IMPLANTABLE SENSOR FOR MEASURING PHYSIOLOGIC INFORMATION

• US 20110137187A1
• Filed: 02/01/2011
• Published: 06/09/2011
• Est. Priority Date: 05/17/2007
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: HOU, Wenbo, YANG, Michael
• Granted Patent: US 8,257,272 B2
• Time in Patent Office: Days
• US Class Current: 600/508
• CPC Class Codes: A61B 2562/0261 Strain gauges
• CPC Class Codes: A61B 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/6869 Heart
• CPC Class Codes: A61B 5/688 using adhesives

Abstract

An implantable sensor is provided that includes a piezopolymer sensor element including a body having a plurality of layers of a piezopolymer, and an attachment device configured to hold the piezopolymer sensor element in direct contact with at least one of a bodily fluid and bodily tissue such that the piezopolymer sensor element is configured to bend in response to motion of the at least one of bodily fluid and bodily tissue. A pair of electrodes is attached to the piezopolymer sensor element and the electrodes are configured to collect an electrical charge that is generated within the piezopolymer sensor element due to the bending of the piezopolymer sensor element.

Claims

1. An implantable lead comprising:

a first piezopolymer sensor element;

a second piezopolymer sensor element; and

an attachment device configured to hold the first piezopolymer sensor element and the second piezopolymer sensor element in direct contact with at least one of a bodily fluid and bodily tissue such that the piezopolymer sensor elements bend in response to motion of the at least one of bodily fluid and bodily tissue;

wherein the first piezopolymer sensor element and the second piezopolymer sensor element are held in approximately perpendicular orientation with respect to one another.

2. The lead of claim 1 wherein the first and second sensor elements comprise polyvinylidene fluoride (PVDF).

3. The lead of claim 1 wherein the attachment device comprises a cable defining an at least partially loop-shaped portion having an open space bounded thereby;

and the first and second sensor elements are held within the open space.

4. The lead of claim 3 wherein the loop-shaped portion defines an at least partially diamond-shaped portion.

5. The lead of claim 4 wherein the diamond-shaped portion comprises one or more cable portions that lie in a common plane with the sensor element and one or more cable portions that bow outwardly from the common plane.

6. The lead of claim 3 further comprising a plurality of supports extending from the cable across the open space, wherein the supports attach to the first and second sensor elements to hold the sensor elements in place within the open space.

7. The lead of claim 1 wherein the attachment device comprises a generally cylindrical cable, and the first and second sensor elements are on an exterior surface of the cable such that the first and second sensor elements at least partially surrounds a portion of the cable.

8. The lead of claim 1 wherein the attachment device comprises a patch having a body portion configured to be attached to a surface of the heart.

9. The lead of claim 1 wherein the attachment device is configured for endocardial placement.

10. The lead of claim 1 wherein the attachment device is configured for pericardial placement.

11. The lead of claim 1 further comprising two pairs of electrodes, one pair attached to each of the first and second sensor elements, the electrodes configured to collect an electrical charge generated within the sensor elements due to the bending of the sensor elements.

12. The lead of claim 1 wherein the first and second sensor elements and the attachment device lie in a common plane.

13. A method for measuring the motion of a heart, said method comprising:

positioning an attachment device with a sensor element within a pericardial space of a heart such that the sensor element is in direct contact with a surface of at least one of a serous pericardium of the pericardium and a fibrous pericardium of the pericardium such that the sensor element bends in response to motion of the at least one of a serous pericardium of the pericardium and a fibrous pericardium of the pericardium;

measuring an output voltage of electrical charges generated on at least one surface of the sensor element due to the bending of the sensor element; and

determining a bending moment of the sensor element based on the measured output voltage.

14. The method of claim 13 wherein positioning the sensor element comprises positioning first and second sensor elements in contact with the at least one of a serous pericardium of the pericardium and a fibrous pericardium of the pericardium and in an approximately perpendicular orientation with respect to one another.

15. The method according to claim 13 wherein positioning the sensor element comprises introducing the sensor element into the pericardial space of a heart through the subxiphoid.

16. The method according to claim 13 wherein positioning the sensor element comprises incorporating the sensor element into a lead of at least one of a pulse generator, a pacemaker, an implantable cardioverter defibrillator, a defibrillator, and/or a therapy delivery module that at least one of paces and provides electrical stimulation to the heart.

17. The method according to claim 13 wherein positioning a sensor element comprises positioning a piezopolymer sensor element.

18. The method according to claim 13 further comprising determining information relating to the motion of the at least one of a serous pericardium of the pericardium and a fibrous pericardium of the pericardium based on a determined bending moment.