System and method for dispensing embolic particles for embolization

Abstract

The system and method for performing embolization to treat various medical indications and targets, such as bleeding and tumors, utilizes a mixture of embolic particles containing very low concentrations of embolic material in the delivery medium and the delivery medium, while intermittently injecting boluses of contrast agent to visualize the progress of the embolization. Furthermore, the system and method are automated to minimize user intervention, and sensors and feedback control processes can be incorporated to control the system and method during embolization.

Description

TECHNICAL FIELD

[0001] The field of the present disclosure relates generally to medical systems and methods, and more specifically to systems and methods for dispensing embolic particles and contrast agents for efficiently embolizing blood vessels in target tissue of a patient. BACKGROUND ART

[0002] Embolization of blood vessels such as arteries using embolic microparticles is a minimally invasive image-guided therapy used to treat various medical conditions. It involves selectively occluding blood vessels by injecting microparticles such as polymer foam pieces and beads into the artery via an intravascular catheter, thereby blocking blood flow to a specific region. This technique has been shown to be effective in managing bleeding, shrinking tumors, and treating certain vascular malformations.

[0003] Typically, this procedure is initiated with the patient lying on an examination table in an angiography suite. After local anesthesia is administered, a small incision is made to access an easily accessible artery such as the femoral artery in the groin. A catheter is then inserted into the artery, and the catheter is guided within the blood vessel using fluoroscopic images that provide real-time X-ray guidance.

[0004] The catheter is often carefully advanced to the target blood vessel using a combination of angiography and roadmapping techniques. These imaging modalities help interventional radiologists visualize the vascular anatomy and identify the blood vessels leading to the site of interest, such as the target arteries and / or capillaries in the region of target tissue to be treated by embolization. For example, the target arteries and / or capillaries to be embolized may supply blood to bleeding target tissue, or target tissue having tumors, uterine fibroids, vascular malformations, or other target tissue in a condition requiring treatment.

[0005] Once the catheter is positioned near the target artery, a contrast agent is injected through the catheter to confirm its precise location and assess blood flow. This allows for the evaluation and planning of microparticle injection, helping to ensure that the microparticles are delivered precisely to the intended area.

[0006] After the optimal position is confirmed, a syringe filled with a mixture of embolic microparticles and contrast agent is injected into the catheter. Embolic particles are generally composed of biocompatible materials such as gelatin sponge or polyvinyl alcohol (PVA) and can take the form of tiny spheres or other shapes ranging in size from 50 to 1,000 micrometers. The size of the particles used depends on the specific condition being treated and the size of the catheter being used. The mixture of embolic microparticles and contrast agent flows through the catheter to the target site in the vascular system. The mixture of embolic particles and contrast agent is released from the distal end of the catheter and flows through the vascular system, where the embolic particles eventually reach smaller blood vessels that supply blood to the targeted tissue area and remain there.

[0007] The practitioner visualizes the progression of the embolic particle / contrast mixture using a contrast agent. Short "puffs" (i.e., high-concentration bursts of the embolic particle / contrast mixture) are intermittently injected through the catheter to visualize the flow of the embolic particle / contrast mixture and the degree of blood flow reduction in the target vessel. Without these "puffs," the injected embolic particle / contrast mixture would only appear as a substantially uniform gray line along the flow path. In contrast, the use of "puffs" makes it possible to effectively visualize the flow velocity and perfusion depth in the blood flow area, indicating the degree of blood flow reduction, and to indicate the progression of embolization by monitoring the reduction in washout time of the contrast agent "puffs" and the decrease in inflow and infiltration.

[0008] However, relatively high-concentration bursts ("puffs") of embolic particles / contrast agent mixtures in relatively high-viscosity media are prone to causing occlusion events at undesirable locations within the vessel and undesirable proximal vascular aggregation. As a result, the degree of distal penetration and the uniformity of the embolization are adversely affected. Furthermore, high-flow, high-viscosity injections are also very likely to cause backflow, where the embolic material or particles flow in the opposite direction during the procedure. Backflow can occur when, after the embolic material has advanced downstream, its path is partially or completely reversed due to high pressure and / or excessive occlusion. This is undesirable as it can lead to unintended embolization in other areas and a decrease in the effectiveness of the embolization.

