Implantable device including a stimulation lead for bioimpedance measurement

Patent metadata

Field	Value
Publication number	US-10420941-B2
Application number	US-201514856999-A
Country	US
Kind code	B2
Filing date	Sep 17, 2015
Priority date	Sep 19, 2014
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

An implantable device includes a lead, for example for neurostimulation of the vagus nerve. The lead includes a series of stimulation electrodes and a series of external electrodes for bioimpedance measurements on blood flow located in the same region, for example on the carotid artery. The device further includes means for separating into frequency bands the measured bioimpedance signal, the bands selected to reflect different respective activities such as vasomotor activity, hemodynamic activity, respiration, and cardiac rhythm activity.

First claim

What is claimed is:

1. An implantable medical device, comprising:
a stimulation lead, comprising:
a plurality of stimulation electrodes coupled to a control device; and
a plurality of electrodes adapted to perform bioimpedance measurements on blood flow in a blood vessel, the electrodes including:
a first pair of electrodes for measuring bioimpedance coupled to a current generator configured to circulate a current in a controlled manner into the blood vessel; and
a second pair of electrodes for measuring bioimpedance connected to the input of an amplification and processing circuit, and configured to pick up a signal from which the bioimpedance measurement can be extracted, the signal being generated in response to the current;
wherein the first pair of electrodes for bioimpedance measurement and the second pair of electrodes for bioimpedance measurement share a common electrode forming a reference electrode.

2. The device of claim 1 , wherein the first pair of electrodes are arranged flush with the surface of a body of the lead.

3. The device of claim 1 , wherein the first pair of electrodes are aligned parallel to an axial direction of the lead.

4. The device of claim 1 , wherein the amplification and processing circuit separates the bioimpedance measurement into frequency bands.

5. The device of claim 4 , wherein the amplification and processing circuit is adapted to determine the signal amplitude variations in the different frequency bands.

6. The device of claim 5 , wherein the frequency bands are chosen to reflect at least two activities among vasomotor activity, respiratory activity, hemodynamic activity and heart rate activity.

7. The device of claim 5 , wherein a frequency band is selected to determine changes in blood pressure over a cardiac cycle.

8. The device of claim 1 , wherein the lead is configured to apply neurostimulation to the vagus nerve, and wherein the first pair of electrodes for bioimpedance measurement are configured to follow a vessel extending generally in the same direction as the vagus nerve.

9. The device of claim 8 , wherein the vessel is the carotid artery, and wherein the first pair of electrodes for bioimpedance measurement are separated by a first distance of greater than about 10 mm but less than about 25 mm and the second pair of electrodes for bioimpedance measurement are separated by a second distance that is less than the first distance.

10. The device of claim 9 , wherein the second distance is in the range of 50% to 95% of the first distance.

11. The device of claim 9 , wherein the first pair of electrodes of bioimpedance measurement have a surface area between about 0.5 and 2 mm 2 .

12. The device of claim 9 , further comprising a control circuit configured to control the neurostimulation according to the bioimpedance measurements.

13. The device of claim 12 , further comprising an implantable housing connected to the lead by a link comprising conductors for neurostimulation and conductors for bioimpedance signal of the lead to the housing.

14. The device of claim 1 , wherein the electrodes of the second pair of electrodes are configured to receive the signal from which said bioimpedance measurements can be independently extracted from contact impedance at the injection point of the current.

Assignees

• Sorin Crm Sas

Inventors

• Bonnet Jean-Luc
• Legay Thierry
• Decoene Dominique
• Gousse Patrick Le
• Collignon Mathieu

Classifications

• A61B5/6877

  Nerve · CPC title

• A61B5/6876 Primary

  Blood vessel · CPC title

• A61N1/36114

  Cardiac control, e.g. by vagal stimulation (stimulating the heart A61N1/362) · CPC title

• A61N1/05

  for implantation or insertion into the body, e.g. heart electrode (A61N1/06 takes precedence) · CPC title

• A61B5/02007

  Evaluating blood vessel condition, e.g. elasticity, compliance · CPC title