ICD using MEMS for optimal therapy

• US 7,181,281 B1
• Filed: 10/08/2003
• Issued: 02/20/2007
• Est. Priority Date: 10/08/2003
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories)
• Inventors: Kroll, Mark W.
• Primary Examiner(s): Pezzuto; Robert
• Assistant Examiner(s): Johnson; Shevon
• Application Number:
  US10/682,774
• Time in Patent Office: 1,231 Days
• Field of Search: 607/4, 607 17- 19, 607/20, 607/24, 607/14
• US Class Current: 607/14
• 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 5/1116 Determining posture transitions
• CPC Class Codes: A61N 1/3622 comprising two or more electrodes co-operating with different heart regions
• CPC Class Codes: A61N 1/36542 controlled by body motion, e.g. acceleration
• CPC Class Codes: A61N 1/3688 configured for switching the pacing mode, e.g. from AAI to DDD

Abstract

An exemplary method includes detecting movement of an in vivo oscillator using one or more in vivo sensors, receiving information from at least one of the one or more sensors, and deciding whether to switch an implanted cardiac therapy device from a lower tier of anti-arrhythmia therapy to a higher tier of anti-arrhythmia therapy based at least in part on the information. An exemplary implantable device includes a micro-electromechanical system (MEMS) capable of measuring acceleration and logic capable of determining postural sway based at least in part on acceleration measured by the MEMS. Various other exemplary methods, devices and systems are also disclosed.

Claims

1. A method comprising:

detecting movement of an in vivo oscillator using one or more in vivo sensors, the one or more in vivo sensors being a micro-electromechanical system (MEMS) capable of measuring acceleration, the MEMS having a first dual-axis accelerometer and a second dual-axis accelerometer, the two axes of the first dual-axis accelerometer defining a first plane and the two axes of the second dual-axis accelerometer defining a second plane, and the first plane differing from the second plane;

receiving information from at least one of the one or more sensors; and

deciding whether to switch an implanted cardiac therapy device from a lower tier of anti-arrhythmia therapy to a higher tier of anti-arrhythmia therapy based at least in part on the information;

wherein the deciding includes determining whether the received information indicates that a patient has exceeded a predetermined acceleration; and

wherein the predetermined acceleration has a substantial component aligned with the acceleration of earth'"'"'s gravity.

2. The method of claim 1, wherein the detecting includes two in vivo sensors wherein each sensor has a predominant axis and the predominant axes of the sensors are oriented orthogonally.

3. The method of claim 1, wherein the deciding includes determining whether the received information indicates that a patient has exceeded a maximum recoverable angle of lean.

4. The method of claim 1, wherein the lower tier of anti-arrhythmia therapy is anti-tachycardia pacing therapy.

5. The method of claim 1, wherein the higher tier of anti-arrhythmia therapy is shock therapy.

6. The method of claim 1, wherein the higher tier corresponds to defibrillation shock therapy.

7. The method of claim 6, wherein the lower tier corresponds to anti-tachycardia pacing therapy.

8. A method comprising:

detecting movement of an in vivo oscillator using one or more in vivo sensors, the one or more in vivo sensors being a micro-electromechanical system (MEMS) capable of measuring acceleration, the MEMS having a first dual-axis accelerometer and a second dual-axis accelerometer, and the MEMS having a mass equal to or less than approximately 500 mm³;

receiving information from at least one of the one or more sensors; and

deciding whether to switch an implanted cardiac therapy device from a lower tier of anti-arrhythmia therapy to a higher tier of anti-arrhythmia therapy based at least in part on the information;

wherein the deciding includes determining whether the received information indicates that a patient has exceeded a predetermined acceleration; and

wherein the predetermined acceleration has a substantial component perpendicular to the acceleration of earth'"'"'s gravity.

