SYSTEM AND METHOD FOR PROVIDING CLOSED LOOP INFUSION FORMULATION DELIVERY

• US 20110184380A1
• Filed: 01/19/2011
• Published: 07/28/2011
• Est. Priority Date: 09/07/2001
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Miller, Michael E., STARKWEATHER, TIMOTHY J., Lebel, Ronald J.
• Granted Patent: US 8,795,224 B2
• Time in Patent Office: Days
• US Class Current: 604/504
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A system and method for providing closed loop infusion formulation delivery which accurately calculates a delivery amount based on a sensed biological state by adjusting an algorithm'"'"'s programmable control parameters. The algorithm calculates a delivery amount having proportional, derivative, and basal rate components. The control parameters may be adjusted in real time to compensate for changes in a sensed biological state that may result from daily events. Safety limits on the delivery amount may be included in the algorithm. The algorithm may be executed by a computing element within a process controller for controlling closed loop infusion formulation delivery. The biological state is sensed by a sensing device which provides a signal to the controller. The controller calculates an infusion formulation delivery amount based on the signal and sends commands to an infusion formulation delivery device which delivers an amount of infusion formulation determined by the commands.

Claims

1-51. -51. (canceled)

52. A method for delivering an insulin formulation, the method comprising:

taking a plurality of samples of a blood glucose level over a period of time;

calculating a difference between the sampled blood glucose level and a predefined blood glucose level threshold;

calculating a rate of change over time in the sampled blood glucose level;

calculating a sum comprising a first proportion of said calculated difference and a second proportion of said calculated rate of change; and

delivering an amount of insulin formulation based on the amount of said sum.

53. The method recited in claim 52, wherein said calculated rate of change is based on a derivative of the sampled blood glucose as a function of time.

54. The method recited in claim 52, wherein an amount of said first proportion or said second proportion is selectively changeable.

55. The method recited in claim 54, wherein said second proportion is set as a first value when said sampled blood glucose level is increasing over time and is set as a second value when said sampled blood glucose level is decreasing over time.

56. The method recited in claim 52, wherein said sum further comprises a basal amount of insulin formulation.

57. The method recited in claim 56, wherein said basal amount of insulin formulation can be set to change as the part or time of the day changes.

58. The method recited in claim 57, further comprising:

disabling insulin delivery of an amount over that of said basal amount within a predefined amount of time of an event.

59. The method recited in claim 58, wherein said event is related to a meal, sleep, awakening, exercise, stress-inducing event, or medication.

60. The method recited in claim 56:

wherein each sample of the plurality of samples is taken at a time that is separated by a time period from a time at which a next sample or a previous sample was taken;

wherein, when the sampled blood glucose level is falling over time, said time period is of increased length as compared to a previous time period.

61. The method recited in claim 56, wherein the basal amount or the second proportion is zero for the purpose of said sum when the sampled blood glucose level is below a predefined threshold and the sampled blood glucose level is falling over time.

62. A system for delivering an insulin formulation, the system comprising:

a data acquisition unit for taking a plurality of samples of a blood glucose level over a period of time;

a calculator for calculating a difference between the sampled blood glucose level and a predefined blood glucose level threshold;

wherein said calculator is further configured to calculate the rate of change over time in the sampled blood glucose level acquired by the data acquisition unit;

wherein said calculator is further configured to calculate a sum comprising a first proportion of said calculated difference and a second proportion of said calculated rate of change; and

a controller for basing the amount of insulin formulation to be delivered on the amount of said sum.

63. The system recited in claim 62, wherein said calculated rate of change is based on a derivative of the sampled blood glucose as a function of time.

64. The system recited in claim 62, wherein an amount of said first proportion or said second proportion is selectively changeable.

65. The system recited in claim 64, wherein said second proportion is set as a first value when said sampled blood glucose level is increasing over time and is set as a second value when said sampled blood glucose level is decreasing over time.

66. The system recited in claim 62, wherein said sum further comprises a basal amount of insulin formulation.

67. The system recited in claim 66, wherein said basal amount of insulin formulation can be set to change as the part or time of the day changes.

68. The system recited in claim 67, wherein said controller is further configured to disable insulin delivery of an amount over that of said basal amount within a predefined amount of time of an event.

69. The system recited in claim 68, wherein said event is related to a meal, sleep, awakening, exercise, stress-inducing event, or medication.

70. The system recited in claim 66:

wherein each sample of the plurality of samples is taken at a time that is separated by a time period from a time at which a next sample or a previous sample was taken;

wherein, when the sampled blood glucose level is falling over time, said time period is of increased length as compared to a previous time period.

71. The system recited in claim 66, wherein the basal amount or the second proportion is zero for the purposes of said sum when the sampled blood glucose level is below a predefined threshold and the sampled blood glucose level is falling over time.