Fluid injection devices and related methods

1. A non-transitory computer-readable medium comprising executable instructions that, when read and executed by a processor, cause the processor to:

receive user input indicative of a desire to administer a bolus;

receive, via a communications network, one or more measurement values from a sensing arrangement including one or more interstitial sensing elements;

determine an adjusted measurement value corresponding to a time for the bolus to be delivered in response to receiving the user input indicative of the desire to administer the bolus based at least in part on the one or more measurement values;

recursively determine an active amount of fluid in a body of a patient at the time for the bolus to be delivered based at least in part on historical bolus data associated with previous boluses delivered to the patient, by iteratively determining a plurality of intermediate values of active amount of fluid in the body of the patient associated with a plurality of intermediate times between (a) a most recent fluid delivery time and (b) the time for the bolus to be delivered, wherein each of the plurality of intermediate values of active amount of fluid in the body is determined for a particular intermediate time, from the plurality of intermediate times, that occurs after the most recent fluid delivery time and before the time for the bolus to be delivered; and

determine a bolus delivery amount of the fluid based at least in part on the active amount of the fluid and a difference between the adjusted measurement value and a target value.

2. The computer-readable medium of claim 1 , wherein the instructions cause the processor to determine a bolus dosage command for configuring a fluid injection device to deliver the bolus delivery amount.

3. The computer-readable medium of claim 2 , wherein the instructions cause the processor to transmit the bolus dosage command to the fluid injection device via the communications network.

4. The computer-readable medium of claim 1 , wherein the instructions cause the processor to generate a graphical user interface for a client application that includes a graphical user interface element that may be manipulated by a user to confirm the bolus delivery amount.

5. The computer-readable medium of claim 1 , wherein the instructions cause the processor to generate a graphical user interface for a client application that includes a graphical user interface element that may be manipulated by a user to adjust the bolus delivery amount.

6. The computer-readable medium of claim 1 , wherein the instructions cause the processor to generate a graphical user interface for a client application that includes a graphical user interface element that may be manipulated by a user to manually input a patient-specific parameter value and recursively determine the active amount of fluid in the body of the patient at the time for the bolus to be delivered based at least in part on the historical bolus data associated with previous boluses delivered to the patient using the patient-specific parameter value.

7. The computer-readable medium of claim 1 , wherein the instructions cause the processor to generate a graphical user interface for a client application that includes a graphical user interface element that may be manipulated by a user to manually input a patient-specific parameter value and determine the bolus delivery amount of the fluid based at least in part on the active amount of the fluid and the difference between the adjusted measurement value and the target value using the patient-specific parameter value.

8. The computer-readable medium of claim 1 , wherein the one or more measurement values comprise one or more interstitial glucose measurement values from an interstitial glucose sensing arrangement including the one or more interstitial sensing elements.

9. The computer-readable medium of claim 8 , wherein the fluid comprises insulin.

10. The computer-readable medium of claim 9 , wherein the adjusted measurement value comprises an adjusted glucose measurement value and the target value comprises a target glucose value.

11. The computer-readable medium of claim 1 , wherein the historical bolus data includes insulin delivery amounts for boluses previously delivered and respective delivery times associated with the respective insulin delivery amounts, wherein the instructions cause the processor to recursively determine the active amount by iteratively calculating a current insulin on board at the time associated with the user input based on the respective insulin delivery amounts, the respective delivery times, and an insulin action speed associated with the patient, wherein the insulin action speed represents an amount of time required to clear a unit of insulin from the body of the patient.

12. The computer-readable medium of claim 1 , wherein the instructions cause the processor to determine a trend in the one or more measurement values and determine the adjusted measurement value in a manner that is influenced by the trend in the one or more measurement values.

13. The computer-readable medium of claim 1 , wherein the instructions cause the processor to determine a correction bolus delivery amount (CB) using the equation

CB

=

BG

-

T

H

ISF

-

IOB

when the adjusted measurement value (BG) is greater than a high target glucose value (T H ), where IOB represents the active amount of the fluid and ISF is a patient-specific insulin sensitivity factor.

