Access system and method

Abstract

Systems and methods for dialysis cannulation, including devices including structures configured to place a needle or cannula to provide vascular access, or methods relating to the structures. In one approach, a self-cannulation system for hemodialysis is provided.

Description

[Technical Field]

[0001] TECHNICAL FIELD The present disclosure relates generally to systems and methods for cannulating a vasculature or graft. [Background technology]

[0002] There is a continuing need for effective alternative approaches to providing vascular access, particularly for hemodialysis. Additionally, there is a need for easy-to-use, effective access systems that can be used in the clinic or at home.

[0003] Hemodialysis has become the conventional approach to treating patients with kidney disease. The hemodialysis process, commonly referred to as dialysis, involves filtering waste products from the blood, supporting or replacing the biological function of healthy kidneys. Effective dialysis helps balance substances in the blood, including calcium, potassium, and sodium, and also helps control blood pressure.

[0004] Hemodialysis involves pumping blood through a dialyzer, which acts as a filter to balance blood components, acting like an external kidney. In a hospital or clinic setting, medical personnel are responsible for setting up the dialyzer and connecting the patient to the machine. This involves gaining access to a cannula in the patient's vascular system, placing a needle that is connected or connectable to the cannula, and connecting tubing to the dialyzer.

[0005] Typically, hemodialysis takes about four hours, performed three times a week, but some patients require more frequent and longer treatments. Add to this the time it takes to travel to the treatment center and the waiting time for the dialysis machine to be connected and disconnected, and the burden on patients in terms of both time and effort becomes significant.

[0006] Due to these limitations associated with dialysis performed in treatment centers, more efficient hemodialysis, including cannulation either at a treatment center or at home, has become a desirable alternative. Therefore, there is a desire to make not only dialysis, but also insertion site assessment and cannulation itself, more efficient and / or less skilled. Research has shown that home dialysis performed 5–7 times per week dramatically improves treatment outcomes in many ways, including extending lifespan and improving survival rates. Home dialysis eliminates the need for travel to a dialysis center. Home dialysis also allows patients to choose their own convenient dialysis times, offering greater flexibility and a greater sense of control by providing independence and self-management.

[0007] However, unless home healthcare is utilized, there are often no medical professionals in the home environment to monitor treatment or answer urgent questions. Importantly, treatment centers have few medical professionals available to assist with or perform the cannulation techniques required to insert a needle into a patient's blood vessels so they can be connected to a dialysis machine. Cannulation is a skilled nursing task. Self-cannulation is also challenging for many patients, and many lack the dexterity and technique necessary to repeatedly, effectively, and efficiently insert a needle to access the vascular system from the insertion site. Because proper and repeatable cannulation is so important for successful hemodialysis and to avoid infections and other complications, unassisted home dialysis is currently not a practical option for many patients.

[0008] Therefore, there is a need for effective and efficient devices and approaches to cannulation that minimize or shorten the time it takes to receive hemodialysis, and that can be performed in a treatment center or at home with easy-to-use systems that help minimize trauma and infection. These approaches must provide predictable results and be relatively easy to adopt.

[0009] The present disclosure addresses these and other needs. Summary of the Invention

[0010] Briefly and generally, the present disclosure is directed to access systems and methods, including cannulation systems, that facilitate providing vascular access. Such approaches to cannulation systems are configured to define permissible access paths that prevent a user or system from entering unacceptable paths or inserting beyond a defined terminal point, as well as a small range of permissible paths and a most desirable path. In one aspect, the defined terminal point resides within a wall defining a target graft or vessel.

[0011] The cannulation system is configured for use in a center or home dialysis setting and can be operated by the patient, a skilled medical professional, or an unskilled individual. In one embodiment, the cannulation system includes a detection bed, an armature attached to the detection bed, and a needle holder attached to the armature. The detection bed includes a structure that achieves repeatable and consistent fixation of the patient's body part to the detection bed relative to the armature. This cannulation system is particularly suited for patients requiring multiple repeat cannulations. By pre-planning and pre-determining the cannulation site and route to the site, the system is thus configured to allow rapid, repeatable, and identical arm / vessel placement and confirmation without having to collect information about the patient or the cannulation site every time a cannulation procedure is performed.

[0012] In one embodiment, one or more fiducials are implanted into a patient through a pre-scan process, where the fiducials are used to register the patient and map the precise location of the targeted vasculature, whether it be an artificial graft or a natural access anatomical structure, including fistulas or the vessel itself. Additional scans are performed as needed, such as periodically, to confirm the location of the target vessel or graft relative to the implanted fiducial or other landmark. In one approach, additional scans may be performed on a schedule, such as every six months or more. The pre-scan process can involve a medical professional developing a strategy and plan for mapping an approach for advancing one or more needles via acceptable pathways into the target vasculature. The strategy or plan can include a small range of acceptable pathways, as well as the most desirable pathway for vascular access. This plan can include mapping pathways to multiple predetermined cannulation sites that can be alternately accessed via a rope ladder access technique. All acceptable cannulation sites and routes can be determined after a pre-scan step and before the patient undergoes dialysis. Thus, in one embodiment, the cannulation site and route to cannulation do not need to be calculated in real time, but can all be determined before the patient places their arm in the detection bed.

[0013] In use, in one embodiment, the patient simply fastens their arm or other body part to the detection bed, and the cannulation system recognizes the patient and knows the acceptable path the needle should take to achieve cannulation. The cannulation system can guide the movement of the needle through the acceptable path and prevent the needle from entering an unacceptable path or being inserted beyond a defined termination point.

[0014] In one embodiment, the cannulation system is servo-controlled, with a servo motor attached to each moving part of the armature and a sensor associated with each servo motor so that the patient or other person can grasp the needle or needle holder and move the needle through a path guided or constrained by the servo motor.

[0015] In another embodiment, the cannulation system is manually operated by a user who sets each moving part of the cannulation system according to a predetermined plan, wherein the armature of the cannulation system is free of electronics such as servo motors or sensors.

[0016] In yet another embodiment, once the body part is secured to the sensing bed and the patient is enrolled, the cannulation system operates autonomously to achieve vascular access.

[0017] In one embodiment, the cannulation system includes structure and functionality for targeting vasculature and placing one or more needles within the target vasculature without the need for a trained operator. The needle or needles are held within a needle holder, and once the detection bed registers the patient, an armature is employed to advance the needle or needles into the target vasculature, graft, or fistula along a path calculated based on real-time fiducials or anatomical data and / or pre-recorded anatomical data. In one aspect, the needle or needles are advanced at a predetermined angle and depth within the patient's body and the target vasculature. Importantly, the system is effective in providing vascular access and aids in cannulation of the entire body, including, in particular, radiocephalic, brachial-brain, and brachial-vesical fistulas, potentially extending from the forearm to the upper arm or elsewhere on the body.

[0018] In one preferred embodiment, the system embodies a cannulation system including a sensing bed with or associated with a body part fixation structure, and an armature including a needle holder attached to or associated with the sensing bed, wherein localization technology is embedded in the sensing bed and is fixed relative to the body part fixation structure and the armature.

