Cuff electrode with integrated tendril

A neurostimulation lead includes a lead body having a proximal portion and a distal portion and a first conductor extending through the lead body. An electrode cuff can be secured relative to the distal portion of the lead body. The electrode cuff includes a cuff body, a first tendril extending from a first region of the cuff body, a second tendril extending from a second region of the cuff body and a first electrode disposed on the cuff body and electrically connected to the first conductor.

TECHNICAL FIELD

The present invention relates generally to implantable medical devices. More specifically, the present invention relates to medical device leads including helical neurostimulation electrodes

BACKGROUND

A significant amount of research has been directed both to the direct and indirect stimulation and sensing of the left and right vagus nerves, the phrenic nerve, the sacral nerve, the cavernous nerve, and portions of the anatomy with baroreceptors (e.g., the carotid artery) to treat a wide variety of medical, psychiatric, and neurological disorders or conditions. For example, stimulation of the vagus nerve has been proposed as a method for treating various heart conditions, including heart failure. The nerves stimulated and/or sensed may be sympathetic or parasympathetic in character.

In a nerve stimulation and sensing system, one or more electrodes are formed on a lead that are electrically connected to an implanted electronic package, such as a pulse generator. Electrical energy is delivered to the electrodes by conductors that extend from the pulse generator at a proximal end of the lead to the electrodes at a distal end of the lead. For direct stimulation of a nerve, the electrodes may be configured to be secured directly to, wrapped around, or laid next to the nerve.

SUMMARY

Example 1 is a neurostimulation lead including a lead body and a first conductor extending through the lead body. An electrode cuff is secured relative to a distal portion of the lead body. The electrode cuff includes a cuff body, a first tendril extending from a first region of the cuff body, a second tendril extending from a second region of the cuff body and a first electrode disposed on the cuff body and electrically connected to the first conductor.

Example 2 includes Example 1 and specifies that the first tendril extends from the first region of the cuff body at an acute angle and is biased to a curved configuration in which the first tendril curves in a first direction.

Example 3 includes either of Examples 1 and 2 and specifies that the second tendril extends from the second region of the cuff body at an acute angle and is biased to a curved configuration in which the second tendril curves in a second direction opposite the first direction.

Example 4 includes Example 1 and specifies that the first tendril extends substantially perpendicularly from the first region of the cuff body.

Example 5 includes Examples 1 and 4 and specifies that the second tendril extends substantially perpendicularly from the second region of the cuff body.

Example 6 includes Example 5 and specifies that the first tendril and the second tendril both extend in a same direction from the cuff body.

Example 7 includes Example 5 and specifies that the first tendril and the second tendril extend in opposite directions from the cuff body.

Example 8 includes any of Examples 1 through Example 7 and specifies inclusion of a second conductor extending through the lead body and a second electrode disposed on the cuff body and electrically connected to the second conductor.

Example 9 includes any of Examples 1 through Example 8 and specifies inclusion of a first suture molded into and extending through the first tendril and a second suture molded into and extending through the second tendril.

Example 10 includes any of Examples 1 through Example 9 and specifies that the cuff body is configured to extend less than about 360 degrees about the nerve.

Example 11 includes any of Examples 1 through Example 10 and specifies that the first and second tendrils are each configured to extend more than about 360 degrees about the nerve.

Example 12 includes any of Examples 1 through 9 and specifies that the cuff body is configured to be wrapped around the nerve, thereby extending more than about 360 degrees about the nerve.

Example 13 includes any of Examples 1 through 12 and specifies that the first tendril and the second tendril are portions of a unitary tendril, the unitary tendril biased to a wrapping direction that reverses direction near a midpoint of the unitary tendril.

Example 14 is a neurostimulation lead including a lead body, a first conductor extending through the lead body and a second conductor extending through the lead body. A first cuff is secured relative to a distal portion of the lead body. A second cuff is secured relative to a distal portion of the lead body. A first electrode is disposed on the first cuff body and is electrically connected to the first conductor. A second electrode is disposed on the second cuff body and is electrically connected to the second conductor. The first cuff includes a first cuff body, a first tendril extending from the first cuff body and biased to a curved configuration in which the first tendril curves in a first direction. A second tendril extends from the first cuff body and is biased to a curved configuration in which the second tendril curves in a second direction opposite the first direction. The second cuff includes a second cuff body, a third tendril extending from the second cuff body and biased to a curved configuration in which the third tendril curves in a third direction. A fourth tendril extends from the second cuff body and is biased to a curved configuration in which the second tendril curves in a fourth direction opposite the third direction.

