CN105682593B - Stimulation device adapter - Google Patents

Abstract

The stimulation device comprises an adaptation means for increasing the usability of the stimulation device. The adapter may be a bipolar adapter arranged to be connected to the housing of the stimulation device. The adapter may include a clamp having a first passage configured to receive the operative element therein and a second passage having a return operative element therein. A return operative element is in electrical communication with the electrical circuit of the stimulation control device. Alternatively, the adapter may be a percutaneous adapter that includes a connector configured to connect to an operating element of the stimulation device and a lead connected to the connector. The needle may be connected to a lead to deliver electrical stimulation signals to target tissue positioned beneath the skin of a target patient.

Description

Stimulation device adapter

Cross Reference to Related Applications

This application is a continuation of co-pending U.S. patent application serial No.13/934384, filed on 3/7/3/2013 and entitled "systems and methods for intra-operative stimulation", U.S. patent application serial No.13/934384 is a continuation of co-pending U.S. patent application serial No.13/466,485, filed on 9/20/2012 and entitled "systems and methods for intra-operative stimulation", U.S. patent application serial No.13/466,485 is a continuation of co-pending U.S. patent application serial No.13/014,452, filed on 9/1/2011 and 26/2011 and entitled "systems and methods for intra-operative stimulation", U.S. patent application serial No.13/014,452 is a continuation of co-pending U.S. patent application serial No.11/651,165, filed on 9/1/2007 and 9/2007 and entitled "systems and methods for intra-operative stimulation", U.S. patent application serial No.11/651,165 is a continuation of co-pending U.S. patent application serial No.11/651,165, filed on 6/4/2005 and entitled "systems and methods for intra-operative stimulation". The continuation of U.S. patent application serial No.11/099,848, U.S. patent application serial No.11/099,848 claims priority of U.S. provisional patent application serial No.60/657,277, filed 3/1/2005 and entitled "systems and methods for intraoperative stimulation," and the continuation of co-pending U.S. patent application serial No.11/337,319, also filed 1/23/2006 and entitled "systems and methods for differentiating and/or identifying tissue regions innervated by a target for diagnostic and/or therapeutic purposes," are hereby incorporated herein by reference in their entirety.

Technical Field

The present invention relates generally to tissue identification and integrity testing, and more particularly to systems and methods for protecting nerves and muscles from damage during surgery, localization and stimulation of nerves and muscles, identification and assessment of nerve and muscle integrity following traumatic injury, and validation of range of motion and muscle contraction attributes during reconstructive surgery.

Background

Even with today's sophisticated medical devices, surgery is not risk-free. The anatomy of each patient varies, requiring the surgeon to be kept vigilant of these differences at all times to achieve the desired result. The positioning of nerves and other tissue within the human or animal body is one example of how the internal anatomy differs from patient to patient. Although these differences may be subtle, if the surgeon does not properly identify one or several nerves, the nerves may be bruised, stretched, or even severed during the procedure. The negative effects of nerve damage can range from a lack of sensation on this part of the body to a loss of muscle control.

Trauma usually requires surgical repair. It is not always possible to determine the extent of muscle and nerve damage using visual inspection. The use of an intraoperative stimulator enables accurate assessment of the neuromuscular system in this area. This assessment provides valuable knowledge for guided repair/reconstructive surgery after traumatic injury and while performing various surgical procedures.

It may be desirable to differentiate and/or identify the presence of targeted sympathetic and/or parasympathetic nerves within a tissue region for diagnostic and/or therapeutic reasons. Furthermore, it may be desirable to target specific nerves and tissue regions and to limit stimulation to the target region.

Disclosure of Invention

The present invention provides devices, systems and methods for intraoperative stimulation that enable accurate assessment of the neuromuscular system to guide repair or reconstructive surgery.

One aspect of the present invention provides devices, systems and methods that include a tissue stimulation system including a housing having a proximal end and a distal end; an operative element having a conductive surface sized and configured for electrical stimulation of a target tissue region; and an operating element extends from the proximal end of the housing. The housing proximal end may include an operating element adjustment portion to allow movement of the operating element such that the electrical stimulation is in the form of a stimulation signal having an amplitude and duration for providing the first indication. The stimulation control device is electrically coupled to the operating element, and includes a power source and a stimulation signal generating circuit. The tissue stimulation system may comply with the IPX1 water intrusion standard.

In one aspect of the invention, a stimulation control device is positioned within the housing. The housing may include a clamping base portion and an operating element adjustment portion. The operating element adjustment portion includes a flexible nose cone.

The first indication comprises a visual indication positioned on the housing, and the housing may be tubular. The visual indication may also include a reflective element. The visual indication may comprise an illuminated peripheral ring indicator which is visible around the periphery of the tubular housing.

In yet another aspect, the present invention provides devices, systems and methods that include a tissue stimulation system including a housing, such as a tubular housing, having a proximal end and a distal end; an operative element having a conductive surface sized and configured for electrical stimulation of a target tissue area, the operative element extending from the proximal end of the housing, and wherein the electrical stimulation is in the form of a signal having an amplitude and duration to provide a first indication to a user proximate the operative element to the target tissue area; and a stimulation control device electrically coupled to the operative element, the stimulation control device including a stimulation signal generation circuit. The housing may comprise first control means for switching the stimulation signal to the operating element on and off and for providing an adjustment of the amplitude of the stimulation signal, the first control means being electrically coupled to the stimulation control means. The housing may further comprise a second control means for providing an adjustment of the duration of the stimulation signal, this second control means being electrically coupled to the stimulation control means.

Other aspects of the invention provide for a tissue stimulation system that can be sterilized, for example, using ethylene oxide, and prepackaged for single use. The stimulation signal of the tissue stimulation system includes an amplitude that may range between about zero milliamps and about 20 milliamps to allow for accurate selective stimulation of the muscle to the nerve, and in addition nerve to muscle identification, muscle attachment, or contraction of the muscle to assess the quality of the surgical procedure. The tissue stimulation signal duration may, for example, comprise a range between about zero microseconds and about 200 microseconds. The first indication provided by the tissue stimulation system may comprise, for example, an audible and visual indication. The tissue stimulation system may further include a second indicator device to provide confirmation that the power source is on to the device and to transmit a stimulation signal to the electrically conductive surface. The first and second indicating means may be combined in a single indicating means. The operative element of the tissue stimulation system may, for example, comprise a probe, wherein the electrically conductive surface of the probe comprises between about 1mm and about 10mm of the proximal end of the probe, and the probe comprises a diameter of between about 0.5 mm and about 1.5 mm. The tissue stimulation system may further include a return electrode electrically coupled to the stimulation control device.

Other aspects of the invention provide tissue stimulation systems, such as medical devices, comprising: a housing having a proximal end and a distal end, the housing being sized and configured to be held in either a left or right hand by a user; a probe having a conductive surface sized and configured for electrical stimulation of a target tissue region, the probe extending from the proximal end of the housing. The housing proximal end may include a probe adjustment portion to allow movement of the probe. The electrical stimulation is in the form of a signal having an amplitude and duration to provide a physical motor response, a stimulation control device electrically coupled to the probe and sized and configured to be positioned within the housing, the stimulation control device including stimulation signal generation circuitry. The housing may comprise a first control means for switching the stimulation signal to the probe on and off and for providing an adjustment of the amplitude of the stimulation signal, this first control means being electrically coupled to the stimulation control means. The housing may further comprise a second control means for providing an adjustment of the duration of the stimulation signal, this second control means being electrically coupled to the stimulation control means.

According to another aspect of the invention, the stimulation control device is electrically coupled to at least one surgical tool, which may include, for example, a cutting, clamping, drilling, screwing, and/or viewing tool. Applying a stimulation voltage or current to such a device allows the clinician to observe muscle contractions or changes in the response of the nervous system when the surgical tool is in close proximity to viable nerve or muscle tissue. The surgical tool thus becomes a nerve/muscle stimulation electrode. In use, different surgical tools deployed separately in association with different medical procedures may utilize a single stimulation control device to which selected surgical tools may be temporarily coupled for use.

According to another aspect of the invention, a stimulation control device may be embedded within a surgical tool to provide a medical device capable of providing stimulation as described above.

Another aspect of the invention provides devices, systems, and methods that include a stimulation monitor or probe and at least one electrode. In one embodiment, a handheld stimulation probe or monitor includes a stimulation control device and at least one stimulation electrode within the same standard housing to provide an ergonomic stimulation device. The hand-held stimulation probe may be a sterile, single-use device for use during a surgical procedure to identify nerve-to-muscle, muscle attachment, or to contract muscles to assess the quality of the surgical procedure or the need for a surgical procedure, or to estimate the function of a nerve that has been identified by visual or auditory means or by other nervous system monitoring means.

Yet another aspect of the present invention provides devices, systems, and methods, including methods of testing a tissue region of a patient, the methods including providing a tissue stimulation system having an operating element extending from a proximal end of a housing, the proximal end of the housing may include an operating element adjustment portion to allow movement of the operating element; moving the first control device to the actuated position causing a stimulation signal to be generated by the stimulation system and transmitted to the operating element; engaging the patient with the operative element at the target tissue region; and observing the target tissue region for a first indication.

The method may further include engaging the patient with a second electrode electrically coupled to the stimulation system, the second electrode allowing the stimulation signal to flow from the operative element, through the body of the patient to the second electrode, and back to the stimulation system.