[0019] Once the patient's arm is stabilized on the bed, the position of the fiducial within the patient's arm or other body part is detected and linked via system software. The fiducial's position can be compared to a previously recorded 3D dataset, virtually mapping the location of the vascular access site and the expected or indicated needle tip placement location onto the armature. The needle-holding structure is attached to the needle in a fixed and reproducible manner, so the needle tip (once secured to the needle-holding structure) knows its relative position relative to all anatomical landmarks via the system software. Once the needle is locked into the needle-holding structure, data provided by the software informs the proposed direction of each degree of freedom of the needle support structure. In a manual approach, these settings are communicated to the user via a display, and the user configures each joint or moving part of the armature. In a servomotor-based approach, the various degrees of freedom of the armature are guided or constrained by servomotors to allow the needle to move along the ideal path for each degree of freedom.

[0020] In a preferred embodiment, the patient's arm is stabilized by a sensing bed in the cannulation system, which scans a fiducial implanted in the arm to determine the arm's precise orientation within the cannulation system and relative to one or more components of the cannulation system. The arm's position may be normal or expected, or it may be slightly rotated or offset from expected. The system adjusts a previously calculated, known path to account for slight differences in arm position, whether translational, rotational, or a combination thereof. The cannulation system performs these adjustments automatically, semi-automatically, or manually with guidance. If the arm position differs significantly from expected, the system can alert the patient or healthcare provider. In such cases, the system can calculate a partially new or entirely new path or trajectory based on the new information.

[0021] During the pre-scanning, mapping, and planning process, one or more of MRI scans, CT scans, ultrasound scans, infrared views, or 3D photographs are employed to gather information about the patient's vascular morphology and anatomy. In one embodiment, information about the target anatomy and / or vasculature relative to the implanted fiducials is collected and stored in the cannulation system's memory. In one particular aspect, the cannulation system includes an array of passive limiters that fix the range of motion for each degree of freedom of the armature; in various approaches, information about the setting of each passive limiter is determined using a combination of imaging data and information from real-time fiducials corresponding to the vascular access target and displayed on the device.

[0022] In various embodiments, the system can also track insertion site, size, position and shape, insertion date, flow rate, treatment frequency, and treatment duration, and further allow patient input so that complications or infections can be tracked and monitored. In certain alternative embodiments, the system can suggest insertion sites and provide options for needle placement to the patient or healthcare provider based on a combination of historical data regarding the patient's previous cannulations with the device and the patient's anatomical image data, and in light of the patient's input. In certain alternative embodiments, the system can also leverage crowd data from other patients on the system with similar anatomy and vascular morphology who have been successfully cannulated at a given site to further inform the system's recommendations. Furthermore, in alternative embodiments, the system includes a remote interface or computer that allows the patient, healthcare provider, or other connected health device (e.g., via Bluetooth) to input patient health information, including heart rate, blood pressure, blood flow, as well as the patient's diet, medications, and exercise.

[0023] In alternative embodiments, the system controller manages or provides an assessment of the fistula or graft prior to cannulation. If an obstruction is detected, the system may alert the patient or healthcare provider to avoid the cannulation procedure and allow further assessment and / or intervention to be performed. Various sensors and actuation mechanisms are provided to automate the assessment process, or portions thereof. In certain approaches, the system embodies one or more sensors that recognize tremors or vibrations, and acts like a stethoscope to track the bruit (i.e., the sound of a heartbeat or blood flow) or listen to the flow, looking for obstructions.

[0024] In one or more aspects, the access system includes one or more fiducials or markers that facilitate the introduction of a needle into the patient's skin relative to the vascular access site. In alternative embodiments, the fiducials or markers may be one or more implants, tattoos, magnetic markers, radio-opaque materials, or other features naturally present near or at the intended vascular access site.

[0025] In a preferred approach, fiducial markers are configured to be implanted and attached to the radius and / or ulna bones of the forearm, or placed at one or more locations in bone or soft tissue near the vascular access site. The vascular access site fiducials or markers can be co-registered to a previously acquired infrared view, MRI, ultrasound, or CT scan to initially establish patient data for subsequent cannulation.

[0026] In alternative embodiments, the system can be configured to readjust the trajectory and / or depth of needle movement if the patient moves before, during, or between cannulations. Further, the fiducials or markers can alternatively or additionally be one or more RFID chips, electromagnetic implants, metallic implants, radio-opaque materials, or other features naturally present near or at the intended vascular access site.

[0027] Another alternative approach to inserting a needle into a vascular access site provides a sensor pack that can simultaneously identify and evaluate the location of a fistula or graft prior to cannulation. The sensor pack can be attached to an automated mechanism that moves along the arm or incorporated into a sleeve or other structure that the patient can move along the insertion site. Information obtained by the sensor pack is fed into a system to facilitate determining the desired cannulation location. Additionally, the sensor pack can be configured to continuously evaluate the status of the cannulation and communicate it to the patient or healthcare provider.

[0028] In one or more alternative approaches, the patient can move cannulation system components and advance the needle themselves, taking into account their own sensation, pain, or comfort, where the system ensures that the needle does not take an incorrect path or penetrate deeper than the defined desired termination point. Additionally, in each of the disclosed embodiment approaches or one or more alternative approaches, the system can automatically position, aim, and advance the needle during the cannulation procedure. Additionally, in alternative embodiments and approaches, the patient and system can collaborate to varying degrees, for example, allowing the patient to guide the system in needle positioning but wanting to push the needle into the vasculature, or the patient can move a needle-holding structure and have the system push the needle into the vasculature either when the system is ready or when the patient indicates their readiness and signals that cannulation should be performed, such as by pressing a cannulation button.

[0029] In one embodiment, the cannulation system includes a sleeve or chamber that can be positioned over or into the patient's arm. The sleeve is configured to lock onto the patient's arm, facilitating fixation of the patient's arm relative to the sensing bed. In another approach, the sleeve or chamber includes a molded insert that is contoured to receive the patient's arm and position it relative to the sensing bed, where the molded insert is created, for example, via 3D printing, from a model of the patient's arm so that the contours of the molded insert allow the arm to fit securely and comfortably within the molded insert. The system can communicate with the sensing bed to adjust the position of the arm.

[0030] In various additional alternative embodiments, the cannulation system can include one or more non-visible optical, acoustic, pressure, or visual sensors for determining and tracking blood flow. In this way, the patient's health status as well as the effectiveness of the cannulation can be confirmed and monitored. The system can also alternatively or additionally employ acoustic, e.g., ultrasound, or audio triangulation, or wavelengths of light, e.g., near-infrared imaging, to locate, identify, and target the vasculature. For example, an IR sensor can be positioned and configured to emit a near-IR beam that identifies the targeted fistula or cannulation site. Thus, in various approaches, one or more access points within the AV fistula or graft can be suggested or selected by the system or by a healthcare provider, depending on the patient's alternative approach. Furthermore, in alternative approaches, the system can indicate whether cannulation was successful and alert the patient or healthcare provider regarding the success or failure of the cannulation. In yet another embodiment, the system can alternatively or additionally employ acoustic, e.g., ultrasound, or audio triangulation, or wavelengths of light, e.g., near-infrared imaging, to identify the patient. Additionally, acoustic or optical wavelengths can be used to register the system in relation to the target vasculature.