[0009] When embolic particles accumulate, they can block or embolize blood vessels, obstructing blood flow and causing ischemia (deficiency of blood supply) in the target tissue area. Embolization of blood vessels can lead to tumor reduction by controlling bleeding when treating hemorrhage, or by cutting off nutrients and oxygen from the target tissue when treating tumor tissue.

[0010] After the injection is complete, the catheter is removed and the incision is closed to prevent bleeding. The patient then undergoes outpatient observation for several hours or hospital observation overnight to check for any immediate complications.

[0011] Microparticle embolization offers several advantages over conventional surgical interventions. It is less invasive, requires smaller incisions, reduces pain, and shortens hospital stays. The targeted approach minimizes damage to healthy tissue, making it an effective treatment option for both malignant and benign diseases.

[0012] The specific outcomes of arterial embolization vary depending on the underlying disease being treated. In cases of bleeding, this procedure can rapidly stop bleeding and stabilize the patient's condition. In cases of tumors, embolization can reduce tumor size, alleviate symptoms, and facilitate subsequent surgical resection. Microparticle arterial embolization is an effective image-guided treatment technique for managing bleeding, reducing tumor size, controlling neovascular inflammation, and treating vascular malformations. By selectively occluding blood vessels, this minimally invasive procedure offers a viable alternative to conventional surgery, resulting in reduced risk, shorter recovery times, and improved treatment outcomes for patients.

[0013] Nevertheless, there remains a need for improved devices, systems, and methods for performing arterial embolization that overcome the shortcomings and problems of conventional arterial embolization techniques. [Overview of the project]

[0014] This specification discloses innovative systems and methods for performing embolization to treat various medical indications and targets, including bleeding, tumors, uterine fibroids, prostate, thyroid, and genitourinary artery. In one highly innovative embodiment, the system and method are configured to intermittently inject boluses of contrast agent to visualize the progress of the embolization while injecting a mixture of embolic particles and a delivery medium with a very low concentration of embolic material relative to the delivery medium.

[0015] According to one embodiment of the disclosure, the embolization system comprises a first dispenser for dispensing an embolic particle mixture into a catheter. For example, the first dispenser may be a syringe, a pressure chamber connected to a pressure source, or a gravity-feed dispenser having a valve for dispensing control, a metering pump, or any other suitable dispenser capable of controlling the dispensing of a fluid at a specific pressure, flow rate, or bolus volume. The embolic particle mixture comprises a mixture of embolic particles and a delivery medium. In various embodiments, the delivery medium may be saline solution or other suitable fluid for carrying the embolic particles. The first dispenser is electronically controllable for controllable dispensing of the embolic particle mixture.

[0016] The embolization system also includes a second dispenser for dispensing contrast agent into the catheter. The second dispenser may be any of the dispenser types described for the first dispenser, and may be the same type as the first dispenser or a different type.

[0017] The first and second dispensers are each connected to a manifold, which is in fluid communication with both the first and second dispensers, and the first and second dispensers discharge into the manifold. The manifold has an outlet for discharging from the manifold into the catheter. Thus, the embolization system can switch between injecting two distinctly different fluid mixtures with different purposes: a contrast-free embolic particle mixture for embolizing a target tissue area and a contrast-containing mixture for visualizing the embolization. The embolization system can dispense these two different fluid mixtures in different repeating patterns. In an additional embodiment, the embolization system is also configured to automatically control (e.g., control the injection rate) the first dispenser discharging the embolic particle mixture and the second dispenser discharging the contrast agent. In this specification, the terms “automatic,” “automatic,” and / or other forms of the terms mean, with respect to the control of a discharge / injection function, that the flow rate, duration, and / or amount of fluid to be discharged is controlled without human operation or intervention, but “automatic” discharge is permitted to be triggered manually or automatically. For example, automatic injection (or automatic discharge) is an injection performed by a total amount and flow rate of fluid controlled by the system's controller, which may be performed by a user manually initiating the injection, such as by pressing a button on the controller.

