Detection of apex motion for monitoring cardiac dysfunction

• US 7,445,605 B2
• Filed: 03/30/2006
• Issued: 11/04/2008
• Est. Priority Date: 01/31/2003
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Francis, Daniel, Mead, R. Hardwin, Overall, William Ryan, Angel, Aimee Brigitte
• Primary Examiner(s): Hindenburg; Max
• Assistant Examiner(s): NGUYEN, HUONG Q
• Application Number:
  US11/394,449
• Publication Number:
  US 20070032749A1
• Time in Patent Office: 950 Days
• Field of Search: 600/595, 600/587, 600/508, 600/481, 600/483, 600/527, 607/9, 607 17- 19
• US Class Current: 600/595
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/02444 Details of sensor A61B5/02427 takes precedence

Abstract

Systems, devices and methods for detecting and monitoring cardiac dysfunction. The devices include motion sensors for detecting signals representative of the total movement of the heart, and of the apex of the heart in particular.

Claims

1. A method for detecting an ischemic condition in a patient, the method comprising:

sensing the motion of the ventricular apex of the heart in two or more directional axes with at least one motion sensor implanted at the heart;

processing signals generated by the at least one motion sensor, the processing comprising relating the signals from two or more directional axes of movement to at least one predetermined baseline value of the movement of the apex of the heart; and

wherein the location of an ischemic condition of the heart is determined by the deflection of said path that the ventricular apex traverses over time, wherein the deflection is in a direction away from affected myocardium of the heart.

2. The method according to claim 1, wherein the sensing is performed with a single multiple dimensional motion sensor that provides two or three-dimensional measurements.

3. The method according to claim 1, further comprising producing an output, wherein the output is a cardiac pacing signal.

4. The method according to claim 1, further comprising producing an output, wherein the output is the delivery of a therapeutic agent to the heart.

5. The method according to claim 1, further comprising producing an output, wherein the output is an alarm signal produced when a processed signal is determined to be outside a predetermined threshold range.

6. The method according to claim 1, further comprising performing an electrocardiogram of the heart with another sensor.

7. The method according to claim 1, wherein the at least one sensor is implanted endocardially.

8. The method according to claim 1, wherein the at least one sensor is implanted epicardially.

9. The method of claim 1, wherein said at least one motion sensor is a rotational motion sensor.

10. The method of claim 1, wherein the at least one motion sensor is adapted to be sensitive to acceleration in axes perpendicular to the sensor'"'"'s lead.

11. A method for detecting an ischemic condition in a patient, the method comprising:

sensing the motion of the ventricular apex of the heart in two or more directional axes with at least one motion sensor implanted at the heart;

processing signals generated by the at least one motion sensor at apical motion frequencies to 4 Hz, the processing comprising relating the signals from two or more directional axes of movement to at least one predetermined baseline value of the movement of the apex of the heart,

wherein the location of an ischemic event is determined by the deflection of said path that the ventricular apex traverses over time, wherein the deflection is in a direction away from affected myocardium of the heart.

12. The method of claim 11, wherein the at least one motion sensor is a multiple-dimensional sensor that provides two or three-dimensional measurements.

13. The method of claim 11, wherein said at least one motion sensor comprises a multiple-dimensional sensor that provides two or three-dimensional measurement, and a rotational motion sensor.

14. The method of claim 13, wherein six degrees of motion information are combined for processing.