[0031] Additionally, in other aspects, various approaches to cannulation systems are provided with the structure and functionality to controllably position one or more needles relative to a target insertion site in three-dimensional space. In one approach, the cannulation system includes one or more standard needle cassette assemblies that can be configured to controllably translate along an armature that includes a rotatable U-frame arranged to position the needles in three-dimensional space and relative to the target insertion site. In an alternative embodiment, an armature that includes an articulating split frame is provided to independently position two or more needles relative to the insertion site.

[0032] Various other alternative approaches to the armature structure may also be used, so long as effective cannulation is achieved. For example, a curved arm that supports the needle cassette and traverses in an arcuate path, or a structure including a ball joint, or other approaches that provide multi-axis movement may be employed.

[0033] These and other features of the present disclosure will become apparent to those skilled in the art upon reading the details of the systems and methods described in detail below. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 shows a schematic of the hemodialysis process and device. [Figure 2] FIG. 2 is a plan view showing the graft in a first approach for vascular access. [Figure 3] FIG. 3 is a plan view showing an AV fistula in a second approach to vascular access. [Figure 4] FIG. 4 is a plan view showing cannulation in a second approach to vascular access. [Figure 5] FIG. 5 is a plan view showing blood flow resulting from cannulation. [Figure 6] FIG. 6 is a cross-sectional view showing one approach to fiducials. [Figure 7] FIG. 7 is a partial perspective view showing an apparatus for implanting a fiducial into tissue. [Figure 8] FIG. 8 is a schematic diagram showing the anatomical structure containing the implanted fiducial. [Figure 9] FIG. 9 is a side view showing the movement of the bones of the forearm. [Figure 10] FIG. 10 is a side view showing the movement of the bones of the forearm. [Figure 11] FIG. 11 is a side view showing the attachment of the marker to the bone. [Figure 12] FIG. 12 is a schematic diagram showing a scanning system. [Figure 13] FIG. 13 is a side view showing the vessel and controlled needle insertion path. [Figure 14] FIG. 14 is a perspective view showing one approach to the cannulation system. [Figure 15] FIG. 15 is a perspective view showing another approach to the cannulation system. [Figure 16A] FIG. 16A is a perspective view showing yet another approach for the cannulation system. [Figure 16B] FIG. 16B is a perspective view showing the system of FIG. 16A in use on a patient's arm with a stabilizing device. [Figure 17] FIG. 17 is a perspective view showing the use of the cannulation system. [Figure 18] FIG. 18 is a perspective view showing the use of the cannulation system. [Figure 19] FIG. 19 is a perspective view showing the use of the cannulation system. [Figure 20] FIG. 20 is a perspective view showing another approach to the cannulation system. [Figure 21] FIG. 21 is a perspective view showing another approach to the cannulation system. DETAILED DESCRIPTION OF THE INVENTION

[0035] Before the present systems and methods are described, it is to be understood that this disclosure is not limited to particular embodiments described, which may, of course, vary. Also, the scope of the present disclosure will be limited only by the appended claims, and it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0036] Where a range of values ​​is specified, unless the context clearly dictates otherwise, each intervening value, to the tenth of the unit of the lower limit, between the upper and lower limit of that range is understood to be specifically disclosed. Each smaller range between any stated or intervening value in a range and any other stated or intervening value in that range is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included or excluded, and each range in which either, either, or both upper limits are included in the smaller range is also encompassed within the disclosure, subject to any specifically excluded upper limit in the stated range. Where a stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included within the disclosure.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of this disclosure, the preferred methods and materials are described.

[0038] It should be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to a "system" includes a reference to one or more systems and equivalents thereof known to those skilled in the art, and so forth.

[0039] Referring to Figure 1, a hemodialysis system 50 and related equipment are shown. During hemodialysis, a patient's blood passes through a dialyzer 52, which filters the blood. The patient is prepared by flushing the area where the blood exits and then returns to the patient's blood vessels. Steps are taken to prepare the patient's vascular system for dialysis, as described below. Once the patient's blood vessels are thus prepared, a pair of needles 54, 56 are inserted into the patient's arm at the start of hemodialysis. A numbing agent may be used to facilitate needle insertion and minimize pain. Each needle is attached to a flexible tube or cannula 58 that connects to the dialysis system 50. The dialysis system 50 pumps blood through the dialyzer 52 and back into the patient's body. During this process, blood pressure is monitored and controlled by the dialyzer, thereby controlling the flow rate of blood through the filter and the rate at which blood flows to and from the patient.

[0040] As blood enters the filter, it is forced through many thin, hollow fibers. At the same time, dialysate passes through the fibers in the opposite direction. Waste products are removed from the blood and carried by the dialysate. The filtered blood is then returned to the patient's vascular system. In this way, excess salt, potassium, calcium, and water are removed from the blood.

[0041] A critical step before starting hemodialysis treatment is undergoing surgery to create a vascular access site. Vascular access is a term used to describe the location within a patient's body where blood flows from and returns to the patient's vascular system, such as during hemodialysis. Hemodialysis vascular access sites can be catheters, arteriovenous (AV) grafts 60 (Figure 2), or arteriovenous (AV) fistulas 70 (Figure 3). It is important to note that catheter approaches are generally used for temporary access and are not suitable as a permanent solution for home or treatment center dialysis.

[0042] To create an AV graft 60 (Figure 2), in an outpatient procedure, a surgeon makes an incision in the skin to access the target blood vessel. The surgeon then uses an artificial tubing graft 60 to connect the artery that carries blood away from the heart to the vein that carries blood to the heart. The surgical site is then closed, leaving the graft ready for dialysis. Dialysis needles are repeatedly used to access the tubing during the hemodialysis procedure described above. The AV graft approach is generally used in patients with veins that cannot be used for AV fistula creation, as this approach is often associated with repeated infections and blood clots that can obstruct blood flow and make dialysis difficult or impossible.

[0043] The most commonly accepted long-term vascular access method is the AV fistula 70 (Figure 3). This method offers the greatest blood flow for dialysis, is less susceptible to infection and blood clots, and lasts longer than other vascular access methods. Here, surgeons create an AV fistula by directly connecting an artery to a vein (usually in the patient's arm). Connecting the vein to the artery increases its size, making it easier to repeatedly insert the dialysis needle. The AV fistula itself is also enlarged in diameter to allow blood to quickly exit and return to the patient. The goal is to create a system with high blood flow, maximizing the amount of blood passing through the dialyzer. Figure 4 shows the cannulation of two needles 54, 56 at the AV fistula 70 site, and Figure 5 shows the blood flow into and out of the AV fistula 70 during dialysis. It should be noted that when using the presently disclosed cannulation system, any number of treatment protocols can be specified by the treating medical professional and built into the software, such as rotating the needle cannulation site as in the rope ladder technique or using it repeatedly as in the buttonhole technique.

[0044] Once a patient has been provided with a vascular access site, the challenge is inserting a needle into that site. As previously mentioned, many patients have difficulty or are unable to self-cannulate. Furthermore, inexperienced nurses find cannulation difficult.

[0045] Accordingly, various approaches to access methods and devices are presented. The disclosed approaches are designed to provide a repeatable, effective, and optimal approach to self-cannulation or healthcare professional-assisted cannulation. The disclosed approaches are intended for use in a center or home environment for hemodialysis.