In another aspect, the present invention provides devices, systems and methods comprising a handheld tissue stimulation device comprising a tubular housing having a grasping base and an operating element adjustment portion, the grasping base comprising a first housing element and a second housing element; a stimulation control device positioned within the grip base; a battery positioned within the grip base and coupled to the stimulation control device to provide power to the stimulation control device; a visual indication coupled to the proximal end of the grip base, the visual indication comprising an illuminated circumferential ring indicator visible around a perimeter of the tubular housing; and an operating element having a conductive surface sized and configured for electrical stimulation of a target tissue region, the operating element coupled to the stimulation control device and extending from a proximal end of the operating element adjustment portion.

The operating element adjustment portion may include a flexible nose cone sized and configured to allow movement of the operating element, and the visual indication further includes a reflective element. The return electrode may be electrically coupled to the stimulation control device.

According to yet another aspect of the invention, a kit provides tissue stimulation of a target tissue region. The kit may include a hand-held stimulation probe including a housing sized and configured to be held by either a left or right hand, the stimulation probe being sterile and disposable and including an operative element extending from a proximal end of the housing, the proximal end of the housing may include: an operating member adjusting portion that allows movement of the operating member; a lead comprising a return electrode coupled to the stimulation probe; and instructions for describing the procedure of removing the stimulation probe in contact with the tissue for stimulation of the probe.

Other aspects of the invention provide a stimulation control device electrically coupled to the tissue cutting device, or to the drilling device, or to the pilot auger for hard surface rotation detection prior to pilot hole drilling, or to a fixation device typically used in spinal stabilization and endosseous fixation procedures.

In another aspect, the present invention provides a first apparatus for generating and providing a stimulation current to tissue. The device, system and method further comprise a second means for sensing the presence or absence of a desired physiological response to the application of the electrical stimulation current. The presence of the expected physiological response is indicative of the innervation of the target nerve fibers or branches within the tissue region. Once distinguished and identified, the target nerve fiber or branch may be manipulated to achieve a desired diagnostic and/or therapeutic outcome.

The devices, systems, and methods are well suited to, for example, distinguishing and/or identifying local branches of the vagus nerve. The vagus nerve extends from the brain, through the face and thorax to the abdomen. It is a mixed nerve that includes parasympathetic nerve fibers. The vagus nerve has the most widespread distribution of cranial nerves. Its pharyngeal and laryngeal branches transmit the motor impulse to the throat; its cardiac branch is used to slow the heart rate; the branch of the bronchus is used for limiting the bronchus; and its esophageal branches control involuntary muscles in the esophagus, stomach, gall bladder, pancreas, small intestine and stimulate enterokinesia and gastrointestinal secretions. Being able to distinguish and/or identify the presence of branches of the vagus nerve within a given tissue region within the body enables the development and application of a variety of diagnostic and/or therapeutic techniques for parasympathetic modulation of a variety of anatomical functions, for example, in the digestive system, respiratory system, or heart.

For example, one aspect of the present invention provides devices, systems and methods capable of differentiating and identifying epicardial fat pads on the surface of the heart innervated by parasympathetic vagal nerve fibers. The devices, systems, and methods thereby enable access to the parasympathetic nervous system of the heart for therapeutic effects, such as controlling ventricular rate or providing physiological control of the atrioventricular node fat pad.

Another aspect of the invention provides systems and methods for treating a heart, including positioning a region of a fat pad on a heart innervated by parasympathetic nerves using a first means for generating and applying a stimulation current, and then manipulating the parasympathetic nervous system of the heart in the region of the fat pad for diagnostic or therapeutic purposes.

In an embodiment, an adapter is provided. This adapter may be configured to connect to a stimulation control device. The adapter may be a bipolar adapter arranged to be connected to the housing of the stimulation device. The adapter may include a clamp having a first passage configured to receive the operative element therein and a second passage having a return operative element therein. A return operative element is in electrical communication with the electrical circuit of the stimulation control device.

In an embodiment, the adapter may be a percutaneous adapter that includes a connector configured to connect to an operative element of a stimulation device and a lead connected to the connector. The needle may be connected to a lead to deliver electrical stimulation signals to target tissue positioned beneath the skin of a target patient.

The features and advantages of the present invention are set forth in the following description and drawings, as well as in the appended description of the technical features.

Drawings

FIG. 1 is a schematic diagram of a system that may be used in conjunction with different monitoring and treatment device families used in different medical procedures.

Fig. 2 is a perspective view illustrating an exemplary embodiment of the system shown in fig. 1, the stimulation control device being removably coupled to the stimulation probe and illustrating a stimulation signal path through the system.

Fig. 3A is a side view, partially broken away and in cross-section, showing a stimulation probe with a stimulation control device embedded within the stimulation probe.

Fig. 3B is a side view, partially broken away and in section, showing a stimulation probe with a stimulation control device embedded within the stimulation probe, and showing an optional needle-like return electrode.

Fig. 3C is a side view, partially broken away, and in cross-section, shows other embodiments of a stimulation probe having a housing including a gripping base and a flexible nose cone, and an illuminated annular indicator.

Fig. 4A is a side view of the stimulation probe of fig. 3c, showing the user's hand in position on the stimulation probe to move the flexible nose cone.

FIG. 4B is a side view of the stimulation probe of FIG. 4A showing the user's hand bending the flexible nose cone.

FIG. 5 is a side view with portions broken away and showing in cross-section the elements of the flexible nose cone, the annular indicator, and the grip base.

Fig. 6 is a graphical view of a desired biphasic stimulation pulse output of the stimulation device.

Fig. 7 is a diagram illustrating how the geometry of the stimulation control device shown in fig. 2 assists in its positioning during a surgical procedure.

Fig. 8 is a block diagram of a circuit that the stimulation control device shown throughout the figures may include.

Fig. 9A and 9B are perspective views illustrating a stimulation control device for a cutting device.

Fig. 10A and 10B are perspective views illustrating a stimulation control device for a drilling or screwing device.

Fig. 11A and 11B are perspective views illustrating a stimulation control device for a pilot auger device.

Fig. 12A and 12B are perspective views illustrating a stimulation control device for a fixation device.

Fig. 13 is a plan view of a kit for use with the stimulation probe shown in fig. 3C and includes the stimulation probe along with instructions for use.

Fig. 14 is a perspective view of the stimulation probe shown in fig. 3C.

Fig. 15 is an exploded view of the stimulation probe shown in fig. 14.

Fig. 16 is a schematic diagram of a system for distinguishing and/or identifying regions of tissue that are locally innervated by a target nerve.

Fig. 17A is a side view of a device used in conjunction with the system shown in fig. 1 for generating and applying a stimulation current to tissue in the region of a target nerve fiber or branch.

Fig. 17B is a side view of an alternative embodiment of the device shown in fig. 2A, and having separate amplitude and duration selection switches.

Fig. 18A is an enlarged view of one embodiment of a bipolar electrode array that the device shown in fig. 17A or 17B may carry at its distal end.

Fig. 18B is an enlarged view of other embodiments of bipolar electrode arrays that the device shown in fig. 17A or 17B may carry at its distal end.

Fig. 18C is an enlarged view of other embodiments of bipolar ring electrode arrays that the device shown in fig. 17A or 17B may carry at its distal end.

FIG. 19 is an illustrative view of a clinician manipulating the device shown in FIG. 17A in connection with the system shown in FIG. 16.

Fig. 20 is an anatomical rear view of a human heart showing the location of the fat pad innervated by parasympathetic nerves, which when approximated, can provide a therapeutic effect.

Fig. 21 and 22 are schematic diagrams of the use of the system shown in fig. 16 for distinguishing and/or identifying regions of fat pad tissue that are locally innervated by parasympathetic nerves.

Fig. 23 is a stimulation device connected to a bipolar adapter.

Figure 24 is a bipolar adapter connector.

Figure 25 is a front view of the bipolar connector adapter.

Fig. 26 is a bipolar adapter connector connected to a stimulation device.

Fig. 27 is a bipolar adapter connected to a stimulation device by a clamp.

Figure 28 is a bipolar adapter with cell holder.

Fig. 29 is a unit jig.

Fig. 30 is a percutaneous adapter.

The present invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Detailed Description

The present specification discloses methods and systems for protecting against nerve, muscle and tendon injury or identifying nerve, muscle, and tendon identity and/or location and assessing their function or the function of the muscles innervated by these nerves during surgery. The system and method are particularly well suited to assist surgeons in identifying nerves and muscles in order to ensure nerve and muscle integrity during medical procedures using medical devices such as stimulation monitors, cutting, drilling, and screwing devices, pilot augers, and fixation devices. For this reason, the system and method will be described in the context of these medical devices.

The system and method desirably allow for application of a sufficiently high level of stimulation signals to locate, stimulate and assess nerve or muscle, or nerve and muscle integrity in a number of medical procedures, including but not limited to assessment of adjacent target tissue areas, adjacent nerve assessment or to identify nerve tissue, assessing whether the nerve is intact (i.e., after trauma) to determine whether repair is likely to be required, assessing muscle contraction to determine whether the muscle is innervated and/or is intact and/or is severed, and assessing muscle and tendon length and effect after repair or tendon delivery before completion of the surgical procedure.

Further, it should be understood that the disclosed systems and methods may be adapted for use with a variety of medical devices in a variety of medical procedures. By way of non-limiting example, aspects of the present invention have application in procedures requiring clamping of a medical device with an internal viewing device.

I. Overview of a System

Fig. 1 shows an illustrative system 20 for locating and identifying tissue and protecting against tissue and/or bone damage during a surgical procedure. In the illustrated embodiment, the system 20 is configured to locate, monitor and stimulate tissue and other structures throughout the body. System 20 includes stimulation control device 22 operating alone or in conjunction with one or more of a family of stimulating medical devices including, for example, stimulation monitor or probe 100, cutting device 200, drilling or screwing device 300, pilot auger 400, and fixation device 500.

