WO2001022877A1

WO2001022877A1 - Flat interface nerve electrode and a method for use

Info

Publication number: WO2001022877A1
Application number: PCT/US2000/026698
Authority: WO
Inventors: Dustin Tyler; Dominique M. Durand
Original assignee: Neurocontrol
Priority date: 1999-09-28
Filing date: 2000-09-28
Publication date: 2001-04-05
Also published as: AU7620900A; US6456866B1

Abstract

A flat interface nerve electrode (10) is provided along with a method for use. The electrode provides a plurality of conductive elements (12) embedded in a non-conductive cuff structure, which acts to gently and non-evasively redefine the geometry of a nerve through the application of a force so as to apply pressure to a nerve in a defined range, namely from 2 to 40 mmHG and more preferably from 15 - 30 mmHG and most preferably from 15 mmHG to 20 mmHG. This range is selected to minimize the reduction of blood flow within the tissue, which preferably is at least 70 % of the initial value, more preferably 90 % of the initial value. The cuff has an opening, which is elongated relative to the diameter of the nerve to which it is applied. Preferably, the cuff is constructed from an elastic bio-compatible material having top and bottom beam members configured to define a nerve opening.

Description

FLAT INTERFACE NERVE ELECTRODE AND A METHOD FOR USE

FIELD OF INVENTION The invention relates to implantable biomedical interfaces, and more particularly to a cuff for biological soft tissue which can be used as an electrode for selective stimulation and/or monitoring of nerve groups. Likewise, the cuff can be used as a delivery system for localized application of medication, such as bachlofin. The cuff also has application for use as a sensor for chemical removal.

BACKGROUND OF THE INVENTION

As the level of sophistication has increased in biomedical arts, advances have been made in implantable therapies. Therapies have evolved which involve the precise application of stimulus including electrical stimulus medication.

This invention relates in particular to a nerve electrode cuff for use in functional electrical stimulation. Functional electrical stimulation of the nervous system can be used to help to restore or maintain some de- gree of lost sensory and motor function in neurologically impaired individuals. In addition, there are certain specialized applications, such as the treatment of sleep apnea, where it is necessary to simultaneously monitor and generate electrical signals in nerves. The current invention extends to a method which both monitors and generates electrical signals in nerves, in particular of the hypo-glossal nerve for treatment of sleep apnea.

Prior art methods and apparatus which can be used in functional electrical stimulation and/or recording to restore a particular function broadly include:

( 1 ) surface electrodes placed on the skin surface to activate nerves in a general region of interest;

(2) intra muscular and epimysial electrodes to activate nerves to individual muscles; and

(3) the use of neural interfaces to address individual nerves. Specific research in the area of nerve interfaces has involved nerve cuffs for stimulating and monitoring nerve activity. Cuff electrodes are used in peripheral nerve stimulation and produce function with up to 1000 times less charge than required by either surface or intra muscular electrodes. For example, peripheral nerve stimulation with a cuff requires less than 100 nC for full functional recruitment compared to up to 1 0 μC with surface stimulation or up to 4 μC for intramuscular electrical stimulation. The smaller power requirement may result in a potentially safer long term therapy. Other advantages of peripheral nerve electrodes include the fact that an entire muscle can be recruited from a single electrode. In addition, it may be easier to stimulate an appropriate peripheral nerve rather than some muscles which are difficult or impractical to implant with IM or epimysial electrodes (for example as in the larynx) .

Prior art cuff electrodes have included proximity electrodes which are sutured into position. These electrodes require a relatively high amount of current. Half cuff electrodes are generally C-shaped, while cy- lindrical electrodes can be spiral, helical, split-cylinder, or chambered cylinders. C-shaped or split cylinder electrodes generally include a cylinder of dielectric material finding a bore having sufficient diameter to receive a nerve trunk to be electrically stimulated. Single or multiple annular electrodes can be positioned on the inner surface of the bore for applying elec- trical stimuli. The electrical stimuli, for example, may be used to provide functional electrical stimulation, to block neural nerve impulses traveling along the nerve trunk, or to cause other effects.

