US20120239057A1 - Device and method for manipulating and inserting electrode arrays into neural tissues - Google Patents

Abstract

An insertion device for inserting a therapeutic device into organic tissue is disclosed and described. The device is particularly suited to insertion of such as nerve stimulating electrode arrays. The insertion device has at least one controllable positive pressure source (greater than atomospheric), two vacuum sources and a dual vacuum pressure control system. The positive pressure and the dual vacuum pressure control systems are manipulated to allow the manipulation and insertion or retrieval of a therapeutic device. The insertion device can be spatially manipulated by hand, without requiring other equipment for positioning the insertion device.

Description

RELATED APPLICATION
• This application is continuation of U.S. patent application Ser. No. 12/055,053, filed Mar. 25, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 11/970,375, filed Jan. 7, 2008 which claims the benefit of U.S. Provisional Application No. 60/878,781, filed Jan. 5, 2007, which are each incorporated herein by reference.
FIELD OF THE INVENTION
• The present invention is directed toward a therapeutic device insertion device that can be spatially manipulated by hand, and can insert a therapeutic device into organic tissues by utilizing a pneumatic, high-speed insertion mechanism.
BACKGROUND OF THE INVENTION AND RELATED ART
• Therapeutic devices can be used for a wide variety of reasons. As an example, a therapeutic device like the Utah Electrode Array (UEA) or the Utah Slanted Electrode Array (USEA) may be inserted into nerve tissue to allow the array to receive electrical signals from or deliver electrical signals to the nerve tissue. Such an array can be implanted in any type of nerve tissue. The UEA is described in U.S. Pat. No. 5,361,760, which is hereby fully incorporated by this reference.
• Many different types of therapeutic device insertion devices have been developed for inserting a therapeutic device. Previous insertion devices have two main limitations: they do not allow the insertion device to be spatially manipulated by hand, and the insertion devices are unable to retrieve the therapeutic device from the organic tissue. The insertion speed of previous insertion devices is relatively slow, for example 1-4 meters per second. This relatively slow insertion speed made it probable that complete electrode array insertion might not occur during insertion. Also, conventional techniques required the time consuming use of mechanical, robotic or other equipment to reliably position the electrode array prior to insertion.
SUMMARY OF THE INVENTION
• In light of the problems and deficiencies inherent in the prior art, the present invention seeks to overcome these by using an insertion technique that greatly increases the insertion speed for the insertion device and minimizes the time required for array positioning. The insertion device can also retrieve the therapeutic device after it has been inserted.
• In accordance with the invention as embodied and broadly described herein, the present invention includes the use of two vacuum sources as a primary means of inserting a therapeutic device. Control of the two vacuum provides effective control of placement of a therapeutic device using a vacuum tip. Further, the present invention allows the insertion device to be spatially manipulated by hand, as opposed to requiring other equipment to position the insertion device prior to insertion. The insertion speed of the present invention can generally be approximately 8-12 meters per second although other speeds can be achieved and may be suitable in some circumstances. For example, an additional compression source can be fluidly associated with the vacuum tip to allow for application of a positive pressure sufficient to accelerate the therapeutic device towards neural tissue.
• There has thus been outlined, rather broadly, the more important features of the invention so that the detailed description thereof that follows may be better understood, and so that the present contribution to the art may be better appreciated. Other features of the present invention will become clearer from the following detailed description of the invention, taken with the accompanying drawings and claims, or may be learned by the practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings merely depict exemplary embodiments of the present invention and they are, therefore, not to be considered limiting of its scope. It will be readily appreciated that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged, sized, and designed in a wide variety of different configurations. Nonetheless, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
• FIG. 1 is a side cross-sectional view of the insertion device having a UEA retained at the tip in accordance with one embodiment of the present invention.
• FIG. 2 is a side cross-sectional view of a vacuum connection adapter of the insertion device in accordance with one embodiment of the present invention.
• FIG. 3 is a plan bottom view of the adapter ofFIG. 2.
• FIG. 4 is a plan top view of the adapter ofFIG. 2.
• FIG. 5 is a perspective view of the outside barrel of the insertion device in accordance with one embodiment of the present invention.
• FIG. 6 is a perspective view of the central tube connected to the piston stop of the insertion device in accordance with one embodiment of the present invention.
• FIG. 7 is a bottom plan view of the piston stop ofFIG. 6.
• FIG. 8 is a top plan view of the piston stop ofFIG. 6.
• FIG. 9 is a side view of the momentum transfer member of the insertion device in accordance with one embodiment of the present invention.
• FIG. 10 is a top plan view of the momentum transfer member ofFIG. 9.
• FIG. 11 is a side cross-sectional view of the insertion device in accordance with another embodiment of the present invention.
• FIG. 12 is a side cross-sectional view showing dimensions of an alternative inserter tip having a flanged tip portion in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
• The following detailed description of exemplary embodiments of the invention makes reference to the accompanying drawings, which form a part hereof and in which are shown, by way of illustration, exemplary embodiments in which the invention may be practiced. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. Thus, the following more detailed description of the embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the present invention, to set forth the best mode of operation of the invention, and to sufficiently enable one skilled in the art to practice the invention. Accordingly, the scope of the present invention is to be defined solely by the appended claims.