In an exemplary embodiment, and as can be seen in fig. 2, stimulation control device 22 is used in system 20 to generate electrical stimulation signals 29. Stimulation signal 29 flows from stimulation control device 22 through guide 24 to the medical device (e.g., stimulation probe 100). The stimulation signal 29 then flows through a predetermined insulated path 124 within the stimulation probe 100 and to an operative element, such as a conductive surface, i.e., the coupling electrode 110. The electrodes 110 are positioned on or near the area of the patient to be stimulated. In monopolar operation, the return electrode 38 (or an indifferent electrode) provides an electrical path from the body back to the control device 22. As will be described in greater detail later, the stimulation control device 22 may be operated in a monopolar or bipolar configuration.

The stimulus signal 29 is adapted to provide an indication or status of the device. This indication may include a physical movement response (e.g., twitch), and/or one or more visual or audible signals from stimulation control device 22, which indicates to the surgeon the state of the device, and/or the close proximity of electrodes 110 to the nerve, or muscle, or nerve and muscle. The stimulation control device may also instruct the surgeon that the stimulation control device is operating properly and delivering stimulation current.

Medical device

The configuration of the stimulating medical device forming part of the system may vary in form and function. A number of exemplary embodiments of illustrative medical devices will be described.

A. Stimulation probe

Fig. 3A-3C illustrate various embodiments of a handheld stimulation monitor or probe 50 for identifying and testing nerves and/or muscles during a surgical procedure. As shown, the stimulation probe 50 may house the circuitry of the stimulation control device 22 within a generally tubular housing 112. Stimulation probe 50 is desirably an ergonomic, sterile, single-use device intended for use during a surgical procedure to identify nerves and muscles, muscle attachments, or to contract muscles to assess the quality of or need for surgical intervention, or to assess the function of nerves that have been identified by visual means. The stimulation electrode 50 may be sterilized, for example, using ethylene oxide.

The stimulation probe 50 is preferably small enough to be held and used by one hand during surgery and is ergonomically designed for use in either the left or right hand. In an exemplary embodiment, the stimulation probe 50 may have a width of about 20 millimeters to about 30 millimeters, and desirably about 25 millimeters. The length of stimulation probe 50 (excluding operative element 110) may be about 18 centimeters to about 22 centimeters, and desirably about 20 centimeters. The operative element 110 may also include angles and bends to facilitate access to deep structures as well as surface structures without requiring large incisions. The operating element 110 will be described in more detail below. A visual or audio indicator 126 incorporated with the housing 112 provides the surgeon with reliable feedback regarding the stimulation current requirements and delivery.

In one embodiment shown in fig. 3C and 14, the stimulation probe 50 includes a housing 112 that includes a grip base 60 and an operating element adjustment portion 62. An operating element 110 extends from the proximal end of the adjustment portion 62. To assist the surgeon in positioning the operating element 110 at the target tissue region, the adjustment portion, as will be described as nose cone 62, may be flexible. This flexibility allows the surgeon to use the fingers or thumb positioned on the nose cone 62 to fine tune the position of the stimulation tip 111 of the operative element 110 at the target tissue region (see fig. 4A and 4B). The surgeon can grip the gripping base 60 with the fingers and palm of the hand and position the thumb on the nose cone 62 and, with pressure applied by the thumb, cause the stimulation tip 111 to move while maintaining a stable position of the gripping base 62. This flexible nose cone 62 feature allows precise control of the position of the stimulation tip 111 by movement of the surgeon's thumb (or finger, depending on how the stimulation probe is held).

As shown in fig. 5, the flexible nose cone 62 may comprise a single element or it may comprise at least an inner portion 64 and an outer portion 66. To promote some flexibility of the proximal portion 114 of the stimulation probe 50, the interior 64 of the nose cone 62 can be made of a thermoplastic material having some flexibility. An example may be lutran. rtm. abs348, or similar material. The outer portion 66 may include a softer overmolded portion and may be made of a thermoplastic elastomer material having some flexibility. One example may be VERSAFLEX. TM. OM3060-1 from GLS corporation. Nose cone 62 is desirably substantially conical. For example, the nose cone 62 may be rounded, as shown in fig. 3A and 3B, or may be more conical in shape, as shown in fig. 3C.

The nose cone 62 may also include one or more features, such as ribs or recesses 72 as shown in fig. 14, to improve the grip, control, and stability of the stimulation probe 50 in the surgeon's hand.

The grip base 60 of the housing 112 may also include an overmolded portion 68. The overmolded portion 68 may comprise the entire length of the grip base 60 or only a portion of the grip base 60. The soft overmolded portion 68 may include one or more features, such as recesses or ribs 70, as shown, to improve the grip, control and stability of the stimulation probe 50 within the surgeon's hand. The overmolded portion 68 may comprise the same or similar material as the thermoplastic elastomer material used for the outer portion 66 of the flexible nose cone 62.

In one embodiment, the stimulation probe 50 includes a housing 112 carrying an insulating guide 124. An insulating guide 124 connects operating element 110 positioned at housing proximal end 114 to circuitry 22 (see fig. 3A) within housing 112. It should be understood that an insulating guide is not necessary and the operating element 110 may be coupled to the circuit 22 (see fig. 3C). The guide 124 within the housing 112 is insulated from the housing 112 using typical insulation means (e.g., wire insulation, washers, spacers, bushings, etc.). The conductive tip 111 of the operating element 110 is positioned in electrically conductive contact with at least one muscle, or at least one nerve, or at least one muscle and nerve.

As shown, the stimulation probe 50 is monopolar and is fitted with a single operative element (i.e., electrode) 110 at the proximal end 114 of the housing. The return electrodes 130, 131 may be coupled to the stimulation probe 50 and may be any of a variety of electrode types (e.g., paddle, needle, wire, or surface) depending on the surgical procedure being performed. As shown, a plurality of return electrodes 130, 131 are coupled to the housing distal end 118. In an alternative embodiment, the stimulation device 50 itself may be bipolar by including a return electrode in the operating element 110, which precludes the use of a return electrode coupled to the stimulation probe 50.

As shown and described, the stimulation probe 50 may house the circuitry of the stimulation control device 22 within the housing 112. In this arrangement, the stimulation probe 50 may have one or more user-operated controls. Two are shown-155 and 160. The power switch 155 serves the dual purpose of turning the stimulation probe 50 on and off (or waiting), and further can be stepped to control the stimulation signal amplitude selection to be within a predetermined range (e.g., 0.5, 2.0, and 20 mA). In this configuration, the switch may be a four-bit switch. The power switch 155 is in the closed position and keeps the stimulation probe off until the first use of the stimulation probe 50. After the stimulation probe 50 is turned on by moving the switch 155 to amplitude selection, the off position now corresponds to a wait state where no stimulation will be delivered. In one embodiment, once the stimulation probe 50 is turned on, it cannot be turned off, it can only return to a wait state and will remain operational for a predetermined time, for example at least about seven hours. This feature is intended to allow the stimulation probe 50 to be a single use device only, so it cannot be turned off and then used again at a later time.

The pulse control device 160 allows for adjustment of the stimulation signal pulse width from a predetermined range (e.g., about zero to about 200 milliseconds). In one embodiment, the pulse controller 160 may be a potentiometer to allow sliding control to increase or decrease the stimulation signal pulse width within a predetermined range.

The stimulation pulses may have a non-adjustable frequency in the range of about 10Hz to about 20Hz, and desirably about 16 Hz.

As a typical example, the stimulation pulse ideally has a biphasic waveform with a controlled current during the cathodic (main) phase and a net dc current of less than 10 microamperes, the switch is adjustable from about 0.5 microamperes to about 20 microamperes, and the pulse duration is adjustable from about zero microseconds up to about 200 microseconds. A typical biphasic stimulation pulse is shown in fig. 6.

The operating element 110 exits the housing 112 at the proximal end 114 to deliver a stimulating current to excitable tissue. The operative element 110 comprises a length and diameter of conductive material, and is desirably completely insulated except for the proximal-most end, such as about 1.0 mm to about 10mm, and desirably about 4mm to about 6 mm, which is uninsulated and serves as a stimulation tip or surface (or also referred to as an active electrode) 111 to allow the surgeon to deliver stimulation current only to the target tissue. The small area of the stimulation surface 111 (active electrode) of the operating element 110 ensures a high current density that will stimulate excitable tissue in the vicinity. The insulating material 113 may include medical grade heat shrink.

The conductive material of the operating element 110 includes a diameter having a range between about 0.5 millimeters and about 1.5 millimeters, and desirably may be about 1.0 millimeter. The length of the operating element 110 may be about 50 mm to about 60 mm, although it should be understood that this length may vary depending on the particular application. As shown, the operating element 110 may include one or more bends to facilitate accurate placement of the stimulation surface 111. In one embodiment, the conductive material of the operating element 110 is made of stainless steel 304 wire, although other known conductive materials may be used.

As previously described, in monopolar operation, the return electrode (or indifferent electrode) 130 or 131 provides, for example, an electrical path from the body back to the control device 22 within the housing 112. The return electrode 130 (see fig. 3A) may be disposed on the surface of the intact skin (e.g., as a surface electrode for ECG monitoring during a surgical procedure) or it may be needle-like 131 (see fig. 3B and 3C) and disposed at the surgical site or through the intact skin. The housing distal end 118 may include a connector or receptacle 120 that provides an option for a return current path, such as through a surface electrode 130 or needle electrode 131 with associated plunger 122. It should be understood that the return electrode and associated lead may be an integral part of the stimulation electrode 50, i.e., without a plunger or connector as shown in fig. 3C.

