System for Characterizing Patient Tissue Impedance for Monitoring and Treatment

• US 20090198300A1
• Filed: 01/21/2009
• Published: 08/06/2009
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: Siemens Healthineers AG (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Zhang, Hongxuan, Koertge, Detlef W., Steibel, Dennis JR., Wade, Harold James
• Granted Patent: US 8,157,848 B2
• Time in Patent Office: Days
• US Class Current: 607/28
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker

Abstract

A system provides early prediction of heart tissue malfunction and electrophysiological pathology by determining anatomical tissue impedance characteristics for use in medical patient monitoring and treatment decision making. At least one repository of data indicates multiple predetermined expected impedance value ranges for corresponding multiple impedance measurements taken at multiple particular different sites of at least one anatomical organ. An impedance measurement processor automatically determines whether multiple measured impedance values taken at multiple particular different sites of an anatomical organ using an invasive catheter are within corresponding multiple predetermined expected impedance value ranges derived from the at least one repository. An output processor automatically communicates data comprising at least one message to a destination. The at least one message includes data indicating whether the multiple measured impedance values taken at the multiple particular different sites of the anatomical organ are within the corresponding multiple predetermined expected impedance value ranges.

Claims

1. A system for determining anatomical tissue impedance characteristics for use in medical patient monitoring and treatment decision making, comprising:

at least one repository of data indicating a plurality of predetermined expected impedance value ranges for a corresponding plurality of impedance measurements taken at a plurality of particular different sites of at least one anatomical organ;

an impedance measurement processor for automatically determining whether a plurality of measured impedance values taken at a plurality of particular different sites of an anatomical organ using an invasive catheter are within a corresponding plurality of predetermined expected impedance value ranges derived from data in said at least one repository; and

an output processor for automatically communicating data comprising at least one message to a destination, said at least one message includes data indicating whether said plurality of measured impedance values taken at said plurality of particular different sites of said anatomical organ are within said corresponding plurality of predetermined expected impedance value ranges.

2. A system according to claim 1, wherein

said impedance measurement processor synchronizes measurements of said plurality of measured impedance values with a particular time point within a patient heart cycle.

3. A system according to claim 2, wherein

said at least one repository of data indicates a plurality of predetermined expected impedance value ranges for a corresponding plurality of impedance measurements taken at a single site of an anatomical organ at a plurality of different time points within said patient heart cycle and

said impedance measurement processor determines whether a synchronized impedance value measurement at a particular time point within said patient heart cycle is within a corresponding expected impedance value range associated with said particular time point within said patient heart cycle.

4. A system according to claim 1, wherein

said at least one repository of data indicates a plurality of different predetermined expected impedance value ranges and corresponding different treatment decision related information for a corresponding plurality of impedance measurements taken at a single site of an anatomical organ.

5. A system according to claim 4, wherein

said plurality of predetermined impedance value ranges include at least one of, (a) a first value range indicating tissue ablation is not recommended and (b) a second value range indicating tissue ablation may be recommended.

6. A system according to claim 4, wherein

said plurality of predetermined impedance value ranges include at least one of, (a) a first value range indicating a first treatment may be recommended and (b) a second value range indicating a second different treatment may be recommended.

7. A system according to claim 6, wherein

an impedance value range of 50 Ohms to 1 K Ohm is deemed a normal range.

8. A system according to claim 1, wherein

said organ comprises a heart and

said impedance measurement processor determines whether a plurality of measured impedance values taken at a plurality of particular different sites within a heart chamber using an invasive basket catheter are within a corresponding plurality of predetermined expected impedance value ranges derived from said at least one repository.

9. A system according to claim 1, wherein

said impedance measurement processor determines whether a plurality of measured impedance values taken at a plurality of particular different sites of an anatomical organ using an invasive multi-branch catheter are within a corresponding plurality of predetermined expected impedance value ranges derived from said at least one repository.

