System for cardiac condition detection and characterization

• US 8,961,420 B2
• Filed: 11/17/2010
• Issued: 02/24/2015
• Est. Priority Date: 04/01/2010
• Status: Active Grant

• Current Assignee: Siemens Healthcare GMBH (Siemens AG)
• Original Assignee: Siemens Medical Solutions USA Incorporated (Siemens AG)
• Inventors: Zhang, Hongxuan
• Primary Examiner(s): Lamprecht, Joel
• Application Number:
  US12/947,882
• Publication Number:
  US 20110245669A1
• Time in Patent Office: 1,560 Days
• Field of Search: 600/407, 600/424, 600/427, 600/431, 600/437, 600/441, 600/443, 600/450
• US Class Current: 600/450
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/485 involving measuring strain or elastic properties

Abstract

A system monitors and characterizes internal elasticity of a blood vessel to detect abnormality. A catheter system for heart performance characterization and abnormality detection, comprises an ultrasound device for emitting ultrasound wave signals within patient anatomy and acquiring corresponding ultrasound echo signals. A signal processor processes the ultrasound echo signals to, determine a signal indicating displacement of a tissue wall over at least one heart cycle and identify a displacement value in the displacement signal. The displacement value indicates a tissue wall displacement occurring at a point within a heart cycle. A comparator compares the tissue wall displacement value with a threshold value to provide a comparison indicator. A patient monitor, in response to the comparison indicator indicating the tissue wall displacement value exceeds the threshold value, generates an alert message associated with the threshold.

Claims

1. A catheter system for heart performance characterization and abnormality detection, comprising:

an ultrasound device configured to emit ultrasound wave signals within a vessel of patient anatomy and acquire corresponding ultrasound echo signals, said ultrasound device comprising a plurality of sensors, each sensor configured to emit the ultrasound wave signals within the vessel and acquire the corresponding ultrasound echo signals covering at least 120 degrees of an internal circumference of a tissue wall of the vessel;

a signal processor configured to process the ultrasound echo signals to;

determine a displacement signal indicating displacement of a tissue wall over at least one heart cycle; and

identify a displacement value in the displacement signal, said displacement value indicating a tissue wall displacement of the tissue wall of the vessel occurring at a point within a heart cycle;

a comparator configured to compare the tissue wall displacement value with a threshold value to provide a comparison indicator; and

a patient monitor configured to generate an alert message associated with the threshold in response to said comparison indicator indicating the tissue wall displacement value exceeds the threshold value.

2. A system according to claim 1, wherein

said patient monitor, in response to said comparison indicator indicating the tissue wall displacement value lies in a predetermined value range, generates an alert message associated with the value range.

3. A system according to claim 2, wherein

said patient monitor substantially continuously monitors said comparison indicator for at least a 24 hour period.

4. A system according to claim 1, wherein

said threshold value is derived from recorded displacement signal data of said tissue wall for said patient.

5. A system according to claim 1, wherein

said threshold value is derived from recorded displacement signal data of a tissue wall for a population of patients.

6. A system according to claim 5, wherein

said population of patients has similar demographic characteristics including at least two of, (a) age, (b) weight, (c) gender and (d) height, to those of said patient.

7. A system according to claim 1, wherein

said signal processor dynamically adjusts said threshold value in response to a determined sensitivity of arrhythmia detection.

8. A system according to claim 1, wherein

said signal processor determines said tissue wall displacement value at a predetermined point of a heart beat cycle in response to a synchronization signal.

9. A system according to claim 8, wherein

said signal indicating displacement of a tissue wall comprises a digitized electrical signal.

10. A system according to claim 1, wherein

said signal processor determines a displacement value in the displacement signal comprising a peak to peak displacement value.

11. A system according to claim 1, wherein

said signal processor calculates the displacement value by averaging a plurality of corresponding respective displacement values determined at substantially the same point in a heart cycle and over a plurality of heart cycles.

12. A system according to claim 1, wherein

said signal processor determines a displacement value in the displacement signal comprising at least one of, (a) a second highest peak to peak displacement value and (b) a third highest peak to peak displacement value indicating a tissue wall displacement occurring at a point within a heart cycle.

13. A system according to claim 1, including

a repository of predetermined mapping information, associating ranges of the displacement value or values derived from the displacement value, with corresponding medical conditions and

said comparator compares the displacement value or values derived from the displacement value, with said ranges to provide a comparison indicator identifying a medical condition and

said patient monitor generates an alert message identifying said medical condition.

14. A system according to claim 13, wherein

said predetermined mapping information associates ranges of the displacement value or values derived from the displacement value, with particular patient demographic characteristics and with corresponding medical conditions and said system uses patient demographic data including at least one of, age, weight, gender and height in comparing the displacement value or values derived from the displacement value with said ranges.

15. A system according to claim 1, wherein

said ultrasound device emits ultrasound wave signals within patient anatomy and acquires corresponding ultrasound echo signals at a sampling rate of 50-2000 Hz.

16. A system according to claim 1, wherein

said signal processor determines the displacement value in the displacement signal and derives at least one value from the displacement value, the at least one derived value including at least one of, (a) an averaged displacement value determined by averaging a plurality of corresponding respective displacement values determined at substantially the same point in heart cycle and over a plurality of heart cycles and (b) a standard deviation of the displacement value for a particular heart cycle.

17. A system according to claim 1, wherein

said signal processor derives at least one value from the displacement value including at least one of,

18. A system according to claim 1, wherein

said plurality of sensors are arranged substantially symmetrically within a catheter for emitting the ultrasound wave signals substantially perpendicular to a catheter longitudinal axis and acquiring the corresponding ultrasound echo signals to determine vessel wall dynamic movement over a heart cycle or respiratory cycle.

19. A system according to claim 1, wherein the plurality of sensors are configured to acquire the corresponding ultrasound echo signals covering 360 degrees of an internal circumference of a tissue wall of the vessel.

20. A system according to claim 1, wherein the signal processor is further configured to acquire the corresponding ultrasound echo signals on a plurality of channels from multiple vessel sites and de-convolute the acquired corresponding ultrasound echo signals to provide ultrasound waveform data of selected points of a vessel wall.

21. A system according to claim 20, wherein the signal processor is further configured to analyze the corresponding ultrasound echo signals in a time domain and a frequency domain for each of the plurality of channels.