Apparatus and method for sensing spatial displacement in a heart

• US 20030158494A1
• Filed: 02/19/2002
• Published: 08/21/2003
• Est. Priority Date: 02/19/2002
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kallok, Michael J., Dahl, Roger, Sundquist, Steve
• Granted Patent: US 6,976,967 B2
• Time in Patent Office: Days
• US Class Current: 600/526
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• 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: A61N 1/056 Transvascular endocardial electrode systems

Abstract

An electrical lead includes an elongate body having a proximal end, and a sensing unit capable of resolving a change in a spatial configuration of the electrical lead. A medical device includes a control unit, an elongate body having a proximal end coupled with the control unit, and a sensing unit capable of resolving a change in a spatial configuration of the electrical lead and relating it to the amount of blood ejected from the heart. A method includes receiving a signal transmitted from a lead disposed within a heart and determining a change in a dimension of the heart, due to the heart beating, based upon the signal.

Claims

1. An electrical lead, comprising:

an elongate body having a proximal end; and

a sensing unit capable of resolving a change in a spatial configuration of the electrical lead.

2. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a substrate;

a strain gauge mounted to the substrate and being capable of sensing a flexural stress induced in the electrical lead; and

a plurality of conductors extending from the strain gauge toward the proximal end of the electrical lead.

3. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a substrate;

a plurality of strain gauges mounted to the substrate in a pattern and being capable of sensing a flexural stress induced in the electrical lead; and

a plurality of conductors extending from the plurality of strain gauges toward the proximal end of the electrical lead.

4. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a substrate;

a piezoresistive element mounted to the substrate and being capable of sensing a bending stress induced in the electrical lead; and

a plurality of conductors extending from the piezoresistive element toward the proximal end of the electrical lead.

5. An electrical lead, according to claim 1, wherein the electrical lead is capable of being placed within a heart.

6. An electrical lead, according to claim 1, wherein the electrical lead is capable of being placed within a coronary vein.

7. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element toward the proximal end of the electrical lead.

8. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body and being capable of emitting ultrasonic energy;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body, wherein the second ultrasonic element is capable of receiving at least a portion of the ultrasonic energy emitted by the first ultrasonic element; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element toward the proximal end of the electrical lead.

9. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body, wherein the second ultrasonic element is capable of emitting ultrasonic energy; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element toward the proximal end of the electrical lead,

wherein the first ultrasonic element is capable of receiving at least a portion of the ultrasonic energy emitted by the second ultrasonic element.

10. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body such that the first ultrasonic element may be placed within a heart proximate an apex of the heart;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body such that the second ultrasonic element may be placed within the heart proximate a tricuspid valve of the heart; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element toward the proximal end of the electrical lead.

11. An electrical lead, according to claim 1, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body such that the first ultrasonic element may be placed within a coronary vein proximate an apex of the heart;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body such that the second ultrasonic element may be placed within the coronary vein proximate a mitral valve of the heart; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element toward the proximal end of the electrical lead.

12. A medical device, comprising:

a control unit;

an elongate body having a proximal end coupled with the control unit; and

a sensing unit capable of resolving a change in a spatial configuration of the electrical lead.

13. A medical device, according to claim 12, wherein the sensing unit further comprises:

a substrate;

a strain gauge mounted to the substrate and being capable of sensing a bending stress induced in the electrical lead; and

a plurality of conductors extending from the strain gauge and electrically coupled with the control unit.

14. A medical device, according to claim 12, wherein the sensing unit further comprises:

a substrate;

a plurality of strain gauges mounted to the substrate in a rosette pattern and being capable of sensing a bending stress induced in the electrical lead; and

a plurality of conductors extending from the plurality of strain gauges and electrically coupled with the control unit.

15. A medical device, according to claim 12, wherein the sensing unit further comprises:

a substrate;

a piezoresistive element mounted to the substrate and being capable of sensing a bending stress induced in the electrical lead; and

a plurality of conductors extending from the piezoresistive element and electrically coupled with the control unit.