[0018] In another embodiment, the first dispenser dispenses a relatively large amount of embolic particle mixture at a low concentration. This avoids the use of substantially high concentrations of contrast agent, as in conventional systems and methods that dispense a mixture of embolic particles and contrast agent. Since it is important to limit the amount of contrast agent injected into the patient to prevent adverse effects on the kidneys, it is not prudent to use large amounts of contrast agent. In this embodiment, the second dispenser also allows for the separate dispensing of small amounts of high-concentration contrast agent without embolic particles, thereby enabling good visualization of blood flow (i.e., good visualization of the progress of the embolization procedure as blood flow is blocked by the embolization). Furthermore, the contrast agent has a higher viscosity than the embolic particle mixture and is therefore more prone to stagnation or reflux in the arteries.

[0019] In another embodiment, the embolic particle mixture has a specific low concentration of embolic particles relative to the embolic particle mixture being injected. For example, the low concentration of embolic particles relative to the embolic particle mixture can be in the range of 2.0% to 0.05% by volume, or 1.0% to 0.1% by volume. This assumes that the total amount of embolic particle mixture injected is in the range of 50 to 500 cc (cubic centimeters), the amount of contrast agent diluted with physiological saline is injected in the range of 10 to 50 cc, the cumulative injection time of the embolic particle mixture is in the range of 5 to 20 minutes, and the injection flow rate of the embolic particle mixture is in the range of 2.0 to 0.1 cc / second. Therefore, if these embolic conditions are changed from the above range, the low concentration of embolic particles relative to the embolic particle mixture can be appropriately adjusted. The size of the embolic particles may also affect the low concentration of embolic particles relative to the embolic particle mixture.

[0020] In another embodiment of the embolization system, each of the first and second dispensers comprises a powered syringe driven by an actuator, configured to dispense a controllable flow of pressurized fluid. In this specification, the term “powered” means that the device is not manually driven and includes, but is not limited to, devices driven by electricity, pneumatics, hydraulics, etc. For example, the powered syringe may be a motor-driven syringe driven by an electric motor, which is controllable by a motor controller configured to control the speed at which the syringe plunger is actuated, thereby controlling the flow rate and / or pressure of the discharge from each dispenser.

[0021] In another embodiment of the system, the first dispenser may dispense embolic particles and a delivery medium separately and mix them to prepare and dispense an embolic particle mixture. For example, the first dispenser may include a first sub-dispenser for dispensing embolic particles into a mixer and a second sub-dispenser for dispensing a delivery medium into the mixer. The system may further include a mixer that is in fluid communication with the first and second sub-dispensers. The mixer is configured to mix the embolic particles and the delivery medium and output a well-mixed embolic particle mixture. In an additional embodiment, the mixer may be a passive mixer such as a flow-induced mixer, a static mixer, or a vortex mixer, or an active mixer such as a mixer with a movable mixing element, or an integrated mixer with acoustic stirring or a piezoelectric transducer. In another embodiment, the first sub-dispenser and the second sub-dispenser may include motor-driven syringes identical or similar to the motor-driven syringes described herein.

[0022] In yet another embodiment, the embolization system may include a controller operably connected to a first dispenser and a second dispenser. The controller is configured to automatically control the first and second dispensers to controllably dispense an embolic mixture from the first dispenser and a contrast agent from the second dispenser. For example, the controller may have a computer processor or other electronic control logic configured to electronically control the operation of the first and second dispensers. In yet another embodiment, the controller may be selectively programmable by the user to control the characteristics of dispensing the embolic particle mixture from the first dispenser and the contrast agent from the second dispenser. For example, the controller may be configured so that the user can set one or more of the following as characteristics of dispensing by the first and second dispensers: (1) dispensing flow rate, (2) dispensing pressure, (3) contrast agent dispensing frequency, and (4) activation of active mixing.

