Methods and systems for detecting the hydration of sensors

• US 9,885,684 B2
• Filed: 10/16/2013
• Issued: 02/06/2018
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Morgan, Wayne A., Choy, David Y., Henke, James L., Reghabi, Bahar, Soundararajan, Gopikrishnan, Schultz, Peter, Hoss, Udo
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): Toth, Karen
• Application Number:
  US14/055,155
• Publication Number:
  US 20140046154A1
• Time in Patent Office: 1,574 Days
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/327 Biochemical electrodes , e.g. electrical or mechanical details for in vitro measurements
• CPC Class Codes: G01N 27/403 Cells and electrode assemblies
• CPC Class Codes: G01N 27/416 Systems G01N27/27 takes precedence

Abstract

A sensor system includes a sensor and a sensor electronics device. The sensor includes a plurality of electrodes. The sensor electronics device includes a connection detection device, a power source, and a delay circuit. The connection detection device determines if the sensor electronics device is connected to the sensor and transmits a connection signal. The delay circuit receives the connection signal, waits a preset hydration time, and couples the regulated voltage from the power source to an electrode in the sensor after the preset hydration time has elapsed. Alternatively, the sensor electronics device may include an electrical detection circuit and a microcontroller. The electrical detection circuit determines if the plurality of electrodes are hydrated and generates an interrupt if the electrodes are hydrated. A microcontroller receives the interrupt and transmits a signal representative of a voltage to an electrode of the plurality of electrodes.

Claims

1. A sensor system, comprising:

a glucose sensor, the sensor including a plurality of electrodes that are configured to be implanted or disposed subcutaneously within a patient'"'"'s body so as to be in continuous contact with the patient'"'"'s bodily fluids; and

a sensor electronics device that is coupled to the sensor and includes;

a detection circuit that receives a first signal and generates a first interrupt after receipt of the first signal, said first signal being indicative of the level of hydration of said electrodes; and

a microcontroller that receives the first interrupt and sets a first indicator indicating the sensor is hydrated, transmits a second signal, the second signal being representative of a voltage to be applied to the sensor over a stabilization timeframe lasting 10 minutes, 15 minutes, or 20 minutes to stabilize the sensor, and sets a second indicator after said voltage has been applied to the sensor, wherein the microcontroller receives a sensor signal from the sensor, and wherein, when the first and second indicators are set, the microcontroller utilizes said sensor signal representing measurement of the patient'"'"'s blood glucose level.

2. The sensor system of claim 1, the sensor electronics device further including an AC source coupled to an electrode of the plurality of electrodes and supplying the electrode with said first signal, wherein, when the detection circuit detects a level of attenuation in the first signal that is higher than a threshold, the detection circuit generates the first interrupt.

3. The sensor system of claim 1, the sensor electronics device further including a DC source coupled to an electrode of the plurality of electrodes and supplying said first signal to the electrode, wherein, when the detection circuit detects a level of attenuation in the first signal that is higher than a threshold, the detection circuit generates the first interrupt.

4. The sensor system of claim 1, wherein the sensor electronics device further includes a digital-to-analog converter (DAC) that receives said second signal and applies said voltage to the sensor.

5. The sensor system of claim 1, wherein said voltage includes a series of pulses.

6. A program code storage device, comprising:

a computer-readable medium; and

non-transitory computer-readable program code, stored on the computer-readable medium, the computer-readable program code having instructions, which when executed cause a controller to;

receive an interrupt from a detection circuit indicating that a glucose sensor is hydrated, said sensor including a plurality of electrodes that are configured to be implanted or disposed subcutaneously within a patient'"'"'s body so as to be in continuous contact with the patient'"'"'s bodily fluids for measuring the patient'"'"'s blood glucose level;

set a first indicator that the interrupt has been received from the detection circuit;

transmit a stabilization initiation signal to a digital-to-analog converter (DAC) to begin application of a voltage to stabilize the glucose sensor, said voltage being applied to the sensor over a stabilization timeframe lasting 10 minutes, 15 minutes, or 20 minutes; and

set a second indicator once said voltage has been applied to the sensor.

7. The program code storage device of claim 6, the computer-readable program code including instructions, which when executed cause the controller to utilize a sensor signal received from the sensor, once both the first and second indicators have been set, to measure the patient'"'"'s blood glucose level.

8. The program code storage device of claim 6, wherein said voltage includes a series of pulses.