Micro-injection system and methods

Abstract

An apparatus for applying a micro amount of an injectate to a precise intracorporeal location has an elongate sheath, a needle, a chamber, and a plunger. The chamber has an injectate therein. The injectate is fluidly coupled to the needle. The needle is movable relative to the elongate sheath between a proximal position and a distal position, the distal position configured to extend a distal end of the needle a predetermined distance outside the elongate sheath. The plunger is configured to move within the sheath between a proximal position and a distal position, the distal position configured to cause the chamber to expel a first volume of the injectate through the needle. The first volume of injectate is a micro volume of the injectate.

Description

MICRO-INJECTION SYSTEM AND METHODSTECHNICAL FIELD[1] Embodiments herein are related to applying a desired amount of a fluid injectate to a precise location, such as to target tissue in a treated patient.BACKGROUND[2] Recent discoveries of specialized cell culturing and manipulation have made possible injectate materials that are potentially highly effective in micro-doses, generally applied using needle injection catheters.[3] Virtually all needle catheters are designed to transfer an external source of injectate through the entire length of the catheter and into targeted tissue through a needle. However, loading injectate into an external device, such as a syringe and pushing it through a length of tubing before it reaches the injection needle can be highly wasteful. Further, some procedures require a particular depth of injection, and controlling the depth of the injection into the tissue accurately is both critical and difficult. Further, in some procedures, the injections must be made directly into an organ inside the body, at a controlled depth of needle penetration and precise delivery of a desired volume of injectate over a predetermined period of time. A pattern, such as a matrix, of such injections may be required.[4] Some catheter injection systems providing for multiple injections into an organ are currently available, such as for endocardial injections and a tri-needle system, which provides three injection points with each injection. Some catheter systems simply extend a syringe through a tube for remote injection.[5] There therefore remains a need for an improved device and / or method for therapeutic injections and / or other new and useful innovations.SUMMARY[6] An exemplary apparatus for applying a micro amount of an injectate to a precise intracorporeal location has an elongate sheath, a needle, a chamber, and a plunger. Thechamber has an injectate therein, the injectate fluidly coupled to the needle, the needle movable relative to the elongate sheath between a proximal position and a distal position, the distal position configured to extend a distal end of the needle a predetermined distance outside the elongate sheath. The plunger is configured to move within the sheath between a proximal position and a distal position, the distal position configured to cause the chamber to expel a first volume of the injectate through the needle, the first volume of injectate being a micro volume of injectate.[7] A system for applying an injectate to an internal organ includes the apparatus in the preceding paragraph and a control system. The control system has a non-transitory computer-readable medium storing a program including instructions that, when executed by one or more processors, execute a method. The method includes: (a) determining a desired distal position of the needle beyond the sheath; (b) determining the needle is proximal of the desired distal position; (c) sending a first electric signal configured to cause the needle to move distally; (d) determining the needle is in the desired distal position; and (e) sending a second electric signal configured to cause the plunger to move, whereby the first volume of the injectate is expelled through the needle.[8] A method includes providing the system in the preceding paragraph; positioning the apparatus adjacent a first target location on a surface of an internal organ; providing a first user input via the user interface to effectuate movement of the needle to the distal position, whereby the distal end of the needle penetrates the surface of the organ; and providing a second user input via the user interface to cause movement of the plunger, whereby the first volume is injected into the organ.[9] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a schematic side section view of an exemplary needle hub assembly;

[0011] FIG. 2 are schematic side section views of the needle hub assembly in sheathed and extended configurations;

[0012] FIG. 3 is a side cross-section view of an exemplary catheter assembly, with a needle sheathed and carrying an injectate therein;

[0013] FIG. 4 is a side cross-section view of the assembly in FIG. 3, with the needle extended;

[0014] FIG. 5 is a side cross-section view of the catheter assembly in FIG. 3, with the needle extended and plunger partially extended;

[0015] FIG. 6 is a side cross-section view of the catheter assembly in FIG. 3, with the needle extended and plunger advanced;

[0016] FIG. 7 is a partial cross-section view of a catheter assembly having a reciprocating drive;

[0017] FIG. 7a is a partial cross-section view of portions of a catheter assembly having a threaded engagement between a plunger and a chamber;

[0018] FIG. 7b is a side view of an exemplary coil suitable for use in the assembly illustrated in FIG. 7a;

[0019] FIG. 7c is a partial cross-section view of portions of a catheter assembly having a threaded engagement between a plunger and a coil in the chamber;

[0020] FIG. 7d is a partial cross-section view of portions of a catheter assembly having a threaded engagement between a plunger with a coil interleaved with a coil in the chamber;

[0021] FIG. 8 is a schematic of a controller and a catheter assembly;

[0022] FIG. 9 is a partial cross-section view of a catheter assembly having a collapsible bladder;

[0023] FIG. 10 is a partial cross-section view of a catheter assembly having a compressible bladder; and

[0024] FIG. 11 is a partial cross-section view of a bladder cartridge.