[0023] In yet another embodiment, the embolization system may include one or more sensors for monitoring and / or controlling the operation of the embolization system. In one embodiment, the system may further include a first sensor operably connected to a controller and configured to detect the attributes of dispensing by at least one of a first dispenser and a second dispenser and to output a first sensor signal associated with those attributes. For example, the first sensor may be a flow sensor for detecting the flow rate of the fluid dispensed by the first and second dispensers, or a pressure sensor for detecting the pressure of the fluid dispensed by the first and second dispensers. The controller utilizes the first sensor signal in a feedback control process to control the dispensing attributes (e.g., the flow rate, pressure, concentration, etc., of the embolic particle mixture or contrast agent being dispensed). As an example, the controller may use the flow signal to control the operation of the first and / or second dispenser and adjust the dispensing flow rate to a user-preset flow rate. The first sensor may be any suitable sensor such as a flow sensor, pressure sensor, force sensor, actuator torque sensor, or motor current sensor.

[0024] In another embodiment, the controller is configured to automatically perform an embolization process that includes the steps of discharging an embolic particle mixture at a predetermined flow rate or pressure controlled by the controller, and intermittently discharging a bolus of contrast agent at a predetermined flow rate or pressure controlled by the controller.

[0025] In yet another embodiment, the embolization system may also utilize controlled flow straightening and laminar flow effects to further prevent aggregation, surface adsorption, sedimentation, and / or catheter occlusion of the embolic material during embolization. For this purpose, the embolization system may further include a flow straightener having an inlet and an outlet. The inlet is connected to the outlet of the manifold and is in fluid communication with the outlet of the manifold. The outlet of the flow straightener can be connected to the proximal end of the catheter. The flow straightener is configured to adjust the flow pattern of the embolic particle mixture as it passes through the straightener to produce a more uniform flow of embolic particles in the delivery medium. For example, the flow straightener may have a configuration that produces a laminar flow of the embolic particle mixture such that the embolic particles are aligned near the centerline of the flow of the embolic particle mixture at the outlet of the straightener. As an example, the flow straightener may have an inner tube with a tapered outlet, which is coaxially positioned with an outer tube having a tapered outlet, and the outlets of the inner tube and the outer tube intersect. The embolic particles flow through the inner tube and are straightened into a narrow column (or a single column) as they pass through the tapered outlet, while the delivery medium flows through the outer tube, forming a laminar or turbulent flow at the outlet of the outer tube. Subsequently, at the intersection of the two flows, the straightened embolic particles are positioned along the centerline of the combined flow of the embolic particles and the delivery medium.

[0026] In another embodiment, the embolization system is largely similar to the embolization system described above, but differs in that it utilizes a first catheter for injecting an embolic particle mixture and a second catheter for injecting a contrast agent. Thus, the first catheter is connected to and fluid-communicated with a first dispenser, while the second catheter is connected to and fluid-communicated with a second dispenser. This eliminates the need for a manifold to receive the fluid flow from the first and second dispensers and distribute it into a single catheter. The first and second catheters can have various suitable configurations. In one embodiment, the first catheter may be a microcatheter, and the second catheter may be a support catheter, a guide catheter, or a sheath catheter into which the microcatheter is inserted. In this configuration, the first dispenser injects the embolic particle mixture into the microcatheter and delivers it through it, and the second dispenser injects the contrast agent into an annular lumen formed between the outer catheter and the microcatheter and delivers it through it. The first and second catheters may be configured to have a common outlet or different outlets spaced apart axially, for injecting their respective fluids into the target tissue area. Alternatively, the first and second catheters may be positioned side by side, each with a different outlet, or with a common outlet at the distal end of each of the first and second catheters. This configuration of the embolization system allows for the continuous (i.e., uninterrupted) injection of the embolic particle mixture through the first catheter while the contrast agent is injected in pulses through the second catheter.