[0046] The disclosed cannulation system is configured and operative to position a needle or needles and, in some embodiments, advance the needles within a target AV graft, fistula, blood vessel, or blood vessel. The system further includes functionality for positioning the needle in the correct location and trajectory and, in some embodiments, advancing the needle at a predetermined angle and depth within the patient's body and the target vasculature. The system is effective in providing vascular access and aids in systemic cannulation, particularly for radiocephalic, brachial-cephalic, and brachial-vesical fistulas, and may range from the forearm to the upper arm or elsewhere on the body. The system can be easily operated by patients, unskilled personnel, or skilled medical personnel in a home setting or at a treatment center, and functions to successfully cannulate patients while improving outcomes and reducing complications.

[0047] As previously mentioned, as part of the pre-scanning process, one or more of an MRI scan, a CT scan, an ultrasound scan, an infrared view, or a 3D photograph may be employed to gather information about the patient's specific anatomical structure and vascular morphology. In one embodiment, information about the target cannulation site may be collected or stored in the cannulation system memory. This input data about the patient's anatomy and vasculature is acquired (e.g., an anatomical MRI scan, an ultrasound scan, a CT scan, an infrared view, or a 3D photograph) to register the patient and map the approach to cannulation. A cannulation system controller, including system software and / or firmware, then uses such stored patient data to manage the operation of the cannulation needle guidance structure.

[0048] In one or more alternative embodiments, the system controller tracks one or more of insertion site, size, position and shape, insertion date, flow rate, treatment frequency, and treatment duration, and responds to patient health data so that complications or infections can be tracked and monitored. The system can then suggest insertion sites based on the patient's usage data, anatomical features, and vascular morphology, and provide options for needle placement to the nurse or patient. In another embodiment, a remote interface or computer is included and configured to allow the patient or healthcare provider to input patient health information, such as heart rate, blood pressure, blood flow, the patient's diet, medications, and exercise. This patient health information can also be collected passively through connectivity with the patient's wellness devices (e.g., via Bluetooth) or integration with electronic medical record systems.

[0049] In an alternative embodiment, the system provides an assessment of the fistula or graft prior to cannulation. In this regard, such functionality can be fully automated or semi-automated and can further provide communication or alerts to the patient and / or healthcare provider regarding the assessment performed by the system. If an obstruction is detected, the system can alert the patient or healthcare provider so that the cannulation procedure can be avoided and further assessment and / or intervention can be performed. Various sensors and actuation mechanisms are provided to automate the assessment process or portions thereof. The sensors can be one or more of acoustic, tactile, ultrasound, Doppler, infrared, near-infrared, etc.

[0050] In certain alternative approaches, the system includes one or more sensors that recognize tremors or vibrations associated with the cannulation target site, operate like a stethoscope to track brute force (i.e., heart sounds or blood flow sounds), or listen to the flow to look for obstructions. In one or more approaches, sensors are provided to feel tremors or listen to brute force, and sensors are configured to listen for normal, unobstructed flow or for signs of stenosis or clots. Sensors can also be equipped to look for other signs of normal flow or obstruction, such as problems associated with Steal Syndrome, and issue alerts as needed. In one embodiment, a bank of sensors can be provided in a package configured to be translated along the cannulation target site, either manually or automatically. This package can be embodied in a structure similar to a separate cuff or stethoscope head, or can be attached to or form part of the arm or other structure of a needle support assembly. The system itself, or the patient, can be prompted to place the sensor package at the cannulation target site and direct the movement of the sensor package to assess the target site. In one approach, the positioning of the sensor package can be indicated or controlled using fiducial markers, described below.

[0051] Thus, in certain alternative embodiments, the location of the graft or fistula can be confirmed by employing a sensor package. Whether automatically or manually moved, real-time assessment can confirm the location and status of the graft or fistula. Thus, the system can be configured to readjust the trajectory and / or depth of needle movement if the patient moves before, during, or between cannulations. The sensor package can be tracked by the same system that tracks the needle cassette, and the system observes and tracks the relative position of the sensor when a vessel is properly detected. This information can be employed to confirm the location and status of the cannulation site and can also be entered into the system's database to aid in determining and planning the location of the cannulation site along the graft or fistula.

[0052] In one or more additional or alternative embodiments, the access system can include one or more non-visible optical, acoustic, pressure, or visual sensors (not shown) for determining and tracking blood flow. A pressure sensor can identify the location of maximum flow so that the needle can be optimally positioned. Alternatively or additionally, the disclosed system can also incorporate acoustic (e.g., ultrasound or audio triangulation) or a light source (e.g., near-infrared) that provides a wavelength of light for locating or identifying vasculature and identifying the target vasculature. One or more access points within the AV fistula or graft can be suggested by the system or selected by the patient. In this manner, the patient's health as well as the effectiveness of the cannulation can be monitored over time.

[0053] 6-8, approaches to fiducial markers are shown for use in registering a patient and in the pre-scan process for developing a cannulation plan or map. It should be understood that the fiducials may be magnetically or electrically detectable, but may also be imageable using electromagnetic, MRI, CT, or ultrasound, allowing their location relative to the target vessel to be determined.

[0054] As shown in FIG. 6, in one approach, the fiducial can be a bead 200 that includes one or more coils 202 configured within the bead 200. In one particular embodiment, three coils 202 are configured and arranged to provide information about the orientation of the bead 200 in three-dimensional space, such as its orientation relative to the x, y, and z axes, as well as information about its pitch, roll, and yaw. That is, each coil provides positional information about one axis, and in some embodiments, provides positional information about pitch, roll, and yaw. Ideally, the fiducial can be inserted without the need for surgery, but it can also be surgically placed when a vascular access site (e.g., an AV graft or fistula) is created.

[0055] In one approach (FIG. 7), an elongated assembly 210 can be employed to insert fiducial beads 200. A plunger 212 is configured within the needle assembly 210 and longitudinally translatably disposed within the elongated assembly 210 to advance one or more beads 200 out of the distal end of the elongated assembly 210. In devices configured to insert multiple fiducials, the distal end of the device can be configured to deliver a single fiducial at a time, such as by including a chamber or equivalent structure for registering a single fiducial for delivery, while including additional structure for holding additional fiducials for subsequent delivery. Implantation of three fiducials near the insertion site relative to the target vessel 220 (see FIG. 8) may be required, or, if the fiducial 200 itself embodies a known three-dimensional shape or orientation, only one or two fiducials may be needed to assist in positioning the insertion site for a particular patient. Furthermore, when electric fields are used in conjunction with fiducials, each fiducial can contain one to three coils tuned to different resonant frequencies so that their orientation and position can be determined. Thus, in-situ scanning using electromagnetic, MRI, CT, or ultrasound creates a data set that can accurately identify anatomical structures in three-dimensional space based on the relative positions of the fiducials.

[0056] After a fistula or graft is created and stabilized, or the target vasculature is identified, a fiducial can be placed in a subsequent procedure on or adjacent to the fistula or graft, or at a bone location, as described below. During this procedure, a medical professional determines the optimal trajectory of the cannulation and needle path based on the relative position of the fiducial to the target cannulation site. The cannulation system functions to faithfully reproduce the medical professional's relative position and trajectory path of the fiducial implanted at the vascular access site. The fiducial is detected by the access system, and the target vessel or graft is positioned relative to the fiducial. The pitch, roll, yaw, and x, y, and z-axis positioning of the fixture supporting the standard needle set are managed by the cannulation system to ensure that the needle set moves within an acceptable access path. In this way, the cannulation system can conveniently operate to constrain or manage needle movement to an acceptable path, preventing the needle from entering an unacceptable path or being inserted beyond a defined endpoint.