The spiral type of cuff electrode typically includes a self-curling sheet of non-conductive material biased-curl into a spiral. Conductive strips or pads are disposed on the self-curling sheet extending peripherally around the inner surface of the cuff . The conductive segments may be electrically conductive for applying electrical impulses or fluid conductive for infusing or extracting medications. In use, a first edge of a self-curling sheet may be disposed adjacent a nerve truck around which the cuff is positioned. The self-curling sheet is permitted to curl around the nerve forming an annular cuff. Helical electrodes wind around the nerve like a spring allowing nerve flex and fluid exchange with surrounding media (i.e. tissue).

Another approach to electrical stimulation of the nervous system involves small wire electrodes which penetrate the perineurium membrane and are advanced into a fascicle of the nerve, within fascicular en- doneurium. This method has the disadvantage of being highly invasive and can result in permanent damage to the nerve through penetration of the perineurium and mechanical trauma to the axons.

Regeneration type neural interfaces are comprised of a thin sili- con diaphragm with many small holes, which is positioned between the cut ends of a peripheral nerve. Over time the axons will regenerate through the many small holes in the diaphragm. A disadvantage to this therapy is that it requires the nerve to be severed. As well, axons tend to regenerate around the interface rather than through it.

SUMMARY OF INVENTION

The present invention contemplates a soft tissue cuff for use for example, as a nerve cuff electrode. The invention has application in addition for medicinal infusers and implantable biomedical devices for intro- ducing, monitoring, or removing matter, fluids or energy. In contrast to prior art cuffs, the present invention is intended to apply a small, non- circumferiential force over time; this results in a non-damaging pressure within the intrafascicular endonurium so as to effect the nerve shape but not as to occlude blood flow within the nerve. The cuffs of the present invention may be implanted without damage to the subject nerve. Further, the cuff can allow for tissue swelling and movement. The present invention causes the nerve to mimic its natural reaction to forces applied within the body. Specifically, the body naturally applies small forces to the nerves which results in flattening or other shape changes to the nerve. An example of these forces is illustrated by the flattening of the sciatic nerve as it exits the pelvis at the sciatic foramen. Further, some nerves will take on an ellipsoidal shape as they pass through muscle planes. Other nerves have demonstrated significant flattening over time as a result of tumor pressure.

In a preferred embodiment, the present invention recognizes a small range of pressure which will cause nerve reshaping without damaging the nerve. In particular, this cuff electrode is designed to apply a force that does not cause pressure to rise above 40 mmHG (or more specifically, does not cause a reduction of blood flow to less than 70% of normal (i .e. , baseline)) . It is currently believed that tissue pressure cor- relates with blood flow. Specifically, at less than 1 0 to 1 5 mmHG, there is little effect on blood flow. At the range of 1 5 to 20 mmHG the venus blood flow is initially impaired . At 30 mmHG the capillary and arterial blood flow is first impaired. By 80 mmHG, neural blood flow stops completely. In compressive pathologies, such as carpal tunnel syn- drome, damage and pain do not occur until the neural pressure is greater than 30 mmHG. Consequently, the current invention is intended to apply a force resulting in an internal nerve pressure of between about 5 mmHG and 40 mmHG, and more preferably between 1 5mmHG and 30mmHG, and even more preferably from 1 5mmHG to 20mmHG. The current invention has the object of solving the deficiencies in the prior art. The present invention has the advantage of providing selectively, i.e. the ability to activate and record a specific population or subset of axons within a nerve.

A soft tissue cuff is provided which is non-invasive to the soft tis- sue. Further, the electrode is more compact in at least one dimension and may lower charge requirements as it allows for more selective stimulate on specific axons, and especially the central axons. Since the perineurium is reshaped over time, damage to this protective neural tissue is minimized. In accordance with the present invention a nerve cuff is provided which applies the defined pressure to a nerve to cause gradual reshaping over time. This pressure is applied in a way to allow the nerve to adapt to the condition without damage to the nerve. Of course, it should be understood that the amount of time will vary with the nerve as some nerves may adapt faster than others. The required time for reshaping may be 24 hours or as little as 2 hours or up to 1 week or more. The quality and condition of the nerve will also contribute to this time for reshaping.