• The following detailed description and exemplary embodiments of the invention will be best understood by reference to the accompanying drawings, wherein the elements and features of the invention are designated by numerals throughout.
• In describing and claiming the present invention, the following terminology will be used.
• The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a vacuum” includes reference to one or more of such devices and reference to “inserting” refers to one or more such steps.
• As used herein with respect to an identified property or circumstance, “substantially” refers to a degree of deviation that is sufficiently small so as to not measurably detract from the identified property or circumstance. The exact degree of deviation allowable may in some cases depend on the specific context.
• As used herein, “adjacent” refers to the proximity of two structures or elements. Particularly, elements that are identified as being “adjacent” may be either abutting or connected. Such elements may also be near or close to each other without necessarily contacting each other. The exact degree of proximity may in some cases depend on the specific context. As used herein with respect to two parts or elements, “connected” refers to any appropriate means for connecting the two elements, such as complimentary threads, adhesives or other mechanical connections. For example, and not by way of limitation, one element may include inside threads corresponding to outside threads on another element. Similarly, one element may have a diameter that is substantially identical to the diameter of another element and these two elements could be connected by abutting the two elements and cementing them together with an appropriate adhesive.
• As used herein, “fluid communication” refers to a continuous unimpeded fluid path between two volumes, such that fluids, e.g. gases, can flow between the two volumes substantially unimpeded.
• As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.
• Concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a numerical range of about 1 to about 4.5 should be interpreted to include not only the explicitly recited limits of 1 to about 4.5, but also to include individual numerals such as 2, 3, 4, and sub-ranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges reciting only one numerical value, such as “less than about 4.5,” which should be interpreted to include all of the above-recited values and ranges. Further, such an interpretation should apply regardless of the breadth of the range or the characteristic being described.
• In the present disclosure, the term “preferably” or “preferred” is non-exclusive where it is intended to mean “preferably, but not limited to.” Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. Means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; and b) a corresponding function is expressly recited. The structure, material or acts that support the means-plus function are expressly recited in the description herein. Accordingly, the scope of the invention should be determined solely by the appended claims and their legal equivalents, rather than by the descriptions and examples given herein.
• A method and system for inserting therapeutic devices into organic tissue such as nerve or brain tissue is described. Several significant advantages are provided over prior related insertion devices, some of which are recited here and throughout the following more detailed description. First, the manipulation of multiple pressure sources, e.g. two vacuum sources and a positive pressure source, allows for improved handling of a therapeutic device, while also allowing high insertion speeds. The use of vacuum to secure the electrode array to the tip of the inserter allows the present insertion device to be spatially manipulated by hand without requiring the aid of other equipment. Also, the use of vacuum delivered to the tip of the inserter can be used to attach and retrieve a therapeutic device from organic tissue by adjusting relative vacuum sources as described in more detail below.
• Each of the above-recited advantages will be apparent in light of the detailed description set forth below, with reference to the accompanying drawings. These advantages are not meant to be limiting in any way. Indeed, one skilled in the art will appreciate that other advantages may be realized, other than those specifically recited herein, upon practicing the present invention.
• Although illustrated inFIGS. 1-12 generally, two primary embodiments are described in connection withFIGS. 1-10 and11-12, respectively.FIG. 1 in particular shows oneinsertion device10 of the present insertion. The insertion device may be composed of a number of parts or elements and the configuration and assembly of each of the parts may vary depending on the particular embodiment of the insertion device, or thetherapeutic device16 intended to be inserted. Generally, theinsertion device10 may comprise an optional adaptor20 (shown inFIG. 2), two vacuum sources (12 and14), aoutside barrel40, acentral tube50, apiston70, apiston stop60, ahousing80, aninserter90, aposition bias member100, ahead110, and atip120. These individual parts or elements can generally be formed of metals, polymers, alloys, composites and/or other suitable materials. Typically, parts can be formed of stainless steel, although other materials such as titanium, ceramic, or high-density polyurethane can also be suitable. For example, polymers may be suitable for single use or low use embodiments, while titanium, stainless steel and the like can be more suitable for devices intended for repeated use over months or years. The position bias member can generally be a spring, although other mechanisms can also be used such as, but not limited to, flexible tabs, elastic restraints, and the like.
• Referring again toFIG. 1, theinsertion device10 can include thepiston70 which is slidably oriented in aninner chamber42 such that the piston can slide along the inner chamber from one end to an opposite end. Thepiston70 may be restricted to movement within theoutside barrel40 between the upper proximal end of theoutside barrel40 and thepiston stop60 at the distal end of theoutside barrel40. Thepiston stop60 can be oriented at one end and can be associated with an inserter which is located opposite the piston across the piston stop. A momentum transfer member can be oriented on either or both of the piston and the inserter. InFIG. 1 themomentum transfer member98 is oriented on the inserter via members which extend through apertures in the piston stop. Alternatively, themomentum transfer member98 can be analogously oriented on thepiston70 as shown inFIG. 11. The inserter can include the momentum transfer member, ashaft96, and tip120 as separate removable pieces (as shown inFIG. 1) or as a single integrated piece. A vacuum line can be associated with the inserter to allow for selective application of suction at the tip. Typically, a vacuum source can be pulled throughvacuum line28 which is in fluid communication with the tip in order to retain a desired therapeutic device thereon.
