US20160082202A1 - Apparatus for accurately controlling needle extension - Google Patents

Abstract

Devices are illustrated which provide for accurately controlling the extension of a needle from a protective sheath to increase accuracy and improve the outcome of the treatment procedure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application is a divisional application of U.S. application Ser. No. 13/441,368, filed on Apr. 6, 2012, which claimed priority to U.S. Provisional Application No. 61/474,459, filed on Apr. 12, 2011, the entirety of which are each hereby fully incorporated by reference herein.
TECHNICAL FIELD
• The present invention relates to medical devices and more specifically, needles.
BACKGROUND
• Numerous medical procedures require the use of a sheathed needle, that when unsheathed, is used to pierce tissue at a certain depth for delivery of a fluid. For example, Botulinum toxin (trade name Botox®) may be injected into a bladder wall to treat an over-active bladder. Other treatments using sheath-covered needles include those in the field of urology, such as vesicoureteral reflux (VUR) as well as those in the field of gastrointestinal endoscopy such as injection into the gastrointestinal mucosa.
• The needle is sheathed as it is moved to the injection location to protect the patient, endoscope, cystoscope, or other medical device from accidental piercing whilst the needle is being positioned over the target injection site. The sheath is then retracted exposing a portion of the needle. However, current devices are unable to provide for precise needle exposure which is often desired for delivery of a fluid into the area to be treated. The farther away the controlling handle is from the tip, the more pronounced this inability to accurately control component movement becomes, especially when the device is held in a curved orientation. Thus, although a user believes s/he is unsheathing, for example, 2 mm of the needle, the actual amount of needle unsheathed is not 2 mm when the device is held in a curved orientation. Instead, the unsheathed portion of the needle may be greater than or less than that desired due to material tolerances and material flexibility—but those tolerances and flexibility are often desired to properly position the device over the target injection site.
BRIEF SUMMARY
• In a first aspect, a medical device is provided having a needle having a proximal portion and a distal portion, wherein the distal portion of the needle includes a sharpened tip; a sheath having a proximal portion, a distal portion, and a lumen extending between the proximal portion and the distal portion of the sheath, the lumen being defined by an inner surface of the sheath, wherein at least a portion of the needle is movably disposed through the lumen of the sheath; a plurality of spaced apart first engagement members affixed to one of the needle or the inner surface of the sheath; a second engagement member affixed to the other of the needle or the inner surface of the sheath, wherein the second engagement member is configured to releasably engage each of the first engagement members to provide incremental movement of the sheath relative to the needle.
• In a second aspect, a medical device is provided having a needle having a proximal portion and a distal portion, wherein the distal portion of the needle includes a sharpened tip; a sheath having a proximal portion, a distal portion, and a lumen extending between the proximal portion and the distal portion of the sheath, the lumen being defined by an inner surface of the sheath, wherein at least a portion of the needle is movably disposed through the lumen of the sheath; an annular component disposed around a portion of a surface of the needle, wherein the annular component is configured to incrementally engage the inner surface of the sheath; and a handle attached to the sheath and the needle, where the handle is configured for axial retraction and extension of the sheath to incrementally engage the annular component and expose or conceal a distal portion of the needle.
• In a third aspect, a medical device is provided having: a needle having a proximal portion and a distal portion, wherein the distal portion of the needle includes a sharpened tip; a sheath having a proximal portion, a distal portion, and a lumen extending between the proximal portion and the distal portion of the sheath, the lumen being defined by an inner surface of the sheath, wherein at least a portion of the needle is movably disposed through the lumen of the sheath; a first accurate needle extension member in communication with the inner surface of the sheath; and a second accurate needle extension member in communication with the needle, wherein the first accurate needle extension member is configured for engagement with the second accurate needle extension member for accurately extending a length of the needle from the distal portion of the sheath.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
• The embodiments will be further described in connection with the attached drawing figures. It is intended that the drawings included as a part of this specification be illustrative of the exemplary embodiments and should in no way be considered as a limitation on the scope of the invention. Indeed, the present disclosure specifically contemplates other embodiments not illustrated but intended to be included in the claims.
• FIG. 1 illustrates the mismatched radii of curvature of sheath and needle;
• FIG. 2aillustrates a partial cross-sectional side view of an exemplary device and handle for accurately controlling the extension of a needle from a protective sheath in multiple increments;
• FIG. 2billustrates an alternate side view of an exemplary handle for use with a device for accurately controlling the extension of a needle from a protective sheath;