[0027] An embolization system having first and second catheters may include one or more of the other embodiments and features of the embolization system described herein.

[0028] Another embodiment disclosed in the present specification relates to a method for performing a vascular embolization procedure. This method includes automatically controlling the variable infusion of two distinct fluid mixtures with two different purposes. Accordingly, the present method automatically controls the variable delivery of two distinct fluid mixtures with two different purposes, namely, an embolic particle mixture containing no contrast agent for embolizing a target tissue region, and a contrast agent mixture containing a contrast agent for visualizing the embolization. The present method discharges the two different fluid mixtures separately from each other in a controlled variable infusion pattern. In an additional aspect, the delivery of the embolic particle mixture and / or the contrast agent is automatically controlled by a controller.

[0029] The method includes the step of infusing the embolic particle mixture through a catheter into the target tissue region, wherein the infusion of the embolic particle mixture is automatically controlled by a controller. A bolus of contrast agent is intermittently infused through the catheter into the target tissue region to monitor the progress of embolization of the target tissue region on a visualization system. The bolus of contrast agent may be manually infused, for example, by a user manually operating a syringe filled with the contrast agent. The advantage of manual contrast agent infusion (or manually triggered automatic infusion) is that the user can synchronize the on / off switching of the angiography system with the contrast agent infusion, thereby limiting radiation exposure. In another aspect, the infusion of the bolus of contrast agent may also be automatically controlled by the controller. The controller may be the same as or similar to any of the controllers disclosed in the present specification.

[0030] In another aspect of the method, the infusion of the embolic particle mixture is temporarily suspended while the bolus of contrast agent is being intermittently infused. Thereby, a pressure balancing process or system can be realized in which the infusion pressure is maintained substantially constant during the embolization procedure.

[0031] In yet another aspect of the method, the embolic particle mixture is a pre-mixed mixture of embolic particles and a delivery medium disposed in a first dispenser.

[0032] In yet another aspect of this method, the embolic particle mixture contains a specific low concentration of embolic particles in the injected embolic particle mixture. For example, the low concentration of embolic particles relative to the embolic particle mixture can be in the range of 2.0% to 0.05% by volume, or 1.0% to 0.1% by volume. This assumes that the total amount of embolic particle mixture injected is in the range of 50 to 500 cc (cubic centimeters), the amount of contrast agent further diluted with physiological saline is in the range of 10 to 50 cc, the cumulative injection time of the embolic particle mixture is in the range of 5 to 20 minutes, and the injection flow rate of the embolic particle mixture is in the range of 2.0 to 0.1 cc / second. Therefore, if these embolization conditions are changed from the above range, the low concentration of embolic particles relative to the embolic particle mixture can be appropriately adjusted. The size of the embolic particles may also affect the low concentration of embolic particles relative to the embolic particle mixture.

[0033] In additional embodiments, the method may be carried out using any of the embolization systems described herein. For example, an embolic particle mixture may be dispensed by a first dispenser configured to dispense the embolic particle mixture into a catheter, and a contrast agent may be dispensed by a second dispenser configured to dispense the contrast agent into a catheter. In another embodiment of the method, the first dispenser may include a first motor-driven syringe configured to controllly dispense a pressurized flow of an embolic particle mixture from a first motor-driven syringe, and the second dispenser may include a second motor-driven syringe configured to controllly dispense a pressurized flow of a contrast agent from a second motor-driven syringe.

[0034] In yet another embodiment, the embolic particles and the delivery medium may be mixed as they are dispensed from their respective dispensers into the mixer. For example, the first dispenser may include a first sub-dispenser for dispensing embolic particles into the mixer and a second sub-dispenser for dispensing the delivery medium into the mixer. The mixer mixes the embolic particles and the delivery medium and outputs the low-concentration embolic particle mixture described herein. The first and second sub-dispensers may each include a powered syringe configured to dispense a controllable pressurized flow of fluid.