14. The computer-readable medium of claim 1 , wherein the instructions cause the processor to determine a meal bolus delivery amount (MB) using the equation

MB

=

Carb

CR

+

BG

-

T

L

ISF

when the adjusted measurement value (BG) is less than a low target value (T L ), where Carb is an amount of carbohydrates being corrected, CR is a patient-specific carbohydrate-to-insulin ratio, and ISF is a patient-specific insulin sensitivity factor.

15. An injection system comprising:

a fluid injection device; and

a client application on an electronic device coupled to a communications network to receive user input indicative of a desire to administer a bolus, receive, via the communications network, one or more measurement values from a sensing arrangement including one or more interstitial sensing elements, determine an adjusted measurement value corresponding to a time for the bolus to be delivered in response to receiving the user input indicative of the desire to administer the bolus based at least in part on the one or more measurement values, recursively determine an active amount of fluid in a body of a patient at the time for the bolus to be delivered based at least in part on historical bolus data associated with previous boluses delivered to the patient, by iteratively determining a plurality of intermediate values of active amount of fluid in the body of the patient associated with a plurality of intermediate times between (a) a most recent fluid delivery time and (b) the time for the bolus to be delivered, wherein each of the plurality of intermediate values of active amount of fluid in the body is determined for a particular intermediate time, from the plurality of intermediate times, that occurs after the most recent fluid delivery time and before the time for the bolus to be delivered, and determine a bolus delivery amount of the fluid to be delivered by the fluid injection device based at least in part on the active amount of the fluid and a difference between the adjusted measurement value and a target value.

16. The injection system of claim 15 , wherein the client application is configured to transmit a bolus dosage command for configuring the fluid injection device to deliver the bolus delivery amount to the fluid injection device over the communications network.

17. The injection system of claim 15 , wherein the client application is configured to generate a graphical user interface that includes a graphical user interface element that may be manipulated by a user to confirm the bolus delivery amount.

18. The injection system of claim 15 , wherein the client application is configured to generate a graphical user interface that includes a graphical user interface element that may be manipulated by a user to adjust the bolus delivery amount.

19. The injection system of claim 15 , wherein the client application is configured to generate a graphical user interface that includes a graphical user interface element that may be manipulated by a user to manually input a patient-specific parameter value and recursively determine the active amount of fluid in the body of the patient at the time for the bolus to be delivered based at least in part on the historical bolus data associated with previous boluses delivered to the patient using the patient-specific parameter value.

20. A method of operating a fluid injection device to deliver insulin to a patient, the method comprising:

receiving user input indicative of a desire to administer a bolus using the fluid injection device;

receiving, via a wireless network, one or more interstitial fluid glucose measurement values from an interstitial sensing arrangement including one or more interstitial sensing elements;

determining an adjusted glucose measurement value corresponding to a time for the bolus to be delivered in response to receiving the user input indicative of the desire to administer the bolus based at least in part on the one or more interstitial fluid glucose measurement values from the interstitial sensing arrangement;

recursively determining an active amount of the insulin in a body of the patient at the time for the bolus to be delivered based at least in part on historical bolus data associated with previous boluses delivered to the patient using the fluid injection device, by iteratively determining a plurality of intermediate values of active amount of fluid in the body of the patient associated with a plurality of intermediate times between (a) a most recent fluid delivery time and (b) the time for the bolus to be delivered, wherein each of the plurality of intermediate values of active amount of fluid in the body is determined for a particular intermediate time, from the plurality of intermediate times, that occurs after the most recent fluid delivery time and before the time for the bolus to be delivered;

after receiving the user input, determining a bolus delivery amount of the insulin based at least in part on the active amount of the insulin and a difference between the adjusted glucose measurement value and a target glucose value; and

determining a bolus dosage command for configuring the fluid injection device to deliver the bolus delivery amount.