[0025] FIG. 12 is a partial cross-section view of an embodiment of a cartridge assembly suitable for use in the catheter assembly;

[0026] FIG. 13 is a partial cross-section view of another embodiment of a cartridge assembly suitable for use in the catheter assembly;

[0027] FIG. 14 is a flowchart of a method; and

[0028] FIG. 15 is a flowchart of a method.DETAILED DESCRIPTION

[0029] To understand the invention fully, an introduction is first provided. Notably, the inventor of embodiments herein recognized that researchers in the field of cardiology, in particular, are in need of a system to deploy their newly developed therapeutics, and developed a micro-injection system to meet their needs.

[0030] In one example, The Mayo Clinic under the direction of Dr. Atta Behfar, Director of Regenerative Medicine, developed a means of creating autologous myocardial cells for injection into the left ventricle. The process starts with extracting a person's cells, e.g., from the underarm area, and retrograding those cells in the laboratory to their pluripotential stem cell state. The cells are then "trained" to be myocardial cells, compatible with the patient's cardiac musculature and electrical functions. A pattern of micro-injections of this autologous injectate, such as 20 grid-spaced lOOpI injections into the middle of the left ventricle wall has been shown in animal studies to result in a stronger heartbeat and increased ejection fraction. Congestive Heart Failure is currently the most expensive diagnosis largely because, short of a heart transplant or LVAD (Left Ventricular Assist Device), little can be done to increase the ejection fraction and improve the patient's cardiac output. Patients who feel poorly are admitted into the hospital where they're given rest and other care to make them feel better, but nothing to address their cardiac deficiency. This hospital admission and release process is repeated often, resulting in high expense with little real impact.

[0031] Animal studies access the heart to place the injection grid pattern by means of either a sternotomy or thoracotomy. However, when these therapeutic agents become ready for human use, a minimally invasive approach will be preferrable. Access to theepicardium minimally invasively has been described by Fonger, et al, in US Patent 11,229,494. A special endoscope configuration is considered for placement under the pericardial sac with a hood that raises to lift the sac from the epicardium and a camera and light source under the hood to provide high-resolution, full color video for navigation. A working channel is described for application of therapeutics such as RF ablation or injections, however no specifics regarding the details of the injection device are included.

[0032] The Mayo process to create an autologous injectate described above takes many weeks to complete and yields only very small volumes, e.g., a few milliliters. Traditional injection catheters waste more injectate than is available from this process, mandating the need for an ultra-low waste, ultra-small volume micro-injection system capable of creating the required pattern of injections. Embodiments described herein solve this problem.

[0033] In a similar manner, Prolifagen Therapeutics of Pennsylvania is developing a microRNA-302 injectate to halt the progress of myocardial infarction. After a "heart attack" which leads to the death (infarction) of some of the cardiac musculature, data indicates that in about 50% of the cases, the infarction leads to congestive heart failure in about five years. Prolifagen has shown in animal testing that placing a pattern of microRNA-302 injections along the margin area between the infarcted and healthy myocardium will halt and possibly even reverse this progression.

[0034] As with the Mayo injectate, precise location of multiple injections of microliter amounts is required. Also similarly, the microRNA-302 is available in only small quantities, at high cost, again mandating a micro-injection system with ultra-low waste and capable of placing micro-injections in a desired pattern, a problem which is solved by embodiments described herein.

[0035] Additionally, the microRNA-302 must be held in place in the myocardium of the ventricle wall. This capability is being developed in cooperation between Prolifagen and the BioFrontiers Institute at the University of Colorado in Boulder. BioFrontiers has specific expertise in the formulation of hydrogels which could be compounded withmicroRNA-302 to create a high-viscosity injectate to disperse into the myocardial wall in a predictable manner and hold the microRNA-302 in place for a period of time to allow its effect to take place.

[0036] To inject a high-viscosity hydrogel compound may require special considerations in the micro-injector. These may include a larger diameter needle, side ports near the tip of the needle to spread the compound, and / or a gradual taper between the diameter of the injectate chamber and the needle to accommodate the viscosity and shear-thinning or shear-thickening characteristics of the hydrogel. Such adaptations are contemplated within this patent application.

[0037] The invention may include a catheter with a needle at the distal end capable of controlling the depth of the needle penetration into targeted tissue and controlling a very small amount of injectate per injection e.g. microliters. In some embodiments, the invention is configured to provide multiple injections during each procedure, such as a number of micro-injections appropriately placed in a pattern on a bodily organ accessed in a minimally invasive way.

[0038] As previously alluded to herein, needle injection catheters are generally designed to transfer an external source of injectate through the length of the catheter and into tissue through a needle. Wasting any of the injectate, however, by loading it into an external device, such as a syringe and pushing it through a length of tubing before it reaches the injection needle can be very expensive and introduce error and is therefore undesirable. Further, controlling the depth of the injection into the tissue accurately is potentially critical to the safety and efficacy of the therapy. Further, in many cases the injections must be made directly into the organ inside the body, at a controlled depth of needle penetration and precise delivery of a desired volume of injectate over a predetermined period of time.