In addition, the device 50 may desirably include a visual or audio indicator 126 for the surgeon. This visual or audio indicator 126 allows the surgeon to confirm that the stimulator 50 is delivering stimulation current to the tissue it is contacting. By using different tones, colors, different flashing rates, etc., indicator 126 (which may take the form of, for example, a Light Emitting Diode (LED)) allows the surgeon to confirm that stimulation tip 111 is in place, the device is on, and stimulation current is flowing. The surgeon is thus more confident that the failure to cause muscle contraction is due to a failure or some other device problem of the lack of viable neural tissue near the tip 111 of the stimulator 50, rather than the return electrode connection.

As a typical example, in use, the indicator 126 may be configured to continuously illuminate in one color when the stimulation probe 50 is turned on but not in contact with tissue. After contact with the tissue is achieved, the indicator 126 may flash (i.e., flash) to indicate that the stimulus is being delivered. If such stimulation is required, i.e., the stimulation probe is turned on, but no stimulation is delivered due to a lack of continuity between the operating element 110 and the return electrode 130, or an insufficient connection of the operating element 110 or the return electrode 130 to the patient's tissue, the indicator 126 may illuminate in a different color and may illuminate or flash continuously.

In one embodiment, as best seen in fig. 3C and 5, the indicator 126 includes a visually indicating annular indicator 128 that is provided around at least a portion and desirably all of the circumference of the stimulation probe 50 generally adjacent the flexible nose cone 62. The visual annular indicator 128 may be an element of the grip portion 60, or it may be an element of the flexible nose cone 62, or an annular indicator may be positioned between the grip portion 60 and the flexible nose cone 62. The ring indicator 128 may also include a reflective element 129 to improve and concentrate the illumination effect of the light emitting source, such as one or more LEDs. The annular indicator 128 and the reflective element may be a single component, or multiple components (as can be seen in fig. 5 and 15).

Acoustic feedback also makes it possible to assist the surgeon's features during surgery by monitoring neural integrity. An insulated guide 124 is connected to the operating element 110, which in use is positioned within a surgical field on a nerve remote from the surgical site. The nerve stimulation causes the muscle to contract distally. The stimulation control device 22 included within the housing 112 may be programmed to provide an acoustic tone followed by stimulation pulses at prescribed intervals. The sound tone alerts the surgeon to observe the distal muscle contraction to confirm that the nerve is functioning and intact when stimulated.

Fig. 15 shows an exploded view of an exemplary stimulation probe 50. As can be seen, stimulation control device 22 is positioned within housing 112. The battery 34 is electrically coupled to the control device 22. The first and second housing members 90, 92 partially enclose the control device 22. An annular indicator 128 and a reflective element 129 are coupled to the proximal end of the housing 112. The operating element 110 extends through the nose cone 62 and is coupled to the control device 22. Desirably, the stimulation probe 50 will be configured for water intrusion in a manner that complies with at least the IPX1 standard.

Alternatively, as shown in fig. 2, the stimulation control device 22 may be housed in a separate housing, with its own input/output (I/O) controller 26. In this alternative arrangement, stimulation control device 22 is sized small enough to be easily removably secured to a surgeon's arm or wrist during a surgical procedure, or otherwise positioned in close proximity to the surgical site (as shown in fig. 7), to provide sufficient audio and/or visual feedback to the surgeon. In this arrangement, individual stimulation control devices 22 may be temporarily coupled to different families of medical devices for use by the guide.

The present invention includes a method of identifying/locating tissue (e.g., nerve or muscle) in a patient, comprising the steps of: providing a hand-held stimulation probe 50, 100 as described above; engaging the patient with the first operating element 110 and the second electrode 130; moving the power switch 155 to the actuated position causes the stimulation signal 29 to be generated by the stimulation control device 22 and transmitted to the first operating element 110, through the patient's body to the second electrode 130, and back to the stimulation control device 22. The method may further include the step of observing the indicator 126 to confirm that the stimulation probe 50, 100 is generating a stimulation signal. The method may further comprise the step of observing the tissue region to observe tissue movement or lack thereof.

B. Stimulation control device

As shown in fig. 8, stimulation control device 22 includes a circuit 32 that generates an electrical stimulation waveform. The battery 34 desirably provides a source of electrical power. The control device 22 also desirably includes an onboard, programmable microprocessor 36 carrying embedded code. This code expresses preprogrammed rules or algorithms to generate the desired electrical stimulation waveform with stimulation output circuit 46 and for operating the visible or audible indicators 126 based on the controller being actuated by the surgeon.

In one form, the size and configuration of the stimulation control device 22 makes the device less expensive, without manual internal circuit adjustment. It is likely that this type of stimulus control device 22 will be manufactured using an automated circuit board assembly apparatus and method.

C. Incorporating surgical devices

Stimulation control device 22 as just described may be electrically coupled via a guide or embedded within a variety of devices typically used in surgery (as previously described for stimulation probe 50).

1. Cutting device

In fig. 9A and 9B, the device 200 is shown as including all of the features disclosed in the description of the stimulation probes 50, 100, except that the device 200 includes other features that provide an "energized" surgical device or tool. Fig. 9A shows that the tool is a cutting device 200 (e.g., a scalpel) removably coupled to the stimulation control device 22.

In the illustrated embodiment, the cutting device 200 includes a body 212 carrying an insulated guide 224. The insulated lead 224 is connected to an operative element, such as the electrode 210 positioned at the body proximal end 214, and the insertion receiver 219 at the body distal end 118. The lead 224 within the body 212 is insulated from the body 212 using typical insulation means (e.g., wire insulation, washers, spacers, bushings, etc.).

In this embodiment, the electrode 210 performs a cutting feature (e.g., a knife or razor). The electrode 210 performs a cutting feature in electrically conductive contact with at least one muscle, or at least one nerve, or at least one muscle and a nerve. Cutting device 200 desirably includes an insertion receptacle 216 for electrode 210 to allow for the use of a variety of cutting electrode shapes and types (e.g., knife, razor, pointed, blunt, curved) depending on the particular surgical procedure being performed. In this configuration, lead 224 electrically connects electrode 210 to stimulation control device 22 by inserting receptacle 219 with lead 24.

In one embodiment, the cutting device 200 is monopolar and is fitted with a single electrode 210 at the body proximal end 214. In the monopolar mode, the stimulation control device 22 includes a return electrode 38 that serves as a return path for the stimulation signal. The electrodes 38 may be any of a variety of electrode types (paddles, needles, wires, or surfaces) depending on the surgical procedure being performed. The return electrode 38 may be attached to the stimulation device 22 by a connector or plug-in receptacle 39. In an alternative embodiment, the cutting device 200 may be bipolar, which precludes the use of a return electrode 38.

In the embodiment shown in fig. 9B, the cutting device 200 houses the circuitry of the stimulation control device 22 within the body 212. In this arrangement, the cutting device 200 may have at least two operating slide controls 255 and 260. The power switch 255 serves the dual purpose of turning the stimulation signal to the cutting device 200 on and off, and is further stepped to control stimulation signal amplitude selection from a predetermined range (e.g., 0.5, 2.0, and 20 mA). The pulse control switch 260 allows for adjustment of the stimulation signal pulse width from a predetermined range (e.g., zero to 200 microseconds).

At the body distal end 218, a second insertion receiver 220 may be positioned to receive a second guide 222. The lead 222 is connected to an electrode 230, the electrode 230 serving as a return path for the stimulation signal when the cutting device 200 is operated in the monopolar mode.

Further, as previously described, the device 200 may include a visual or audio indicator for the surgeon.

The present invention includes a method of identifying/locating tissue, such as nerves or muscles, in a patient comprising the steps of: providing a cutting device 200 as set forth above; engaging the patient with the first electrode 210 and the second electrode 230; moving the power switch 255 to the actuated position causes the stimulation signal 29 to be generated by the stimulation control device 22 and transmitted to the first electrode 210, through the patient's body to the second electrode 230, and back to the stimulation control device 22. The method further includes the step of observing the indicator 126 to confirm that the cutting device 200 is producing the stimulation signal. The method may further comprise the step of observing the tissue region to observe tissue movement or lack thereof.

2. Drilling device

In fig. 10A and 10B, the device 300 is shown to include all of the features disclosed in the description of the stimulation probes 50, 100, except that the device 300 includes other features that provide an "energized" surgical device or tool that includes a drilling device 300. In fig. 10A, a drilling device 300 is removably coupled to stimulation control device 22.

In the illustrated embodiment, the drilling device 300 includes a body 312 that carries an insulated guide 324. The insulated guide 324 is connected to operational elements, such as an electrode 310 positioned at the body proximal end 314, and an insertion receiver 319 at the body distal end 318. The guide 324 within the body 312 is insulated from the body 312 using typical insulation devices (e.g., wire insulation, washers, spacers, bushings, etc.).

In this embodiment, the electrode 310 performs a drilling feature. The electrode 310 may also perform a screwing feature. The electrode 310 performs a drilling feature in electrically conductive contact with a hard structure (e.g., bone).

Drilling device 300 desirably includes an insertion receiver or chuck 316 for electrode 310 to allow for a variety of drilling and screwing electrode shapes and sizes (e.g., 1/4 and 3/8 inch drill bits, Phillips drives, and flat slot screw drives) to be used depending on the particular surgical procedure being performed. In this configuration, the lead 324 electrically connects the electrode 310 to the stimulation control device 22 by inserting the receptacle 319 with the lead 324.