In a first embodiment, the invention includes an elongated, substantially rectangular central opening having a height, which is smaller than and a width which is longer than the diameter of the nerve to which it is applied. The cuff may be made of a material having a sufficient elasticity and a shape sufficient to cause a force applied selectively across the transverse direction of the nerve. The nerve cuff can be open at a single end or alternatively the nerve cuff may be open at two ends. The open ends are closed such as by staple, an O-ring in a grooved area, a suture, a mechanical interference fit or other closure mechanism. The beams which form the top and/or bottom of the nerve cuff and the connecting juncture for these beams have a structure and/or material characteristic tailored to impart a particular pressure to the nerve. In a further embodiment, the invention can be used both to record sensory neural activity and stimulate motor output. This capability from a single device would be very beneficial for closed loop systems in applications such as restoring hand grasp or obstructive sleep apnea.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a first embodiment of the nerve cuff in accordance with the invention;

Figure 2 is a view of the nerve cuff electrode when it is opened; Figure 3 is a view of the nerve in an initial state;

Figure 4 is a view of the nerve cuff on a nerve after (reshaping has occurred;

Figure 5 is a perspective view of the nerve cuff on a nerve; Figure 6 is a detail of a side view of a second embodiment; Figure 7 is an end cross-section of the embodiment of Figure 6.

DETAILED DESCRIPTION A nerve cuff in accordance with the invention is illustrated generally at 1 0. The cuff includes a non-conductive band 1 4 and segments B which are electrically conductive electrodes 1 2. The band 14 encircles the nerve and gently and non-invasively applies a defined exterior force over time to redefine the geometry of the nerve, such as by flattening. Through simple modification of the structure of the electrodes 1 2, such as by forming fluid conduits or ducts, the elements are adaptable to become medication or fluid conductive. In ad- dition, a selected one or more of the conductive segments may be adapted to be medication conductive while the other segments are adapted to remain electrically conductive for a combined chemical and electrical stimulation. Further, chemical and electrical conduction is not constrained to flow only into the nerve from the cuff . Rather, as a sig- nificant aspect of the invention, the chemical and electrical conductive elements may also be adapted to conduct chemicals and electricity both from the cuff to the nerve and into the cuff from the nerve for stimulating and monitoring various nerve properties, activities, and characteristics, respectively. Accordingly, the cuff is also useful in such applica- tions as treatment of sleep apnea where combined sensor/effector cuff electrodes may be beneficial, for example, for use in monitoring activity on the hypo-glossal nerve. U.S . Patent No. 4,830,008 to Meer, incorporated herein by reference, describes a preferred method and generic apparatus for treating sleep apnea. The present invention extends the pre- ferred cuff embodiments to the Meer teachings for use in treating sleep apnea. With further continued reference to FIGS . 1 -7, each of the plurality of electrodes 1 2 are individually connected through a single lead 1 6 to an operatively associated electrical signal generating source (not shown) or electrical monitoring device (not shown) . In the FIGS ., the fine conductive wires are illustrated as a plurality of individual conductors 50 which extend longitudinally from the conductive segments B to a location between the first edge 1 7 and the second edge 1 8 of the implantable cuff . From that point, the plurality of conductors extend through implantable cuff to a common exit area 1 7 within a lead 1 6. There, the plurality of conductors 1 2 extend away from the nerve encircled by the implantable cuff for subsequent attachment to the operatively associated electrical signal or monitoring device(s) . In the preferred embodiment, the plurality of conductors 1 2 extend from the conductive segments B completely embedded in the non-conductive material comprising the cuff sheet A. In this way, they are insulated from direct contact with either the nerve, other conductors, or other surrounding tissue. Also, the non-conductive sheet A acts as a reinforcing structure and affords a level of structural integrity to the somewhat otherwise frail conductors. Although the preferred embodiment includes electrically conductive segments B having one or more discrete electrodes disposed thereat, one alternative includes forming a micro-multielectrode array in silicon using semiconductor fabrication technology. An example of this approach is set forth in U.S . Patent No. 5,324,322 to Grill Jr. , et al. , and in Wim L.C Rutten, Harmen J . Van Wier and Johan H .M. Put, "Sensitivity and Selectivity of Intraneural Stimulation Using a Silicon Electrode Array, " IEEE Trans. Biomed . , Eng. Vol. 38, pp. 1 92- 1 98, February 1 991 . J . F. Hetke, J . L. Lund, K. Najafi, K. D. Wise, and D. J. Anderson "Si/icon Ribbon Cables for Chronically Implantable Microelectrode Arrays", IEEE Trans. Biomed . , Eng. Vol. 41 , pp. 31 4-321 , April, 1 994. Using this and similar technologies currently available including micro-lithography and micro-integrated electronics, the plurality of conductors may be formed on fine flexible silicon substrates, or polyimide or metalized polymer. In this way, active and intelligent electronics may be included on the cuff apparatus itself. In use, the subject nerve 60 is surgically accessed and the open side of the cuff is slipped over the nerve in the desired position. The cuff is opened as is shown in Figure 2 to completely encircle the nerve at which point the two open and opposing ends 1 3, 1 5 are connected together. Preferably, a connector arrangement such as an o-ring, staple or suture 70 is used to join the ends 1 3, 1 5.