• FIG. 3 illustrates a partial cross-sectional side view of an exemplary device distal tip for accurately controlling the extension of a needle from a protective sheath in multiple increments;
• FIG. 4 illustrates a cross-sectional side view of an exemplary outer sheath;
• FIG. 5 illustrates a side view of an exemplary annular component and needle;
• FIGS. 6a-6dillustrate partial cross-sectional side views of an exemplary incremental progression of a use of an exemplary device for accurately controlling the extension of a needle from a protective sheath;
• FIG. 7 illustrates a partial cross-sectional side view of an exemplary device for accurately controlling the extension of a needle from a protective sheath;
• FIG. 8 illustrates a cross-sectional side view of an exemplary outer sheath;
• FIG. 9 illustrates a side view of an exemplary annular component and needle;
• FIGS. 10a-10dillustrate partial cross-sectional side views of an exemplary incremental progression of a use of an exemplary device for accurately controlling the extension of a needle from a protective sheath;
• FIG. 11 illustrates a partial cross-sectional side view of an exemplary device for accurately controlling the extension of a needle from a protective sheath;
• FIG. 12 illustrates a cross-sectional side view of an exemplary outer sheath;
• FIG. 13 illustrates a side view of an exemplary annular component and needle;
• FIGS. 14a-14eillustrate partial cross-sectional side views of an exemplary incremental progression of a use of an exemplary device for accurately controlling the extension of a needle from a protective sheath;
• FIG. 15 illustrates a perspective view of an exemplary alternate annular component; and
• FIG. 16 illustrates a perspective view of an exemplary alternate sheath.
DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS
• The exemplary embodiments illustrated herein provide exemplary apparatuses for accurately controlling the extension of a needle from a protective sheath and optionally providing direct visualization of needle depth penetration. The present invention is not limited to those embodiments described herein, but rather, the disclosure includes all equivalents. Moreover, the embodiments illustrated herein can be used in the fields of urology and gastrointestinal endoscopy as well as any other field, and they are not limited to the size or shapes illustrated herein. Indeed, the devices can be used in any field where precise control of the movement of components relative to each other is desired and can be sized, manufactured, altered, or changed for the particular treatment needed.
• A more detailed description of the embodiments will now be given with reference toFIGS. 1-16. Throughout the disclosure, like reference numerals and letters refer to like elements. The present disclosure is not limited to the embodiments illustrated; to the contrary, the present disclosure specifically contemplates other embodiments not illustrated but intended to be included in the claims.
• Typical retractable sheath needle devices fail to provide precise needle exposure needed for treating certain ailments, such as over-active bladder, wherein a precise portion of the needle needs to pierce the subject tissue. Their handles typically include preset control positions, whereby the needle sheath can be retracted, thus controlling, although imprecisely, the exposure of needle tip. Some refer to this inability to accurately control sheath retraction (and thus, needle exposure length) as “play.” Typical retractable sheath needle devices are unable to provide precise needle exposure despite having preset control positions on their handle when in a non-straight orientation, such as a curved orientation. For example, if a typical retractable sheath needle device is held in a curved orientation, the ability for it to provide the user with accurate needle extension length diminishes because there exists a certain amount of clearance between the inner diameter of the sheath and the outer diameter of the flexible needle. The clearance is desired to ensure that that the sheath can retract over the flexible needle without any dimensional interference when in a curved orientation. The clearance is also desired because it provides a pathway for ethylene oxide (EtO) sterilization.
• FIG. 1 illustrates the mismatched radii of curvature of a sheath and a needle for a typical retractable sheath needle device. The farther away the controlling handle is from the tip, the more pronounced the inability to accurately control component movement becomes, especially when the device is held in a curved orientation. Thus, although a user believes s/he is unsheathing, for example, 2 mm of the needle, the actual amount of needle unsheathed is not2 mm when the device is held in a curved orientation. Instead, the unsheathed portion of the needle may be greater than or less than that desired due to material tolerances and material flexibility—but those tolerances and flexibility are often desired to properly position the device over the target injection site.
• More particularly, the movement of the needle to sheath results in a mismatch of the radii of curvature of both tubings. As can be seen inFIG. 1, when the sheath is curved, the needle does not curve at the same rate. Thus, the radius for the needle's curvature R2 is different than that of the sheath R1. As a result of the sheath and needle bending at different rates, the needle moves within the sheath, and the curvature of both the needle and the sheath are no longer aligned. This mismatch in radii of curvature increases the distance that the sheath has to retract in order to provide the correct needle extensions at the distal portion of the retractable sheath needle device. As the handle of the typical retractable sheath needle device can only provide pre-defined distances, set by control of the sheath, the typical retractable sheath needle device cannot accurately control sheath retraction (and thus the needle tip's exposure) when the shaft of a typical retractable sheath needle device is placed in a curved orientation.
