Patent Application
20220233772
The present invention relates generally to ambulatory infusion pumps and, more particularly, to operation of ambulatory infusion pumps in a closed-loop or semi-closed-loop fashion.
There are a wide variety of medical treatments that include the administration of a therapeutic fluid in precise, known amounts at predetermined intervals. Devices and methods exist that are directed to the delivery of such fluids, which may be liquids or gases, are known in the art.
One category of such fluid delivery devices includes insulin injecting pumps developed for administering insulin to patients afflicted with type 1, or in some cases, type 2 diabetes. Some insulin injecting pumps are configured as portable or ambulatory infusion devices that can provide continuous subcutaneous insulin injection and/or infusion therapy as an alternative to multiple daily insulin injections via syringe or injector pen. Such ambulatory infusion pumps may be worn by the user, may use replaceable medicament cartridges, and may deliver other medicaments alone, or in combination with insulin. Such medicaments include glucagon, pramlintide, and the like. Examples of such pumps and various features associated therewith include those disclosed in U.S. Patent Publication Nos. 2013/0324928 and 2013/0053816 and U.S. Pat. Nos. 8,287,495; 8,573,027; 8,986,253; and 9,381,297, each of which is incorporated herein by reference in its entirety.
Ambulatory infusion pumps for delivering insulin or other medicaments can be used in conjunction with blood glucose monitoring systems, such as continuous glucose monitoring (CGM) devices. A CGM device consists of a sensor placed under the patient's skin and affixed to the patient via an adhesive patch, a transmitter, and a monitor. A CGM device samples the patient's interstitial fluid periodically (e.g. once every 1-5 minutes) to estimate blood glucose levels over time. CGMs are advantageous because they provide more frequent insights into a user's blood glucose levels yet do not require a finger stick each time a reading is taken.
Ambulatory infusion pumps may incorporate a CGM within the infusion pump device or may communicate with a dedicated CGM directly via a wired connection or indirectly via a wireless connection using wireless data communication protocols to communicate with a separate device (e.g., a dedicated remote device or a smartphone). One example of integration of ambulatory infusion pumps with CGM devices is described in U.S. Patent Publication No. 2014/0276419, which is hereby incorporated by reference herein. Ambulatory infusion pumps typically allow the user or caregiver to adjust the amount of insulin or other medicament delivered by a basal rate or a bolus, based on blood glucose data obtained by a CGM device, and in some cases include the capability to automatically adjust such medicament delivery. For example, based on CGM readings, some ambulatory infusion pumps may automatically adjust or prompt the user to adjust the level of medicament being administered or planned for administration or, in cases of abnormally low blood glucose readings, reducing or temporarily ceasing insulin administration.
In some cases, ambulatory insulin pumps may be configured to deliver insulin based on CGM data in a closed-loop or semi-closed-loop fashion. Some systems including these features may be referred to as automated insulin delivery (AID) systems or artificial pancreas systems because these systems serve to mimic biological functions of the pancreas for persons with diabetes. Some AID systems primarily deliver medicament automatically based on CGM readings, but also enable users to program meal boluses. Consumption of carbohydrates in a meal causes blood glucose to rise, which can be counteracted by insulin or other medicament delivered in a meal bolus.
Disclosed herein are systems and methods for automated insulin delivery that aid in treatment when a user has eaten and has forgotten to deliver a meal bolus to counteract the carbohydrates consumed in the meal. The systems and methods disclosed herein can modify a limiter function that limits an amount by which a basal rate can be increased following a given glucose level reading in certain circumstances. For example, if the user's current or predicted future glucose level is high and the user's glucose level is increasing above a threshold rate, the limit can be increased from a standard limit. This is because a high glucose level, coupled with a high rate of increase warrants a more aggressive response to prevent hyperglycemia. Such a glucose response may indicate that the user has eaten, but forgotten to instruct a meal bolus. By increasing the basal rate increase limit, the system can therefore react to and address the missed meal bolus.
