DISCRETIONARY INSULIN DELIVERY SYSTEMS AND METHODS
A method of facilitating delivery of a discretionary dose of insulin to a user includes: enabling the user or a caregiver to specify, via a computer-based user interface, parameters associated with a discretionary delivery of insulin that may be delivered to the user; subsequently receiving data that represents the user's glucose level during a period of time associated with the discretionary delivery; automatically determining, with a computer-based processor, based on the received data, if, when and how much discretionary insulin should be delivered to the user during the period of time associated with the discretionary delivery; delivering insulin to the user during the period of time associated with the discretionary delivery according to the automatic determination; and delivering insulin to the user with the insulin delivery device according to a non-discretionary insulin delivery schedule unless a discretionary insulin delivery mode has been triggered.
1 . A system comprising:
an insulin delivery device configured to deliver insulin to a user of the system;
a glucose monitor; and
a computer-based control unit having a user interface and a computer-based processor,
wherein the user interface enables a caregiver to specify parameters associated with a discretionary delivery of insulin that may be delivered to the user,
wherein the glucose monitor subsequently monitors a glucose level of the user during a period of time associated with the discretionary delivery and sends data representing the monitored glucose level to the computer-based processor,
wherein the computer-based processor automatically determines, based on the data received from the glucose monitor if, when and how much discretionary insulin should be delivered to the user during the period of time associated with the discretionary delivery,
wherein the insulin delivery device delivers insulin to the user during the period of time associated with the discretionary delivery according to the automatic determination, and
wherein the system is configured to deliver insulin to the user according to a non-discretionary insulin delivery schedule unless a discretionary insulin delivery mode has been triggered.
2 . The system of claim 1 , wherein the insulin delivery device, the glucose monitor and the computer-based control unit are adapted to communicate with each other using wireless communication technology.
3 . The system of claim 1 , wherein the computer-based control unit is physically integrated into either the insulin delivery device or the glucose monitor.
4 . The system of claim 1 , wherein the discretionary insulin delivery is in addition to or in lieu of some or all of the insulin that would be delivered according to the non-discretionary insulin delivery schedule.
5 . The system of claim 1 wherein the insulin delivery device is configured to provide to the computer-based processor data that represents an amount of insulin that has been or will be delivered to the user by the insulin delivery device,
wherein automatically determining if, when and how much discretionary insulin should be delivered to the user during the period of time associated with the discretionary delivery is based, at least on part, on the data that represents an amount of insulin that has been or will be delivered to the user.
6 . The system of claim 1 , wherein the parameters associated with the discretionary delivery of insulin include an authorized maximum amount of insulin to be delivered,
wherein the authorized maximum amount of insulin to be delivered is an authorized maximum amount of delivery to be delivered during the period of time associated with the discretionary delivery, and
wherein how much discretionary insulin should be delivered to the user is an amount between an authorized minimum amount of insulin, which can be zero, and the authorized maximum amount of insulin to be delivered.
7 . The system of claim 1 , wherein the parameters associated with the discretionary delivery of insulin include an authorized maximum rate of insulin delivery,
wherein the authorized maximum rate of insulin delivery is an authorized maximum rate of insulin delivery during the period of time associated with the discretionary delivery, and
wherein the rate of discretionary insulin to be delivered to the user is an amount between an authorized minimum rate of insulin delivery, which can be zero, and the authorized maximum rate of insulin delivery.
8 . The system of claim 7 , wherein the parameters associated with the discretionary delivery of insulin include the period of time associated with the discretionary delivery,
wherein the period of time associated with the discretionary delivery is a period of time in which the caregiver has authorized discretionary delivery to occur.
9 . The system of claim 1 , wherein the glucose monitor is a continuous glucose monitor, a blood glucose meter, an intravenous blood glucose measurement device, or other device adapted to provide glucose data.
10 . The system of claim 1 , wherein the computer-based processor is further configured to constrain delivery of the discretionary insulin delivery based on one or more of the following constraints:
that a maximum rate of insulin delivery not be exceeded;
that no more than a maximum amount of insulin be delivered during a specific window of time;
that at least a minimum rate of insulin delivery be maintained; and
that at least a minimum amount of insulin be delivered to the user during a specified period of time.
11 . The system of claim 1 , wherein the automatic determination includes making a dosing recommendation based one or more of the following:
a current glucose reading;
an implied therapy using a fitting algorithm;
a target glucose reading;
a target range of acceptable glucose readings;
an insulin-on-board level;
a carbohydrate-on-board level; and
a future predicted glucose reading.