In one embodiment, the drilling device 300 is monopolar and is fitted with a single electrode 310 at the body proximal end 314. In the monopolar mode, the stimulation control device 22 includes a return electrode 38 that serves as a return path for the stimulation signal. The electrodes 38 may be any of a variety of electrode types (paddles, needles, wires, or surfaces) depending on the surgical procedure being performed. The return electrode 38 may be attached to the stimulation device 22 by a connector or plug-in receptacle 39. In an alternative embodiment, the drilling apparatus 300 may be bipolar, which precludes the use of a return electrode 38.

In fig. 10B, the drilling device 300 is shown as housing the circuitry of the stimulation control device 22 within the body 312. The drilling apparatus 300 may have at least two operating slide controls 355 and 360. The power switch 355 serves the dual purpose of turning the stimulation signal to the drilling apparatus 300 on and off, and is further stepped to control stimulation signal amplitude selection from a predetermined range (e.g., 0.5, 2.0, and 20 mA). The pulse control switch 360 allows for adjustment of the stimulation signal pulse width from a predetermined range (e.g., zero to 200 microseconds). At the body distal end 318, a second insertion receiver 320 may be positioned to receive a second guide 322. The lead 322 is connected to an electrode 330, the electrode 330 serving as a return path for the stimulation signal when the drilling apparatus 300 is operated in a monopolar mode.

Further, as previously described, the device 300 may include a visual or audio indicator for the surgeon.

The present invention includes a method of identifying/locating tissue, such as nerves or muscles, in a patient comprising the steps of: providing a drilling apparatus 300 as set forth above; engaging the patient with the first electrode 310 and the second electrode 330; moving the power switch 355 to the actuated position causes the stimulation signal 29 to be generated by the stimulation control device 22 and transmitted to the first electrode 310, through the patient's body to the second electrode 330, and back to the stimulation control device 22. The method may further include the step of observing the indicator 126 to confirm that the drilling apparatus 400 generated the stimulation signal. The method may further comprise the step of observing the tissue region to observe tissue movement or lack thereof.

3. Pilot screw drill

Other aspects of the invention provide systems and methods for controlling the operation of a stimulation device family including a stimulation control device electrically coupled to a pilot auger for hard surface rotation detection.

In addition to the other features of this embodiment including providing an "energized" surgical device or tool, this embodiment includes all of the features disclosed in the description of the stimulation probes 50, 100. Fig. 11A shows a pilot screw device 400 removably coupled to stimulation control device 22. In the illustrated embodiment, the pilot auger device 400 includes a body 412 carrying an insulated guide 424. The insulated lead 424 is connected to operational elements, such as the electrode 410 positioned at the body proximal end 414 and the insertion receiver 419 at the body distal end 418. The lead 424 within the body 412 is insulated from the body 412 using typical insulation devices (e.g., wire insulation, washers, spacers, bushings, etc.). In this embodiment, the electrode 410 implements a pilot auger feature. The electrode 410 performs a pilot auger feature in electrically conductive contact with a hard structure (e.g., bone).

The pilot auger device 400 desirably includes an insertion receiver or chuck 416 for the electrode 410 to allow for a variety of pilot auger electrode shapes and sizes (e.g., 1/32, 1/16, and 1/8 inches) to be used depending on the particular surgical procedure being performed. In this configuration, the lead 24 electrically connects the electrode 410 to the stimulation control device 22 by inserting the receptacle 419 with the lead 24.

In one embodiment, the pilot auger device 400 is a monopole and is fitted with a single electrode 410 at the body proximal end 414. In the monopolar mode, the stimulation control device 22 includes a return electrode 38 that serves as a return path for the stimulation signal. The electrodes 38 may be any of a variety of electrode types (paddles, needles, wires, or surfaces) depending on the surgical procedure being performed. The return electrode 38 may be attached to the stimulation device 22 by a connector or plug-in receptacle 39. In an alternative embodiment, the pilot auger device 400 may be bipolar, which eliminates the use of the return electrode 38.

As shown in fig. 11B, the pilot auger device 400 may house the circuitry of the stimulation control device 22 within a body 412. At the body distal end 418, a second insertion receiver 420 may be positioned to receive a second guide 422. The lead 422 is connected to an electrode 430, and when the lead auger device 400 is operated in a monopolar mode, the electrode 430 serves as a return path for the stimulation signal.

The pilot auger device 400 includes a power switch 455. When moved to the actuated position, a stimulation signal is generated by the stimulation control device 22. Further, as previously described, the device 400 may include a visual or audio indicator for the surgeon.

The present invention includes a method of identifying/locating tissue, such as nerves or muscles, in a patient comprising the steps of: providing a pilot auger device 400 as set forth above, engaging the patient with the first electrode 410 and the second electrode 430, moving the power switch 455 to the actuated position, causing a stimulation signal to be generated by the stimulation control device 22 and transmitted to the first electrode 410, through the body of the patient to the second electrode 430, and back to the stimulation control device 22. The method further includes the step of observing the indicator 126 to confirm that the pilot auger device 400 is producing the stimulation signal. The method may further comprise the step of observing the tissue region to observe tissue movement or lack thereof.

D. Combined fixing device

Another aspect of the invention provides systems and methods for controlling the operation of a family of stimulation devices that includes a stimulation control device electrically coupled to a fixture or a wrench or screwdriver for deploying the fixture. Fixation devices (e.g., orthopedic hardware, pedicle screws) are commonly used during spinal stabilization (fusion) and endosseous fixation procedures.

In addition to other features of this embodiment including providing an "energized" fixture or tool, this embodiment includes all of the features disclosed in the description of the stimulation probes 50, 100. Fig. 12A shows a fixation device 500 removably coupled to stimulation control device 22. In the illustrated embodiment, the fixture 500 includes a rectangular shaped body 512 that also serves as an operative element, such as an electrode 510. The fixation device 500 may take on an unlimited number of shapes as necessary for the particular procedure taking place. The fixation device may be secured to the bony structure using pedicle screws 535. The electrode 510 performs a fixation feature in electrically conductive contact with a hard structure (e.g., bone).

The fixture 500 or wrench or screwdriver used to deploy the fixture desirably includes an insertion receiver 519. The fixation device 500 may take on a variety of shapes and sizes, without limitation, depending on the particular surgical procedure to be performed. In this configuration, the lead 24 electrically connects the electrode 510 to the stimulation control device 22 by inserting the receptors 519.

In one embodiment, the fixture 500 is monopolar and is equipped with a single electrode 510. In the monopolar mode, the stimulation control device 22 includes a return electrode 38 that serves as a return path for the stimulation signal. The electrodes 38 may be any of a variety of electrode types (paddles, needles, wires, or surfaces) depending on the surgical procedure being performed. The return electrode 38 may be attached to the stimulation device 22 by a connector or plug-in receptacle 39. In an alternative embodiment, the fixture 500 may be bipolar, which excludes the use of the return electrode 38.

In yet another alternative embodiment (see fig. 12B), the fixation device may be a pedicle screw 535. Pedicle screws 535 are removably coupled to stimulation control device 22. In the illustrated embodiment, the pedicle screw 535 includes a head 570 and a shaft 572, each of which serves as an operative element such as an electrode 574. When the pedicle screw 535 is positioned within a bony structure, the electrode 574 performs a fixation feature in electrically conductive contact with the hard structure (e.g., bone). The lead 24 electrically connects the electrode 574 to the stimulation control device 22 via a disconnection or other similar electrical connection means. The fixation device 535 may take on a variety of shapes and sizes, without limitation, depending on the particular surgical procedure to be performed.

In the monopolar mode, the stimulation control device 22 includes a return electrode 38 that serves as a return path for the stimulation signal. The electrodes 38 may be any of a variety of electrode types (paddles, needles, wires, or surfaces) depending on the surgical procedure being performed. In an alternative embodiment, the fixture 500 may be bipolar, which excludes the use of the return electrode 38.

The present invention includes a method of identifying/locating tissue, such as nerves or muscles, in a patient comprising the steps of: providing a fixture 500 as set forth above; engaging the patient with the first electrode 510 and the second electrode 38; power up the stimulation control device 22 through the I/O controller 26; causing the stimulation signal 29 to be generated by the stimulation control device 22 upon actuation and transmitted to the first electrode 510, through the patient's body to the second electrode 38, and back to the stimulation control device 22. The method further includes the step of observing the indicator 126 to confirm that the fastening device 500 is producing the stimulation signal. The method may further comprise the step of observing the tissue region to observe tissue movement or lack thereof.

Technical characteristics IV

The stimulation control device 22, alone or when incorporated into a stimulation probe or surgical device, may include a variety of technical features to enhance its versatility.

A. Small size

According to one desired feature, the stimulation control device 22 may be sized small enough to be held and used with one hand during a surgical procedure, or mounted within a stimulation probe or surgical device. The angle of the stimulating tip facilitates access to deep structures as well as surface structures without the need for a large incision. Visual and/or audible indications incorporated into the housing provide reliable feedback or status to the surgeon regarding the requirements and delivery of stimulation current.

According to alternative desired technical features, the stimulation control device 22 may also be sized small enough to be easily removably secured to the surgeon's arm or wrist during a surgical procedure, or positioned in close proximity to the surgical site (as shown in fig. 7) so as to provide sufficient audio and/or visual feedback to the surgeon.