[0035] In yet another embodiment, a delivery medium (e.g., saline) may be injected from a second sub-dispenser into a mixer or manifold at a controlled rate, and then embolic particles may be injected from a first sub-dispenser into the mixer at a controlled rate to produce and discharge an embolic particle mixture. Next, to switch to dispensing contrast agent, the second dispenser injects contrast agent into the mixer or manifold. The second sub-dispenser may inject a delivery medium (e.g., saline) into the mixer or manifold at the same time as the second dispenser injects a high concentration of contrast agent into the mixer or manifold, thereby producing and dispensing a contrast agent mixture of diluted concentration. The second sub-dispenser may also inject the delivery medium continuously and at a variable or constant rate when switching from the dispensing of embolic particles by the first sub-dispenser in the first step to the dispensing of contrast agent from the second dispenser. The controller can control the dispensing rate of embolic particles and delivery medium, or contrast agent and delivery medium, to produce the appropriate dilution / concentration of each mixture. The controller may be programmable to set the desired dispensing rate and dilution / concentration for each mixture.

[0036] In an additional embodiment of the present method, the first and second dispensers may be electronically controlled to controllably dispense their respective fluids. In yet another embodiment of the present method, the first and second dispensers may be operably connected to a controller, which automatically controls the operation of the first dispenser to controllably dispense an embolic particle mixture from the first dispenser and the operation of the second dispenser to controllably dispense a contrast agent.

[0037] In another embodiment, the method may further include the step of selectively programming a controller to control the characteristics of dispensing the embolic particle mixture by a first dispenser and dispensing the contrast agent by a second dispenser. In some examples, the characteristics of dispensing by the first and second dispensers may be (a) dispensing flow rate, (2) dispensing pressure, (3) particle concentration in the embolic particle mixture, (4) dispensing frequency of the contrast agent, or (5) bolus volume or time for dispensing the contrast agent.

[0038] In additional embodiments, the method may further include the step of a controller receiving a first sensor signal from a first sensor relating to the attributes of the respective dispensing by a first dispenser and a second dispenser. The controller may use a feedback control process to control the dispensing by the first and second dispensers based on the first sensor signal. In other embodiments, the first sensor may be a flow sensor, a pressure sensor, a force sensor, an actuator torque sensor, and / or a motor current sensor. In other embodiments of the method, the dispensing attribute controlled by the controller may be the infusion flow rate or infusion pressure into the catheter by the first and second dispensers. The controller may achieve pre-defined characteristics of the dispensing into the catheter by controlling the first and second dispensers using a feedback control process. These pre-defined characteristics of the dispensing into the catheter include one or more of the flow rate, pressure, and concentration of the embolic particle mixture or contrast agent being dispensed.

[0039] In another embodiment, the embolization system may further include an on / off switch, such as a button or touchscreen input, for starting and stopping the injection of the embolic particle mixture. The start and stop of the injection of the embolic particle mixture may be controlled manually or automatically by a controller.

[0040] In yet another embodiment, the embolization system may be configured to perform a priming process to remove any air within the system. For example, the system may be configured to automatically inject a delivery medium (e.g., saline solution) into the catheter and other components to purge air from the discharge components of the embolization system.

[0041] In yet another embodiment, the embolization system may be configured to emit a contrast signal indicating that a bolus of contrast agent is about to be injected. This signal is used to notify the user or the angiography system controller that a bolus of contrast agent is about to be injected, thereby allowing the angiography system to be activated manually or automatically to visualize the embolization procedure. The contrast signal may be an audible sound, a light indicator, or an electronic trigger. This allows the angiography system to be turned on only when necessary, in time to the injection of the contrast agent, thereby limiting radiation exposure for the patient and the user. The embolization system controller may be configured to communicate with the angiography system and transmit a contrast signal to the angiography system to activate it.