Figures 4 and 5 illustrates the flat interface nerve cuff electrode of the first preferred embodiment on a nerve 60 on a nerve which has responded to the application of pressure by the cuff to reshape into a final flattened state. Figure 3 illustrates a nerve in its initial state. in general, the nerve 60 is surrounded by a loose membrane called the epineurium membrane 62. The nerve is typically organized into several groups of axons called fascicles 64. Each fascicle 64 is surrounded by a membrane called the perineurium membrane 66. In this embodiment, the flat interface nerve cuff slowly applies transverse pressure to opposing surfaces of the nerve, so as to spread the fascicles 64 and flatten the epineurium membrane 62 (and even ultimately of the perineurium with a corresponding reshaping of the fascicles themselves) of the target nerve 60. This flattening action effectively allows the conductive members B on the sheet A to contact particular fascicle through the epi- neurium membrane 62 without puncturing either the perineurium membrane 66, or the epineurium. Instead, the fascicles 64 are displaced with a subsequent reshaping of the epineurium membrane 62 at locations corresponding to the cuff interface. The method of using this and the other preferred embodiments contacts electrodes with specific nerve fascicles without penetration of the perineurium membrane. Typically, the time period required for the cuff to function properly extends from about one (1 ) hour to several days depending upon particular application and situation. The driving force, which motivates the conductive members B inward, however, is provided by the mechanical spring action at the active end of the cuff as well as by the elastic nature of the cuff material. This unique design illustrated in the figures allows the superficial placement of the electrodes with selective access to the entire axon population but with minimal damage to the nerve itself . The electrodes 1 4 are each capable of activating separate and distinct regions within the nerve, along both the longitudinal and radial axis of the nerve, which was not previ- ously accessible by other types of electrodes without the associated damage described in the background above. The electrodes are also capable of sensing small neural signals with better signal to noise ratios due to the close proximity of each of the electrodes to the axons comprising the fascicles. The lower limit of applied pressure required to reshape the nerve is something greater than that which is naturally occurring in an occurring nerve. This pressure is usually in the vicinity of 2 mmHG .

It is to be appreciated that by controlling the spring constant or force exerted by the cuff surfaces, the cuff can be configured to rest against the surfaces of the epineurium membrane. Figure 4 illustrates the cuff in this type of situation, with contact points 1 3 depicting a portion of the cuff resting on the surface. The desired pressure, which results from the force applied by the cuff is from about 2 to about 80 mmHG; preferably from about 3 to about 30 mmHG and most preferably from about 5 to abut 1 5 mmHG . This pressure is measured as is discussed in the following examples. It is to be further understood that such surface implementation may be accomplished by all the remaining embodiments as well.

The embodiment shown in Figures 6 and 7 varies from the first embodiment as it has a radiused surface 220 for the nerve interface. The gradual curve resulting from the radial surface provides an imposed transition zone to minimize strain on the tissue.