• Another piston vacuum source and a positive pressure source connected viainlet line24 can be used to drive the piston up or down theouter barrel40. Alternatively, movement of the piston can be driven using a combination of the two vacuum sources and a positive pressure source applied to a back and front side of the piston, respectively. This alternative is described in more detail below in connection withFIG. 11.
• As shown inFIG. 2, anadaptor20 facilitates the connection of the twovacuum sources12 and14 to theinsertion device10. Theadaptor20 can be generally cylindrical in shape with two connectors extending from the top of the adaptor, afirst vacuum connector22 and asecond vacuum connector26. Each of these connectors may be cylindrical in shape and can be operatively connected to each of the vacuum sources.
• Thefirst vacuum connector22 defines afirst vacuum conduit24 and may be operatively attached to thefirst vacuum12. Similarly, thesecond vacuum connector26 defines asecond vacuum conduit28 and may be operatively attached to thesecond vacuum14 and a positive pressure (not shown). Theadaptor20 may also be configured to allow attachment to the outside barrel40 (shown inFIGS. 1 and 5), at anoutside barrel connection30 where thevacuum conduits24 and28 line up withvacuum inlet lines24 and28 shown inFIG. 1. The connection can be interference fit, recessed slots, threaded, or any other suitable attachment mechanism.
• In one embodiment of the insertion device, thefirst pressure conduit24 may be substantially linear through theadaptor20 and adjacent the perimeter of theadaptor20 and thesecond vacuum conduit28 may begin adjacent the perimeter of theadaptor20 and angle through theadaptor20 to a central position of theadaptor20 as illustrated inFIG. 2. Thesecond vacuum conduit28 may increase in diameter at the distal end of theadaptor20 near theoutside barrel connection30 to allow for insertion or connection with the proximal end of acentral tube50. The connection between thesecond vacuum conduit28 and thecentral tube50 may be accomplished by any appropriate means and can be designed for connection to various diameter vacuum tubing or the like. Typically, the vacuum tubing can be connected to the inlet conduits via interference fitting although compression fittings, threaded fittings, or other suitable fittings can be used.
• In one very specific embodiment shown inFIGS. 3 and 4, theadaptor20 can be 1.0 inches in length and have a diameter (d₁) of 0.375 inches. Thefirst vacuum connector22 can be 0.75 inches in length and thefirst vacuum conduit24 can have a diameter (d₂) of 0.0626 inches. Thesecond vacuum connector26 can be 0.5 inches in length and thesecond vacuum conduit28 can have a diameter (d₃) of 0.0626 inches. Moreover, the distal end of thesecond vacuum conduit28 can have an increased diameter (d₄) of 0.125 inches and have inside threads to facilitate attachment to thecentral tube50, whichcentral tube50 is shown inFIG. 6. Theoutside barrel connection30 on theadaptor20 can have a diameter (d₅) of 0.30 inches. In this manner the distance between the vacuum lines can be reduced from a first distance (d₆) of 0.2294 inches to a second distance (d₇) of 0.115 inches as shown inFIGS. 3 and 4, respectively.
• Theadaptor20, shown inFIGS. 2-4, may be connected at theoutside barrel connection30 to a proximal end, or first end, of theoutside barrel41, shown inFIG. 5, by any appropriate means. As shown inFIG. 5, theoutside barrel40 is generally cylindrical and defines aninner chamber42. Theoutside barrel40 may be of varying dimensions depending upon the size of thetherapeutic device16 to be inserted. In one embodiment, the outside barrel size can be configured to ergonomically facilitate hand-held operation of the device. As such, the diameter for such embodiments can range from about 0.2 to about 0.5 inches and in one case 0.3750 inches (with an inside diameter of about 0.3016 inches), although other sizes can also be suitable. Similarly, the overall length of the device can typically be from about 3 to about 9 inches such as about 6.0 inches, although other dimensions can be used as long as the insertion speed and accuracy are maintained. Referring again toFIG. 1, theinner chamber42 is in fluid communication with thefirst vacuum conduit24. Theoutside barrel40 may also contain thecentral tube50 and slidably contain thepiston70. Theoutside barrel40 may include a housing connection44 (also shown inFIG. 5) at a distal end, or second end, of theoutside barrel40.
• As mentioned previously, thecentral tube50 may be connected to thesecond vacuum conduit28 and positioned along a central, transverse axis inside theoutside barrel40. Thecentral tube50 defines anaxial chamber52. The axial chamber is in fluid communication with thesecond vacuum conduit28. Thecentral tube50 may have apiston stop60 connected to a distal end of thecentral tube50 as either an integral piece as shown in FIGS.1 and6-8, or as a separate annular sleeve. In this embodiment, theinner chamber42 is concentrically oriented around at least a portion of the axial chamber (i.e. above thepiston stop60 such that the inner chamber has an annular volume). Further, the axial chamber and the inner chamber are fluidly independent from one another such that the first vacuum controls the piston movement while the second vacuum extends through the axial chamber to the tip of the device sufficient to retain a microelectrode array thereon. In this embodiment, each of the axial chamber and the inner chamber are fluidly independent and can be substantially isolated from the other.
• Thepiston stop60 enables the transfer of momentum and/or mechanical energy from thepiston70 to theinserter90 via themomentum transfer member98. The piston stop is also configured to limit the motion of thepiston70. Thepiston stop60 may generally be described as a disc, cylinder or block having at least one aperture. Referring now toFIGS. 7 and 8, the piston stop has acentral stop aperture62 and at least oneradial stop aperture64. Thecentral stop aperture62 allows fluid communication between theaxial chamber52 and atip120 via an inserter conduit96 (shown inFIG. 1). In this way, thecentral tube50 may be connected to thepiston stop60 at thecentral stop aperture62. As shown inFIG. 1, theradial stop apertures64 allowmomentum transfer members98 associated with theinserter90 to extend through thepiston stop60.
