METHOD AND IMPLANTABLE SYSTEM FOR BLOOD-GLUCOSE CONCENTRATION MONITORING USING PARALLEL METHODOLOGIES

• US 20100280348A1
• Filed: 04/30/2009
• Published: 11/04/2010
• Est. Priority Date: 04/30/2009
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Inventors: Falkenberg, Eric, Wenzel, Brian Jeffrey, Farazi, Taraneh Ghaffari, Park, Euljoon, Benser, Michael E.
• Granted Patent: US 8,630,692 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/30 Input circuits therefor
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/4866 Evaluating metabolism A61B5/083 takes precedence
• CPC Class Codes: A61B 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B

Abstract

In an implantable medical device for monitoring glucose concentration in the blood, a blood-glucose concentration analysis is performed using correlations of blood-glucose concentration with measures of metabolic oxygen consumption including oxymetric, and/or temperature. Analysis of electrocardiographic data is used in a parallel method to detect and/or confirm the onset and/or existence and/or extent of hypoglycemia and/or hyperglycemia. Blood-glucose concentration calculation is enhanced by using the combination of the oxygen metabolism analysis and electrocardiographic analysis.

Claims

1. A method for determining blood-glucose concentration in an implantable medical device, the method comprising:

(a) generating a first metric of blood-glucose concentration by monitoring one or more property of one or more cardiac electrical signal;

(b) generating a second metric of blood-glucose concentration by monitoring one or more property of oxygen metabolism; and

(c) using the first metric of blood-glucose concentration and the second metric of blood-glucose concentration to determine an enhanced metric of blood-glucose concentration.

2. The method of claim 1, wherein step (a) comprises generating the first metric of blood-glucose concentration by analyzing at least one of:

a T-wave amplitude;

a Q-T interval; and

an S-T deviation.

3. The method of claim 1, wherein step (b) comprises generating the second metric of blood-glucose concentration using the metabolic oxygen conformation method.

4. The method of claim 1, wherein step (b) comprises generating the second metric of blood-glucose concentration by monitoring at least one of:

a metric of venous oxygen saturation;

a metric of hematocrit; and

a metric of arterial oxygen saturation.

5. The method of claim 1, wherein step (c) comprises using the first metric of blood-glucose concentration to confirm the second metric of blood-glucose concentration if both the first metric of blood-glucose concentration and the second metric of blood-glucose concentration are indicative of the same one of hypoglycemia, normoglycemia, and hyperglycemia.

6. The method of claim 1, wherein step (c) comprises using the second metric of blood-glucose concentration to confirm the first metric of blood-glucose concentration if both the first metric of blood-glucose concentration and the second metric of blood-glucose concentration are indicative of the same one of hypoglycemia, normoglycemia, and hyperglycemia.

7. The method of claim 1, wherein step (b) is performed in response to generating in step (a) a first metric of blood-glucose concentration that is indicative of one of hypoglycemia and hyperglycemia.

8. The method of claim 1, wherein step (a) is performed in response to generating in step (b) a second metric of blood-glucose concentration that is indicative of one of hypoglycemia and hyperglycemia.

9. The method of claim 1, further comprising controlling a therapy in response to the enhanced metric of blood-glucose concentration.

10. The method of claim 1, further comprising generating a warning signal if the enhanced metric of blood-glucose concentration is indicative of one of hypoglycemia and hyperglycemia.

11. An implantable system for monitoring blood-glucose concentration in a patient, comprising:

an EGM sensing circuit that senses one or more cardiac electrical signal and generates EGM data indicative of the one or more cardiac electrical signal;

an EGM analysis unit that receives the EGM data from the EGM sensing circuit and generates a first metric of blood-glucose concentration using the EGM data;

an oxygen metabolism sensor that monitors one or more property of oxygen metabolism and generates oxygen metabolism data indicative of the one or more property of oxygen metabolism;

an oxygen metabolism analysis unit that receives the oxygen metabolism data from the oxygen metabolism sensor and generates a second metric of blood-glucose concentration using the oxygen metabolism data; and

a blood-glucose concentration analysis unit that receives the first metric of blood-glucose concentration and the second metric of blood-glucose concentration and generates an enhanced metric of blood-glucose concentration.

12. The implantable system of claim 11, wherein the EGM analysis unit generates the first metric of blood-glucose concentration using a function of at least one of:

a T-wave amplitude in the EGM data;

a Q-T interval in the EGM data; and

an S-T deviation in the EGM data.

13. The implantable system of claim 11, wherein the oxygen metabolism unit generates the second metric of blood-glucose concentration using the metabolic oxygen conformation method.

14. The implantable system of claim 11, wherein the oxygen metabolism sensor monitors one or more of:

a property of venous oxygen saturation;

a property of hematocrit; and

a property of arterial oxygen saturation.

15. The implantable system of claim 11, wherein the blood-glucose concentration analysis unit uses the first metric of blood-glucose concentration to confirm the second metric of blood-glucose concentration and determine the enhanced metric of blood-glucose concentration.

16. The implantable system of claim 11, wherein the blood-glucose concentration analysis unit uses the second metric of blood-glucose concentration to confirm the first metric of blood-glucose concentration and determine the enhanced metric of blood-glucose concentration.

17. The implantable system of claim 11, further comprising an effector for delivering a therapy in response to the enhanced metric of blood-glucose concentration.

18. The implantable system of claim 11, further comprising a warning control circuit that activates a warning device if the enhanced metric of blood-glucose concentration is indicative of hypoglycemia or hyperglycemia.

19. The implantable system of claim 11, further comprising:

a memory that stores the enhanced blood-glucose concentration generated at a plurality of times; and

a communication circuit adapted to transmit the enhanced blood-glucose concentration generated at a plurality of times from the memory to a device external to the patient.

20. An implantable cardiac stimulation device comprising:

an EGM sensing circuit that senses one or more cardiac electrical signal and generates EGM data indicative of the one or more cardiac electrical signal;

an EGM analysis unit that receives the EGM data from the EGM sensing circuit and generates a first metric of blood-glucose concentration using the EGM data;

an oxygen metabolism input circuit that receives oxygen metabolism signals indicative of one or more property of oxygen metabolism and generates oxygen metabolism data using the oxygen metabolism signals;

an oxygen metabolism analysis unit that receives the oxygen metabolism data from the oxygen metabolism input circuit and generates a second metric of blood-glucose concentration using the oxygen metabolism data;

a blood-glucose concentration analysis unit that receives the first metric of blood-glucose concentration and the second metric of blood-glucose concentration and generates an enhanced metric of blood-glucose concentration; and

an effector that delivers at least one of a therapy, a diagnosis and a warning in response to the enhanced metric of blood-glucose concentration.