IMPLANTABLE LEAD WITH AN ELECTROSTIMULATION CAPACITOR

• US 20090088811A1
• Filed: 09/18/2008
• Published: 04/02/2009
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Wulfman, David R.
• Granted Patent: US 8,406,898 B2
• Time in Patent Office: Days
• US Class Current: 607/9
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/0563 specially adapted for defibrillation or cardioversion
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers

Abstract

One example includes an implantable lead with an elongate lead body including a proximal portion and a distal portion. The lead includes a coupler configured to be coupled to an implantable medical device, a conductor, extending through the coupler, a first electrode, and a first electrostimulation capacitor located at the distal portion of the lead body, the first electrostimulation capacitor including a capacitance value that is large enough to store an electrostimulation charge of an electrostimulation energy that is large enough to perform electrostimulation of tissue. The lead includes a first switch located at the distal portion of the lead body and coupled to the conductor, the first switch configured to selectively couple the first electrostimulation capacitor to the first electrode during a stimulating state and to selectively couple the first electrostimulation capacitor to the conductor during a charging state.

Claims

1. An apparatus comprising:

an implantable lead, comprising an elongate lead body comprising a proximal portion and a distal portion, the lead comprising;

a coupler, located at the proximal portion of the lead body, the coupler configured to be coupled to an implantable medical device;

a conductor, extending from the coupler at the proximal portion of the lead body to a distal portion of the lead body;

a first electrode located at the distal portion of the lead body;

a first electrostimulation capacitor located at the distal portion of the lead body, the first electrostimulation capacitor including a capacitance value that is large enough to store an electrostimulation charge of an electrostimulation energy, wherein the electrostimulation energy is large enough to perform electrostimulation of tissue; and

at least one first switch, located at the distal portion of the lead body and coupled to the conductor, the at least one first switch configured to selectively couple the first electrostimulation capacitor to the first electrode during a stimulating state, the at least one first switch configured to selectively couple the first electrostimulation capacitor to the conductor during a charging state.

2. The apparatus of claim 1, the first electrostimulation capacitor including a capacitance value that is large enough to store an electrostimulation charge of an electrostimulation energy that is large enough to evoke contraction of myocardial tissue.

3. The apparatus of claim 1, comprising:

a second electrostimulation capacitor located at the distal portion of the lead body, the second electrostimulation capacitor including a capacitance value that is large enough to store an electrostimulation charge sized to evoke electrostimulation of tissue; and

at least one second switch located at the distal portion of the lead body and coupled to the conductor, the at least one second switch configured to selectively couple the second electrostimulation capacitor to a second electrode during a stimulating state and to selectively couple the second electrostimulation capacitor to the conductor during a charging state.

4. The apparatus of claim 1, wherein a gauge size of the conductor is smaller than a gauge size needed to deliver the electrostimulation energy at a particular voltage from the coupler to the tissue without using the first electrostimulation capacitor to store the electrostimulation energy at the distal portion of the lead body at the particular voltage.

5. The apparatus of claim 1, wherein the lead body comprises only one conductor extending from the proximal portion of the lead body to the distal portion of the lead body.

6. The apparatus of claim 1, comprising a power converter located at the distal portion of the lead body and coupled to the first electrostimulation capacitor.

7. The apparatus of claim 1, comprising a switching circuit configured to electrically disconnect the distal portion of the lead body from the implantable medical device during delivery of an electrostimulation.

8. The apparatus of claim 1, wherein the lead comprises a controller circuit, located at the distal portion of the lead body, the controller circuit coupled to the conductor and configured to control charging of the electrostimulation capacitor from the implantable medical device via the conductor.

9. The apparatus of claim 8, comprising:

a powering capacitor, located at the distal portion of the lead body, the powering capacitor coupled to the controller circuit; and

at least one second switch located at the distal portion of the lead body and coupled to the conductor, the at least one second switch configured to selectively couple the powering capacitor to the conductor in a charging state and to selectively couple the powering capacitor to the controller circuit during a controller powering state to power the controller circuit.