Example 15 includes Example 14 and specifies that the first cuff is secured relative to the distal portion of the lead body via a first lead extension. The first lead extension is secured to the lead body and the first cuff is attached to the first lead extension.

Example 16 includes Examples 14 and 15 and specifies that the second cuff is secured relative to the distal portion of the lead body via a second lead extension. The second lead is extension secured to the lead body and the second cuff is attached to the second lead extension.

Example 17 includes any of Examples 14 to 16 and specifies inclusion of a strain relief secured to the distal portion of the lead body.

Example 18 includes Example 14 and specifies that the first direction is the same as the third direction, and the second direction is the same as the fourth direction.

Example 19 is a method of securing a neurostimulation cuff to a surgically exposed nerve. The neurostimulation cuff is disposed proximate the nerve, the neurostimulation cuff including a cuff body and first and second tendrils extending from the cuff body. The neurostimulation cuff is positioned in position on the nerve. The first tendril is secured in position by wrapping the first tendril around the nerve in a rotational direction. The second tendril is secured in position by wrapping the second tendril around the nerve in the same rotational direction.

Example 20 includes Example 19 and specifies that the first tendril is biased to extend from the cuff body in a first rotational direction and the second tendril is biased to extend from the cuff in a second rotational direction opposite the first rotational direction in order to permit securement of the first and second tendrils by wrapping the first and second tendrils in the same rotational direction.

DETAILED DESCRIPTION

FIG. 1shows an embodiment of a neurostimulation system10according to the present invention implanted in a patient P. The neurostimulation system10includes an implantable medical device (IMD)12with a lead14having a proximal end16and a distal end18. In one embodiment, the IMD12includes a pulse generator. The IMD12can be implanted subcutaneously within the body, typically at a location such as in a patient's chest or abdomen, although other implantation locations are possible. The proximal end16of the lead14can be coupled to the IMD12via one or more connectors19. Alternatively, the lead14may be formed integrally with the IMD12. The distal end18of the lead14, in turn, can be implanted at a desired location in the patient's body to stimulate excitable tissue.

The distal end18of the lead14includes one or more electrode cuffs20. While a single electrode cuff20is shown inFIG. 1, it will be appreciated that in some embodiments the lead14may include one, two, three or more electrode cuffs20. Further details regarding the construction and implantation of the electrode cuffs20will be described with respect to subsequent FIGS. In some embodiments, a single electrode cuff20may include two electrodes (not shown inFIG. 1). In some embodiments, the lead14may include several electrode cuffs20, each with a single electrode. One electrode may, for example, function as a cathode electrode while another electrode may function as an anode electrode. The electrode(s) is(are) electrically connected to the IMD12via one or more conductors11,13,15(shown inFIG. 1A) extending through the lead14.

During operation, the lead14delivers electrical signals between the IMD12and the electrode cuffs20. The electrode cuffs20may be separately controlled by IMD12, such that energy having different magnitude, phase, and/or timing characteristics may be delivered to or from each of the electrode cuffs20. In some embodiments, one or more of the electrode cuffs20can alternatively be configured as a strain relief cuff that does not carry electrical signals, but secures the distal end18relative to the nerve N to minimize movement of the electrode cuffs20relative to the excitable tissue due to voluntary or involuntary movements of the patient. Furthermore, the IMD12shown is merely by way of illustration, and the IMD12may have any configuration suitable for use in conjunction with the lead14and may be implanted in any suitable location in the patient's body.