9. An implantable cardiac therapy device comprising:

a micro-electromechanical system (MEMS) capable of measuring acceleration, the MEMS having a first dual-axis accelerometer and a second dual-axis accelerometer, the two axes of the first dual-axis accelerometer defining a first plane and the two axes of the second dual-axis accelerometer defining a second plane, and the first plane differing from the second plane;

a shocking circuit; and

control logic operative to control the shocking circuit to deliver a shock based at least in part on acceleration measured by the MEMS;

wherein the control logic causes the shocking circuit to delivery a shock based if a component of the acceleration exceeds a predetermined value.

10. The device of claim 9, wherein the acceleration includes at least one type of acceleration selected from the group consisting of static acceleration and dynamic acceleration.

11. The device of claim 9, wherein the shocking circuit has an electrical connection to a defibrillation electrode.

12. The device of claim 9, further comprising means for delivering anti-tachycardia pacing therapy.

13. The device of claim 12, further comprising control logic capable of causing the means for delivering anti-tachycardia pacing therapy to halt delivery of anti-tachycardia pacing therapy.

14. An implantable cardiac therapy device comprising:

a micro-electromechanical system (MEMS) capable of measuring acceleration, the MEMS having a first dual-axis accelerometer and a second dual-axis accelerometer, the two axes of the first dual-axis accelerometer defining a first plane and the two axes of the second dual-axis accelerometer defining a second plane, and the first plane differing from the second plane;

a shocking circuit; and

control logic operative to control the shocking circuit to deliver a shock based at least in part on acceleration measured by the MEMS;

wherein the control logic determines a tilt angle based on one or more components of the acceleration.

15. An implantable cardiac therapy device comprising:

a micro-electromechanical system (MEMS) capable of measuring acceleration, the MEMS having a first dual-axis accelerometer and a second dual-axis accelerometer, the two axes of the first dual-axis accelerometer defining a first plane and the two axes of the second dual-axis accelerometer defining a second plane, and the first plane differing from the second plane;

a shocking circuit; and

control logic operative to control the shocking circuit to deliver a shock based at least in part on acceleration measured by the MEMS;

wherein the control logic compares a tilt angle to a predetermined angle.

16. An implantable device comprising:

a micro-electromechanical system (MEMS) capable of measuring acceleration; and

logic capable of determining postural sway based at least in part on acceleration measured by the MEMS;

wherein the MEMS includes a first dual-axis accelerometer and a second dual-axis accelerometer; and

wherein the two axes of the first dual-axis accelerometer define a first plane and the two axes of the second dual-axis accelerometer define a second plane and wherein the first plane differs from the second plane.

17. The device of claim 16, wherein the logic determines tilt as a function of time based at least in part on acceleration measured by the MEMS.

18. The device of claim 16, wherein the logic determines whether tilt increases, decreases or remains substantially constant over a time interval.

19. The device of claim 18, wherein the logic determines a risk of falling based at least in part on the determination of whether tilt increases, decreases or remains substantially constant over the time interval.

20. The device of claim 18, wherein the logic assigns a high risk of falling if tilt increases over the time interval.

21. The device of claim 18, wherein the logic assigns a low risk of falling if tilt decreases over the time interval.

22. The device of claim 16, wherein the first dual-axis accelerometer is on a single monolithic integrated circuit.

23. The device of claim 16, wherein the MEMS comprises one or more polysilicon springs that provide a resistance against acceleration forces.

24. An implantable device comprising:

a micro-electromechanical system (MEMS) capable of measuring acceleration; and

logic capable of determining postural sway based at least in part on acceleration measured by the MEMS;

wherein the MEMS includes a first dual-axis accelerometer and a second dual-axis accelerometer; and

wherein the MEMS occupies a volume equal to or less than approximately 500 mm³.

25. An implantable device comprising:

a micro-electromechanical system (MEMS) capable of measuring acceleration; and

logic capable of determining postural sway based at least in part on acceleration measured by the MEMS;

wherein the MEMS includes a first dual-axis accelerometer and a second dual-axis accelerometer; and

wherein the MEMS has a mass equal to or less than approximately 5 grams.