• Other reasons may cause play with respect to the needle and the sheath, including but not limited to, material type, wear, and temperature. Regardless of the reason, play affects the accuracy of the portion of the needle tip exposed from the sheath and the stability of the needle.
• It has been discovered that the mismatch of radii problem can be overcome and the needle stabilized throughout the procedure, without altering the flexibility of the needle and while still permitting the use of a protective sheath by the discovery of a device for accurately controlling the extension of a needle from a protective sheath having an annular component located at the distal portion of the device. Thus, the needle and sheath stay aligned, and incremental control of the device is maintained at the distal end of the device, thus solving the mismatch of the radii of curvature problem.
• FIG. 2aillustrates a first embodiment of anexemplary device200 for accurately controlling the extension of a needle from a protective sheath having anexemplary handle212; other handles are contemplated, including but not limited to that illustrated inFIG. 2b.Device200 includes aproximal portion200aand adistal portion200b.Atproximal portion200aofdevice200 is handle212 having an adaptive connection, such as female luer lock adapter (FLLA)110, configured for receiving an optional syringe.FLLA110 is connected toouter handle component212. Multiple connection means are contemplated, including but not limited to, the use of a screw, adhesive, over molding, thread lock, and ultrasonic welding.Outer handle component212 is connected toinner handle component216 andcontrol knob216athat moves along thepathway channel214; however, alternate handle configurations are contemplated, including those withoutcontrol knob216aandpathway channel214.Inner handle component216 is attached to an adaptive connection, such as a male luer lock adapter (MLLA)112.FLLA110 andMLLA112 are manufactured using plastic injection molding, but other manufacturing techniques are contemplated as are forming MLLA and/or FLLA from other medical grade materials, including but not limited to, stainless steel.MLLA112 connects tosheath208, having a lumen being defined by an inner surface of the sheath. Additionally, it is contemplated, although not required thatMLLA112 can be used to attach the device to the working channel of an endoscope such that it would be locked into place and free a user's hand from holding device.
• The portion ofneedle206 in the proximal-most direction is flared and sandwiched betweenFLLA110 andouter handle component212, although other methods for attachment are contemplated, including but not limited to, screwing, gluing, and over molding. The portion ofsheath208 in the proximal-most direction is flared and sandwiched betweeninner handle component216 andMLLA112, although other methods for attachment are contemplated, including but not limited to, screwing, gluing, and over molding. Whensheath208 is retracted, by for example, pullinginner handle component216 in a proximal direction, it exposesneedle206. Whensheath208 is extended/advanced by using, for example,inner handle component216, by pushing, for example, it in a distal direction withinchannel214 relative to handle212, it concealsneedle206.
• Needle206 (and other needles illustrated below) is a 23 gauge needle, although other gauges are contemplated depending upon the needs of the patient and the area to be treated. It is contemplated that needle206 (and other needles illustrated below) is machine ground to a desired sharpness for piercing the area to be treated, including but not limited to, skin, muscle, tissue, bone, or combination thereof. Moreover, needle206 (and other needles illustrated below) is contemplated to being of any size and shape suitable for delivering a fluid or solid or other treatment mechanism, and it can be manufactured in whole or in part from plastic, stainless steel, or other suitable medical-grade materials, including but not limited to, echogenic and other materials that may or may not provide for direct or indirect visualization using a visualization device, including but not limited to fluoroscopy, x-ray, ultrasound, or magnetic resonance imaging (MRI).
• Needle206 (and other needles illustrated below) is a stainless steel sharpened tube about one inch long and is bonded to flexible plastic tubing. In some embodiments, the flexible tube is constructed to be sufficiently flexible to assist with positioning and maintaining the scope in an angulated or deflected state. Accordingly, it is preferred that the device be flexible such that it does not unduly diminish or excessively hinder scope angulation. Other configurations and materials are contemplated depending upon the needs of the patient and the area to be treated. Throughout, patient is not limited to being a human being, indeed animals and others are contemplated. User is contemplated throughout the disclosure as being anyone or thing capable of using the device, including but not limited to, a human being and machine.
• Handle components are manufactured using plastic injection molding, although other methods are contemplated as are other materials. The overall length ofdevice200 is 70 cm, although other dimensions are contemplated depending upon the needs of the patient, the area to be treated, and the method utilized forpositioning device200.
• Auser positions device200 havingsheath208 extended overneedle206 through a flexible endoscope, cystoscope, or other device or method for positioning a needle over a treatment area.Sheath208 is retracted by pullinginner handle component216 in a proximal direction relative to handlecomponent212, thereby exposing desired depth ofneedle206 as determined by annular component202 (illustrated inFIGS. 4-6dand described below). An optional syringe is attached toFLLA110,needle206 is pushed into tissue to the desired depth as determined byannular component202, and the substance is injected as needed.