The electrode cuffs20include electrodes that are configured for stimulation or sensing of a nerve or nerve bundle. In the embodiment shown, the distal end18is secured to the vagus nerve N. The electrode cuffs20may be arranged around the nerve, with the IMD12configured to deliver energy to the electrode cuffs20to stimulate the nerve. Stimulating the sympathetic and parasympathetic nervous systems can have effects on physiological parameters associated with the heart H, such as heart rate and blood pressure. In addition, stimulating the sympathetic nervous system dilates the pupil, reduces saliva and mucus production, relaxes the bronchial muscle, reduces the successive waves of involuntary contraction (peristalsis) of the stomach and the motility of the stomach, increases the conversion of glycogen to glucose by the liver, decreases urine secretion by the kidneys, and relaxes the wall and closes the sphincter of the bladder. Stimulating the parasympathetic nervous system (inhibiting the sympathetic nervous system) constricts the pupil, increases saliva and mucus production, contracts the bronchial muscle, increases secretions and motility in the stomach and large intestine, and increases digestion in the small intestine, increases urine secretion, and contracts the wall and relaxes the sphincter of the bladder. The functions associated with the sympathetic and parasympathetic nervous systems are many and can be complexly integrated with each other.

The vagus nerve N has afferent properties, such that the neural stimulation is transmitted to the central nervous system (CNS). Vagal stimulation simultaneously increases parasympathetic and decreases sympathetic activity, and is believed to prevent further remodeling or predisposition to fatal arrhythmias in post-myocardial infarction (MI) patients, to help restore autonomic balance and increase heart rate variability (HRV), to increase parasympathetic and reduce sympathetic tone in hypertrophic cardiac myopathy (HCM), neurogenic hypertension, and arrhythmia protection, to reduce anginal symptoms, to increase coronary blood flow (CBF), and to prevent development or worsening of congestive heart failure (CHF) following MI. The electrode cuffs20may be configured and arranged to stimulate the vagus nerve N to provide any of the physiological responses described. While the electrode cuffs20are shown arranged around the right vagus nerve N inFIG. 1, the electrode cuffs20can be configured and arranged to stimulate the left vagus nerve to treat other physiological and psychological conditions, such as epilepsy and depression.

FIG. 2provides a side view of a portion of the lead14that includes a lead body30and three (as illustrated) electrode cuffs20. In some embodiments, the lead14also includes one or more of a first lead extension32and a second lead extension34. The first and second lead extensions32,34can, if included, each include electrical conductors that provide electrical connections between the IMD12and one or more of the electrode cuffs20. In some embodiments, the electrode cuffs20include a strain relief36, a first electrode cuff38and a second electrode cuff40. In some embodiments, the strain relief36is secured to the lead body30in order to help mitigate movement of the first and second electrode cuffs38,40. The first electrode cuff38can be secured to the first lead extension32while the second electrode cuff40can be secured to the second lead extension34. In some embodiments, as illustrated, the strain relief36can be secured to the lead body30by a connector48. In some embodiments, the connector48can also secure at least one of the first lead extension32and/or the second lead extension34, if present, to the lead body30.

FIG. 3is similar toFIG. 2but shows a portion of a lead14having a strain relief42that is configured as a helical winding that is biased to a coiled configuration as shown. In some embodiments, the strain relief42includes a first end44and a second end46, and the strain relief42can be wrapped around the nerve N by pulling each of the first end44and the second end46and wrapping each of the first end44and the second end46around the nerve N. In some embodiments, as illustrated, the strain relief42can be secured to the lead body30by a connector48. In some embodiments, the connector48can also secure at least one of the first lead extension32and/or the second lead extension34, if present, to the lead body30.

FIGS. 4 and 5provide an illustration of an electrode cuff50and an exemplary method of securing the electrode cuff50to the nerve N. The electrode cuff50is an example of an electrode cuff20that can be used in combination with the lead14. In the illustrated embodiment, the electrode cuff50has a first region52and a second region54. A first tendril56extends from the first region52of the electrode cuff50and a second tendril58extends from the second region54of the electrode cuff50. In some embodiments, the first tendril56and the second tendril58curve in opposite directions (with respect to an observer viewing the Figure).