In an embodiment, a system for closed loop diabetes therapy can include a pump mechanism configured to facilitate delivery of insulin to a user, a communications interface adapted to receive glucose levels from a continuous glucose monitor, a user interface and at least one processor functionally linked to the pump mechanism, the user interface and the communications device. The processor can be configured to automatically modify a basal rate of insulin delivered to the user with a closed loop delivery algorithm based on glucose levels received from the continuous glucose monitor with the closed loop delivery algorithm configured to calculate modifications to the basal rate to maintain the user's glucose levels at a glucose target and include a limiter function providing a limit on an amount by which the basal rate can be increased from a previous basal rate. If it is determined based on the glucose levels received from the continuous glucose monitor that the user may have eaten a meal and not taken a bolus of insulin to counteract the carbohydrates consumed in the meal, the amount by which the limiter function will permit the basal rate to be increased from the previous basal rate can be increased. A modified basal rate can then be determined according to the increased amount insulin automatically delivered to the user with the pump mechanism according to the modified basal rate.
In an embodiment, a system for closed loop diabetes therapy can include a pump mechanism configured to facilitate delivery of insulin to a user, a communications interface adapted to receive glucose levels from a continuous glucose monitor, a user interface and at least one processor functionally linked to the pump mechanism, the user interface and the communications device. The processor can be configured to automatically modify a basal rate of insulin delivered to the user with a closed loop delivery algorithm based on glucose levels received from the continuous glucose monitor with the closed loop delivery algorithm configured to calculate modifications to the basal rate to maintain the user's glucose levels at a glucose target and include a limiter function providing a limit on an amount by which the basal rate can be increased from a previous basal rate. If it is determined based on the glucose levels received from the continuous glucose monitor that that a glucose level of the user is above the glucose target by more than a predetermined amount and that the user's glucose levels are increasing at greater than a predetermined rate, the amount by which the limiter function will permit the basal rate to be increased from the previous basal rate can be increased. A modified basal rate can then be determined according to the increased amount insulin automatically delivered to the user with the pump mechanism according to the modified basal rate.
In an embodiment, a system for closed loop diabetes therapy can include a pump mechanism configured to facilitate delivery of insulin to a user, a communications interface adapted to receive glucose levels from a continuous glucose monitor, a user interface and at least one processor functionally linked to the pump mechanism, the user interface and the communications device. The processor can be configured to automatically modify a basal rate of insulin delivered to the user with a closed loop delivery algorithm based on glucose levels received from the continuous glucose monitor with the closed loop delivery algorithm configured to calculate modifications to the basal rate to maintain the user's glucose levels at a glucose target and include a limiter function providing a limit on an amount by which the basal rate can be increased from a previous basal rate. If it is determined based on the glucose levels received from the continuous glucose monitor that that a current glucose level of the user is over a high glucose threshold and a predicted future glucose level of the user is a predetermined amount over the glucose target, the amount by which the limiter function will permit the basal rate to be increased from the previous basal rate can be increased. A modified basal rate can then be determined according to the increased amount insulin automatically delivered to the user with the pump mechanism according to the modified basal rate.
The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.
In some embodiments, all elements of an infusion pump system such as, e.g., the user interface, processor(s), pump mechanism, etc., reside in a single device, such as an infusion pump. In other embodiments, an infusion pump system may be a distributed system in which portions of the functionality such as, e.g., the user interface, speaker, processor, dosing algorithm, etc. may reside in separate devices such as in the infusion pump, dedicated remote control and/or other mobile device such as a mobile phone, or central computer system such as a cloud computing system.