16. A medical device, according to claim 12, wherein the electrical lead is capable of being placed within a heart.

17. A medical device, according to claim 12, wherein the electrical lead is capable of being placed within a coronary vein.

18. A medical device, according to claim 12, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element and electrically coupled with the control unit.

19. A medical device, according to claim 12, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body and being capable of emitting ultrasonic energy;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body, wherein the second ultrasonic element is capable of receiving at least a portion of the ultrasonic energy emitted by the first ultrasonic element; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element and electrically coupled with the control unit.

20. A medical device, according to claim 12, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body, wherein the second ultrasonic element is capable of emitting ultrasonic energy; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element and electrically coupled with the control unit,

wherein the first ultrasonic element is capable of receiving at least a portion of the ultrasonic energy emitted by the second ultrasonic element.

21. A medical device, according to claim 12, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body such that the first ultrasonic element may be placed within a heart proximate an apex of the heart;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body such that the second ultrasonic element may be placed within the heart proximate a tricuspid valve of the heart; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element and electrically coupled with the control unit.

22. A medical device, according to claim 12, wherein the sensing unit further comprises:

a first ultrasonic element disposed proximate and adjoined to a distal end portion of the elongate body such that the first ultrasonic element may be placed within a coronary vein proximate an apex of the heart;

a second ultrasonic element adjoined to the elongate body and disposed intermediate the first ultrasonic element and the proximal end portion of the elongate body such that the second ultrasonic element may be placed within the coronary vein proximate a mitral valve of the heart; and

a plurality of conductors extending from each of the first ultrasonic element and the second ultrasonic element and electrically coupled with the control unit.

23. A method, comprising:

receiving a signal transmitted from a lead disposed within a heart; and

determining a change in a dimension of the heart, due to the heart beating, based upon the signal.

24. A method, according to claim 23, further comprising determining a heart activity based upon the change in the dimension of the heart.

25. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises:

determining a change in flexure in the lead; and

calculating the change in the dimension of the heart based upon the change in flexure in the lead.

26. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises determining a change in a distance between an apex of the heart and a valve of the heart.

27. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises determining a change in a distance between an apex of the heart and a tricuspid valve of the heart.

28. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises determining a change in a distance between an apex of the heart and a mitral valve of the heart.

29. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises determining a change in a distance between a first portion of the heart proximate an apex of the heart and second portion of the heart proximate a valve of the heart.

30. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises determining a change in a distance between a first portion of the heart proximate an apex of the heart and second portion of the heart proximate a tricuspid valve of the heart.

31. A method, according to claim 23, wherein determining the change in the dimension of the heart further comprises determining a change in a distance between a first portion of the heart proximate an apex of the heart and a second portion of the heart proximate a mitral valve of the heart.

32. An apparatus, comprising:

means for receiving a signal transmitted from a lead disposed within a heart; and

means for determining a change in a dimension of the heart, due to the heart beating, based upon the signal.

33. An apparatus, according to claim 32, further comprising means for determining a heart activity based upon the change in the dimension of the heart.

34. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises:

means for determining a change in flexure in the lead; and

means for calculating the change in the dimension of the heart based upon the change in flexure in the lead.

35. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining a change in a distance between an apex of the heart and a valve of the heart.

36. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining a change in a distance between an apex of the heart and a tricuspid valve of the heart.

37. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining a change in a distance between an apex of the heart and a mitral valve of the heart.

38. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining a change in a distance between a first portion of the heart proximate an apex of the heart and second portion of the heart proximate a valve of the heart.

39. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining a change in a distance between a first portion of the heart proximate an apex of the heart and second portion of the heart proximate a tricuspid valve of the heart.

40. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining a change in a distance between a first portion of the heart proximate an apex of the heart and a second portion of the heart proximate a mitral valve of the heart.

41. An apparatus, according to claim 32, wherein the means for determining the change in the dimension of the heart further comprises means for determining the volume of blood ejected from the heart.