12 . The system of claim 1 , wherein the computer-based processor is configured to constrain the delivery of discretionary insulin to the user, even if the automatic determination reveals that some amount of discretionary insulin should be delivered to the user, if one or more criteria have been satisfied.
13 . The system of claim 12 , wherein the one or more criteria include one or more of:
if IOB−(current bg−target bg)/( C — 1*ISF)− C — 2>0,
or
if more than a fixed amount of insulin has been delivered in a previous certain amount of time,
wherein IOB represents insulin-on-board, current bg represents a current glucose reading, target bg represents a target glucose reading, ISF represents an insulin sensitivity factor for the user, and C — 1 and C — 2 are constants.
14 . The system of claim 1 , wherein the computer-based processor is configured to:
ascertain whether a cumulative amount of discretionary insulin delivered during a specific time period has exceeded a first threshold amount or is less than a second threshold amount; and
cease the discretionary delivery of insulin if the cumulative amount of discretionary insulin delivered during the specific time period has exceeded the first threshold amount or is less than the second threshold amount.
15 . The system of claim 14 , further comprising:
triggering an alarm if the delivery of discretionary insulin has been suspended because the cumulative amount of insulin delivered during the specific time period exceeded the first threshold amount.
16 . The system of claim 15 , wherein the computer-based user interface is configured to enable the user to acknowledge the alarm;
wherein the processor is configured such that:
if the alarm is acknowledged within a predetermined amount of time after the alarm is triggered, the processor causes subsequent delivery of insulin to the user to occur according to a non-discretionary schedule of delivery; and
if the alarm is not acknowledged within the predetermined amount of time after the alarm is triggered, the processor causes subsequent delivery of less insulin than would be delivered according to the non-discretionary schedule of delivery.
17 . The system of claim 16 , further comprising:
wherein the processor is configured such that, after the delivery of less insulin than would be delivered according to the non-discretionary insulin delivery schedule, the processor causes a subsequent delivery of insulin according to the non-discretionary delivery schedule.
18 . The system of claim 14 , wherein the first threshold amount is a first predetermined amount of insulin above what would have been delivered to the user according to a non-discretionary delivery schedule over the specific time period, and
wherein the second threshold amount is a second predetermined amount of insulin less than what would have been delivered to the user according to the non-discretionary delivery schedule over the specific time period.
19 . The system of claim 14 , further comprising:
repeating the ascertaining step on an iterative basis,
wherein the specific time period for each iteration is a period of time relative to when the specific iteration is occurring.
20 . The system of claim 19 , wherein the processor is configured such that, if the discretionary delivery is ceased, all iterations are terminated.
21 . The system of claim 1 , wherein the user interface includes one or more: keyboard, touch screen, mouse, tracking device, microphone or other data input and/or output device or any combination thereof.
22 . A non-transitory, computer-readable medium that stores instructions executable by a computer-based processor to perform the steps comprising:
enabling a caregiver to specify parameters at a computer-based user interface, wherein the specified parameters are associated with a discretionary delivery of insulin that may be delivered to a user;
subsequently receiving data that represents the user's glucose level during a period of time associated with the discretionary delivery; and
automatically determining, based on the received data, if, when and how much discretionary insulin, up to a maximum amount that corresponds with the specified parameters, should be delivered to the user during the period of time associated with the discretionary delivery; and
causing a delivery of insulin to the user during the period of time associated with the discretionary delivery according to the automatic determination.
23 . A method of facilitating delivery of insulin to a user, the method including:
enabling a caregiver to specify, via a computer-based user interface, parameters associated with a discretionary delivery of insulin that may be delivered to a user;
subsequently receiving data that represents a glucose level of the user during a period of time associated with the discretionary delivery;
automatically determining, with a computer-based processor, based on the received data, if, when and how much discretionary insulin should be delivered to the user during the period of time associated with the discretionary delivery;
delivering insulin to the user with an insulin delivery device during the period of time associated with the discretionary delivery according to the automatic determination; and
delivering insulin to the user with the insulin delivery device according to a non-discretionary insulin delivery schedule unless a discretionary insulin delivery mode has been triggered.
24 . The method of claim 23 , wherein the discretionary insulin delivery is in addition to or in lieu of some or all of the insulin that would be delivered according to the non-discretionary insulin delivery schedule.
25 . The method of claim 23 , further comprising:
receiving data at the computer-based processor that represents an amount of insulin that has been or will be delivered to the user by the insulin delivery device over time,
wherein automatically determining if, when and how much discretionary insulin should be delivered to the user during the period of time associated with the discretionary delivery is based, at least in part, on the data that represents the amount of insulin that has been or will be delivered to the user over time.