• FIG. 2billustrates an alternate side view of anexemplary handle300 for use with a device for accurately controlling the extension of a needle from a protective sheath. Handle300 includes an adaptive connection, such as female luer lock adapter (FLLA)110, configured for receiving an optional syringe.Finger grip302 provides a place for a user to place an index (or other finger) there between, to provide stability to handle300.Slider304 is in communication with a device for accurately controlling the extension of a needle from a protective sheath and provides for sheath retraction or extension thereby exposing an accurate portion of needle tip.
• FIG. 3 illustrates a partial cross-sectional view of anexemplary device200 for accurately controlling the extension of a needle from a protective sheath. As illustrated inFIG. 2aand further illustrated inFIG. 3,sheath208 hasproximal portion208aanddistal portion208b.Sheath208 (and other sheaths illustrated below) is made from a polymer such as fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE). However, sheath208 (and other sheaths illustrated below) can be manufactured in whole or in part from other materials, including but not limited to, stainless steel, plastic, or other suitable medical-grade materials, including but not limited to echogenic and other materials that may or may not provide for visualization using an indirect or direct visualization device, including but not limited to, fluoroscopy, x-ray, ultrasound, direct endoscopic visualization, MRI, or combination thereof. Sheath208 (and other sheaths illustrated below) is manufactured as an insert that can be press-fit into position, although not required as other manufacturing techniques are contemplated. Sheath208 (and other sheaths illustrated below) can be manufactured by deep drawing, although not required, so as to achieve the step change for creatingslots210.
• FIG. 4 illustrates a cross-sectional view of an exemplaryouter sheath208, andFIG. 5 illustrates a side view of an exemplaryannular component202 andneedle206. As further illustrated inFIGS. 4-5, along withFIG. 3, withinsheath208 is an exemplary accurate needle extension member,annular component202, havingridge202athat engagesslots210.Annular component202 is attached to an exemplary accurate needle extension member,inner component204, having a lumen extending throughout, which attaches toflexible needle206. Annular component (and other annular components illustrated below) is made from stainless steel, however it is contemplated that it can be made from other materials, including but not limited to, metallic materials, platinum, polymers, or other materials, including but not limited to, injection molded plastic, polyether ether ketone (PEEK), or combination thereof. Annular component202 (and other annular components illustrated below) can be attached to inner component204 (and other inner components illustrated below) by a number of processes, including but not limited to, crimping, gluing, soldering, etc., or combination thereof.
• As can be seen inFIG. 5,optional markers502 are etched onto the surface ofneedle206 and provide an additional means for providing accurate needle depth using, for example, direct endoscopic visualization at the increments of, for example, 2, 4, 6, and 8 mm such that the user knows the depth at which needle206 penetrates the area to be treated, including but not limited to, the wall of the lower urinary tract.Markers502 may be located elsewhere, at different positions, and in different numbers. Additionally, becausemarkers502 are optionally set apart at a known distance, they can also aid in measuring internal structures. Additionally, it is contemplated thatmarkers502 can be made from a variety of materials that provide for indirect visualization, for example, by way of ultrasound. Examples include but are not limited to havingmarkers502 made from Platinum-Iridium alloy or any echogenic material, including but not limited to, gold and tungsten having surface irregularities. An echogenic material includes surface irregularities that reflect ultrasonic waves and thus, allow the material to be seen with ultrasonic imaging devices. Echogenic techniques are described in U.S. Pat. No. 5,081,997 and U.S. Pat. No. 5,289,831 and are hereby incorporated by reference in their entirety.Markers502 may be made by laser or chemical etching. It is contemplated thatmarkers502 can be manufactured in whole or in part from other materials, including but not limited to, stainless steel or other suitable medical-grade materials, including but not limited to, radiopaque materials, such that the material provides for visualization outside the patient using a visualization device, including but not limited to, fluoroscopy, x-ray, and MRI.
• FIGS. 6a-6dillustrate a partial cross-sectional view of an exemplary incremental progression of a use of anexemplary device200 for accurately controlling the extension of a needle from a protective sheath. Bi-directional control ofdevice200 is operated by retracting or extendingsheath208, respective to inner component assembly (which includesinner component204,annular component202, and needle206) to causeridge202aofannular component202 to engage one ofslots210 ofsheath208. Due to the flexible nature ofsheath208 compared toannular component202, a user can overcome the frictional resistance ofslot210 by applying more force to, for example,inner handle component204 orsheath208. Indeed, it is contemplated that the materials may be reversed, thus havingsheath208 be more rigid thanannular component202. Once the initial resistance to movement is overcome,ridge202aofannular component202 will engage thenext slot210 ofsheath208, and it will remain locked there until enough force is applied to overcome the resistance. The retracting or extending ofsheath208 will causesheath208 to expose accurate portions ofneedle206.