[0057] In one particular approach, the fiducial is implanted and attached to one or more of the ulna and radius of the forearm. As shown in Figures 9 and 10, the ulna 221 and radius 222 of the forearm move relative to one another as the forearm rotates. However, the ulna 221 and radius 222 are still useful locations for attaching the fiducial 200, providing a reliable reference for the vasculature targeted for dialysis needle insertion when the forearm is held in the position expected or indicated by the access system.

[0058] 11 , an insertion tool 226 is employed to penetrate tissue in the forearm and attach one or more fiducials 200 to one or both of the ulna 221 and radius 222. The insertion tool 226 includes an elongated shaft 210 extending from a handle 230. A distal end 223 of the shaft 210 defines a needle tip and houses a plunger 212 ( FIG. 7 ) configured to advance one or more fiducials 200 out of the distal end 223 and into engagement with the bones of the ulna 221 and radius 222 (see also FIG. 7 ).

[0059] As described above, one to three fiducials can be implanted depending on the type of fiducial employed and the location where the fiducial is implanted. Handle 230 is configured to be used to advance device 226 through tissue and form a cavity in bone or otherwise prepare the bone to receive the fiducial. Handle 230 is connected to plunger 212 to cause longitudinal movement of plunger 212. For example, handle 230 may be locked while insertion tool 226 advances through tissue and engages bone to form an implantation site for fiducial 200. Thereafter, handle 230 can be unlocked, such as by rotating the handle one-quarter turn, and moved longitudinally to advance the plunger, thereby moving fiducial 200 into fixed engagement with the bone.

[0060] Once the fiducial is positioned as desired, the forearm or other body part containing the implanted fiducial is scanned using a method configured and arranged to create a three-dimensional image, which correlates the location of the fiducial with the location, relative dimensions, and trajectory of the target vessel. This information can be used to cannulate the target vessel to facilitate access.

[0061] In an alternative embodiment, the cannulation system includes structure and functionality to determine whether one or more implanted fiducials have migrated. The system detects when the fiducials are not in an expected position and evaluates whether the fiducial displacement is significant and / or affects a predetermined path to cannulation. For example, the system can measure the fiducial displacement in three dimensions and record the displacement information. The displacement information can then be analyzed to determine whether a new or adjusted cannulation path is needed. The cannulation system can also alert a user or healthcare provider, who can notice the migration and consider whether a new or adjusted path is needed, as well as whether other measures should be taken, such as removal and / or replacement of the migrated fiducial.

[0062] In one approach, a scanning system 250 (FIG. 12) is employed to plan the placement of a vascular access set or kit 252, including a needle or cannula 254, within the target vessel 220 for safe entry at the correct angle and depth. Accordingly, the scanning system 250 is configured to generate images, such as, for example, a three-dimensional image 262 on a user-accessible computer interface 264, by employing an MRI scan, CT scan, ultrasound scan, infrared view, 3D photography, or other scan to gather information about the patient. Again, information about the target anatomy and / or vasculature is collected or stored in system memory, such as in a data cloud 266.

[0063] Based on the pre-scanning step, the cannulation system 320 is equipped with a map or plan for positioning the vascular access set 252. In certain embodiments, the scanning system 250 is employed to suggest insertion sites based on patient history, system usage data (e.g., previously successful insertion trajectories), and input, providing the patient with options regarding needle placement at the target vascular insertion site 220. In one aspect, the system can manage, but is not limited to, a rope ladder or buttonhole site strategy for cannulation as needed or directed by the system or a medical professional.

[0064] Additionally, in alternative embodiments, the scanning system 250 may be configured to allow the patient or healthcare provider to input patient health information, including heart rate, blood pressure, blood flow, and other data that may be relevant to the patient's diet, medications, and exercise, or effective cannulation. The system may include internet or Bluetooth connectivity. This data may also be entered passively through connected wellness devices or electronic medical record systems.

[0065] In one particular approach, the scanning system 250 includes a scanning assembly 285 that includes a bed 286 and further includes a fixation means 288 for holding an arm or other body part 290 relative to the bed 286 in a repeatable and precise manner. Various approaches to the fixation means are contemplated for the purpose of maintaining a precise orientation of the body part relative to the bed 286. That is, various mounting devices, sleeves, or molded body part receivers can be employed as the fixation means. Furthermore, the bed 286 can be a simple platform or a detection bed embodied in a cannulation system, as described below. In either case, the bed used in the scanning procedure supports or holds the scanned body part in precisely the same orientation as achieved by the detection bed of the cannulation system.

[0066] Once the body part (e.g., arm) 290 is positioned and immobilized on the bed 286, an MRI scan, CT scan, ultrasound scan, infrared view, 3D photography, or other scan is performed to gather information used to define and map an acceptable access path for cannulation that prevents the needle set 252 from entering an unacceptable path or being inserted beyond its termination point 281 ( FIG. 13 ). This acceptable path may be defined by the physician or mathematically modeled based on the patient's anatomy and implanted fiducials. The acceptable path may also be defined incrementally over a treatment session using machine learning algorithms applied to trajectory data of past successful insertions for a given patient, and may include angles for entering the target vessel or graft, as well as paths that avoid certain other anatomical structures.

[0067] The scanning system 250, configured in this manner, functions to plan or map the placement of a needle or needles into an access site, AV graft, or fistula, with the goal being to provide the patient with a self-cannulation or healthcare professional-assisted cannulation system that defines at least an acceptable access path 280 to and within the target vasculature 220 (see FIG. 13 ) and prevents the cannulator from entering an unacceptable path or inserting beyond the defined termination point 281.

[0068] In alternative embodiments, a management system may further be provided that communicates with the dialysis machine to provide further feedback regarding cannulation success. In alternative embodiments, automated or healthcare professional-generated messages regarding cannulation success may be provided to the patient, as well as suggestions regarding necessary interventions, such as the need for recannulation. A telehealth video interface may also be included for real-time feedback via an internet connection. Trajectory restrictions may also be defined based on the patient's anatomy as defined by ultrasound scans, infrared views, MRIs, CT scans, or other imaging modalities, so that the system does not allow trajectories that place the needle in sensitive or non-target anatomy.

[0069] Referring now to FIG. 14 , one approach to a cannulation system 320 may embody an armature including a pair of articulating, L-shaped frames 322, each including a track 324 along which a standard access kit 252 may be mounted and configured to translate. It should be appreciated that the cannulation system 320 need not include such an articulating frame and may embody one or more of the features of the other approaches disclosed herein, or their equivalents, so long as it is capable of controllably manipulating an access kit or other needle assembly to effectively cannulate a graft or fistula. Furthermore, the cannulation system may include joints or other moving parts, each with only a single degree of freedom, thereby greatly simplifying the calculations associated with software or autonomous control of the armature to select the best path toward the target and also simplifying the complexity of the user interface. Furthermore, needles from various manufacturers or suppliers may be recognized by the system, such as by reading barcodes or other identifying information, allowing the cannulation procedure to be tailored to different needle sets.