26 . The method of claim 23 , wherein the parameters associated with the discretionary delivery of insulin include an authorized maximum amount of insulin to be delivered.
27 . The method of claim 26 , wherein the authorized maximum amount of insulin to be delivered is an authorized maximum amount of delivery to be delivered during the period of time associated with the discretionary delivery.
28 . The method of claim 26 , wherein how much discretionary insulin should be delivered to the user is an amount between an authorized minimum amount of insulin, which can be zero, and the authorized maximum amount of insulin to be delivered.
29 . The method of claim 23 , wherein the parameters associated with the discretionary delivery of insulin include an authorized maximum rate of insulin delivery.
30 . The method of claim 29 , wherein the authorized maximum rate of insulin delivery is an authorized maximum rate of insulin delivery during the period of time associated with the discretionary delivery.
31 . The method of claim 29 , wherein the rate of discretionary insulin to be delivered to the user is an amount between an authorized minimum rate of insulin delivery, which can be zero, and the authorized maximum rate of insulin delivery.
32 . The method of claim 23 , wherein the parameters associated with the discretionary delivery of insulin include the period of time associated with the discretionary delivery,
wherein the period of time associated with the discretionary delivery is a period of time that the caregiver has authorized discretionary delivery to occur.
33 . The method of claim 23 , wherein the data that represents the user's glucose is received from a continuous glucose monitor, a blood glucose meter, an intravenous blood glucose measurement device, or other device adapted to provide glucose data.
34 . The method of claim 23 , further comprising:
constraining delivery of the discretionary insulin delivery based on one or more of the following constraints:
that a maximum rate of insulin delivery not be exceeded;
that no more than a maximum amount of insulin be delivered during a specific window of time;
that at least a minimum rate of insulin delivery be maintained; and
that at least a minimum amount of insulin be delivered to the user during a specified period of time.
35 . The method of claim 23 , wherein the automatic determination includes making a dosing recommendation based one or more of the following:
a current glucose reading;
an implied therapy using a fitting algorithm;
a target glucose reading;
a target range of acceptable glucose readings;
an insulin-on-board level;
a carbohydrate-on-board level; and
a future predicted glucose reading.
36 . The method of claim 35 , wherein making the dosing recommendation based upon the current glucose reading, the target glucose reading and the insulin-on-board level comprises utilizing the following relationship:
dose — t =Max(0, ((BG_cur−BG − target)/( C — 1*ISF))−( C — 2*IOB)+ C — 3),
wherein dose_t represents a recommended dosing at time t, BG_cur represents the current glucose reading, BG_target represents the target glucose reading, ISF represents an insulin sensitivity factor for the user, and C — 1, C — 2 and C — 3 are constants.
37 . The method of claim 35 , wherein making the dosing recommendation based on the implied therapy using the fitting algorithm comprises utilizing the following relationship:
dose — t= Max(0, ( C — 1*(BGcur−BGtarg)/ISF)+( C — 2*COB/carb ratio)−( C — 3*IOB)+ C — 4),
wherein dose_t represents a recommended dosing at time t, BG_cur represents the current glucose reading, BG_target represents the target glucose reading, ISF represents an insulin sensitivity factor for the user, COB represents carbohydrates-on-board for the user, carb ratio represents a number of carbohydrates that one unit of insulin offsets for the user, IOB represents insulin-on-board for the user, and C — 1, C — 2, C — 3 and C — 4 are constants.
38 . The method of claim 35 , further comprising:
calculating the future predicted glucose reading utilizing a proportional-derivative extrapolation of the future predicted glucose reading from the current glucose reading and a recent trend in glucose readings.
39 . The method of claim 35 , further comprising:
calculating the future predicted glucose reading utilizing one or more of the following:
a proportional, plus integral, plus derivative extrapolation of the future predicted glucose reading from the current glucose reading and a recent trend in glucose readings;
an autoregressive model; and
a compartmental model of glucose and insulin transport.
40 . The method of claim 35 , wherein making the dosing recommendation based on the target range of BG levels comprises determining, with the computer-based processor, an error associated with the projected future glucose reading relative to the target range of acceptable glucose readings, wherein:
the error is a function of the projected future glucose reading and an upper value in the target range of acceptable glucose readings that increases as the absolute difference between the two values increases, if the projected future glucose reading is greater than the upper value;
the error is a function of the projected future glucose reading and a lowest value in the target range of acceptable glucose readings that decreases as the absolute difference between the two values increases, if the projected future glucose reading is less than the lowest value; and
the error is zero if the projected future glucose reading is equal to the lowest value or the upper value or is between the lowest value and the upper value.