B. Power supply

According to one desired technical feature, power is provided for a single use by one or more primary batteries 34 positioned inside the housing and coupled to the control device 22. Representative batteries 34 may include alkaline batteries of size "N". In one embodiment, two size "N" alkaline cells are included in series to provide a 3 volt power supply. This configuration is sized and configured to provide an operational lifetime of at least seven hours of operation with continuous or intermittent stimulation.

C. Microprocessor/microcontroller

In accordance with one desired feature, the stimulation control device 22 desirably uses a standard, commercially available micro-power source, flash programmable microcontroller 36. The microcontroller 36 reads the controls operated by the surgeon, controls the timing of the stimulation pulses, and controls feedback to the user regarding the status of the device (e.g., with 1, 2, or more colored LEDs that can be turned on, off, or blinking).

The microcontroller operates at low voltage and low power. The microcontroller sends the low voltage pulses to a stimulation output stage 46 that converts these low voltage signals into higher voltage, controlled voltage, or controlled current, stimulation pulses that are applied to the electrode circuit. The stimulation output phase 46 generally involves the use of a series of capacitors to prevent the presence of DC current flow in the electrode circuit in normal operation or in the event of a failure of an electronic component.

Representative use of stimulation probes

The stimulation probe 50, 100 as described enables application of a sufficiently high level of stimulation signals for the purpose of locating, stimulating and assessing nerves or muscles or nerve and muscle integrity in a number of medical procedures, including but not limited to a region of assessment adjacent a target tissue area, adjacent nerve assessment or to identify nerve tissue, assessing whether nerves are intact (i.e., after trauma) to determine whether repair is likely to be required, assessing muscle contraction to determine whether muscles are innervated and/or muscles are intact and/or muscles are severed, and assessing muscle and tendon length and effect after repair or tendon delivery before completion of a surgical procedure.

Instructions 80 are desirably included in a kit 82 along with the stimulation probe 50. The kit 82 may take a variety of forms. In the illustrated embodiment, the kit 82 includes a sterile, packaged assembly. The representative kit 82 includes an internal tray 84 holding contents, for example, made of die cut cardboard, plastic sheet, or thermoformed plastic material. The kit 82 also desirably includes instructions for use 80 to utilize the contents of the kit to perform a desired therapeutic and/or diagnostic purpose.

The instructions 80 instruct the user through the steps of removing the stimulation probe 50, positioning the electrodes, and discarding the single-use disposable stimulator 50. Representative descriptions may include, but are not limited to:

(1) the stimulation probe 50 is removed from the sterile packaging 88.

(2) The cover 94 (e.g., a silicone cover) is removed from the operating element 110.

(3) The protective cover 86 is removed from the return electrode 131.

(4) Positioning the return electrode 131 in contact with the patient causes:

(a) the return electrode is desirably positioned in an area remote from the area to be stimulated;

(b) the return electrode is ideally not positioned across the body from the side being stimulated; and

(c) the return electrode is desirably not positioned in muscle tissue.

(5) The stimulation probe 50 is turned on by moving the power switch 155 from off to the 0.5mA setting (or greater).

(6) The stimulation probe 50 is desirably turned on before the operating element 110 is brought into contact with the tissue.

(7) If the stimulation probe 50 is on but not in contact with the tissue, the indicator 126 will be illuminated yellow (for example) continuously.

(8) Bringing the tissue into contact with the operating element 110.

(9) The pulse controller 160 is gradually adjusted to increase the level of stimulation.

(10) The indicator 126 will flash yellow to indicate that the stimulus was delivered.

(11) A flashing red indicator 126, for example, means that stimulation is required, but stimulation is not delivered because of insufficient connection of the operating element 110 or return electrode 131 to the patient tissue.

(12) The return electrode contact and position are checked and the operating element 110 contact and position are checked.

(13) Placing the power switch 155 in the off/standby position will stop the stimulus and the visual indicator 126 will be continuously illuminated yellow.

(14) Placing the pulse controller 160 at the minimum position will stop the stimulation and the visual indicator 126 will be illuminated yellow continuously.

(15) The low/depleted battery 34 will cause the stimulation probe 50 to automatically turn off and will not illuminate the visual indicator 126.

(16) It would be possible to not use the stimulator 50 any further.

(17) At the end of use, the power switch 155 is moved to the off/standby position and the pulse controller 160 is moved to the minimum position.

(18) The return electrode 131 is cut off and the return electrode 131 is discarded into an appropriate sharps/biohazard container.

(19) The stimulation probe 50 is processed according to hospital or facility guidelines.

In the embodiment shown in fig. 16-22, the system may include a bipolar stimulation device as further described below.

System for controlling a power supply

Fig. 16 illustrates a system 610 for distinguishing and/or identifying the presence of a target nerve fiber or branch within a tissue region TR. The system 610 includes a first system 612 for generating and applying a stimulation current to tissue in a region TR of a target nerve fiber or branch. This system 610 also includes a second system 614 for sensing the presence or absence of a desired physiological response to the application of the electrical stimulation current. The presence of the expected physiological response distinguishes and/or identifies the presence of a target nerve fiber or branch within the tissue region TR. Once distinguished and identified, the nerve fibers or branches of the target may be manipulated for desired diagnostic and/or therapeutic reasons.

A. First device

As shown in fig. 17A-19, the first system 612 includes a handle 616 that is preferably sized small enough to be held and used like a flashlight or screwdriver to allow the thumb to push a button to control the application of the stimulation current (see fig. 19). The handle 616 carries an insulated probe 618. The probe 618 carries an electrode assembly 620 (see fig. 18A) at its distal end. The first system 612 is preferably a sterile, single-use device.

In the exemplary embodiment, handle 616 is cylindrical in shape and has a maximum diameter of about 25mm at its proximal end. The handle 616 tapers from the proximal end to the distal end to a smaller diameter of about 10 mm. In an exemplary embodiment, the length of the handle 616 is approximately 17 cm.

In an exemplary embodiment, the probe 618 extends approximately 8cm from the distal end of the handle 616 and includes an electrode assembly 620 at its distal end. In a representative embodiment, the probe 618 has a diameter of about 10 mm.

The electrode assembly 620 (see fig. 18A) is sized and configured to accurately identify the tissue region innervated by the target nerve. The electrode assembly 620 may be configured like something like a dental mirror and may have a diameter in the range of about 10mm to about 15 mm. The assembly 620 may be slightly offset (e.g., 10 to 50 degrees) from the probe 618 to provide for ease of use and a more ergonomic configuration. The electrode assembly 620 may include a bipolar array of two contacts 622 and 624 exposed on the distal face 626 of the probe 618. The contacts 622 and 624 may have a diameter in the range of about 1 (one) mm to about 3mm and may protrude beyond the distal end face by 1 (one) mm or less. The spacing between contacts 622 and 624 on distal face 626 may be about 1 (one) mm to about 4 mm. The edges of the contacts 622 and 624 are desirably rounded so as not to damage tissue. The small area of contacts 622 and 624 ensures a high current density that will stimulate nearby excitable tissue.

It should be understood that other configurations for the electrode assembly may be possible. For example, fig. 18B and 18C show two additional possible configurations. Fig. 18B shows electrode assembly 640 with contacts 642 and 644 exposed on distal face 646 of probe 618. Contacts 642 and 644 are circumferentially spaced 180 degrees apart. As shown, contacts 642 and 644 are exposed on distal face 646 of probe 618, each occupying about 90 degrees to about 95 degrees of the circumference of distal face 646 of probe 618. Contacts 642 and 644 also desirably extend proximally along the probe by about 5mm and project a short distance, e.g., 1mm, beyond the distal face 646 of the probe 618. The spacing between contacts 642 and 644 on distal face 646 may be about 1 (one) mm to about 4 mm. The edges of contacts 642 and 644 are desirably rounded so as not to damage tissue. Fig. 3C shows a ring electrode assembly having an outer contact 652 and an inner contact 654 exposed on the distal face 656 of the probe 618. The outer contact 652 may also extend proximally along the probe.

Contacts 622 and 624 (and their alternative embodiments) may comprise, for example, stainless steel, silver, platinum, or platinum treated with platinum black. The probe 618 comprises, particularly at its distal face 626, a plastic material that is poorly wetted with body fluids, preferably by blood, saline, to minimize the risk of passing current through the fluid path when there is no direct tissue contact. The probe 618 is insulated from the handle 616 using typical insulation means (e.g., wire insulation, washers, spacers, bushings, etc.).

Alternatively, a unipolar arrangement may be used. In this embodiment, a return electrode (or indifferent electrode) must be provided to provide an electrical path from the body back to the device. The return electrode may be disposed on the surface of the intact skin (e.g., a surface electrode such as used for ECG monitoring during a surgical procedure) or it may be needle-shaped and disposed at the surgical area or through the intact skin.

An electrical stimulation control circuit 628 is carried within the handle 616 (see fig. 17A and 17B). The control circuit 628 generates a stimulation current that is applied through the contacts 622 and 624. The control circuit 628 is driven by a primary battery (for single use applications) located within the handle 616. The battery may be rechargeable if the device is not intended for single use.

The control circuit 628 desirably comprises an on-board, programmable microprocessor that carries embedded code. This code expresses pre-programmed rules or algorithms for generating the desired electrical stimulation waveform. In a representative embodiment, the stimulation frequency is 20Hz, (although the frequency may be adjustable, e.g., 3Hz to 100Hz), and this waveform comprises a charge-balanced biphasic waveform (i.e., no net DC current flowing).

Other operating parameters of the control circuit 628 may be adjusted by controls conveniently carried on the handle 616.