[0070] In use, the patient simply places their arm or other body part into the cannulation system, which recognizes the patient and knows the acceptable path the needle should take to achieve cannulation. The cannulation system guides the movement of the needle through the acceptable path, preventing the needle from entering an unacceptable path or being inserted beyond the defined termination point.

[0071] In one preferred approach, the cannulation system is servo-controlled, with a servo motor attached to each moving part of the armature, and a sensor associated with each servo motor, allowing the patient or medical professional to grasp the needle and move it through a path guided or constrained by the servo motor. Here, the sensor detects the precise angular or translational position of the armature components. In another preferred approach, the cannulation system is manually operated by a user, who sets each moving part of the cannulation system according to a predetermined plan. Here, the cannulation system armature is devoid of servo motors, sensors, or other electronics. In yet another approach, a body part is secured to a sensing bed, and once the patient is registered, the cannulation system operates autonomously to achieve vascular access.

[0072] In a preferred embodiment, the cannulation system controller includes an array of passive limiters that fix the range of motion for each degree of freedom of the needle support structure; in various approaches, information regarding the setting of each passive limiter is determined and displayed on the device using a combination of image data and information from real-time fiducials corresponding to the vascular access target. Note that scans can be performed periodically so that the positional relationship of the fiducials to the target graft or vessel can be confirmed or modified based on changing conditions, including selective changes in the access insertion site. The operator can also move the needle into position, with the system only limiting deviation from the most desirable needle path.

[0073] In another approach, the system can provide haptic feedback so that if a human operator begins to deviate from an optimally defined trajectory, they can feel resistance and correct, within tolerances, to the intended trajectory.

[0074] While it is contemplated that a standard needle set will be employed, various alternative embodiments may provide the user with a choice of needles based on the patient's anatomy or preferences. In this context, the system may be equipped with the ability to differentiate between needles so that the location of the needle tip can be determined. Information regarding the selected needle may be manually entered into the system or scanned during workflow, such as via a barcode. Multiple means for inserting the needle into the cannulation system may also be provided, such as patient- or other user-controlled activation of a button, joystick, or other input system that advances the needle. The system may also allow for incremental needle advancement (e.g., once contacting the skin) or the ability to select the rate of advancement. Such functionality may be based on patient preference, all within the system's safety guidelines, which may include knowing the maximum distance of advancement and maintaining the desired path. Additionally, the user may be able to physically advance the needle but be constrained by the system to prevent it from overadvancing or going off-track. Again, the system may provide tactile feedback, sufficient stability, and damping as the user advances the needle.

[0075] 14, a body part holding or immobilization device is attached to or incorporated into a detection bed 325 of a cannulation system 320, and an articulating L-shaped frame 322 is attached to the bed 325. The localization technology is incorporated into the bed 325 of the cannulation system 320 and is fixed relative to the holding device.

[0076] Once the patient's arm is stabilized on the bed 325, the position of the fiducial within the arm is detected and linked via system software, which compares the fiducial's position to a previously recorded 3D dataset and virtually maps the location of the vascular access site relative to the armature and where the needle tip is expected to be located or pointed. The needle holder is attached to the needle in a fixed and repeatable manner, and the needle tip's position relative to all anatomical landmarks is known via the system software. Once the needle is secured to the needle support structure, data from the software calculates the proposed orientation of each degree of freedom of the needle support structure.

[0077] In another preferred embodiment, these settings are communicated to the user by a display, which the user can manually set for each joint or moving part of the needle support structure, or the degrees of freedom can be guided by servo motors that guide the user to the desired path for each degree of freedom without manual input.

[0078] Thus, the real-time positional relationship of the fiducial relative to the access kit 252 can be observed and corrected by employing an electromagnetic energy-based navigation system integrated into the sensing bed 325 that identifies and tracks the position of a fiducial, such as one implanted in a bone of the forearm. A predetermined positional relationship between the fiducial and the armature structure of the cannulation system is ensured by fixating the arm or other limb to the bed 325. Such a platform can be the same or equivalent device used when obtaining images (e.g., CT or MRI) of the target vessel with respect to the implanted fiducial and input into the access system 250. Fixation means such as those described above are employed to ensure the expected positional relationship between the body part in which the fiducial 200 is implanted relative to the movable access kit 252, as required by the access system 250 or as determined, for example, from a CT or MRI scan.

[0079] In one preferred approach, the servo motors 326 are configured to allow movement of the access kit 252 in two directions: along the base of the L-shaped frame 322 and perpendicular to the base of the L-shaped frame 322. Sensors are associated with each servo motor so that the positions of the various moving parts of the armature are known.

[0080] In another preferred approach, the cannulation system lacks electronics and needle positioning is performed manually. Manual manipulation of the armature of such a cannulation system can be guided by a pre-scan plan that instructs the user to position the moving parts of the cannulation device at specific angles or positions. Furthermore, the system would provide the user with instructions on how and in what order the various components supporting the needle should be moved and positioned to ultimately achieve the desired cannulation. Here, the cannulation device can be provided with angular or longitudinal markings and a means for locking the moving parts to assist in proper positioning of the access kit relative to the target.

[0081] Each access kit 252 may include a stop 327 to limit movement of the access kit 252 generally in a direction perpendicular to the base of the L-shaped frame 322 or as determined by the distal insertion depth point of the container. As noted, movement of the armature components may be performed manually as prescribed by the system. Also, as noted, a servo motor 326 may be provided at the connection between the L-shaped frame 322 and the bed 325 to provide both rotational control of the L-shaped frame 322 relative to the bed 325 and translational control of the L-shaped frame 322 along the bed 325. In this manner, the access kit 252 may be positioned and advanced as directed by the pre-scan plan.

[0082] In certain approaches, one or more of the servo motors may be omitted or configured to be selectively activated so that some of the steps of moving or positioning the access kit 252 can be performed manually. For example, the motors may be configured to support the weight of the system to allow the user to smoothly and easily manipulate the needle support structure, but may also be configured to resist movement along undesirable paths. Here, tactile feedback may be employed and adjusted based on the speed or mode of movement of the fixture by the user.

[0083] 15 , the armature of the cannulation system 330 may alternatively be embodied in a single articulating U-shaped frame 332 having a track 334 along which the access kit 252 may be configured to translate. Servo motors 326 may be provided to control the relative movement of the U-shaped frame 332 with respect to the bed 325 and the relative movement of the access kit 252 with respect to the U-shaped frame 332. Not shown are means for securing the body part in which the fiducial is implanted to the bed 325. Again, the system 330 may be free of electronics, allowing for manual control of the movement of the various components of the armature to position the access kit relative to the cannulation site.

[0084] 16A-B, another alternative approach to the cannulation system 340 includes a structure for manipulating and positioning the access kit 252 relative to the target insertion site. While a single access kit 252 is shown attached to the cannulation system 340, the device may be configured to support two access kits 252. Additionally, as with other contemplated cannulation systems, movement of the various components may be servo-controlled or manual, or a combination thereof.