10. The apparatus of claim 1, wherein the lead comprises:

a controller circuit, located at the distal portion of the lead body, the controller circuit coupled to the at least one first switch to control coupling of the electrostimulation capacitor to an electrostimulation location via the first electrode in response to a communication signal received from the implantable medical device via the conductor.

11. A method, comprising,

delivering electrical energy from a power source in an implantable medical device to an elongate lead body including a proximal portion and a distal portion such that a conductor located in the lead body and extending from the proximal portion to the distal portion conducts energy from the power source and through the lead body;

storing electrical energy, at a location that is at the distal portion of the lead body, in an amount that is enough to evoke electrostimulation of tissue; and

selectively switching, at the distal portion of the lead body, to deliver the stored energy to tissue.

12. The method of claim 11, comprising:

communicating encoded information from the implantable medical device to a control circuit that is located at the distal portion of the lead; and

using the information at the control circuit to control the selectively switching, at the distal portion of the lead body, to deliver the stored energy to tissue.

13. The method of claim 12, comprising:

storing electrical energy, at a location that is at the distal portion of the lead body, in an amount that is enough to power the control circuit during a time when the control circuit is unconnected to the implantable medical device.

14. The method of claim 11, wherein storing electrical energy, at a location that is at the distal portion of the lead body, in an amount that is enough to evoke electrostimulation of tissue, comprises storing electrical energy using a capacitor at the location that is at the distal portion of the lead body.

15. The method of claim 14, further comprising storing electrical energy, at a location that is at the distal portion of the lead body, in an amount that is enough to power electronic circuitry located at the distil portion of the lead body during a time period when the electronic circuitry located at the distal portion of the lead body is electrically isolated from the implantable medical device.

16. The method of claim 14, further comprising storing electrical energy, at a location that is at the distal portion of the lead body, in an amount that is enough to power a controller circuit located at the distal portion of the lead body during a time period when the controller circuit located at the distal portion of the lead body is electrically isolated from the implantable medical device.

17. The method of claim 14, comprising electrically disconnecting the distal portion of the lead body from the implantable medical device during delivery of an electrostimulation.

18. The method of claim 14, comprising performing the method using a lead that comprises only one conductor extending from the proximal portion of the lead body to the distal portion of the lead body.

19. An apparatus comprising:

an intravascular implantable cardiac function management lead, comprising an elongate lead body comprising a proximal portion and a distal portion, the lead comprising;

a coupler, located at the proximal portion of the lead body, the coupler configured to be coupled to an implantable cardiac function management device;

a first electrode located at the distal portion of the lead body;

a conductor, extending from the coupler at the proximal portion of the lead body to a distal portion of the lead body, wherein a gauge size of the conductor is smaller than a gauge size needed to deliver the electrostimulation energy at a particular voltage from the coupler to the tissue without using the first electrostimulation capacitor to store the electrostimulation energy at the distal portion of the lead body at the particular voltage;

a power converter located at the distal portion of the lead body and coupled to the first electrostimulation capacitor.

a first electrostimulation capacitor located at the distal portion of the lead body, the first electrostimulation capacitor including a capacitance value that is large enough to store an electrostimulation charge of an electrostimulation energy, wherein the electrostimulation energy is large enough to perform electrostimulation of tissue to evoke a resulting heart chamber contraction;

a controller circuit, located at the distal portion of the lead body, the controller circuit coupled to the conductor and configured to control charging of the electrostimulation capacitor from the implantable medical device via the conductor;

a powering capacitor, located at the distal portion of the lead body, the powering capacitor coupled to the controller circuit; and

at least one second switch located at the distal portion of the lead body and coupled to the conductor, the at least one second switch configured to selectively couple the powering capacitor to the conductor in a charging state and to selectively couple the powering capacitor to the controller circuit during a controller powering state to power the controller circuit; and

at least one first switch, located at the distal portion of the lead body and coupled to the conductor, the at least one first switch configured to selectively couple the first electrostimulation capacitor to the first electrode during a stimulating state, the at least one first switch configured to selectively couple the first electrostimulation capacitor to the conductor during a charging state.

20. The apparatus of claim 19, wherein the lead body comprises only one conductor extending from the proximal portion of the lead body to the distal portion of the lead body.