[0039] Embodiments disclosed herein may solve the above-stated problems by providing a micro injection catheter or catheter system specifically designed for such control of needle penetration depth, volume of injectate delivered and rate of delivery. Embodiments may minimize the amount of injectate trapped in containers or lumensand not deliverable such that essentially all of the injectate is dispensed, thereby minimizing waste. Some embodiments are capable of multiple injections at different locations with a single catheter insertion. As an example, some therapies might require twenty injections or more or less at predetermined spacing of the surface of an organ such as the liver or heart. In some embodiments, when being repositioned between injections, the needle tip may be capable of being covered, sheathed or shielded so as to prevent unintended damage from the sharp needle tip to tissues which may be encountered during the repositioning. In some embodiments, the process of penetrating the target tissue to the desired depth, delivering the required volume of injectate at a controlled infusion rate, withdrawing the needle and sheathing / shielding the tip is controlled to be done in a rapid, controlled manner to minimize the overall time of the procedure.

[0040] Embodiments herein also include a method of treating tissue with an injectate.

[0041] On the distal end of a catheter sized, e.g., 4 Fr to 9 Fr in range, but may be a specific size for each purpose, insert into the hollow of the catheter body the precise amount of injectate to be used - either by aspiration or external insertion, including accounting for the amount of injectate in the needle itself. The assembly is surrounded by a needle-protective sheath which serves to protect the needle tip when sheathed and is controllable with millimeter or sub-millimeter precision to expose the needle to a selected penetration distance when desired. The catheter body may have a plunger in contact with the injectate which can be precisely controlled forward for injection or reverse for aspiration or refilling as one approach to load the device with the injectate. The process of exposing the needle, performing the injection, withdrawing the needle, re-sheathing the needle and repositioning the catheter distal tip can be performed multiple / numerous times in a single procedure with the tissue penetration depth, the amount of injectate administered and time of injectate administration held constant or varied from injection to injection.

[0042] In some embodiments, a provision is made in the current invention to allow external injectate, which may be termed "supply injectate" herein, to be available aswell with a micro-lumen feeding the primary injectate chamber at the distal end of the catheter. This allows for "refilling" the chamber when needed during a procedure.

[0043] Turning now to Fig. 1, shown is a needle 101 having a hub 102 attached thereto, the combination of which may be referenced herein as a needle / hub assembly. The needle tip may be ground to any typical or needed shape and tissue penetration profile. The needle may have openings near the tip to allow the injectate to travel through the openings into the tissue as well as or as an alternative to exiting directly through the tip. The hub may be dimensioned to fit an inner diameter ID of an injectate chamber 108, shown in Fig. 3. Attachment between the needle and hub may be by injection molding, adhesive bonding or any other suitable means based on the materials used. The needle may be made from a stainless steel canula. The hub may be made of metal or hard plastic.

[0044] Fig. 2 illustrates the needle / hub assembly from Fig. 1 inside a protective sheath, 104. The sheath 104 may be moved relative to the needle / hub assembly to completely enclose the needle 101 as shown on the left, or to expose a desired length of the needle 101 to penetrate target tissue as shown on the right. The distal end of the sheath may contact the tissue surrounding the needle puncture and may be configured to limit penetration to the depth of the amount of the needle 101 exposed.

[0045] Fig. 3 shows the full distal construction of a catheter assembly 100. The outer sleeve 106 may be attached to the sheath 104 in some embodiments. The outer sleeve 106 may be the sheath 104 without a separate sheath component. Those skilled in the art will recognize that, although the catheter assembly 100 is shown straight for convenience of illustration, the assembly 100 may be flexible. The flexible nature of the catheter assembly 100 may allow it to travel through a f lexible / a rticu lati ng guide sheath or similar anatomical access device.

[0046] An injectate chamber, 108, may be positioned between a plunger 110 and the hub 102. The chamber 108 may be selected to be of any convenient length or size based on the amount of injectate to be dispensed. While shown as an integral part of the catheter assembly 100, the injectate chamber 108 may be constructed as a separatecartridge assembly to be placed into the delivery catheter. The plunger 110 may seal the injectate chamber 108.

[0047] In some embodiments, the chamber 108 has a maximum capacity of 4 ml or less. In some embodiments, the chamber 108 has a maximum capacity of 2 ml or less. In some embodiments, the chamber 108 has a maximum capacity of 1 ml or less. In some embodiments, the chamber 108 has a maximum capacity of 0.1 ml or less.