[0042] Thus, this specification discloses an improved embolization system and method capable of dispensing a low-concentration embolic particle mixture. By using a low concentration of embolic particles in the embolic particle mixture, this system and method can reduce the likelihood of occlusion (i.e., embolization of non-target vessels) and reflux. Furthermore, this embolization system and method has the function of injecting a contrast agent bolus separately from the injection of the embolic particle mixture. This makes it possible to inject a puff or bolus of contrast agent without injecting a relatively large burst of embolic particle mixture, which is prone to causing occlusion and reflux. In addition, the use of electronic control and automation allows the system and method to be used comfortably by the operator for extended periods without fatigue, even when injecting extremely low concentrations of embolic particle mixture over longer periods than conventional manual control systems, and also reduces the risk of human error during embolization procedures inherent in manual systems as described above. [Brief explanation of the drawing]

[0043] The drawings illustrate the design and usefulness of various aspects of the disclosure, and similar elements are denoted by common reference numerals in the drawings. The drawings are not necessarily drawn to scale. A more specific description of the disclosure is provided in the accompanying drawings to better understand how the above-mentioned and other advantages and objectives are achieved. These drawings are merely illustrative of the disclosure and should not be considered limiting in scope, but rather to illustrate and facilitate the following detailed description. [Figure 1] Figure 1 is a schematic side view of an embolization system according to an example disclosed herein. [Figure 2] Figure 2 shows a pressure-balanced discharge mechanism for the embolic system shown in Figure 1. [Figure 3] Figure 3 shows a flow-balanced discharge method for the embolic system shown in Figure 1. [Figure 4] Figure 4 is a schematic side view of an embolization system according to another example disclosed herein. [Figure 5] Figure 5 is a schematic side view of an embolization system relating to yet another example disclosed herein. [Figure 6] Figure 6 shows a pressure-balanced discharge mechanism for the embolic system shown in Figure 5. [Figure 7] Figure 7 shows a flow-balanced discharge method for the embolic system shown in Figure 5. [Figure 8] Figure 8 is a schematic side view of the outlet of the embolic particle mixture flow, illustrating how embolic particles can aggregate and cause blockage. [Figure 9] Figure 9 is a schematic side view of a flow rectifier for use with the embolic system disclosed herein. [Figure 10] Figure 10 is a schematic side view of the distal end of an embolization system attached to a hub and catheter assembly, relating to another example disclosed herein. [Modes for carrying out the invention]

[0044] This specification describes exemplary embodiments, aspects, and uses of the disclosure. However, this disclosure is not limited to those exemplary embodiments, aspects, and uses, nor is it limited to how the exemplary embodiments, aspects, and uses operate, or how they are described herein. Furthermore, drawings may be simplified or partial, and the dimensions of elements in the drawings may be exaggerated or disproportionate. Furthermore, elements having similar structure or function are indicated by the same reference numerals throughout the drawings. Furthermore, illustrated aspects are not required to have all the features or advantages of the disclosure. Features or advantages described in relation to a particular aspect are not necessarily limited to that aspect and may be implemented in other aspects even if not illustrated as such.

[0045] The following defined terms shall apply unless otherwise given in the claims or elsewhere herein.

[0046] When referring to a list of elements (for example, elements a, b, c), such a reference is intended to include any single element in the list, any combination of some elements in the list, and / or all combinations of elements in the list.

[0047] In this specification, “substantial” means sufficient to perform the intended purpose. Therefore, the term “substantial” allows for minor and insignificant variations from absolute or perfect conditions, dimensions, measurements, results, etc., as expected by those skilled in the art, but which do not significantly affect the overall performance. The term “ones” is plural.