41 . The method of claim 23 , further comprising:
constraining the delivery of discretionary insulin to the user, even if the automatic determination reveals that some amount of discretionary insulin should be delivered to the user, if one or more criteria have been satisfied.
42 . The method of claim 41 , wherein the one or more criteria include one or more of:
if IOB−(current bg−target bg)/( C — 1*ISF)− C — 2>0,
or
if more than a fixed amount of insulin has been delivered in a previous certain amount of time,
wherein IOB represents insulin-on-board, current bg represents a current glucose reading, target bg represents a target glucose reading, ISF represents an insulin sensitivity factor for the user, and C — 1 and C — 2 are constants.
43 . The method of claim 23 , further comprising:
ascertaining whether a cumulative amount of discretionary insulin delivered during a specific time period has exceeded a first threshold amount or is less than a second threshold amount; and
ceasing the discretionary delivery of insulin if the cumulative amount of discretionary insulin delivered during the specific time period has exceeded the first threshold amount or is less than the second threshold amount.
44 . The method of claim 43 , further comprising:
triggering an alarm if the delivery of discretionary insulin has been suspended because the cumulative amount of insulin delivered during the specific time period exceeded the first threshold amount.
45 . The method of claim 44 , further comprising:
enabling the user to acknowledge the alarm;
if the alarm is acknowledged within a predetermined amount of time after the alarm is triggered, subsequently delivering insulin to the user according to a non-discretionary insulin delivery schedule; and
if the alarm is not acknowledged within the predetermined amount of time after the alarm is triggered, subsequently delivering less insulin than would be delivered according to the non-discretionary insulin delivery schedule.
46 . The method of claim 45 , further comprising:
after delivering less insulin than would be delivered according to the non-discretionary insulin delivery schedule, delivering insulin according to the non-discretionary delivery schedule.
47 . The method of claim 46 , wherein subsequently delivering less insulin than otherwise would be delivered according to the non-discretionary insulin delivery schedule at least partially offsets additional insulin that the user may have received as a result of the discretionary delivery.
48 . The method of claim 46 , wherein subsequently delivering less insulin than would be delivered according to the non-discretionary insulin delivery schedule comprises:
delivering an amount of insulin that is between 0 and a multiple of the first threshold amount less than what would be delivered according to the non-discretionary schedule of delivery from a beginning of the discretionary insulin delivery period until a termination of the discretionary insulin delivery period.
49 . The method of claim 43 , wherein the first threshold amount is a first predetermined amount of insulin above what would have been delivered to the user according to a non-discretionary delivery schedule over the specific time period, and
wherein the second threshold amount is a second predetermined amount of insulin less than what would have been delivered to the user according to the non-discretionary delivery schedule over the specific time period.
50 . The method of claim 43 , further comprising:
repeating the ascertaining step on an iterative basis,
wherein the specific time period for each iteration is a period of time relative to when the specific iteration is occurring.
51 . The method of claim 50 , wherein all iterations are terminated upon the occurrence of a ceasing of discretionary delivery.
52 . A control system configured to control an amount of insulin delivered to a user, the control system comprising:
a computer-based control unit having a user interface and a computer-based processor;
a first interface unit configured to allow the computer-based processor to communicate with a glucose monitor; and
a second interface unit configured to allow the computer-based processor to communicate with an insulin delivery device which is configured to deliver insulin to a user of the system,
wherein the user interface enables a caregiver to specify parameters associated with a discretionary delivery of insulin that may be delivered to the user,
wherein the computer-based processor is configured to subsequently receive data from a glucose monitor through the first interface unit, wherein the received data represents a glucose level of the user during a period of time associated with the discretionary delivery,
wherein the computer-based processor is configured to automatically determine, based on the data received from the glucose monitor if, when and how much discretionary insulin should be delivered to the user during the period of time associated with the discretionary delivery,
wherein the computer-based processor is configured to send data to an insulin delivery device through the second interface unit such that the insulin delivery device can deliver insulin to the user during the period of time associated with the discretionary delivery according to the automatic determination, and
wherein the computer-based processor is configured to send data to an insulin delivery device through the second interface unit such that the insulin delivery device can deliver insulin to the user according to a non-discretionary insulin delivery schedule unless a discretionary insulin mode has been triggered.
53 . The control system of claim 52 , wherein the first interface unit comprises a wireless receiver or transceiver, and the second interface unit comprises a wireless transmitter or transceiver.
54 . The control system of claim 52 , wherein the computer-based processor is configured to send data to an insulin delivery device to deliver insulin to the user without the use of data received from a glucose monitor in providing a predetermined, non-discretionary insulin delivery schedule to the insulin delivery device.