[0048] The plunger 110 can be movable within the catheter assembly 100 and relative to the sleeve 106 by means of a push / pul I tube 112. The push / pul I tube 112 may be designed to be dimensionally stable under compression (i.e., pushing) or in tension (i.e., pulling), yet flexible radially. The push / pul I tube 112 may have a thin-wall tube material such as polyimide, which has a metal braid embedded in the wall. Movement of the plunger 110 may control the volume of injectate dispensed when pushed. For example, a micro volume may be dispensed. The micro volume may be 100 microliters or less. The micro volume may be 50 microliters or less. The micro volume may be 30 microliters or less. Control over the movement of the plunger 110 is key to precise injectate volume dispensed. A positional reference sheath, 124, may also be included in some embodiments which may add precision to the adjustment of plunger 110 relative to outer sheath 106.

[0049] The plunger 110 may also be moved away from the hub 102 to achieve either aspiration e.g., for filling the injectate chamber 108 or to balance refilling the injectate chamber 108 through the micro-filling lumen 114. An external source of injectate controlled to flow through the lumen 114 may be balanced by coordinated withdrawal of plunger 110 such that the injectate chamber 108 is refilled without pushing injectate out of the needle or aspirating through the needle.

[0050] Turning now to Figs. 7a through 7d, various optional details of the plunger, chamber, and / or sheath are now described.

[0051] In some embodiments, and as illustrated in Fig. 7a, the plunger 110 and fluid chamber 108 may be threaded and configured such that rotating the plunger inside the fluid chamber causes predictable linear movement of the plunger, and thus predictabledisplacement of volume in the fluid chamber. For example, the plunger 110 may have a threaded exterior surface 711 configured to engage a threaded interior surface 713 to convert relative rotational movement into linear movement. In some embodiments, the apparatus 100 has a threaded engagement between the plunger 110 and the chamber 108, whereby rotation of the plunger relative to the chamber effectuates a linear distal movement of the plunger.

[0052] As illustrated in Fig. 7b and Fig. 7c, a coil 702 such as a wire coil, polymer coil, or coil spring shown in Fig. 7b may be positioned on or embedded into an inner wall 704 of the chamber 108, and the exterior surface of the plunger 110 may be grooved 715, as shown in Fig. 7c, whereby the chamber 108 has a threaded engagement with the plunger 110. The coil 702 may be embedded into the wall 704 by heating the wall 704 and / or using a co-extrusion process. In some embodiments, the chamber comprises a coil 702 embedded into an interior wall 704 of the chamber 108, the coil 702 forming a threaded engagement with the plunger 110.

[0053] As illustrated in Fig. 7d, the chamber 108 may be provided with a coil 702 as described in the preceding paragraph, while the plunger 110 may have a corresponding interweaving coil 717 embedded on the exterior surface to allow rotation of the plunger 110 to drive the plunger 110 distally and / or proximally. In some embodiments, the plunger 110 comprises a coil 717 embedded into an exterior wall 719 of the plunger 110, the coil 717 forming a threaded engagement with the chamber 108.

[0054] In some embodiments, the coil 702 and / or the coil 717 may be fabricated of metal. In some embodiments, the coil 702 and / or the coil 717 may be fabricated of polymer materials. In some embodiments, the coil 702 and / or the coil 717 have a memory-retaining property.

[0055] In some embodiments, the plunger 110 is made of a first material, and the chamber is made of a second material different from the first material. The first material may be harder than the second material.

[0056] In some embodiments, the plunger 110 is made of a material that is harder than the material of the chamber 108. In some embodiments, the chamber 108 and outer sleeve 106 are made of a flexible tubing, such as a polymeric material.

[0057] Continuing with Figs. 7a - 7d, and with brief reference to Fig. 8, a valve 823 such as a microvalve may be provided to selectively allow the lumen 114 to fluidly couple a supply injectate to the chamber 108 in a manner known to those skilled in the art. The valve 823 may be any mechanism known to those skilled in the art to allow a user to selectively inject supply injectate 821 into the chamber 108.

[0058] Returning to Fig. 4, the figure illustrates the assembly 100 from Fig. 3, wherein the needle 101 has been extended, but with the same amount of injectate in the chamber 108.

[0059] Fig. 5 illustrates the assembly 100 from Fig. 4, wherein the plunger 110 has been moved into the injectate chamber 108, thus dispensing a portion of the chamber contents.

[0060] Fig. 6 illustrates the assembly 100 from Fig. 5, wherein the plunger 110 has been moved into contact with the hub 102, dispensing all of the injectate from chamber 108, leaving only the amount of the injectate trapped in the needle itself as unused. For reference, a 29 gauge needle 10 mm in length would trap 0.27 pL (0.00027 mL) of injectate. Use of a smaller gauge needle would result in less injectate trapped. The amount trapped in the needle is essentially all the injectate that would go unused in this embodiment.

[0061] With reference now to Figs. 3-7, a method of moving sleeves, sheaths and lumens can include several approaches. For example, as should be understood from Figs. 3-6 holding on to one or more tubes / sleeves while pushing or pulling another may impart relative movement between the components to extend / withdraw the needle 101 or move the plunger 110.