With the infusion pump and CGM interfaced, the CGM can automatically transmit the CGM data to the pump. The pump can then use this data to automatically determine therapy parameters and suggest a therapy adjustment to the user or automatically deliver the therapy adjustment to the user. These therapy parameters including thresholds and target values can be stored in memory located in the pump or, if not located in the pump, stored in a separate location and accessible by the pump processor (e.g., “cloud” storage, a smartphone, a CGM, a dedicated controller, a computer, etc., any of which is accessible via a network connection). The pump processor can periodically and/or continually execute instructions for a checking function that accesses these data in memory, compares them with data received from the CGM and acts accordingly to adjust therapy. In further embodiments, rather than the pump determining the therapy parameters, the parameters can be determined by a separate device and transmitted to the pump for execution. In such embodiments, a separate device such as the CGM or a device in communication with the CGM, such as, for example, a smartphone, dedicated controller, electronic tablet, computer, etc. can include a processor programmed to calculate therapy parameters based on the CGM data that then instruct the pump to provide therapy according to the calculated parameters.
For example, if the CGM readings indicate that the user has or is predicted to have a high blood glucose level, the ambulatory infusion system can automatically calculate an insulin dose sufficient to reduce the user's blood glucose level below a threshold level or to a target level and automatically deliver the dose. Alternatively, the ambulatory infusion system can automatically suggest a change in therapy upon receiving the CGM readings such as an increased insulin basal rate or delivery of a bolus, but can require the user to accept the suggested change prior to delivery rather than automatically delivering the therapy adjustments.
By way of further example, if the CGM readings indicate that the user has or is predicted to have a low blood glucose level (hypoglycemia), the ambulatory infusion system can, for example, automatically reduce or suspend a basal rate, suggest to the user to reduce a basal rate, automatically deliver or suggest that the user initiate the delivery of an amount of a substance such as, e.g., a hormone (glucagon) to raise the concentration of glucose in the blood, automatically suggest that the patient address the hypoglycemic condition as necessary (e.g., ingest carbohydrates), singly or in any desired combination or sequence.
A schematic representation of a control algorithm for automatically adjusting insulin delivery based on CGM data is depicted in
The estimated IOB level determined at step 206 is then taken as the command (cmdIOB) for the inner loop and based on a difference of an IOB feedback value (fdbkIOB) and the cmdIOB set point at step 208, an IOB error value (errIOB) is determined. At step 210, the errIOB value is multiplied by a constant kl (relating to insulin-dependent glucose uptake in the body) and an estimate of the total daily insulin (TDI) of the user. This adjusts the errIOB to be proportional to the constant and the user's total daily intake of insulin. At step 212, a limiter function is applied to the value calculated at step 210. As will be discussed in further detail below, the limiter function can prevent the calculated amount from being larger or smaller than preset limits. The result is an insulin amount dU, which is the amount by which the user's stored basal rate should be modified. The insulin delivery rate for the user for the next closed loop interval is therefore calculated by modifying the user's stored basal rate profile by the dU value at step 214.
After the dose is calculated, it can be delivered to the user at step 216 and can also be used to update the estimated TDI for the user at step 218. The dose can also be used to update the estimated IOB level for the user at step 220 by comparing the actual insulin delivered to the programmed basal rate. The updated estimated IOB then becomes the new fdbkIOB for the IOB comparison at step 208. When new CGM values are received from the CGM, an estimated true CGM can be determined based on various factors such as, for example, the calibration status of the CGM sensor. The estimated true CGM value then becomes the new fdbkGLUCOSE value for the outer loop comparison with cmdGLUCOSE at step 204 or the estimated true CGM value can be used to update the predicted future glucose level (i.e., Gpred30) for the comparison. The algorithm then proceeds through to calculate a new estimated IOB and to the inner IOB loop for calculation of an insulin dose as described above. In one embodiment, a new CGM value is received every 5 minutes and therefore the algorithm executes as set forth above every 5 minutes.