• FIG. 6aillustratesdevice200 in a fully un-retracted position whereinneedle206 is not exposed and is covered bysheath208. When in the fully un-retracted position,annular component202 andridge202ain particular, are disposed proximally of theproximal-most slot210.
• FIG. 6billustratessheath208 partially retracted over inner componentassembly causing ridge202aofannular component202 to engage with the first (proximal-most)slot210 and thus accurately expose 2 mm ofneedle206 fromsheath208.
• FIG. 6cillustratessheath208 partially retracted over inner componentassembly causing ridge202aofannular component202 to engage with thesecond slot210 and thus accurately expose 4 mm ofneedle206 fromsheath208.
• FIG. 6dillustratessheath208 fully retracted over inner componentassembly causing ridge202aofannular component202 to engage with thethird slot210 and thus accurately expose 6 mm ofneedle206 fromsheath208.
• The procedure illustrated inFIGS. 6a-6dcan be repeated in whole or part to movesheath208 distally or proximally respective to inner component assembly.
• Slots210 are illustrated as being spaced apart at increments of 2 mm such that whensheath208 is retracted over inner component assembly, a length of 2 mm, 4 mm, or 6 mm ofneedle206 is exposed fromsheath208. However, various other lengths of needle extension/exposure are contemplated, including but not limited to, those that are not at constant increments, such as 2 mm, 4 mm, 8 mm, or combination thereof. Indeed, more orless slots210 are contemplated to provide various numbers of controlled needle extensions. By varying the number and spacing ofslots210, it is possible to have an infinite number of combinations ofneedle206 extension length fromsheath208 for use in any type of treatment where a sheathed needled is desired, although not required.
• FIG. 7 illustrates a partial cross-sectional view of an alternate embodiment of anexemplary device700 for accurately controlling the extension of a needle from a protective sheath havingproximal portion700a,distal portion700b,and handle as illustrated inFIG. 2afor connecting to an optional syringe.Sheath704 hasproximal portion704aanddistal portion704b.
• FIG. 8 illustrates a cross-sectional view of an exemplaryouter sheath704, andFIG. 9 illustrates a side view of an exemplaryannular component702 andneedle206.Sheath704 has a sharp decrease of internal diameter which produces a concentric constriction,ridge706. It is the interaction ofridge706 withslots702aofannular component702 that provides accurate control ofneedle206 extension.
• As further illustrated inFIGS. 8-9, along withFIG. 7, withinsheath704 isannular component702 havingslots702athat engageridge706 ofsheath704.Annular component702 is attached toinner component204 which attaches toflexible needle206, or is formed monolithically with theneedle206. Alternatively,annular component702 may attach directly to theflexible needle206.
• FIGS. 10a-10dillustrate a partial cross-sectional view of an exemplary incremental progression of a use of anexemplary device700 for accurately controlling the extension of a needle from a protective sheath. Bi-directional control ofdevice700 is operated by retracting or extendingsheath704 using, for example, inner component assembly (which includesinner component204,annular component702, and needle206), to cause one ofslots702aofannular component702 to engageridge706 ofsheath704. Due to the flexible nature ofsheath704 compared toannular component702, a user can overcome the frictional resistance ofridge706 by applying more force toinner handle component204. Indeed, it is contemplated that the materials may be reversed, thus havingsheath704 be more rigid thancomponent702. Once the initial resistance to movement is overcome, thenext slot702aofannular component702 will engageridge706 ofsheath704, and it will remain locked there until enough force is applied to overcome the resistance. The retracting or extending ofsheath704 will causesheath704 to expose accurate portions ofneedle206.
• FIG. 10aillustratesdevice700 in a fully un-retracted position whereinneedle206 is not exposed and is covered bysheath704. When in the fully un-retracted position,annular component702 is disposed proximally of theridge706.
• FIG. 10billustratessheath704 partially retracted over inner component assembly causingfirst slot702aofannular component702 to engage withridge706 and thus accurately expose 2 mm ofneedle206 fromsheath704.
• FIG. 10cillustratessheath704 partially retracted over inner component assembly causingsecond slot702aofannular component702 to engage withridge706 and thus accurately expose 4 mm ofneedle206 fromsheath704.
• FIG. 10dillustratessheath704 fully retracted over inner component assembly causingthird slot702aofannular component702 to engage withridge706 and thus accurately expose 6 mm ofneedle206 fromsheath704.
• The procedure illustrated inFIGS. 10a-10dcan be repeated in whole or part to movesheath704 proximally or distally with respect to inner component assembly distally.
• Slots702aofannular component702 are illustrated as being spaced apart at increments of 2 mm such that whensheath704 is retracted over inner component assembly, a length of 2 mm, 4 mm, or 6 mm ofneedle206 is exposed fromsheath704. However, various other lengths of needle extension/exposure are contemplated, including but not limited to, those that are not at constant increments, such as 2 mm, 3 mm, 5 mm, or combination thereof. Indeed, more orless slots702aofannular component702 are contemplated to provide various numbers of controlled needle extensions. By varying the number and spacing ofslots702aofannular component702, it is possible to have an infinite number of combinations ofneedle206 extension length fromsheath704 for use in any type of treatment where a sheathed needled is desired, although not required.