The present invention involves a flat interface nerve electrode (FINE) shown in Figure 1 that applies small forces on opposing sides of the nerve while allowing the nerve to expand in other directions. The hypothesis is that a small force does not significantly decrease nerve blood flow and will reshape the nerve into an elongated or flattened oval geometry that approximates the "ideal" geometry of a flat cable.

The FINE is shown as a pair of beams closed at the ends to form a rectangular opening. Electrical contacts are embedded in the walls. When the electrode is first placed around a nerve, the beams are deformed around the nerve. The thickness (t), width (w), length (I), and cross-sectional profile of the beams of the electrode will determine the magnitude of the force that will be applied to the nerve.

Compared to a circular geometry, the flat geometry of the present invention offers several advantages. For the same cross-sectional area, the circumference of the flattened geometry is larger, allowing more contacts to be placed around the nerve. The maximum distance from any axon to an electrical contact on the FINE is smaller than for a circular electrode, effectively moving central tissue to the surface of the nerve. The flat geometry aligns the nerve fascicles to increase selectivity and access to every fascicle.

The feasibility of reshaping electrodes requires that the force that reshapes the nerve is less than the force that causes axon damage or loss. The following examples summarize studies of the FINE selectivity and chronic safety.

Example I In acute experiments the FINE was implanted on the sciatic nerve of six cats for 36 hours and tested for reshaping and selective stimulation. The nerve geometry was measured from histology of the nerve cross-section. The FINE aligned and significantly (p < 0.0001 , Wilcoxon Rank-sum test of eccentricity measurements) reshaped the fascicles compared to the proximal or distal sections of the nerve.

Monopolar stimulation from contacts on the FINE selectively reproduced the individual outputs of the major fascicles of the common sciatic nerve in 1 2 of 1 4 trials (86 %) . The FINE, therefore, demon- strated the ability to selectively activate sub-populations of axons within the common sciatic nerve.

Example II FINE electrodes were also implanted chronically on the sciatic nerve of 40 rats. FINEs of three different wall thickness, t in Figure 4, (Figure 2), were implanted for 1 , 7, and 28 days and compared to sham implants. The thicker the wall thickness, the greater the force applied to the nerve. Nerve physiology was assessed weekly by measurements of the footprint during normal gait. Only the FINE with the greatest wall thickness produced any changes in the nerve physiology. The changes were significantly different (p < 0.05, two-tail t-test of the mean) from the sham trials only between 1 and 1 4 days post-implant and had recovered by 21 days post-implant. Measurement of nerve geometry demonstrated that all three FINE designs significantly reshaped the nerve and fascicles compared to sham (p < 0.05, Wilcoxon Rank-sum test of ec- centricity measurements) .

The histology of sham trials was not different than the histology from nerves implanted with the smallest wall thickness FINE. The FINE with the thickest wall produced changes in the nerve histology that indicated a remyelination process and demonstrated evidence of axon sprouting and regeneration. The intermediate thickness FINE demonstrated mixed results and appeared to be sensitive to surgical manipulation . The blood-nerve-barrier permeability was examined using fluoro- scopic techniques (Rydevik and Lundborg 1 977; Lundborg 1 983) . The thin walled FINE results were not significantly different from the sham results, the intermediate thickness FINE gave mixed results, and the thick walled FINE significantly increased the blood-nerve barrier perme- ability.

Acute stimulation experiments with a preliminary FINE show that an electrode that produces a flattened nerve geometry can selectively stimulate different unique functions within a common nerve trunk. Chronic trials have shown that a thin walled FINE, which applies small forces to the nerve, can reshape the nerve without damage. The preliminary FINEs were designed by trial and error testing on the specific nerve to be implanted. This is not adequate for commercial electrode development, which requires a systematic design approach and rigorous safety guidelines.

While in accordance with the patent statutes the best mode and preferred embodiment has been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached Claims.