Referring now to
Referring now to
In addition, to providing a higher limit 408 for dU in circumstances where the glucose level rate of change exceeds a threshold, the system can include additional stepped or tiered limits depending on the degree to which the user's glucose levels are over the threshold and/or increasing above the threshold rate. For example, the initial higher limit 308 may be utilized when the current or predicted glucose level is 180-190 mg/dL, the next higher limit 310 at 190-200 mg/dL and the highest limit 312 at over 200 mg/dL. In other embodiments, narrower or wider glucose level ranges can be utilized to separate the tiers, such as, for example, 180-195 mg/dL for limit 308, 195-210 mg/dL for limit 310 and above 210 mg/dL for limit 312. Alternatively or additionally, the higher tiers can be employed based on how high above the threshold rate of change the current glucose rate of change has been measured. It should be understood that although three steps or tiers are depicted, that any number of tiers could be utilized. The use of such tiers further protects against hyperglycemia by allowing more aggressive basal rate increases when the user has higher glucose levels.
Although embodiments described herein may be discussed in the context of the controlled delivery of insulin, delivery of other medicaments, singly or in combination with one another or with insulin, including, for example, glucagon, pramlintide, etc., as well as other applications are also contemplated. Device and method embodiments discussed herein may be used for pain medication, chemotherapy, iron chelation, immunoglobulin treatment, dextrose or saline IV delivery, treatment of various conditions including, e.g., pulmonary hypertension, or any other suitable indication or application. Non-medical applications are also contemplated.
With regard to the above detailed description, like reference numerals used therein may refer to like elements that may have the same or similar dimensions, materials, and configurations. While particular forms of embodiments have been illustrated and described, it will be apparent that various modifications can be made without departing from the spirit and scope of the embodiments herein. Accordingly, it is not intended that the invention be limited by the forgoing detailed description.
The entirety of each patent, patent application, publication, and document referenced herein is hereby incorporated by reference. Citation of the above patents, patent applications, publications and documents is not an admission that any of the foregoing is pertinent prior art, nor does it constitute any admission as to the contents or date of these documents.
Also incorporated herein by reference in their entirety are commonly owned U.S. Pat. Nos. 6,999,854; 8,133,197; 8,287,495; 8,408,421 8,448,824; 8,573,027; 8,650,937; 8,986,523; 9,173,998; 9,180,242; 9,180,243; 9,238,100; 9,242,043; 9,335,910; 9,381,271; 9,421,329; 9,486,171; 9,486,571; 9,492,608; 9,503,526; 9,555,186; 9,565,718; 9,603,995; 9,669,160; 9,715,327; 9,737,656; 9,750,871; 9,867,937; 9,867,953; 9,940,441; 9,993,595; 10,016,561; 10,201,656; 10,279,105; 10,279,106; 10,279,107; 10,357,603; 10,357,606; 10,492,141; 10/541,987; 10,569,016; 10,736,037; 10,888,655; 10,994,077; 11,116,901; and 11,224,693 and commonly owned U.S. Patent Publication Nos. 2009/0287180; 2012/0123230; 2013/0053816; 2014/0276423; 2014/0276569; 2014/0276570; 2018/0071454; 2019/0240398; 2019/0307952; 2020/0206420; 2020/0261649; 2020/0306445; 2020/0329433; 2020/0368430; 2020/0372995; 2021/0001044; 2021/0113766; 2021/0154405; and 2021/0353857 and commonly owned U.S. patent application Ser. Nos. 17/368,968; 17/459,129; 17/517,885 and 17/573,705.
Modifications may be made to the foregoing embodiments without departing from the basic aspects of the technology. Although the technology may have been described in substantial detail with reference to one or more specific embodiments, changes may be made to the embodiments specifically disclosed in this application, yet these modifications and improvements are within the scope and spirit of the technology. The technology illustratively described herein may suitably be practiced in the absence of any element(s) not specifically disclosed herein. The terms and expressions which have been employed are used as terms of description and not of limitation and use of such terms and expressions do not exclude any equivalents of the features shown and described or portions thereof and various modifications are possible within the scope of the technology claimed. Although the present technology has been specifically disclosed by representative embodiments and optional features, modification and variation of the concepts herein disclosed may be made, and such modifications and variations may be considered within the scope of this technology.
This application claims the benefit of U.S. Provisional Application No. 63/142,813 filed Jan. 28, 2021, which is hereby fully incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63142813 | Jan 2021 | US |