• FIG. 11 illustrates a partial cross-sectional view of an alternate embodiment of anexemplary device1100 for accurately controlling the extension of a needle from a protective sheath havingproximal portion1100a,distal portion1100b,and handle as illustrated inFIG. 2afor connecting to an optional syringe.Sheath1104 hasproximal portion1104aanddistal portion1104b.
• FIG. 12 illustrates a cross-sectional view of an exemplaryouter sheath1104, andFIG. 13 illustrates a side view of an exemplaryannular component1102 andneedle206. As further illustrated inFIGS. 12-13, along withFIG. 11, withinsheath1104 isannular component1102 havingwings1102athat engage varyinginner diameters1106 ofsheath1104.Annular component1102 is attached toinner component204 which attaches toflexible needle206.
• FIGS. 14a-14eillustrate a partial cross-sectional view of an exemplary incremental progression of a use of anexemplary device1100 for accurately controlling the extension of a needle from a protective sheath.FIG. 14aillustratesdevice1100 in a fully un-retracted position whereinneedle206 is not exposed and is covered bysheath1104.Spring component wings1102aare in a relaxed state whereby the wingspan ofwings1102ais greater that the diameter ofsheath1104. Control ofdevice1100 is operated by retractingsheath1104, using, for example, inner component assembly (which includesinner component204,annular component1102, and needle206) causingwings1102aofannular component1102 to compress due to the step change of varyinginner diameters1106 ofsheath1104. Due to the flexible compression nature ofwings1102acompared tosheath1104, a user can overcome the frictional resistance ofwings1102aby applying more force to, for example,inner handle component204. Indeed, it is contemplated that the materials may be reversed, thus havingsheath1104 be more rigid thanwings1102a.Once the initial resistance to movement is overcome, the next varyinginner diameter1106 ofsheath1104 will engagewings1102aofannular component1102, and it will remain locked there until enough force is applied to overcome the resistance because thespring component wings1102awingspan increases assheath1104 is further retracted. The retracting ofsheath1104 will causesheath1104 to expose accurate portions ofneedle206.
• FIG. 14aillustratessheath1104 fully un-retracted over inner component assembly. When in the fully un-retracted position,annular component1102 is disposed proximally of the proximal-most varyinginner diameter1106.
• FIG. 14billustratessheath1104 partially retracted over inner component assembly causing first varyinginner diameter1106 ofsheath1104 to engagewings1102aofannular component1102 and not exposing any distal portion ofneedle206.
• FIG. 14cillustratessheath1104 partially retracted over inner component assembly causing second varyinginner diameter1106 ofsheath1104 to engagewings1102aofannular component1102 and thus accurately expose 2 mm ofneedle206 fromsheath1104.
• FIG. 14dillustratessheath1104 partially retracted over inner component assembly causing third varyinginner diameter1106 ofsheath1104 to engagewings1102aofannular component1102 and thus accurately expose 4 mm ofneedle206 fromsheath1104.
• FIG. 14eillustratessheath1104 fully retracted over inner component assembly causing fourth varyinginner diameter1106 ofsheath1104 to engagewings1102aofannular component1102 and thus accurately expose 6 mm ofneedle206 fromsheath1104.
• Varyinginner diameters1102aofannular component1102 are illustrated as being spaced apart at increments of 2 mm such that whensheath1104 is retracted over inner component assembly, a length of 2 mm, 4 mm, or 6 mm ofneedle206 is exposed fromsheath1104. However, various other lengths of needle extension/exposure are contemplated, including but not limited to, those that are not at constant increments, such as 2 mm, 3 mm, 5 mm, or combination thereof. Indeed, more or less varyinginner diameters1106 ofsheath1104 are contemplated to provide various numbers of controlled needle extensions. By varying the number and spacing of varyinginner diameters1106 ofsheath1104, it is possible to have an infinite number of combinations ofneedle206 extension length fromsheath1104 for use in any type of treatment where a sheathed needled is desired, although not required.
• Furthermore, the step changes of varyinginner diameters1106 ofsheath1104 compressesspring components wings1102asuch that it is not possible to advancesheath1104 in a distal direction tore-sheath needle206. To overcome that, optional retraction mechanisms can be added todevice1100.
• FIG. 15 illustrates a perspective view of an exemplary alternate annular component.Annular component1102 further includesretrieval loop1501 that threads fromwings1102athrough body ofannular component1102band alonginner component204 out to a user's hand or other control mechanism. To advancesheath1104 overneedle206, user pullsretrieval loop1501 in the direction of ArrowA causing wings1102ato compress smaller than varyinginner diameters1106 andpermit sheath1104 to be extended overneedle206.
• FIG. 16 illustrates a front view of an exemplary alternate sheath havingretrieval slot1601. To advancesheath1104 overneedle206, user rotatesneedle206 such thatwings1102aare in communication withretrieval slot1601 permittingsheath1104 to be extended overneedle206 such thatwings1102aslide axially withinretrieval slot1601.Handle channel214 would be configured with, for example, a wider slot or additional slot, such thatneedle206 orsheath1104 would be rotatable respective to the other.
• From the foregoing, it can be seen that the present disclosure provides devices that result in an accurate injection depth of a sheath covered flexible needle. The improved accuracy provides the user with more control over the device used and improves the outcome of the treatment procedure.