Claims

WHAT IS CLAIMED IS:

1 . A cuff for a biological filament having an external configuration soft tissue with a height Y and a width X, the cuff comprising an elastic collar member defining an internal opening which has an internal configuration having a height less than Y and a width longer than X, and further having an interface for the delivery of therapy or reception of information from the soft tissue filament whereby said collar exerts a force on said soft tissue filament which will cause it to gradually reshape to the internal configuration of said opening and wherein the resulting pressure in said soft tissue filament is less than 80 mmHG .

2. A soft tissue cuff as set forth in Claim 1 , wherein said collar has a top beam and a bottom beam.

3. A soft tissue cuff as set forth in Claim 1 , wherein said top beam has a first side joined to a first side of said bottom beam by a web member.

4. A soft tissue cuff as set forth in Claim 1 , wherein said collar comprises an elastomeric material.

5. A soft tissue cuff as set forth in Claim 4, wherein said collar comprises a silicone elastomer.

6. A soft tissue cuff as set forth in Claim 1 , wherein said collar exerts a force which results in a pressure in said soft tissue of from about 2 to about 50 mmHG .

7. A soft tissue cuff as set forth in Claim 1 , wherein said soft tissue is a nerve and said interface is an electrode.

8. A soft tissue cuff as set forth in Claim 7, wherein said inter- face is a plurality of electrodes and wherein said cuff is comprised of a material which is nonconductive.

9. A method of altering a biological soft tissue comprising; surgically accessing a soft tissue in the form of a filament, having a height Y and a width X; placing a cuff around said soft tissue filament, said cuff comprising a collar defining an internal opening which receives said soft tissue filament, and said opening having an internal configuration with a height less than Y and a width greater than X, and said collar further including an interface for said soft tissue filament; and applying a gradual force to said soft tissue filament by means of said collar which results in a pressure in said soft tissue filament of less than 80 mmHg.

1 0. A method as set forth in Claim 9, which includes the further step of delivering a stimulus to or receiving a stimulus from said soft tissue filament by means of said interface in said cuff .

1 1 . A method as set forth in Claim 10, wherein said cuff com- prises an elastic material.

1 2. A method as set forth in Claim 1 1 , wherein said resilient material is a silicon elastomer.

1 3. A method as set forth in Claim 10, wherein said soft tissue is a muscle.

1 4. A method as set forth in Claim 10, wherein said soft tissue is a nerve.

1 5. A method as set forth in Claim 14, wherein said interface is an electrode.

1 6. A method as set forth in Claim 1 5, wherein said interface comprises a plurality of electrodes.

1 7. A method as set forth in Claim 9, wherein said nerve is the hypo-glossal nerve.

1 8. A cuff for a biological filament having an external configura- tion soft tissue having a blood flow Z with a height Y and a width X, the cuff comprising an elastic collar member defining an internal opening which has an internal configuration having a height less than Y and a width longer than X, and further having an interface for the delivery of therapy or reception of information from the soft tissue filament whereby said collar exerts a force on said soft tissue filament which will cause it to gradually reshape to the internal configuration of said opening and wherein the blood flow in said tissue is not reduced to less than 70 % of Z.

1 9. A soft tissue cuff as set forth in Claim 1 8, wherein said collar has a top beam and a bottom beam.

20. A soft tissue cuff as set forth in Claim 1 9, wherein said top beam has a first side joined to a first side of said bottom beam by a web member.

21 . A cuff as set forth in Claim 20, wherein said internal opening has a radiused area so as to define a gradual tapering toward the center of said internal opening.

22. A soft tissue cuff as set forth in Claim 21 , wherein said collar comprises a silicone elastomer.

23. A soft tissue cuff as set forth in Claim 22, wherein said blood flow is not reduced to less than 85 % of Z.

24. A soft tissue cuff as set forth in Claim 23, wherein said soft tissue is a nerve and said interface is an electrode.

25. A soft tissue cuff as set forth in Claim 24, wherein said inter- face is a plurality of electrodes and wherein said cuff is comprised of a material which is nonconductive.

26. A method of altering a biological soft tissue comprising; surgically accessing a soft tissue in the form of a filament, having a height Y and a width X and a blood flow Z; placing a cuff around said soft tissue filament, said cuff comprising a collar defining an internal opening which receives said soft tissue filament, and said opening having an internal configuration with a height less than Y and a width greater than X, and said collar further including an interface for said soft tissue filament; and applying a gradual force to said soft tissue filament by means of said collar which results in a reduction of said blood flow to not less than 70% of Z.

