparatus; and is

The calculating step calculates the sensor quality metric based on the sensor age data, measurement noise of the raw sensor output values, and changes in sensor-generated values that cannot be attributed to the user's natural physiological condition,

or wherein:

the fluid drug delivery device is an insulin infusion device;

when the sensor quality metric indicates an indeterminate quality, the insulin infusion device responds by enabling automatic basal insulin delivery, disabling automatic bolus delivery functionality, and disabling generation of any user alarms associated with the current sensor-generated value of indeterminate quality;

when the sensor quality metric indicates high quality, the insulin infusion device responds by enabling automatic basal insulin delivery, enabling the automatic bolus delivery function, and disabling generation of any user alerts related to the current sensor-generated value having high quality;

when the sensor quality metric indicates a medium quality, the insulin infusion device responds by enabling automatic basal insulin delivery, enabling limited automatic bolus delivery functionality, and disabling generation of any user alarms associated with the current sensor-generated value having a medium quality; and is

When the sensor quality metric indicates low quality, the insulin infusion device responds by enabling a safe basal insulin delivery mode, disabling the automatic bolus delivery function, and generating a user alert to prompt the user to take corrective action.