• Dimensions of the piston stop can vary. For example, and not by way of limitation,FIG. 7 shows apiston stop60 having a diameter of 0.3126 inches and a height of 0.25 inches. Thecentral stop aperture62 of this embodiment can have a diameter of 0.069 inches, while theradial stop apertures64 may have a diameter of 0.08 inches. These dimensions can vary, for example, based on the momentum transfer member design.
• Referring now toFIG. 1, thepiston70 provides the momentum and/or mechanical energy to actuate theinserter90 upon impact with themomentum transfer member98. Thepiston70 can have a weight and size designed for insertion with a particular therapeutic device and/or insertion speed. Further, several pistons of varying weights can be provided with asingle insertion device10, which are readily interchangeable. Using pistons of different masses would be helpful when the therapeutic device being inserted is of a respectively different mass. A change in therapeutic device mass would be directly proportional to a change in piston mass to conserve the same momentum transfer from the piston to the therapeutic device. For example, inserting a UEA with a wireless transmitter chip on the back increases mass and would be appropriate to use a piston of greater mass. In one embodiment, thepiston70 includes apiston aperture72 that allows thepiston70 to be slidably engaged along the outside of thecentral tube50. The piston can include anoptional lip73 which prevents movement of the piston past a correspondingstep74 in thehousing80. Thus, the piston can be sized and designed such that the piston is halted by contact with either thestep74, thepiston stop60, or both simultaneously, as long as themomentum transfer members98 are sufficiently contacted to trigger the inserter. The width of the step can vary but in one case can be about 0.06 inches.
• The piston dimensions can vary, for example and not by way of limitation, thepiston70 can have a total length of 0.5 inches, the proximal length, or upper length, of thepiston70 can be 0.125 inches in length and can have a diameter of 0.3 inches. The distal length, or lower length, of thepiston70 can be 0.375 inches in length and have a diameter of 0.25 inches while thepiston aperture72 can have a diameter of 0.125 inches.
• Thehousing80 provides the structural support for the transfer of momentum and/or mechanical energy in theinsertion device10. Thehousing80 may be generally cylindrical and defines theinserter chamber82. The housing section encloses the piston stop and other members where high impact occurs. Therefore, the housing section can generally be made of robust material exhibiting sufficient strength to withstand repeated impacts over the expected useful life of the device. The housing may be connected to the distal end, or second end, of theoutside barrel40 at the proximal end, or first end, of thehousing80. The housing also provides a head connection86 and may be connected to thehead110 thereby. The inserter chamber can be substantially isolated from theinner chamber42 as well as theaxial chamber52 and also enclosed so as to be isolated from external atmosphere. The distal end of thehousing80, or head connection86, can have inside threads to facilitate connection with thehead110 or can be connected via interference fitting or other suitable approach.
• Referring now toFIG. 9, theinserter90 provides the structure for retaining and inserting the therapeutic device. The inserter may be configured to have aninserter head92 at the proximal end, or first end, of aninserter shaft94. The inserter shaft defines aninserter conduit96 along a transverse axis of the inserter shaft. The inserter conduit is in fluid communication with the axial chamber via an aperture extending through the inserter head (more readily seen onFIG. 10). As shown inFIG. 1, theinserter head92 is positioned adjacent the distal side of thepiston stop60. Theinserter head92 is kept adjacent the distal side of thepiston stop60 by a position bias member100 (e.g. a spring) in a biased position. Referring again toFIG. 9, theinserter90 can have at least onemomentum transfer member98 attached to theinserter head92.FIG. 10 shows a configuration of fourmomentum transfer members98 oriented radially about the center aperture opening of theinserter conduit96. Referring back toFIG. 1, themomentum transfer member98 may be sized and positioned to extend through a correspondingradial stop aperture64. In this manner, theinserter90 may be actuated by thepiston70 by momentum transfer and/or mechanical means as it impacts the momentum transfer members.
• Although the dimensions can vary,FIG. 10 illustrates aninserter head92 having a disk-like shape, a diameter of 0.25 inches and a height of 0.125 inches. In this embodiment, theinserter shaft94 has a length of 1.5 inches and outside threads or other features at the distal end of theinserter shaft94 to facilitate connection to the tip. In this specific embodiment, themomentum transfer members98 can have a length of 0.375 inches and a diameter of 0.0626 inches.
• Referring toFIG. 1, thehead110 of theinsertion device10 may provide thefoundation112 for the position bias member, may close the distal end of theinserter chamber82, and may help align and direct theinserter90 during operation. Thehead110 may be generally cylindrical at the proximal end of thehead110 and may be conical at the distal end of thehead110. Thehead110 may be connected to the distal end of thehousing80 at a connection which can be interference fit, threaded, slot-lock, detents, or any other suitable connection mechanism. Thehead110 may include afoundation112 for theposition bias member100 that maintains theposition bias member100 between theinserter head92 and thefoundation112. Thehead110 may include ahead aperture114 that allows theinserter shaft94 to extend beyond the distal, conical end of thehead110. A sufficient space or tolerance is allowed between the inner surface of the head aperture and the outer surface of the inserter shaft for movement of the shaft during insertion while also maintaining position accuracy (i.e. reducing looseness or play between the two members).
• Thetip120 provides the interface between theinserter shaft94 and thetherapeutic device16. Thetip120 may be connected to the distal end of theinserter shaft94 by threads, interference fitting, gluing, welding, or other suitable mechanism. Thetip120 may define at least onetip aperture122, which is in fluid communication with theinserter conduit96. Thetip120 may be configured in a variety of shapes. In one embodiment, thetip120 is conical at the proximal end of thetip120 where it may connect with theinserter shaft94 and substantially flat on the distal surface of thetip120. Thetip120 may also include multiple tip apertures to facilitate retention and insertion of a therapeutic device having varied shapes or non-planar contours. Thetip120 may also be coated with a flexible substance, such as silicone, to facilitate retention and insertion of atherapeutic device16 and provide for increased interface contact between the tip and the therapeutic device sufficient to increase a vacuum seal between these surfaces.