[0062] In some embodiments, the assembly 100 includes threaded components, whereby linear motion is imparted by twisting the tubes / sleeves relative to one another. In some embodiments, the assembly is configured or calibrated such that agiven number of turns effectuates a given length of motion of one sleeve or tube relative to another for precise positioning. Threads may be constructed by creating grooves in the materials, or by using one or more interleaved helical components such as stainless steel springs or coils or polymer coils which are stiffer or harder than the flexible tube components. Such polymers may include polycarbonate or polyetheretherketone (PEEK).

[0063] In some embodiments, and as illustrated in Fig. 7, threaded features 116 on some components may include thread patterns that alternate after a certain distance. One can gain linear motion in either direction by twisting one piece less than 360° relative to another, and then reversing the direction of rotation when the alternate thread pattern is reached. The amount of rotation corresponding to linear movement before reversing the direction of rotation could be less than 360° such as 180° or even 90° alternating pattern. Such thread patterns prevent continuous rotation of one tube or sleeve relative to another and mechanical difficulties that may be associated therewith.

[0064] Turning now to Fig. 8, shown is a system 800 having a control system or controller 802 and catheter assembly 100, which may be substantially the assembly 100 previously described herein. The controller 802 may be configured to control or manage the movement of the components of the catheter assembly 100. The controller 802 may include an outer sleeve controller 804 and a plunger position controller 806. The outer sleeve controller 804 may be configured to hold or move the outer sleeve 106 and / or sheath 104 to control needle exposure depth. As previously discussed, this could be direct linear movement between the sleeves / tubes or by relative rotation using threaded components. In some embodiments, control of the position reference sheath 124 may also be included.

[0065] Similarly, the plunger position controller 806 may be configured to control the push / pul I tube 112 relative to the outer sleeve 106, which in turn controls the position of the plunger 110 relative to the injectate chamber 108. As described for outer the sleeve controller 804, motion can be direct linear actuation or rotational activationusing threaded components. In some embodiments, control of the position reference sheath 124 may also be included.

[0066] Although an electro-mechanical device is generally contemplated, those skilled in the art will recognize that the system may be designed as a totally mechanical device. Mechanical knobs and / or sliders may be positioned on a "handle" or a table-top assembly for control of the micro-injection catheter. Mechanical indicators showing the extension depth of the needle 101 and the position of the plunger 110 in the injectate chamber 108 may allow precise control of the procedure. As an example only, a gear system may be configured in a manner known to those skilled in the art to translate a large motion by a user, such as turning a knob, into a small movement, or micro movement, of the needle to achieve very precise injection depth. Movement of the plunger may be similarly controlled, to achieve a micro injection in response to a "macro" movement of the user, such as by turning a knob. The mechanical controller may be configured with human factors in mind for easiest, most intuitive operation which is likely to yield performance acceptable to users. A "table-top" can be any flat surface such as a stainless steel cart next to a patient in a hospital setting.

[0067] Optionally, in some embodiments, the controller 802 comprises one or more motors 808, 810 to impart motion in the outer sleeve controller 802 and Push / Pull Tube Controller 806. The motors may be of any appropriate type and size including stepper motors, DC motors or brushless motors if needed, any of which motor configurations can be augmented with encoder feedback.

[0068] In some embodiments, the motors 808, 810, may be activated by an electronic controller 812. In some embodiments, the electronic controller 812 is responsive to settings entered by the user.

[0069] For example, a small table-top controller, 802, powered by batteries preferably, could have a user interface, for a user to enter a desired needle penetration depth, such as in millimeters, and / or the volume of each injection, such as in microliters, and / or the number of seconds over which the volume is injected. An "inject" or start button could be used to initiate a sequence of 1 extend needle, 2 dispense injectate and 3 retractneedle. The speeds of each of the operations could be pre-set or controlled by settings on the controller. The "inject" button may be located either on the controller 802 or a manipulation handle positioned around the catheter shaft. The "inject" button may also be tied to a safety enable control such that only the two controls used simultaneously would initiate the injection sequence. The two controls may be ergonomically placed so as to make injection easy but at the same time requiring the activation to be deliberate.

[0070] For the user, once the settings for needle penetration depth, microliter injection volume, and / or injection time period are set, the sequence may be as follows: (A) Position the distal tip of the catheter where the injection is desired. (B) Activate the injection. (C) Move to the next injection site.

[0071] In some embodiments, a communications link 814 is provided. This feature may allow the electronic controllers 812 to be connected to one or more external devices 816 for monitoring and recording and / or for control with proper safety considerations.Such communication may be over wires or wireless. It may include communicating with external injectate controller 818, which may include an external supply of additional injectate, and / or external computer systems 816 such as smartphones, tablets, PCs or mainframe computers in the therapy facility.