In the illustrated embodiment (see fig. 17A), the stimulation amplitude and stimulation pulse duration are adjusted by a rotary switch 630 or wheel near or on the proximal end of the handle 616. The rotary control switch 630 desirably has a label for identifying a plurality of setting selections. For example, the first few settings may include different amplitudes, each amplitude having the same fixed pulse duration. Other settings may provide a series of selectable settings including a particular combination of amplitude and pulse duration. The rotary control switch 630 also desirably has detents that provide the clinician with good tactile feedback when moving from one setting to the next. The range of labeled stimulation settings may include, for example, off, wait, 1.5mA at 100 μ sec, 3mA at 100 μ sec, 5mA at 300 μ sec, and 10mA at 500 μ sec.

A momentary button 632, e.g., on the side of the housing 616, used by the thumb, for example, controls the delivery of the stimulating current through the contacts 622 and 624. The momentary button 632 allows the first system 612 to be controlled, for example, by turning the stimulation current on and off with only one hand. Only if momentary button 632 is pressed, stimulation current is delivered through contacts 622 and 624 (at the amplitude/duration set by rotary switch 630). If button 632 is not pressed, no stimulation current is delivered.

In an alternative embodiment (see fig. 17B), the stimulation pulse duration may be adjusted by an adjustable stepped slide switch 634 on the handle 616. Thus, if momentary button 632 is pressed, a stimulation current is applied at a prescribed magnitude and for a prescribed duration. If button 632 is not pressed, no stimulation current is delivered. The slide switch 634 desirably has a label to identify the selected pulse duration. The slide switch 634 desirably also has a detent that provides the clinician with good tactile feedback when moving from one pulse duration step to the next. The range set by the pulse duration of the flag may include, for example, off, 100 musec, 300 musec, or 500 musec. The slide switch 634 may also have an identified waiting position.

Alternatively, if the pulse duration slide switch 634 is not provided, and the pulse duration is not selected via the rotary control switch 630, then the stimulation pulse duration may be fixed at a nominal selected duration, for example 250 μ sec.

The control circuit 628 desirably includes an optical indicator, i.e., a light emitting diode LED638 on the handle that provides a variety of indications to the surgeon. For example, the LED638 may confirm the battery status and the stimulator on/off status. It is also desirable that the LED638 flashes green when sufficient stimulus is delivered, and that the LED638 flashes red when insufficient stimulus is delivered. Further, the LED638 may blink or illuminate only if the actual delivered current is within a desired percentage of the desired magnitude, such as within 25% of the desired value. The control circuit 628 thus provides the clinician with reliable feedback regarding the stimulation current that is required to be delivered.

In an alternative embodiment, the control circuit 628 may also generate an acoustic tone only when the stimulation current is delivered. The tone is transmitted by indicator 636 on handle 616.

By using different tones, colors, different flash rates, etc., the control circuit 628 may allow the clinician to confirm that the probe is in contact with the tissue, that the device is on, that the battery has sufficient power, and that the stimulation current is flowing. The clinician is thus more confident that the desired response cannot be elicited because of the lack of visible nerve tissue near the tip of the probe rather than the failure of the electrode connector or the problem of some other device.

B. Second device

The second system 614 may take a variety of forms depending on the physiological function of the target tissue region and the nature and characteristics of the physiological response expected based on the electrical stimulation current applied by the first system 612.

For example, electrical stimulation of parasympathetic nerves affecting respiratory activity causes breathing to be slow. Thus, when it is desired to distinguish and/or identify the presence or absence of parasympathetic nerves affecting respiratory activity, a reduction in respiratory rate may be used as the desired physiological response. In this arrangement, the second system 614 may include a device that monitors respiration. The device may comprise, for example, a chest position sensor and a spirometer box that monitors the movement of the chest. The device may also include a respiration sensor worn around the chest, such as a respiration (extension) sensor or a thoracograph. A decrease in the respiratory rate detected by the second device indicates that the first device is positioned at or near the parasympathetic nerve.

As another example, stimulation of parasympathetic nerves affecting cardiac function increases resting potential and decreases the rate of diastolic depolarization. In these cases the heart rate slows down. Thus, when it is desired to distinguish and/or identify the presence or absence of parasympathetic nerves affecting cardiac activity, the cardiac rate may be used as the expected physiological response. In this arrangement, the second system 614 may include an Electrocardiogram (EKG) device.

As another example, stimulation of parasympathetic nerves affecting digestion (e.g., during the head phase of gastric secretion) modulates reflex gastric secretion. Thus, when it is desired to differentiate and/or identify the presence or absence of parasympathetic nerves affecting gastric activity, the reduction in gastric secretion can be used as the desired physiological response. In this arrangement, the second system 614 may include a device that senses gastric fluid secretion.

As another example, the second system 614 may include an Electromyography (EMG) device. The EMG device measures nerve impulses within the muscle. The EMG system includes electrodes disposed in muscles in the tissue innervated by parasympathetic nerves, and the electrical response to the operation of the first system 612 can be observed with a device (e.g., oscilloscope) that displays the movement of the current. As the muscles contract, they emit weak electrical signals that can be detected, amplified, and tracked as the expected physiological response.

Use of the System

In use, the first system 612 is positioned in contact with tissue in the target tissue region TR. The clinician may operate the first system 612 with one hand to apply the stimulation current. The clinician's other hand may then adjust the stimulation current as necessary. The second system 614 monitors the physiological response. The first system 612 is positioned and repositioned (if necessary) until the monitored physiological response indicated by the second system 614 matches or is close to the desired physiological response. This indicates the presence of the target nerve fiber or branch, and the identified location may then be marked. A desired treatment regime may then be performed, for example to manipulate the parasympathetic nervous system for therapeutic effect.

For example, without the need for tissue ablation and without the need for physiologic conduction interruptions, it has been observed that the parasympathetic nervous system of the heart can be manipulated to coordinate with cardiac conduction and/or serve as a function of atrial fibrillation. It is known that parasympathetic nerve fibers of the vagus nerve can be manipulated to affect cardiac cycle length. It is also known that parasympathetic nerve fibers of the vagus nerve selectively coordinate the epicardial Atrioventricular (AV) node fat pad and the Sinoatrial (SA) node fat pad (as shown in fig. 20).

The system 610 enables, for example, distinguishing from identifying epicardial atrioventricular node fat pads on the surface of the heart and thereby enabling access to the parasympathetic nervous system of the heart at this location for therapeutic effect.

More specifically, a first system 612 of the systems 610 causes highly localized electrical stimulation to be applied to the surface of the heart while a second system 614 monitors the heart rate. The clinician may initiate application of the stimulation current at the lowest amplitude setting and increase the amplitude setting as necessary. Due to physiological differences in the patient and tissue regions of the patient, modulation may be necessary. After a visual inspection of the tissue region TR indicates that a higher initial setting may be necessary, the clinician may also begin to apply stimulation current at a setting other than the lowest amplitude setting.

When the first system 612 applies stimulation and is ultimately positioned at or near the area of the atrioventricular nodal fat pad (see fig. 22), the heart rate (monitored by the second system 614, e.g., an EKG device) will decrease. The EKG device 614 will indicate a decrease in heart rate by an increase in the R-to-R spacing observed on the EKG (compare the R-to-R spacing shown in fig. 21 with the increased R-to-R spacing shown in fig. 22). The clinician may then stop applying the stimulation current to the tissue region, such as the identified atrioventricular node fat pad, and observe the heart rate increase back to the original heart rate (the decrease in R to R observed on the EKG). The clinician may go through the steps of applying a stimulation current, observing an increase in the R-to-R spacing, stopping the application of the stimulation current, and observing a decrease in the R-to-R spacing to confirm the exact location of the target tissue region, such as the atrioventricular nodal fat pad. In this manner, the system 610 allows the surgeon to systematically and accurately position the atrioventricular nodal fat pad (and other areas selectively innervated by parasympathetic nerves) on the surface of the heart.

Once located, the clinician may use the first system 612 to apply a stamp or other marker to maintain identification of the atrioventricular node fat pad. Alternatively, a separate applicator may be used to apply the punch or other marking, or the clinician may use visual skills with their fingers, for example, to maintain identification of atrioventricular fat pads. The clinician may then take steps to perturb the parasympathetic nervous system of the heart for therapeutic effect. For example, the clinician may treat or prevent uncontrolled atrial fibrillation or perform other desired treatments, or the clinician may apply a closed loop feedback control algorithm that provides physiological control of the atrioventricular node rate, by electrical or non-electrical manipulation of the atrioventricular node fat pad located by the system 610.

Manipulation of the atrioventricular node fat pad positioned by the system 610 maintains physiologic conduction. By electrical manipulation, its beneficial effects can be turned on and off simultaneously with no attenuation of the effect. Manipulation of the atrioventricular node fat pad may provide a viable alternative to atrioventricular node fat ablation in the treatment of atrial fibrillation, which does not preserve physiologic conduction and instead leads to patient fidgeting to cardiac pacing reliance.

Adapter design

In an embodiment, the system 20 may be configured to receive an adapter. The adapter may be configured to connect to a portion of the system 20, such as to the stimulation probe 50. This adapter may provide other functions, usability, and control of the stimulation probe 50.

In an embodiment, as shown in fig. 23-29, the adapter may be a bipolar adapter 710. The adapter may be configured to attach to the control device 22, such as the stimulation probe 50, to allow the device to function as a bipolar device having all of the functions of the bipolar device described above.