• In order to retain the therapeutic device at the tip, a vacuum control system can be operatively connected to the device. As shown inFIG. 1, afirst vacuum source14 can be fluidly coupled to theinner chamber42 at thefirst vacuum inlet24. This first vacuum provides a vacuum to theinner chamber42 behind or at a back side of thepiston70, at the proximal end of theoutside barrel40, moving the piston to the proximal end of the inner chamber. Asecond vacuum source12 can be fluidly coupled to theaxial chamber52 via thesecond vacuum inlet28. This second vacuum provides a vacuum to theaxial chamber52 behind thetherapeutic device16, at the proximal end of theoutside barrel40 through themomentum transfer members98 and inserter axial conduits to thetip120.
• A pressure control system can be used to manipulate the two vacuum sources such that the movement of the piston and suction/release of the therapeutic device can be coordinated. The pressure control system is capable of independently controlling each of the vacuum pressures supplied by each of the first and second vacuums (12 and14) described above. In one embodiment of theinsertion device10, movement of the piston can be substantially entirely controlled by sequential application of vacuum and then positive pressure and retention and release of thetherapeutic device16 can be substantially entirely controlled by thesecond vacuum12.
• This pressure control system is capable of generating an insertion speed for thetherapeutic device16 approximately from 8-12 meters per second. The pressure control system incorporates a timing circuit that delivers positive pressure behind thetherapeutic device16 after insertion, which helps ensure that thetherapeutic device16 is released from thetip120. For example, a compression source can also be attached to theinlet28 and pressure relief valves can be added to allow manipulation of a piston driving pressure and the amount of vacuum force at the tip. This allows for insertion pressure and vacuum pressures to be readily controlled and adjustable depending on the specific therapeutic device and/or conditions. Also, thesecond vacuum12 may be utilized to retrieve atherapeutic device16 after insertion. The valves can be controlled by a timing circuit. These valves can be three way so that the valves switch between a compression source and a vacuum source. The amount of applied pressure is controlled by a pressure relief valve on each line. Timing of each valve to the open or closed position can be changed, and the suction is controlled to release the therapeutic device. For example, suction can be released approximately 100 ms after the piston is fired. As a general guideline, the duration of the compression behind the piston can vary from 10-500 ms.
• FIG. 11 illustrates another alternative embodiment of theinsertion device10 where the movement of thepiston70 is controlled by adjusting differential pressure on the back and front sides of the piston. Thepiston70 can be slidably contained in aninner chamber42. Thepiston70 is allowed to move within the inner chamber from a proximal end to a distal end of theinner chamber42. Thepiston70 can include amomentum transfer member98 that extends toward the distal end of theinner chamber42. The distal end of theinner chamber42 can also include apiston stop60 configured to limit motion of thepiston70 and allow themomentum transfer member98 to extend therethrough.
• Afirst vacuum12 is attached to theinner chamber42 at the proximal end of theinner chamber42. Thisfirst vacuum12 provides a first pressure to theinner chamber42 behind thepiston70, or at a back side of thepiston70 proximate to the proximal end. Asecond vacuum14 can be operatively associated with the distal end of theinner chamber42 via an outeraxial chamber52. Theaxial chamber52 may be in fluid communication with theinner chamber42 and theinserter conduit96, as illustrated inFIGS. 11 and 12. Thissecond vacuum14 provides a second pressure in front of thepiston70, or at a front side of thepiston70, opposite the back side of thepiston70.
• A pressure control system is used to manipulate the two vacuum sources. The pressure control system is capable of independently controlling each of the vacuum pressures supplied by each of the first and second vacuums (12 and14) described above. In this manner movement of thepiston70 can be substantially entirely controlled by varying the relative strength of each vacuum and optionally positive pressures applied to the back side of the piston viaconduit24.
• An inserter can be slidably contained in ahousing80 proximate the distal end of theinner chamber42 opposite thepiston stop60. This inserter includes aninserter conduit96 extending along a transverse axis of the inserter and aninserter head92. The inserter conduit allows fluid communication between the distal end of theinner chamber42 and atip120 of the inserter.
• Aposition bias member100 can be operatively associated with the inserter and configured to bias the inserter toward thepiston stop60 in a biased position. Theposition bias member100 can generally be a spring, although other mechanisms can also be used such as, but not limited to, flexible tabs, elastic restraints, and the like.
• Thehousing80 also may include avent84, ormultiple vents84, oriented to allow fluid communication with the distal end of theinner chamber42 when the inserter is in an unbiased position. As shown inFIG. 11, thevents84 can be oriented circumferentially around thehousing80 between thepiston stop60 and thetip120. Typically, thevents84 can be oriented within about 1-2 mm of thepiston stop60 in order to readily release the pressure generated by thesecond vacuum14.
• Themomentum transfer member98 of theinsertion device10 can generally extend beyond thepiston stop60 throughpassage67 in the piston stop. The portion which extends beyond thepiston stop60 can be adjusted in length in order to balance momentum and mechanical transfer mechanisms. This allows theinserter tip120 to be moved by both mechanical and momentum transfer means. In one embodiment, themomentum transfer member98 can include a portion which extends up to and in contact with theinserter tip120 but does not extend more than about 0.1 mm beyond thepiston stop60. In another embodiment, themomentum transfer member98 can extend further past thepiston stop60. A longer momentum transfer member generally corresponds to a larger degree of mechanical movement, i.e. inelastic collision, of the inserter tip while a shorter transfer member corresponds to a larger degree of momentum transfer, i.e. elastic collision.