[0072] In some embodiments, inside of Push / Pul I tube 112, or as an integrated lumen with the tube 112 is a micro-lumen 114 for injectate to be transferred to the injectate chamber 108.

[0073] In some embodiments, the injectate chamber 108 is refilled by the following steps: the user removes the catheter 100 from the patient, inserts the needle 101 into a supply of the injectate, and withdraws the plunger to aspirate injectate into the chamber. In this embodiment, the amount of wasted injectate is only a single needle volume. With the 10 mm long 29 gauge needle mentioned before, that is 0.266 pL of waste.

[0074] In some embodiments the injectate chamber 108 may be refilled through the micro-lumen 114. If the inside diameter ID of the micro-lumen catheter is the same as the ID of the 29 gauge needle, 0.184 mm, the volume would be 0.675 pL per 25.4 mmlength i.e., 0.675 piL per inch. Assuming a 50 cm length of the catheter, the volume in the full length of the micro-lumen would be 13.3 pL.

[0075] Fig. 8 illustrates a syringe 820 having a supply injectate 821 connected to the proximal end of micro-lumen 114 and controlled electronically by external injectate controller 818 and / or push / pul I tube controller 806 to supply additional injectate to the catheter 100. The implementation shown also has a Comms Links module so the controller 802 can coordinate activities with external injectate controller 818. Such coordination is important. Controller 802 may be configured to indicate when the plunger is at the end of injectate chamber 108 i.e., injectate chamber 108 is empty. To refill injectate chamber 108, controller 802 may simultaneously cause external injectate controller 818 to push injectate and at a specific number of microliters per minute or per second while withdrawing plunger 110 at that same rate of microliters per minute or per second and stopping the operation at a predetermined total volume.

[0076] Other considerations include the material properties of the injectate. Its viscosity and shear stress response characteristics may limit the flow rate within a given lumen size, which can impact the refill time for the procedure.

[0077] With reference to Fig. 8 and Fig. 14, in some embodiments, the system 800 includes the catheter assembly 100 and a control system such as controller 812 having a non-transitory computer-readable medium 830 storing a program including instructions that, when executed by one or more processors, execute a method 1400.

[0078] The method 1400 includes determining a desired distal position of the needle 1402, determining the needle is proximal of the desired distal position 1404, sending a first electric signal configured to cause the needle to move distally 1406, determining the needle is in the desired distal position 1408 and sending a second electric signal configured to cause the plunger to move, whereby the first volume of the injectate is expelled through the needle 1410.

[0079] Determining a desired distal position of the needle 1402 may be in response to a user inputting the desired distal position directly, or the determining may be a calculation based on other input factors. For example, the user may input an organ typeor condition of an organ, such as wall condition, and the determining 1402 may determine an ideal distal position based on that information.

[0080] In some embodiments, the method 1400 includes receiving one or more parameters and, responsive to the receiving, determining a desired needle penetration depth. The receiving may be achieved by receiving data from one or more sensors, such as, by way of example only, ultrasonic measurement devices, a computer tomography (CT) test result, other images and / or data related to the patient's anatomy, the thickness of the organ, and / or the thickness of the organ wall at the position of the needle.

[0081] The system 800 may include a user interface 832, the control system 812 responsive to the user interface 832, whereby a user may input at least one of a desired distal position of the needle or a desired volume the first volume of the injectate to release. Those skilled in the art will recognize that, although the user interface 832 is depicted in Fig. 8 as being on an external device 816 and in electronic communication with the control system 812, the user interface may be positioned and configured on or coupled to any of the components of the system 800.

[0082] The method 1400 may include sending a third electric signal configured to cause the needle to move proximally (that is, to withdraw from the organ tissue). The method 1400 may include sending another signal to cause the needle to move distally another time. The method 1400 may include sending a fourth electric signal configured to cause the plunger to move distally another time, whereby a second volume of the injectate is expelled through the needle. Those skilled in the art will recognize the components required to convert the electric signals into mechanical movement, such as linear or rotational.

[0083] The system 800 may include a micropump configured to control movement of at least a portion of the injectate. The plunger 110 may be a component of the micropump.

[0084] The system 800 may include a threaded gear system, such as a gear system including the gear system depicted in Fig. 7, whereby linear motion of at least one of theneedle 101 or the plunger 110 is effectuated by rotational motion of at least one of the elongate sheath 106 or a sleeve.

[0085] Turning now to Fig. 9, those skilled in the art will recognize the basic intent of embodiments herein is primarily to allow the injection of small amounts of injectate from the end of a catheter that allows injection into internal body organs or structures with minimal loss of injectate in the process. As shown in Fig. 9, in some embodiments, the injectate chamber 108 may be a collapsible bladder 118 containing the injectate. Pressure may be put on the outside of the bladder in many ways such as a mechanical squeeze mechanism, hydraulic squeeze pressure, or pneumatic squeeze pressure. The bladder 118 may reside within a catheter body. As shown in Fig. 9, the plunger 110 may compress the bladder 118, although those skilled in the art will recognize other features may function.