27. A method as set forth in Claim 26, which includes the further step of delivering a stimulus to or receiving a stimulus from said soft tis- sue filament by means of said interface in said cuff .

28. A method as set forth in Claim 27, wherein said cuff comprises an elastic material.

29. A method as set forth in Claim 28, wherein said resilient material is a silicon elastomer.

30. A method as set forth in Claim 26, wherein said soft tissue is a muscle.

31 . A method as set forth in Claim 26, wherein said soft tissue is a nerve.

32. A method as set forth in Claim 31 , wherein said interface is an electrode.

33. A method as set forth in Claim 32, wherein said interface is an electrode.

34. A method as set forth in Claim 33, wherein said nerve is the hypo-glossal nerve.

35. A cuff for soft tissue from the hypo-glossal nerve, said tissue having a height Y and a width X, and the cuff comprising; an elastic collar member defining an opening which has an internal configuration having an electrode interface for the delivery of therapy or reception of information from the soft tissue filament whereby said collar exerts a force on said soft tissue filament which will cause it to gradually reshape to the internal configuration of said opening and wherein the resulting pressure resulting pressure in said soft tissue filament is less than 80 mmHG .

36. A soft tissue cuff as set forth in Claim 35, wherein said collar has a top beam and a bottom beam.

37. A soft tissue cuff as set forth in Claim 35, wherein said top beam has a first side joined to a first side of said bottom beam by a web member.

38. A method of simultaneously monitoring and stimulating a biological soft tissue comprising; surgically accessing a soft tissue in the form of a filament, having a height Y and a width X; placing a cuff around said soft tissue filament, said cuff compris- ing a collar defining an internal opening which receives said soft tissue filament, and said opening having an internal configuration with a height less than Y and a width greater than X, and said collar further including an electrode interface for said soft tissue filament; applying a gradual force to said soft tissue filament by means of said collar which results in a pressure in said soft tissue filament of less than 80 mmHg; and utilizing said electrode interface to simultaneously monitor and stimulate said biological soft tissue.

39. A method as set forth in Claim 38, wherein said simultaneous monitoring and stimulating is intermittent with no monitoring or stimulating, or with only monitoring or only stimulating the soft tissue.

40. A method as set forth in Claim 39, wherein said cuff com- prises an elastic material.

41 . A method as set forth in Claim 40, wherein said resilient material is a silicon elastomer.

42. A method of treating sleep apnea comprising the steps of: surgically accessing at least a portion of the hypo-glossal nerve; placing a cuff around said portion of said nerve, said cuff defining an internal opening which receives said portion, and said cuff having an electrical interface with said nerve; simultaneously monitoring and stimulating said nerve portion through said electrical interface.

43. A method of treating sleep apnea as set forth in Claim 42, wherein said cuff applies a force to said nerve portion over time to cause a reshaping of said nerve.

44. A method of treating sleep apnea as set forth in Claim 43, wherein the pressure resulting from said force is less than 80mmHG .

45. A cuff for use in one or more of monitoring and stimulating a nerve comprising; an elastic collar having a top beam with a first side joined to a first side of a bottom beam by a web member, the second side of said top beam and said bottom beam being open, and one or more of the bottom side of said top beam and the top side of bottom beam having a radiused area to cause the opening forming between said top and bottom beam to have a transitional loading zone which tapers in the inward direction.

46. A cuff as set forth in Claim 45, wherein both said bottom side of said top beam and said top side of said top beam are advised .

47. A cuff as set forth in Claim 46, wherein said cuff has an elec- trode interface for said nerve.

48. A cuff as set forth in Claim 45, wherein said collar comprises a silicone elastomer.

49. A cuff as set forth in Claim 45, wherein said second side of said top and bottom beams include a groove which forms the seat for an O-ring.

50. A cuff as set forth in Claim 45, wherein said second side of said top and bottom beams are sutured closed.