• Theinserter chamber82 and/orinserter head92 may be configured to allow insertion of a particular length oftherapeutic device16. In particular, aninserter chamber82 may have a predetermined length that only allows theinserter head92 to travel a predetermined distance to prevent theinserter tip120 from traveling a farther distance than the length of corresponding electrodes on atherapeutic device16 to be inserted. Several different interchangeable tips can be provided for varying insertion depths. Alternatively, aninserter chamber82 may have a given length and the width of theinserter head92 may be varied to increase or decrease the actual distance inside theinserter chamber82 where theinserter head92 moves transversely, thus thetip120 is prevented from traveling a farther distance than the length of the corresponding electrodes on atherapeutic device16 to be inserted. Similarly, mechanical stops can be provided within theinserter chamber82 to adjust the insertion depths. For example,FIG. 12 shows analternative inserter assembly91 similar to that illustrated inFIG. 11 where theinserter chamber82 defines the distance theinserter head92 can move during operation and therefore also controls the insertion depth of atherapeutic device16. Thus, atherapeutic device16 having a desired 1.5 mm insertion depth can use aninserter chamber82 that allows theinserter head92 to travel 1.5 mm.
• Referring again toFIG. 1, during operation, the first vacuum pressure of theinsertion device10 can be adjusted to move thepiston70 toward the proximal end of theinner chamber42. In contrast, the first vacuum pressure can be released to allow movement of thepiston70 toward the distal end of theinner chamber42. Valves controlling each of the first and/or second pressures can be a needle valve or any other mechanism which allows for fine control of pressure. The second pressure of theinsertion device10 can be reduced to pickup atherapeutic device16. This is also how theinserter tip120 can be used to retrieve atherapeutic device16.
• Although a wide range of insertion speeds can be achieved, this method of manipulating the two vacuum sources of theinsertion device10 can achieve a rate of insertion speed of approximately 8-12 meters per second. This relatively fast insertion speed appears to be an optimal range which allows for complete electrode insertion, reduced tissue damage, and minimizes potential for electrode damage.
• Theinsertion device10 can be configured for disassembly to allow easy replacement of parts, cleaning, sterilization, and adjustment. For example, referring toFIGS. 1 and 11 a threaded engagement (not shown) can be prepared near either end of theoutside barrel40 to allow removal or replacement of thepiston70. Similarly, a threaded engagement (not shown) can be provided for removal and/or replacement of theinserter90 and/orinserter tip120.
• Theinsertion device10 may also be formed by single parts that perform the same function as previously described multiple parts. For example, theoutside barrel40 and thehousing80 may be a single, continuous piece, which may also include thecentral tube50 that creates theinner chamber42 and theaxial chamber52. Also, theinserter shaft94 and thetip120 may be a single, continuous piece. Also, thepiston stop60 may be formed as part of theoutside barrel40 and/orhousing80. There are numerous combinations of pieces of theinsertion device10 that may be combined into a single piece, or separated further into individual pieces, while maintaining the function of the resultinginsertion device10. One reason for developinginsertion devices10 composed of fewer separate parts may be to facilitate development of a single-use insertion device that may be specially designed for a specifictherapeutic device16.
• A variety of methods may be employed to help insert atherapeutic device16 into different types of organic tissue. Thetip120 of theinsertion device10 can be formed to any functional shape. In one embodiment,tips120 can have a conical shape. Alternatively, thetips120 can form a flanged inverted cone which flares outward, as illustrated inFIG. 1. In this embodiment, thetip120 can have a larger surface area over which to contact thetherapeutic device16 which can help to improve contact with a backside of thetherapeutic device16. Additionally, thetip120 may contain more than onetip aperture122. This is particularly beneficial when thetherapeutic device16 has an uneven or rough surface. In yet another alternative aspect, thetip120 of the insertion device can be coated with a flexible material which improves sealing of the vacuum upon contact with atherapeutic device16. One flexible material which is particularly suitable can include or consist essentially of silicone.
• Further, theinsertion devices10 can include members which help to control penetration depth of thetherapeutic device16. Theinsertion device10 shown inFIG. 11 will have an insertion depth which is at least partially determined by the distance that theinsertion device10 is held from the tissue during insertion. However, there is some margin of leeway as the tissue can flex upon insertion when impacted. This does not guarantee that thetherapeutic device16 will be fully inserted. Therefore, in one alternative embodiment, thetip120 of theinsertion device10 can be fitted with a sleeve to control the depth of the insertion. The sleeve can extend past thetip120 and encompass thetherapeutic device16, when present. The length of the sleeve can then be useful in adjusting insertion depth for differenttherapeutic device16, i.e. therapeutic device having longer or shorter electrodes. The sleeve may be formed into a variety of shapes, such as curved.
• The method for inserting atherapeutic device16 utilizing thepresent insertion device10 will now be described. Thepresent insertion device10 utilizes at least two vacuum sources and a dual vacuum/pressure control system. The dual vacuum/pressure control system can be manipulated to control motion of thepiston70. Thepiston70 transfers momentum to aninserter90 which can similarly be slidably disposed within theinsertion device10. Manipulation of the dual vacuum/pressure control system enables a rate of insertion of approximately 8-12 meters per second to be achieved.
• The dual vacuum/pressure control system can be set in a predetermined condition for inserting thetherapeutic device16. For example, the first vacuum pressure can be smaller than the second vacuum pressure before insertion such that thepiston70 is held against a proximal end of theinsertion device10 from thetip120 while a vacuum is being pulled through thetip120 and/orinserter shaft94. Thetherapeutic device16 is loaded onto thetip120 and/orinserter shaft94 of theinsertion device10 and held in place via vacuum suction. The second vacuum pressure holds thetherapeutic device16 onto theinserter tip120. The fact that a vacuum pressure holds thetherapeutic device16 onto theinserter tip120 will be beneficial for wirelesstherapeutic device16 because there will be no lead wires to manage during the insertion process and positioning thetherapeutic device16 can be accomplished by appropriate positioning of theinsertion device10.