Claims (20)

What is claimed is:

1. A medical device comprising:

a needle comprising a proximal portion and a distal portion, wherein the distal portion of the needle comprises a sharpened tip;

a sheath comprising a proximal portion, a distal portion, and a lumen extending between the proximal portion and the distal portion of the sheath, the lumen being defined by an inner surface of the sheath, wherein at least a portion of the needle is movably disposed through the lumen of the sheath;

a plurality of spaced apart first engagement members affixed to one of the proximal portion of the needle or the inner surface of the sheath;

a second engagement member affixed to the other of the proximal portion of the needle or the inner surface of the sheath, wherein the second engagement member is configured to releasably engage each of the first engagement members to provide incremental movement of the sheath relative to the needle.

2. The medical device ofclaim 1, further comprising a handle in communication with the sheath, where the handle is configured for axial retraction or extension of the sheath to expose or conceal the distal portion of the needle.

3. The medical device ofclaim 1, wherein the second engagement member comprises an annular component comprising at least one ridge disposed about a surface of the annular component;

wherein the plurality of first engagement members is affixed to the inner surface of the sheath comprising at least one slot disposed into the inner surface of the sheath;

wherein the ridge of the annular component is configured to frictionally engage the slot of the sheath.

4. The medical device ofclaim 3, wherein the at least one slot of the sheath further comprises a first slot disposed into the inner surface of the sheath, a second slot disposed into the inner surface of the sheath and apart from the first slot, and a third slot disposed into the inner surface of the sheath and apart from the second slot and first slot.