[0086] With reference to Fig. 10, in some embodiments, the injectate chamber 108 may be in the form of collapsible tubing 120 that functions as a bladder that is squeezed to force out the injectate. In some embodiments, the plunger 110 may be configured to move longitudinally along the exterior of the collapsible tubing 120 to move injectate into the patient, much like squeezing a toothpaste tube.

[0087] In some embodiments, and as shown in Fig. 11 a cartridge 1102 may be provided, with its own plunger 110 for example, that may be filled with injectate and placed into a catheter. The cartridge 1102 may include a sleeve 106, an injectate chamber 108, collapsible tubing 120, and a hub 102. The cartridge 1102 may be positioned in a catheter or otherwise connected to a needle assembly to deliver injectate.

[0088] In some embodiments, and as shown in Fig. 12, a cartridge 1202 may be provided, with its own plunger 110 for example, that may be filled with injectate and placed into a catheter. The cartridge 1202 may include a sleeve 106, an injectate chamber 108, collapsible bladder 118, and a hub 102. The cartridge 1102 may be positioned in a catheter or otherwise connected to a needle assembly to deliver injectate.

[0089] In some embodiments, and as shown in Fig. 13, a cartridge 1302 may be provided, with its own plunger 110 for example, that may be filled with injectate and placed into a catheter. The cartridge 1202 may include a sleeve 106, an injectate chamber 108 and a hub 102. The cartridge 1102 may be positioned in a catheter or otherwise connected to a needle assembly to deliver injectate.

[0090] In some embodiments, such as those illustrated in Figs. 9 through 12, the plunger 110 reshapes the chamber 118 as the plunger 110 moves distally, whereby the volume in the chamber 108 is reduced and the injectate 109 is forced through the needle. The reshaping may be by collapsing or compressing the chamber 118 as the plunger 110 passes down.

[0091] With reference now to Fig. 15, a method 1500 is described. The method 1500 includes providing 1502 a system 800, such as the system 800 previously described herein, and positioning 1504 the apparatus 100 or catheter assembly adjacent a first target location on a surface of an internal organ, such as, for example, positioning the distal end of the catheter assembly adjacent the heart wall. The method 1500 includes providing a first user input 1506 via the user interface to effectuate movement of the needle 101 to the distal position, whereby the distal end of the needle penetrates the surface of the organ. The method 1500 includes providing a second user input 1508 via the user interface to cause movement of the plunger 110, whereby the first volume is injected into the organ.

[0092] The method 1500 may include positioning 1510 the apparatus adjacent a second target location on the surface of the internal organ. The method 1500 may include providing 1512 a third user input to cause movement of the plunger, whereby a second volume of the injectate is ejected into the organ.

[0093] Although embodiments herein have been described generally in reference to applying an injectate or a liquid at a somewhat remote location i.e., the distal end of the catheter, non-medical uses might include long-term lubricating fluids dripped or injected into a mechanism, micro plant watering, dripping micro amounts of an additive into a chemical process, allowing an operator to be at a distance from a toxic substanceand inject or drip a liquid into such a substance. The invention may be used anywhere a small amount of liquid is desired to be dispensed at a location slightly remote, such as from the operator at the length of the catheter.

[0094] Each of the various elements disclosed herein may be achieved in a variety of manners. This disclosure should be understood to encompass each such variation, be it a variation of an embodiment of any apparatus embodiment, a method or process embodiment, or even merely a variation of any element of these. Particularly, it should be understood that the words for each element may be expressed by equivalent apparatus terms or method terms— even if only the function or result is the same. Such equivalent, broader, or even more generic terms should be considered to be encompassed in the description of each element or action. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled.

[0095] As but one example, it should be understood that all action may be expressed as a means for taking that action or as an element which causes that action. Similarly, each physical element disclosed should be understood to encompass a disclosure of the action which that physical element facilitates. Regarding this last aspect, the disclosure of a "attachment mechanism" should be understood to encompass disclosure of the act of "attaching" —whether explicitly discussed or not— and, conversely, were there only disclosure of the act of "attaching", such a disclosure should be understood to encompass disclosure of a "attaching mechanism". Such changes and alternative terms are to be understood to be explicitly included in the description.

[0096] Moreover, the claims shall be construed such that a claim that recites "at least one of A, B, or C" shall read on a device that requires "A" only. The claim shall also read on a device that requires "B" only. The claim shall also read on a device that requires "C" only. The claim shall also read on a device that requires "A+B". The claim shall also read on a device that requires "A+B+C", and so forth.

[0097] Those skilled in the art can readily recognize that numerous variations and substitutions may be made in the invention, its use and its configuration to achieve substantially the same results as achieved by the embodiments described herein.

[0098] Accordingly, there is no intention to limit the invention to the disclosed exemplary forms. Many variations, modifications and alternative constructions fall within the scope and spirit of the invention as expressed in the claims.