• Theinsertion device10 is then placed adjacent to a surface of organic tissue that is intended to receive thetherapeutic device16. Adjacent refers to a distance which is sufficiently close so as to achieve the desired effect. Adjacent can generally refer to actual direct contact, although small distances can be allowable. For example, in some cases it may be acceptable to allow up to about 0.3 mm distance between the device and the organic tissue, depending on theinsertion device10 and/orinserter90 configuration. Placement of theinsertion device10 can be achieved either by hand or by using a suitable mechanism, e.g. a stereotaxic device.
• Theinsertion device10 can then be triggered by adjusting the relative pressure of the two vacuums so as to insert thetherapeutic device16 into the organic tissue. In one embodiment, the first vacuum pressure is rapidly increased to move thepiston70 toward the distal end, or second end, of theinner chamber42. Thepiston70 impacts thepiston stop60, and in some embodiments themomentum transfer member98, causing theinserter90 to rapidly insert thetherapeutic device16 into the organic tissue. As theinserter tip120 inserts the therapeutic device into the organic tissue, the second vacuum pressure is switched to a positive pressure to facilitate release of thetherapeutic device16 from the inserter tip. The dual vacuum pressure control system utilizes a timing chip to switch the second vacuum pressure to a positive pressure at the appropriate moment.
• In one embodiment, the first vacuum pressure becomes larger than both the second vacuum pressure and atmospheric pressure. As the first vacuum pressure becomes larger than both the second vacuum pressure and atmospheric pressure, thepiston70 moves toward the distal end, or second end, of theinner chamber42. Thepiston70 impacts thepiston stop60, and in some embodiments themomentum transfer member98, causing theinserter90 to rapidly insert thetherapeutic device16 into the organic tissue. As theinserter tip120 moves toward the organic tissue, a series ofvents84 are opened to the atmosphere. This reestablishes atmospheric pressure on the back of theinserter tip120 and releases the vacuum pressure holding thetherapeutic device16, thus allowing thetherapeutic device16 to be released from the inserter tip. The first vacuum pressure can then be returned to its original value causing thepiston70 to return to the proximal end of theinner chamber42. Theposition bias member100 in thehousing80 pushes theinserter90 back toward thepiston stop60, blocking thevents84 and restoring the second vacuum pressure. This change in relative pressures can be timed in order to prevent bouncing of thepiston70 against thepiston stop60 multiple times. Rather, it is generally desirable to adjust the pressures such that thepiston70 impacts the piston stop60 a single time for each insertion. The use of relative pressure control across two ends of thepiston70 allows for elegant control of thepiston70 movement.
• With respect to the embodiment illustrated inFIG. 11, the dualpressure insertion device10 results in less recoil during insertion as compared to previous insertion devices utilizing more mechanical means of insertion. Likewise, thisinsertion device10 minimizes debris from the insertion device, which can occur during insertion of atherapeutic device16 by allowing debris to be removed viavacuum source14 throughinlet28.
• The preferable pressure for the second vacuum pressure depends on the size of thetherapeutic device16 to be inserted. Likewise when retrieving atherapeutic device16, the preferable pressure for the second vacuum pressure depends on the size of thetherapeutic device16 to be retrieved.
• As an example and not be way of limitation, a suitable pressure for the second vacuum pressure to insert a 4×4 UEAtherapeutic device16 can be from approximately 4 in Hg to about 4.5 in Hg below atmospheric pressure. Lower pressures result in the first vacuum pressure becoming larger than the second vacuum pressure, causing thepiston70 to rest at the distal end of theinner chamber42 as opposed to the proximal end of theinner chamber42. Higher pressures result in the strongest possible suction force not being applied, which then limits the range theinsertion device10 can be moved without dropping thetherapeutic device16.
• The second vacuum pressure can be between 4-4.5 in Hg below atmospheric pressure to better attach atherapeutic device16 if the resting value for the first vacuum pressure is also decreased. One parameter that largely determines the minimum value for the second vacuum pressure is that the second vacuum pressure can be greater than the first vacuum pressure and less than atmospheric pressure.
• The dual vacuum pressure control system may also be manipulated in a manner that allows retrieval of thetherapeutic device16. Generally, the relative vacuum pressures can be reversed from the insertion process in order to retrieve or pick up atherapeutic device16. As an example and not by way of limitation, the preferable pressure for the second vacuum pressure to retrieve a 4×4 UEAtherapeutic device16 can be approximately 6 in Hg below atmospheric pressure, or less. The preferable pressure for the second vacuum pressure to retrieve a 10×10 UEAtherapeutic device16 can be approximately 8 in Hg below atmospheric pressure, or less.
• FIG. 12 illustrates analternative inserter assembly91 having a flanged or expandedtip121 which increases contact area with a UEA or other similar substantially planartherapeutic device16. Thisflanged inserter91 is interchangeable with theinserter92 shown inFIG. 11.
• The foregoing detailed description describes the invention with reference to specific exemplary embodiments. However, it will be appreciated that various modifications and changes can be made without departing from the scope of the present invention as set forth in the appended claims. The detailed description and accompanying drawings are to be regarded as merely illustrative, rather than as restrictive, and all such modifications or changes, if any, are intended to fall within the scope of the present invention as described and set forth herein.
• More specifically, while illustrative exemplary embodiments of the invention have been described herein, the present invention is not limited to these embodiments, but includes any and all embodiments having modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the foregoing detailed description. The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the foregoing detailed description or during the prosecution of the application, which examples are to be construed as non-exclusive.