[0085] In one approach, the ball joints 342, 343 are configured at the articulation points to provide the instrument with the ability to move the access kit 252 as directed by the cannulation system, or alternatively, manually by a user, such as the patient or healthcare provider. Servo motors can be configured to control the movement at the ball joints 342, 343, or manually operable locking structures can be placed at the ball joints 342, 343 for a manual approach, or the cannulation system 340 can include a combination of automatic and manual functionality and associated structures. A first arm 344 extending from the first ball joint 342 is connected to a second curved arm 345. The second curved arm 345 includes a track 346 along which the second ball joint 343 is translatable, where the second ball joint 343 holds the access kit 252. Again, a servo motor can be configured at the articulation joint to facilitate automated articulation of the first arm 344 and automated articulation and translation of the access kit 252 relative to the track 346 of the second arm 345. A servo motor (not shown) can also be configured to move the access kit 252 generally perpendicular to the ball joint 343 or curved arm 345. Positioning the access kit 252 above the target insertion point is achieved by system-directed adjustment of the various moving parts of the cannulation device 340, and the access kit 252 is then advanced as desired within the graft or fistula, as directed by the system. The system provides such directed adjustment whether the cannulation system 340 is configured for automatic or manual control.

[0086] As shown in FIG. 16B, the cannulation system 340 can be attached to a base 348 configured to engage a body portion associated with the targeted insertion site. In one specific approach, the base 348 can define a stabilizing or distension element that can be configured to move to stretch, expand, or stabilize the insertion site and the graft or fistula to prevent the graft or fistula from rolling or otherwise moving during cannulation. Such movement and application of stabilizing pressure by the base 348 can be automated by the system or manually controlled by the operator. The base 348 can be completely passive or can embody active arms or stays 349 that move together, apart, downward, or at various angles to match the needle insertion trajectory and apply uniform or non-uniform pressure as deemed necessary or directed by the system. In this manner, stability of the insertion site is provided during cannulation. Sensors (not shown) may also be provided to provide force feedback directly or through the cannulation system and to the operator.

[0087] 17-19, the cannulation system 320 of FIG. 14 is shown being used to insert the needle 254 of the access kit 252 into the target vasculature. Such use may be to provide vascular access for hemodialysis. Additionally, some of the functionality may be servo-controlled by the system or may be performed manually as described.

[0088] Once the positional relationship of the implanted fiducial to the vessel or graft targeted for cannulation has been established and the end depth of needle insertion has been established and stored or transmitted to the system, the body part or arm 290 is positioned on the bed of the cannulation system 320. As previously described, the arm 290 may be restrained (not shown) to the bed 325 to provide accurate and repeatable orientation of the arm 290 relative to the bed 325. By positioning the arm 290 on the bed 325 as necessary and as instructed, the system recognizes the patient and the path the needle should take to achieve cannulation. In one approach, a first L-shaped frame 322 carrying an access kit 252 is moved along the bed 325, and the access kit 252 is moved relative to the L-shaped frame 322 to position the needle 254 of the access kit 252 within the graft or vessel 60, 70 ( FIG. 18 ). The depth of travel of the access kit 252 is controlled by the system 320 and can be limited by a stop 327 attached to the access kit 252 .

[0089] In an alternative embodiment, once cannulation is achieved, the system can confirm that the cannulation was successful. The system can communicate whether the cannulation was successful to the patient or medical personnel, potentially sounding an alarm if the cannulation was not successful. The sensor package described above can then be employed to continue watching the cannulation to ensure all is well, including providing a visual to confirm the needle's presence and position. Again, one or more acoustic sensors can provide acoustic information about the flow, IR can provide visual flow information, and a pressure or visual sensor can be provided at the rear of the needle or tubing to look for backflush or pulsating blood. Needle plunger pullback can be automatic or manual.

[0090] The now-inserted access kit 252 may be removed from the L-shaped frame 322 and connected to tubing flowing to the hemodialysis system (see, e.g., FIG. 1). Next (FIG. 19), the second L-shaped frame 322 is manipulated to position the needle 254 of the second access kit 252 as required and directed by the system 250 and within the target graft or vessel 60, 70. Such manipulation may require both rotating the L-shaped frame 322 relative to the bed 325, moving it along the bed 325, and moving the access kit 252 relative to the L-shaped frame 322. After the needle 254 is positioned as desired within the vessel or graft 60, 70 and proper cannulation has been confirmed, the second access kit 252 may also be removed from the L-shaped frame 322 and connected via tubing to the hemodialysis system. Dialysis may then begin as previously prescribed or directed by a physician.

[0091] 20-21 , in an alternative embodiment, a cannulation system 400 can be provided that includes a handheld needle insertion assembly 402, which achieves the components necessary to align the needle trajectory to a desired path. The cannulation system 400 can include both mechanical and electrical components necessary to manipulate the needle trajectory as well as sensing capabilities to assist in fine positioning of the needle during insertion. In certain aspects, the handheld needle insertion assembly 402 is configured to facilitate effective and efficient access to challenging anatomical structures due to its size and minimal degrees of freedom.

[0092] The cannulation system 400 may further include a user interface 404 that allows a technician to interact with the handheld needle insertion assembly 402, a monitoring and localization probe 406 that is used to gather information about the target anatomical structure, such as position, blood flow information, etc., and an articulating mounting arm 408 designed to stabilize the handheld needle insertion assembly 402. A cart 410 may further be provided and configured to house a processing computer and control system designed to coordinate the operation of the various components of the cannulation system 400. The cart 410 may also include the components necessary to provide power and data transmission to the remainder of the system 400.

[0093] In one embodiment, the cannulation system 400 can embody a handheld robot or needle insertion assembly 402 attached to a passive arm 408 that can be positioned and locked into place by a user or technician. The handheld robot or needle insertion assembly 402, which delivers the needle, can be designed to be compact and include functionality and structure that provides the necessary degrees of freedom to not only insert the needle into the target vessel, but also to position and align the needle during insertion. The handheld robot or needle insertion assembly 402 can be equipped with light- or sound-based sensing capabilities (such as near-infrared or ultrasound) intended to provide fine positioning information and assist with needle placement. The monitoring and localization probe 406 can cooperate with the handheld robot or needle insertion assembly 402 and be configured to provide acoustic or light-based information that can monitor blood flow, pulse rate, etc., or can also be used to locate the vessel using near-infrared light and associated processing capabilities. As previously mentioned, the cart 410 can provide power and data processing / communication capabilities as well as further include processing capabilities.

[0094] With particular reference to FIG. 21 , the handheld needle insertion assembly 402 is a small, portable device that can include the mechanisms necessary to position, align, and insert a needle along a determined or desired path or trajectory. The handheld robot or needle insertion assembly 402 is electrically connected to a power and data processing unit and can be connected to a support or mounting arm 408 or operated independently from the support or mounting arm 408. A monitoring and localization probe 406 provides information for adjusting needle movement as well as providing data regarding the target anatomy. In one embodiment, the handheld needle insertion assembly 402 can also include a localization probe used to assist in fine positioning and trajectory correction. Light-based or acoustic signals can be employed to generate the information needed for monitoring or localization.

[0095] Thus, a system and method for accessing a vessel in a consistent manner without requiring a skilled operator is presented. In one embodiment, such a system can include an implantable fiducial that can be one or more of passive, active, or activatable. The system includes a detection scheme for detecting the position of the fiducial in three-dimensional space and functionality designed to co-register such three-dimensional position to a previously stored three-dimensional data set containing relative position information for the target vessel. The stored data is retrieved and co-registered with the three-dimensional position of a previous access session, reusing the site or determining a new desired access point site. Other approaches using sensors without fiducials can also be utilized to identify the cannulation site. The access device and system are then guided to place the access kit into the target vessel at the desired orientation, depth, and location.