The bipolar adapter 710 may be used with a monopolar stimulation device to provide more accurate stimulation control. In particular, the bipolar adapter 710 can provide a return element 716 in addition to the primary operational element 110 of the stimulation probe 50 to define the stimulation electric field and direct the stimulation to a particular desired location, such as a target nerve. The return element 716 may comprise a wire or any other insulated electrical conductor and may comprise a tip or electrode 718 for making electrical contact with the target tissue.

In an embodiment, adapter 710 may include a connector 712. The connector 712 may be any suitable size and shape, such as generally elongated as shown in fig. 23 and 24. The connector 712 may be generally tapered so as not to obstruct the user's view during the procedure. The connector 712 may be configured to connect to the stimulation probe 50. For example, the connector may include an opening 714 for receiving a portion of the operative element 110 of the stimulation probe 50 therein. Opening 714 may extend through a portion or all of connector 712. The opening 714 may be sized and shaped to receive the operating element 110 therein. For example, the operating element 110 may extend from a first end of the connector 712 through an opening and protrude through the opening 714 at a second or opposite end of the connector 712. Conductive portions of the operative element 110 can be exposed to allow current to flow to the target tissue.

The opening 714 may be configured to hold the operating element 110 in place. For example, the opening 714 may be tapered to hold the probe in a press fit. The opening 714 may be further configured to include a set screw or other retaining feature to retain the operating element 110 at a desired position.

The connector 712 may include a second probe or return element 716. As shown in fig. 25, return operating element 716 may be spaced a particular distance D from opening 714. The distance D may be measured from the center of the opening 714 to the center of the return element 716, and may be any suitable distance such as 2 millimeters, 1 millimeter, or any other suitable distance.

The return element 716 may be any suitable diameter. For example, the stimulation probe 50 operative element 110 can have a diameter of about 0.04 inches. The return element 716 may have a smaller diameter, such as 0.02 inches, or any other suitable diameter.

The bipolar adapter 710 may also include ultra-soft, thin strands 720 extending from the connector 710. The ultra-soft fine strands 720 may be any suitable length and may be configured as an electrical ground or any suitable electrical circuit. For example, the ultra-soft fine strands 720 may include a connector 722 at one end to accommodate a luer connection or other electrical connection.

In the embodiment shown in fig. 26, connector 712 may be configured to directly receive an electrical connection from the return operative element. For example, the connector 712 may include a plunger 724 adjacent the opening 714 for receiving the operating element 110. Plunger 724 may receive a luer connector or any other suitable electrical connector. Plunger 724 may be in electrical connection with return member 716.

In an embodiment, the bipolar adapter 710 may be arranged to clamp or snap onto the stimulation probe 50. Adapter 710 can include a return element 716 having an insulating portion 730 and an exposed portion 732. The adapter 710 may also include one or more clamps for connecting the return element 716 to the stimulation probe 50. For example, as shown in fig. 27, the adapter 710 may include a first clamp 734 arranged to connect to a body or housing of the stimulation probe 50. A further clamp 736 may be arranged to be connected to the operating element 110 of the stimulation probe 50. Other clips 736 may allow the return element 716 to follow the path of the operating element 110 to prevent any obstruction to the user's view. The adapter 710 may include a receiving member 738 coupled to the return element 716. The receiving member 738 may be configured to receive an electrical connector, such as a luer connector, to provide a ground or other electrical signal on the return element 716.

In an embodiment, as shown in fig. 28 and 29, the adapter 710 may include a single unit clamp 740. The unit clamp 740 may be designed to receive the return element 716 of the adapter and the operative element 110 of the stimulation probe 50.

The cell holder 740 may include a first channel 742 and a second channel 744. The first channel 742 may be configured to receive the primary operating element 110 therein, and the second channel 744 may be configured to receive the return element 716 therein. The channel may be substantially circular or have a substantially circular or semi-circular cross-section, or any suitable shape to retain and retain the element 110, 716. The channels may have different diameters to accommodate the different diameters of the electrodes 110, 716. For example, the first channel 742 may be configured to receive a component having a diameter of about 0.04 inches, while the second channel may be configured to receive a component having a diameter of about 0.02 inches. As shown in fig. 28 and 29, the channels 742, 744 can be of different lengths. For example, the first channel 742 may be longer and extend to the base of the operative element 110, while the second channel 744 may be shorter and may allow the return element 716 to extend away from the body of the stimulation probe 50.

The operating element 110 may be positioned in the first channel 742 such that the tip 111 of the operating element 110 extends beyond the end of the unit clamp 740. Likewise, the return operating element 716 may be positioned in the second channel 744 such that the tip 718 of the return operating element 716 extends beyond the end of the unit clamp 740.

The cell holders 740 may be curved or angled. For example, as shown in fig. 28 and 29, the unit clamp may include a first portion 750 and a curved portion 752 angled away from the first portion. The angle of the curved portion 752 may be designed to follow the angle of the operating element 110 and match the angle of the operating element 110. The curved portion 752 may be angled downwardly relative to a user holding the stimulation probe 50 to prevent any visual obstruction and allow the user to maintain a clear line of sight.

The adapter 710 may include a receiving member 746 that is coupled to the return operating element 716. Receiver 746 may be configured to receive an electrical connector therein, such as a needle or luer connector. The receiving member 746 can allow the return operative element 716 to be connected to electrical ground or complete the electrical circuit of the stimulation probe 50.

The clamp described in any of the above embodiments may be adjustable. For example, the clamp may be malleable, slidable, or otherwise movable to allow selective adjustment of the distance between the operating element tip 111 and the return element tip 718. The user may adjust the clamp to achieve a desired distance for a given application.

In an embodiment, as shown in fig. 30, the adapter may be a percutaneous adapter 810. The percutaneous adapter 810 may be configured to allow the stimulation probe 50 to deliver a stimulation signal beneath the skin of the target patient.

The percutaneous adapter 810 may include a connector 812. The connector 812 may be configured to connect to the operative element 110 of the stimulation probe 50. For example, the connector may include an opening 814 for receiving the operating element 110 therein. The opening 814 may be tapered to retain the operative element 110 within the connector 812 with a press fit. The connector may also include other retaining features, such as set screws or clamps, to maintain the connection between the connector 812 and the operating element 110.

The percutaneous adapter 810 may include leads 816 extending from the connector 812. The leads 816 may be electrical conductors that electrically connect to the operative element 110 inserted into the connector 812. The wire 816 may be any suitable length, such as 24 inches or a length between 12 inches and 48 inches. The lead may further be any suitable gauge, such as a 24AWG wire.

The percutaneous adapter 810 may include a needle 820 connected to the lead 816. The needle may be made of any suitable material, such as stainless steel. Preferably, the needle may be made of an electrically conductive material and is in electrical communication with the lead 816. A sheath 822 may be positioned at the base of the needle 820 to ensure a connection between the lead 816 and the needle 820. A portion of the needle 820 may be insulated. For example, the needle may be insulated up to 5 millimeters away from its tip 824. The exposed tip 824 of the needle 820 may deliver electrical stimulation signals to target tissue below the skin surface.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While preferred embodiments have been described, the details may be changed without departing from the invention, which is defined by the claims.

Claims (14)

1. A bipolar adapter, comprising:

a clip arranged to be connected to a monopolar stimulation control device having an operating element capable of applying an electrical stimulus, the clip comprising: a first channel configured to snap or clamp to an operating element of the monopolar stimulation control device; and a second channel;

a return operating element positioned within the second channel,

wherein the return operative element of the bipolar adapter is configured to be in electrical communication with the circuitry of the monopolar stimulation control device, and

wherein the clamp includes a first portion and a second portion formed at an angle relative to the first portion.

2. The bipolar adapter of claim 1, wherein the operative element comprises an insulated portion and a non-insulated tip extending beyond an end of the clamp.

3. The bipolar adapter of claim 1, wherein the return operative element comprises an insulated portion and a non-insulated tip extending beyond an end of the clamp.

4. The bipolar adapter of claim 1, wherein the angle of the first and second portions is configured to match an angle of the operating element.

5. The bipolar adapter of claim 1, wherein the first channel and the second channel have a substantially semi-circular cross-section.

6. The bipolar adapter of claim 1, further comprising a receiver connected to the return operative element, wherein the receiver is configured to receive an electrical connector therein.

7. The bipolar adapter of claim 1, wherein a distance between a tip of the operative element positioned in the first channel and a tip of the return operative element positioned in the second channel is 2 millimeters.

8. The bipolar adapter of claim 1, wherein the clamp is adjustable to adjust a distance between the tip of the operating element and the tip of the return operating element.

9. A stimulation system, comprising:

a monopolar stimulation control device, comprising:

a housing; and

an operating element extending from the housing, the operating element capable of applying an electrical stimulus; a bipolar adapter connected to the monopolar stimulation control device, comprising:

a clamp arranged to connect to the monopolar stimulation control device and having a first channel and a second channel; and

a return operative element positioned within the second channel; wherein the operating element is snapped or clamped in the first channel and

wherein the clamp includes a first portion and a second portion formed at an angle relative to the first portion.

10. The stimulation system of claim 9, wherein said return operative element is connected to electrical ground.

11. The stimulation system of claim 9, wherein said stimulation control device is configured to generate an electrical stimulation signal.

12. The stimulation system of claim 11, wherein said stimulation control device is configured to control the amplitude and duration of said electrical stimulation signal.

13. The stimulation system of claim 9, wherein said housing is sized and configured to be held in and controlled by a single human hand.

14. The stimulation system of claim 9, wherein the diameter of the tip of the return operative element is approximately 0.02 inches.