Claims (14)

1. A therapeutic device insertion device, comprising:

a piston slidably contained in an inner chamber to allow movement of the piston from a first end to a second end of the inner chamber, said second end including a piston stop configured to limit motion of the piston;

a first vacuum operatively associated with the inner chamber at the first end providing a first pressure to the inner chamber at a back side of the piston proximate to the first end;

a second vacuum operatively associated with a first end of an axial chamber and providing a second pressure within the axial chamber, the second vacuum being operatively associated with the first end of the axial chamber and the second end of the inner chamber and providing a second pressure at a front side of the piston opposite the back side;

a pressure control system capable of independently controlling vacuum pressures supplied by each of the first and second vacuums;

an inserter slidably contained in a housing proximate the second end opposite the piston stop, said inserter including at least one aperture extending along a transverse axis of the inserter to allow fluid communication between the axial chamber and a tip of the inserter and the second pressure sufficient to retain a therapeutic device at the tip;

a position bias member operatively associated with the inserter and configured to bias the inserter toward the piston stop in a biased position.

2. The insertion device as inclaim 1, said inner chamber is concentrically oriented around at least a portion of the axial chamber, said axial chamber and said inner chamber being fluidly independent from one another.

3. The insertion device as inclaim 1, wherein said inserter includes at least one momentum transfer member extending through the piston stop so as to move said inserter by both mechanical and momentum transfer means.

4. The insertion device as inclaim 1, wherein said second pressure is reducible to pick up the therapeutic device.

5. The insertion device as inclaim 1, wherein a rate of insertion speed of approximately 8-12 m/s is achieved.

6. The insertion device as inclaim 1, wherein said tip is fitted with a sleeve to control the depth of the insertion.

7. The insertion device as inclaim 6, wherein said sleeve is curved.

8. The insertion device as inclaim 1, wherein said tip forms a cone.

9. The insertion device as inclaim 1, wherein said tip is coated with silicone.

10. The insertion device as inclaim 1, wherein said piston includes a momentum transfer member extending toward the second end and able to extend through said piston stop;

said inserter including at least one aperture extending along the transverse axis of the inserter also allows fluid communication between the second end of the inner chamber, the axial chamber and a tip of the inserter;

and said housing including at least one vent oriented to allow fluid communication with the second end of the inner chamber when the inserter is in an unbiased position.

11. The insertion device as inclaim 10, wherein said first pressure is solenoid valved open to move said piston toward said second end and said first pressure is solenoid valved closed to move said piston toward said first end.

12. The insertion device as inclaim 10, wherein said second pressure is reducible to pickup a therapeutic device.

13. The insertion device as inclaim 1, wherein each of the first and second vacuums are fluidly independent from the other.

14. The insertion device as inclaim 1, wherein the position bias member is a spring.

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