[0096] As previously described, in each or more of the disclosed embodiments and approaches, the patient can move system components and advance the needle themselves, taking into account their own sensations, pain, or comfort, where the system ensures that the needle does not take an incorrect path or is inserted too deeply beyond a defined, desired termination point. Furthermore, in each or more of the disclosed embodiments and approaches, the system can automatically position, aim, and advance the needle during the cannulation procedure. Furthermore, in each or more of the disclosed embodiments and approaches, the patient and system can cooperate to varying degrees, such as allowing the system to automatically position the needle but desiring to push the needle into the vascular access site, or allowing the patient to move a needle-holding structure and have the system push the needle into the vascular access site either when the system is ready or when the patient indicates their readiness and signals that cannulation should be performed.

[0097] In alternative embodiments, real-time involvement of a remotely located medical professional may be provided, allowing the cannulation to be visualized and guided remotely, or allowing the medical professional to provide remote advice or information regarding the cannulation procedure. A telemedicine video connection for real-time guidance of the system, troubleshooting, and insertion path recommendations may be included via an internet connection. In another alternative embodiment, an augmented reality system may also be incorporated into the system to collect patient data and display real-time guidance for positioning the cannula needle or other components of the access device.

[0098] While the present disclosure has been described with reference to specific embodiments thereof, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process step or steps, to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the present disclosure.

Claims

1. 1. A system for positioning a needle at a vascular access site in a patient, comprising: A needle insertion device; a needle holder attached to the needle insertion device; The system guides needle movement through an acceptable access path and avoids needle movement through an unacceptable path or needle insertion beyond a defined termination point. system.

2. One or more fiducials are implanted into the patient; The system of claim 1 .

3. further comprising a structure for securing the body part to the detection bed; 3. The system according to claim 1 or 2.

4. the sensing bed senses one or more fiducials; The system of claim 3.

5. In response to sensing the one or more fiducials, the system enrolls the patient. A system according to any one of claims 1 to 4.

6. Once the patient has secured the body part to the detection bed, the system identifies the patient and, based on a predetermined identification of the cannulation site and the path to the cannulation site, the system recognizes an acceptable access path through which the needle can move. A system according to any one of claims 1 to 5.

7. the system is configured to be connected to a hemodialysis system; A system according to any one of claims 1 to 6.

8. One or more of an MRI scan, a CT scan, an ultrasound, an infrared view, or a 3D photograph is employed to provide information about the patient's anatomy and develop mapping that is used to create an acceptable access path to be taken by the needle; A system according to any one of claims 1 to 7.

9. the vascular access site is an AV fistula; A system according to any one of claims 1 to 8.

10. the vascular access site is an AV graft; A system according to any one of claims 1 to 9.

11. The system guides or restricts the path that the armature can take, A system according to any one of claims 1 to 10.

12. The patient is scanned periodically to develop a mapping that is used to create an acceptable access path to be taken by the needle; A system according to any one of claims 1 to 11.

13. the armature further includes a plurality of articulating or movable joints; A system according to any one of claims 1 to 12.

14. and further including servo motors configured at one or more articulating or movable joints, and sensors associated with the servo motors. A system according to any one of claims 1 to 13.

15. The system is completely manually operated and has no electronic components; A system according to any one of claims 1 to 14.

16. the armature further includes a pair of articulating L-shaped frames; A system according to any one of claims 1 to 15.

17. the armature further includes a U-shaped frame; A system according to any one of claims 1 to 16.

18. the armature further includes a curved arm and one or more ball joints; A system according to any one of claims 1 to 17.

19. The system provides a small range of acceptable routes and a most desirable route; A system according to any one of claims 1 to 18.

20. Access is provided to a fistula or graft location, including one or more of a radial-brain fistula, a brachial-brain fistula, and a brachial-vesical fistula location; A system according to any one of claims 1 to 19.

21. The real-time positional relationship of one or more fiducials to the needle is monitored and corrected by an electromagnetic energy-based navigation system integrated into the sensing bed that identifies and tracks the position of one or more fiducials, such as those implanted in the bones of the forearm. A system according to any one of claims 1 to 20.

22. an array of passive limiters for fixing the range of movement of each degree of freedom of the needle; Information regarding the setting of each passive limiter is determined using a combination of image data and information from real-time fiducials corresponding to the vascular access target and displayed on the device. A system according to any one of claims 1 to 21.

23. The position of one or more fiducials in the arm is detected and linked via system software, which compares the position of the one or more fiducials with a previously recorded 3D data set to virtually map the location of the vascular access site relative to the armature and where the needle will be oriented to be located; A system according to any one of claims 1 to 22.

24. The system administers or provides an assessment of the fistula or graft prior to cannulation; A system according to any one of claims 1 to 23.

25. If an obstruction is detected, the system will avoid the cannulation procedure. A system according to any one of claims 1 to 24.

26. If an obstruction is detected, the system alerts the patient or healthcare provider. A system according to any one of claims 1 to 25.

27. the system provides automatic assessment of fistulas or grafts; A system according to any one of claims 1 to 26.

28. Assessment of the target insertion site involves the perception of one or more of vibrations, bruits, or sounds associated with blood flow or obstructions; A system according to any one of claims 1 to 27.

29. further comprising a fiducial marker configured to be attached to the radius or ulna; A system according to any one of claims 1 to 28.

30. further comprising a sensor pack configured to locate or assess a fistula or graft prior to cannulation or to assess the status of cannulation; A system according to any one of claims 1 to 29.

31. further comprising one or more of a non-visible light, acoustic, pressure, or visual sensor for determining and tracking blood flow; A system according to any one of claims 1 to 30.

32. further comprising an IR sensor configured to identify the target site; A system according to any one of claims 1 to 31.

33. the needle holder is embodied as an arm that supports the needle cassette; The support structure includes one or more ball joints that facilitate desired movement of the needle cassette relative to the target insertion site. A system according to any one of claims 1 to 32.

34. The termination point is within the wall defining the target graft or vessel; A system according to any one of claims 1 to 33.

35. The system provides real-time assessment of the cannulation procedure. A system according to any one of claims 1 to 34.

36. the controller is an array of passive limiters that fix the range of motion of each degree of freedom of the needle holder; A system according to any one of claims 1 to 35.

37. Information regarding the setting of each passive limiter is determined using a combination of image data and information from real-time fiducials corresponding to the vascular access target and displayed on the device. A system according to any one of claims 1 to 36.

38. The operator guides part of the needle path, and the system guides or restricts part of the needle path; A system according to any one of claims 1 to 37.

39. the system provides instructions to the operator regarding needle positioning by instructing the operator to move one or more components of the armature to various positions to achieve cannulation of the vascular access site; A system according to any one of claims 1 to 38.

40. The system is configured to readjust the needle trajectory or needle insertion depth if the patient moves before or during cannulation. A system according to any one of claims 1 to 39.

41. The system can automatically position, aim, and advance the needle during the cannulation procedure. A system according to any one of claims 1 to 40.

42. 1. A system for positioning one or more needles relative to a vascular access site of a patient, comprising: Armature and a needle attached to the armature; Each degree of freedom of the armature's movement is manually set based on information provided by the system software that constrains the needle to move along an acceptable access path within the patient. system.

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