5. The medical device ofclaim 1, wherein the second engagement member comprises an annular component comprising at least one slot disposed into the surface of the annular component;

wherein the plurality of first engagement members is affixed to the inner surface of the sheath, wherein each sheath further comprises at least one ridge disposed about the inner surface of the sheath;

wherein the slot of the annular component is configured to frictionally engage the ridge of the sheath.

6. The medical device ofclaim 5, wherein the at least one slot of the annular component further comprises a first slot disposed into the surface of the annular component, a second slot disposed into the surface of the annular component and apart from the first slot, and a third slot disposed into the surface of the annular component and apart from the second slot and first slot.

7. The medical device ofclaim 1, wherein the second engagement member comprises an annular component comprising at least one wing disposed about an outer surface of the annular component;

wherein the plurality of first engagement members is affixed to the inner surface of the sheath further comprising at least one change in a diameter,

wherein the wing of the annular component is configured to frictionally engage the change in the diameter of the sheath.

8. The medical device ofclaim 7, wherein the at least one change in the diameter of the sheath further comprises:

a first change in diameter;

a second change in diameter; and

a third change in diameter;

wherein the first change in diameter comprises a diameter smaller than a diameter of the second and third changes in diameter, wherein the second change in diameter comprises a diameter larger than the first change in diameter, and wherein the third change in diameter comprises a diameter larger than the second change in diameter.

9. The medical device ofclaim 8, wherein the first change in diameter, second change in diameter, and third change in diameter each traverse a length of the sheath along a longitudinal axis of the sheath.

10. The medical device ofclaim 9, wherein each of the first, second, and third changes in diameter traverse a different length of the sheath along the longitudinal axis.

11. The medical device ofclaim 7, wherein the annular component further comprises a retrieval loop comprising a proximal portion and a distal portion, wherein the distal portion is attached to the at least one wing of the annular component, and wherein the retrieval loop is configured to compress the at least one wing of the annular component when the proximal portion of the retrieval loop is pulled.

12. The medical device ofclaim 7, wherein the sheath further comprises a retrieval slot disposed about an inner surface of the sheath, wherein the retrieval slot is configured to slideably engage the at least one wing of the annular component.

13. The medical device ofclaim 1, wherein the proximal portion of the needle is sufficiently flexible such that angulation of an endoscope is not unduly diminished or hindered when disposed through a working channel of the endoscope.

14. The medical device ofclaim 1, wherein the plurality of spaced apart first engagement members are affixed to the proximal portion of one of the needle or the inner surface of the sheath;

and the second engagement member is affixed to the proximal portion of the other of the needle or the inner surface of the sheath.

15. A medical device comprising:

a needle comprising a proximal portion and a distal portion, wherein the distal portion of the needle comprises a sharpened tip;

a sheath comprising a proximal portion, a distal portion, and a lumen extending between the proximal portion and the distal portion of the sheath, the lumen being defined by an inner surface of the sheath, wherein at least a portion of the needle is movably disposed through the lumen of the sheath;

an annular component disposed around a portion of a surface of the needle, wherein the annular component is configured to incrementally engage the inner surface of the sheath; and

a handle attached to the sheath and the needle, where the handle is configured for axial retraction and extension of the sheath to incrementally engage the annular component and expose or conceal a distal portion of the needle.

16. The medical device ofclaim 15, wherein the needle further comprises at least one marker, wherein the marker is configured for visualization by a direct or indirect visualization device.

17. The medical device ofclaim 15, further comprising a connector connected to a proximal portion of the handle, wherein the connector is configured to receive a syringe.

18. The medical device ofclaim 15, wherein the proximal portion of the needle is sufficiently flexible such that angulation of an endoscope is not unduly diminished or hindered when disposed through a working channel of the endoscope.

19. A medical device comprising:

a needle comprising a proximal portion and a distal portion, wherein the distal portion of the needle comprises a sharpened tip;

a sheath comprising a proximal portion, a distal portion, and a lumen extending between the proximal portion and the distal portion of the sheath, the lumen being defined by an inner surface of the sheath, wherein at least a portion of the needle is movably disposed through the lumen of the sheath;

a first accurate needle extension member in communication with the inner surface of the sheath; and

a second accurate needle extension member in communication with the needle, wherein the first accurate needle extension member is configured for engagement with the second accurate needle extension member for accurately extending a length of the needle from the distal portion of the sheath.

20. The medical device ofclaim 19, wherein the first accurate needle extension device comprises an annular component disposed about the needle, and the second accurate needle extension member is disposed in the inner surface of the sheath.

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