To secure the electrode cuff50to the nerve N, the electrode cuff50is disposed proximate the nerve N. The electrode cuff50can be rotated in a direction indicated by an arrow60, thereby bringing the first tendril56and the second tendril58into contact with the nerve N. In some embodiments, the first tendril56and the second tendril58are sufficiently stiff to permit adequate securement of the electrode cuff50to the nerve N without requiring that either of the first tendril56or the second tendril58extend much beyond a half circle. In some embodiments, the first tendril56and/or the second tendril58may be sufficiently flexible to permit uncoiling and recoiling the first tendril56and/or the second tendril58around the nerve N.

FIG. 6is a schematic illustration of an electrode cuff70disposed about the nerve N. The electrode cuff70is an example of an electrode cuff20that can be used in combination with the lead14. The electrode cuff70includes a cuff body72and an electrode74that is disposed on or otherwise secured to the cuff body72. In some embodiments, the electrode74may be a foil electrode. While a single electrode74is shown, in some embodiments the cuff body72may include two or more electrodes74.

The cuff body72includes a first region76and a second region78. A first tendril80extends from the first region76of the cuff body72and a second tendril82extends from the second region78of the cuff body72. In some embodiments, the first tendril80is biased to a curved configuration as shown. In some embodiments, the second tendril82is biased to a curved configuration as shown. In some embodiments, as illustrated, the first tendril80extends at an acute angle with respect to the cuff body72and the second tendril82extends at an acute angle with respect to the cuff body72. For illustrative purposes, this acute angle is indicated as angle alpha (α), which can be in a range greater than zero degrees and less than 90 degrees.

The first tendril80, the second tendril82and the cuff body72can be formed of any suitable material. In some embodiments, the first tendril80, the second tendril82and the cuff body72are each formed of a polymeric material such as silicone.FIGS. 6A and 6Bare cross-sectional views of the first tendril80and the second tendril82, respectively.

In some embodiments, as illustrated, the first tendril80can include a first suture86that is molded within the first tendril80and that extends through the first tendril80. In some embodiments, as illustrated, the second tendril82can include a second suture88that is molded within the second tendril82and that extends through the second tendril82. The first suture86and the second suture88can, if present, aid in deployment of the electrode cuff70by providing the surgeon with something that can be grasped and pulled on in order to appropriately wrap the first tendril80and/or the second tendril82around the nerve N. In some embodiments, as illustrated, the first suture86can extend out of the end of the first tendril80so that the surgeon can grasp it. In some embodiments, as illustrated, the second suture86can extend out of the end of the second tendril82so that the surgeon can grasp it.

FIG. 7is an illustration of a unitary tendril90that can form part of the electrode cuffs20described herein. The unitary tendril90includes a first portion92and a second portion94. The unitary tendril90also includes a midpoint96where the unitary tendril90switches wrapping direction. In some embodiments, as illustrated, the first portion92of the unitary tendril90can be considered as having a first coil direction indicated by arrow98while the second portion94of the unitary tendril90can be considered as having a second coil direction indicated by arrow100.

By having either end biased to opposite coil directions, it will be appreciated that the surgeon installing an electrode cuff with such a unitary tendril90can wrap or unwrap either end in the same direction, i.e., both ends can be wrapped or unwrapped in a clockwise direction or in a counter-clockwise direction by virtue of the two ends of the unitary tendril90extending from opposite ends of the electrode cuff20. In some situations, this can simplify and speed up the deployment of the electrode cuff20.

FIG. 8illustrates an electrode cuff110. The electrode cuff110is an example of an electrode cuff20that can be used in combination with the lead14. The electrode cuff110includes a cuff body112and one or more electrodes (not shown). The cuff body112includes a first region114and a second region116. A first tendril118extends from the first region114of the cuff body112and a second tendril120extends from the second region116of the cuff body112. In some embodiments, the first tendril118is biased to a curved configuration as shown. In some embodiments, the second tendril120is biased to a curved configuration as shown. While in some respects the electrode cuff110is similar to the electrode cuff70(FIG. 6), in this instance the first tendril118and the second tendril120are long enough to wrap several times around the nerve N. In some embodiments, the first tendril118and the second tendril120are biased to a coiled configuration in which the first and second tendrils118,120have an overall diameter that is greater than a diameter of the cuff body112.