10. A system according to claim 1, wherein

said at least one repository of data comprises a plurality of previously performed impedance measurements taken at a plurality of particular different sites of an anatomical organ of a particular patient and

said impedance measurement processor automatically determines whether differences between,

a plurality of measured impedance values taken at a plurality of particular different sites of the anatomical organ of said particular patient and

said previously performed impedance measurements, exceed a predetermined threshold.

11. A system according to claim 1, wherein

said impedance measurement processor automatically successively determines said measured impedance values by successively altering a known impedance value in an impedance bridge network.

12. A system according to claim 11, wherein

said measured impedance value and range is resistive and

said impedance measurement processor applies DC voltage to said impedance bridge network in successively altering a known impedance value in said impedance bridge network to determine whether an impedance value lies in a particular range.

13. A system according to claim 11, wherein

said measured impedance value and range is reactive and comprises complex number values and

said impedance measurement processor applies AC voltage to said impedance bridge network in successively altering a known impedance value in said impedance bridge network to determine whether an impedance value lies in a particular range.

14. A system according to claim 1, including

an electrical signal processor for acquiring electrical signals at said plurality of particular different sites of said anatomical organ using said invasive catheter and for processing the acquired electrical signals for use in diagnosis.

15. A system according to claim 14, including

a mode switch for adaptively switching between impedance measurement in a first mode using said impedance measurement processor and electrical signal acquisition in a second mode using said electrical signal processor.

16. A system for determining anatomical tissue impedance characteristics for use in medical patient monitoring and treatment decision making, comprising:

at least one repository of data indicating a plurality of predetermined expected impedance value ranges for a corresponding plurality of impedance measurements taken at a plurality of particular different sites of at least one anatomical organ;

an impedance measurement processor for automatically,

measuring impedance values at a plurality of particular different sites of an anatomical organ using an invasive catheter and synchronously with a particular time point within a patient heart cycle and

determining whether the measured impedance values are within a corresponding plurality of predetermined expected impedance value ranges derived from said at least one repository; and

an output processor for automatically communicating data comprising at least one message to a destination, said at least one message includes data indicating whether said plurality of measured impedance values taken at said plurality of particular different sites of said anatomical organ are within said corresponding plurality of predetermined expected impedance value ranges.

17. A system for determining anatomical tissue impedance characteristics for use in medical patient monitoring and treatment decision making, comprising:

at least one repository of data previously performed impedance measurement values taken at a plurality of particular different sites of an anatomical organ of a particular patient;

an impedance measurement processor for automatically determining whether differences between,

a plurality of measured impedance values taken at a plurality of particular different sites of the anatomical organ of said particular patient and

said previously performed impedance measurement values, exceed a predetermined threshold; and

an output processor for automatically communicating data comprising at least one message to a destination, said at least one message includes data representative of whether said differences between said plurality of measured impedance values taken at a plurality of particular different sites of the anatomical organ of said particular patient and said previously performed impedance measurement values, exceed a predetermined threshold.

18. A system for determining anatomical tissue impedance characteristics for use in medical patient monitoring and treatment decision making, comprising:

at least one repository of data indicating a plurality of predetermined expected impedance value ranges for a corresponding plurality of impedance measurements taken at a plurality of particular different sites of at least one anatomical organ;

an impedance measurement processor for automatically determining whether a plurality of measured impedance values taken at a plurality of particular different sites of an anatomical organ using an invasive catheter are within a corresponding plurality of predetermined expected impedance value ranges derived from said at least one repository;

an electrical signal processor for acquiring electrical signals at said plurality of particular different sites of said anatomical organ using said invasive catheter and for processing the acquired electrical signals for use in diagnosis; and

an output processor for automatically communicating data comprising at least one message to a destination, said at least one message includes data indicating whether said plurality of measured impedance values taken at said plurality of particular different sites of said anatomical organ are within said 2 corresponding plurality of predetermined expected impedance value ranges.

19. A system according to claim 18, including

a mode switch for adaptively switching between impedance measurement in a first mode using said impedance measurement processor and electrical signal acquisition in a second mode using said electrical signal processor.