Claims

CLAIMS1. An apparatus for applying a micro amount of an injectate to a precise intracorporeal location, comprising: an elongate sheath; a needle; a chamber carrying an injectate therein, the injectate fluidly coupled to the needle, the needle movable relative to the elongate sheath between a proximal position and a distal position, the distal position configured to extend a distal end of the needle a predetermined distance outside the elongate sheath; and a plunger configured to move within the sheath between a proximal position and a distal position, the distal position configured to cause the chamber to expel a first volume of the injectate through the needle, the first volume of injectate being a micro volume of injectate.

2. The apparatus of claim 1, wherein: the first volume of the injectate comprises substantially all injectate in the chamber.

3. The apparatus of claim 1, wherein: the predetermined distance is adjustable.

4. The apparatus of claim 1, wherein: the elongate sheath is flexible.

5. The apparatus of claim 1, wherein: the chamber comprises at least one of a flexible wall or a compressible wall.

6. The apparatus of claim 5, wherein: the plunger is configured to reshape the chamber as the plunger moves distally.

7. The apparatus of claim 1, further comprising: a removable cartridge, the removable cartridge housing the chamber.

8. The apparatus of claim 1, further comprising: a lumen configured to selectively fluidly couple a supply injectate to the chamber.

9. The apparatus of claim 8, further comprising: a valve configured to selectively fluidly couple and decouple the supply injectate to the chamber.

10. The apparatus of claim 1, wherein: the micro volume is 100 microliters or less.

11. The apparatus of claim 1, wherein: the chamber has a maximum capacity of 2 milliliters or less.

12. The apparatus of claim 1, wherein: the chamber has a maximum capacity of 4 milliliters or less.

13. The apparatus of claim 1, further comprising: a threaded engagement between the plunger and the chamber, whereby rotation of the plunger relative to the chamber effectuates a linear distal movement of the plunger.

14. The apparatus of claim 13, wherein: at least one of: the chamber comprises a coil embedded into an interior wall of the chamber, the coil forming a threaded engagement with the plunger; orthe plunger comprises a coil embedded into an exterior wall of the plunger, the coil forming a threaded engagement with the chamber.

15. The apparatus of claim 13, wherein: at least one of: the chamber comprises a metal coil embedded into an interior wall of the chamber, the metal coil forming a threaded engagement with the plunger; or the plunger comprises a metal coil embedded into an exterior wall of the plunger, the metal coil forming a threaded engagement with the chamber.

16. The apparatus of claim 13, wherein: at least one of: the chamber comprises a polymeric coil embedded into an interior wall of the chamber, the polymeric coil forming a threaded engagement with the plunger; or the plunger comprises a polymeric coil embedded into an exterior wall of the plunger, the polymeric coil forming a threaded engagement with the chamber.

17. The apparatus of claim 13, wherein: the plunger is made of a first material; and the chamber is made of a second material different from the first material; wherein the first material is harder than the second material.

18. A system for applying an injectate to an internal organ, comprising: the apparatus of claim 1; and a control system having a non-transitory computer-readable medium storing a program including instructions that, when executed by one or more processors, execute a method, the method comprising:(a) determining a desired distal position of the needle beyond the sheath;(b) determining the needle is proximal of the desired distal position;(c) sending a first electric signal configured to cause the needle to move distally;(d) determining the needle is in the desired distal position; and(e) sending a second electric signal configured to cause the plunger to move, whereby the first volume of the injectate is expelled through the needle.

19. The system of claim 18, further comprising: a user interface, the control system responsive to the user interface, whereby a user may input at least one of:(a) the desired distal position of the needle;(b) the first volume of the injectate to release; or(c) a desired time period over which the injectate is to be released.

20. The system of claim 18, wherein the method further comprises:(a) sending a third electric signal configured to cause the needle to move proximally; and(b) sending a fourth electric signal configured to cause the plunger to move, whereby a second volume of the injectate is expelled through the needle.

21. The system of claim 18, further comprising: a micropump configured to control movement of at least a portion of the injectate.

22. The system of claim 18, further comprising:a threaded gear system, whereby linear motion of at least one of the needle or the plunger is effectuated by rotational motion of at least one of the elongate sheath or a sleeve.

23. The system of claim 18, wherein: the threaded gear system is configured to move the at least one of the needle or the plunger in a distal direction and a proximal direction.

24. A method, comprising: providing the system of claim 18; positioning the apparatus adjacent a first target location on a surface of an organ; providing a first user input via the user interface to effectuate movement of the needle to the distal position, whereby the distal end of the needle penetrates the surface of the organ; and providing a second user input via the user interface to cause movement of the plunger, whereby the first volume is injected into the organ.

25. The method of claim 24, further comprising: positioning the apparatus adjacent a second target location on the surface of the organ; and providing a third user input to cause movement of the plunger, whereby a second volume of the injectate is ejected into the organ.

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