FIGS. 9 and 10provide illustrations of electrode cuffs that are configured to minimize the overall length of the electrode cuff and thus minimize the overall cut-down length required for deployment of the electrode cuff.FIG. 9illustrates an electrode cuff130deployed on the nerve N. The electrode cuff130is an example of an electrode cuff20that can be used in combination with the lead14. The electrode cuff130includes a cuff body132and an electrode134. The cuff body132includes a first region136and a second region138. A first tendril140extends from the first region136of the cuff body132and a second tendril142extends from the second region138of the cuff body132.

In the illustrated embodiment, the first tendril140extends perpendicularly or at least substantially perpendicular to the cuff body132. The second tendril142extends perpendicularly or at least substantially perpendicularly to the cuff body132. In some embodiments, the first tendril140and/or the second tendril142extend more than 360 degrees around the nerve N and thus overlap on the cuff body132. In some embodiments, the first tendril140and/or the second tendril142may extend less than 360 degrees around the nerve N. The first tendril140and the second tendril142extend from a common side144of the cuff body132.

FIG. 10illustrates an electrode cuff150deployed on the nerve N. The electrode cuff150is an example of an electrode cuff20that can be used in combination with the lead14. The electrode cuff150includes a cuff body152and an electrode154. The cuff body152includes a first region156and a second region158. A first tendril160extends from the first region156of the cuff body152and a second tendril162extends from the second region158of the cuff body152.

In the illustrated embodiment, the first tendril160extends perpendicularly or at least substantially perpendicular to the cuff body152. The second tendril162extends perpendicularly or at least substantially perpendicularly to the cuff body152. In some embodiments, the first tendril160and/or the second tendril162extend more than 360 degrees around the nerve N and thus overlap on the cuff body152. In some embodiments, the first tendril160and/or the second tendril162may extend less than 360 degrees around the nerve N. In the illustrated embodiment, the first tendril160extends from a first side164of the cuff body152and the second tendril162extends from a second side166of the cuff body152.

As noted, each of the electrode cuffs described herein, such as the electrode cuff50, the electrode cuff70, the electrode cuff110, the electrode cuff130or the electrode cuff150can be used in combination with the lead14as one or more of the electrode cuffs20. Each of the electrode cuffs described herein can be formed of any suitable material including a polymeric material such as silicone. In some embodiments, the tendrils can be biased to a particular curved or coiled configuration. In some embodiments, the tendrils can be formed of a shape memory material such as a shape memory polymer.

FIG. 11illustrates a method that can be carried out using the lead14and the electrode cuffs described herein. An electrode cuff having a first tendril and a second tendril can be disposed proximate the nerve N as generally indicated at block170. At block172, the electrode cuff can be positioned on the nerve N. The first tendril can be secured in position on the nerve N as generally indicated at block174. In some embodiments, the first tendril can be secured by wrapping the first tendril around the nerve in a rotational direction. The second tendril can be secured in position on the nerve N as generally indicated at block176. In some embodiments, the second tendril can be secured by wrapping the second tendril around the nerve N in the same rotational direction.

FIG. 12illustrates a lead214that includes a first electrode cuff220secured to a lead body extension221and a second electrode cuff222secured to a lead body extension223. The first electrode cuff220includes a first cuff body224and a first tendril226extending from the first cuff body224. The first tendril226is biased to a curved configuration in which the first tendril226curves in a first direction228. A second tendril230extends from the first cuff body224and is biased to a curved configuration in which the second tendril230curves in a second direction232.

The second electrode cuff222includes a second cuff body234and a third tendril236extending from the second cuff body234. The third tendril236is biased to a curved configuration in which the third tendril226curves in a third direction238. A fourth tendril240extends from the second cuff body234and is biased to a curved configuration in which the fourth tendril240curves in a fourth direction242. In some embodiments, the first direction228and the third direction238can be the same. In some embodiments, the second direction230and the fourth direction240can be the same.

By having opposing ends of each electrode cuff220and222biased to opposite coil directions, it will be appreciated that the surgeon installing the electrode cuffs can wrap or unwrap either end in the same direction, i.e., both ends of each electrode cuff230,232can be wrapped or unwrapped in a clockwise direction or in a counter-clockwise direction. In some situations, this can simplify and speed up the deployment.