[0048] In this specification, all numerical values, whether expressly indicated or not, are defined by the term “approximately.” The term “approximately” generally refers to a range of numerical values ​​that a person skilled in the art would consider equivalent to (i.e., having the same function or result as) the stated value. Often, the term “approximately” includes numerical values ​​rounded to the nearest significant figure. When numerical ranges are given by endpoints, all numerical values ​​within that range are included (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0049] In this specification and the attached claims, the singular forms "a," "an," and "the" refer to multiple subjects unless otherwise explicitly stated. In this specification and the attached claims, the term "or" is generally used to mean "and / or" unless otherwise explicitly stated.

[0050] Referring to Figure 1, an example of an embolization system 100 for performing medical embolization procedures to embolize a target tissue area in the human body is shown. The embolization system 100 includes a first dispenser 102 and a second dispenser 104 housed in a housing 106. The first dispenser 102 is for containing and dispensing a fluid containing an embolization particle mixture 103, which includes a mixture of embolization particles and a delivery medium. The second dispenser 104 is for dispensing a fluid containing a contrast agent 105 for visualizing the embolization procedure using the embolization system 100.

[0051] In the embodiment shown in Figure 1, the first dispenser 102 and the second dispenser 104 each include motor-driven syringes 108a and 108b, respectively. Each motor-driven syringe 108a and 108b includes barrels 110a and 110b (also referred to as chambers 110a and 110b) for containing the respective fluid to be discharged, and plungers 112a and 112b positioned within the barrels 110a and 110b to push the fluid out of the barrels 110a and 110b. Each syringe 108a and 108b also has syringe outlet ports 114a and 114b at the distal end of the barrels 110a and 110b.

[0052] Each motor-driven syringe 108a, 108b also includes actuators 116a, 116b for operating plungers 112a, 112b. In the illustrated example, actuators 116a, 116b comprise electric motors 118a, 118b and couplings 120a, 120b for connecting the electric motors 118a, 118b to the plungers 112a, 112b. The couplings 120a, 120b may be one or more gears 122a, 122b (e.g., pinions or worm gears) or other coupling devices for converting the rotational motion of the electric motors 118a, 118b into the linear motion of the plungers 112a, 112b. The plungers 112a and 112b may have rack-type gears 124a and 124b that mesh with gears 122a and 122b to convert the rotational motion of gears 122a and 122b into the linear motion of plungers 112a and 112b.

[0053] Outlet port 114a is connected to manifold 126 and is in fluid communication with the manifold, and outlet port 114b is also connected to manifold 126 and is in fluid communication with the manifold. As a result, the first dispenser 102 and the second dispenser 104 discharge their respective fluids into manifold 126. Manifold 126 has an outlet 128 for draining the fluids from the first dispenser 102 and the second dispenser 104 out of manifold 126 and into catheter 130. Embolization system 100 has a connector 129 configured to connect to the proximal hub 131 of catheter 130.

[0054] Optionally, the first dispenser 102 may also include a mixer 107 configured to mix the embolic particle mixture 103 within the first dispenser 102. For example, the embolic particles used may tend to settle over time. The mixer 107 helps maintain a uniform particle concentration in the embolic particle mixture 103 being injected into the first dispenser 102. The mixer 107 may be any suitable mixer, such as a stirring rod, a recirculation pump or pulse pump, a vibrating mixer, a tilting mixer, or a device that rotates or shakes the first dispenser 102.

[0055] The embolization system 100 has a control module 136 (also referred to as the "controller 136") for monitoring and controlling the operation of the embolization system 100. The control module 136 may include a pair of manual on / off switches 138a, 138b for turning on / off a first dispenser 102 and a second dispenser 104, respectively. This allows the user to manually turn on / off the first dispenser 102 to controllably dispense the embolic particle mixture 103 into the catheter 130, and to manually turn on / off the second dispenser 104 to controllably dispense the contrast agent 105. Manual operation may be useful for priming the system 100 by purging any trapped air within the system 100. The on / off switches 138a, 138b are adjustable to control the dispensing flow rates of the first dispenser 102 and the second dispenser 104 by changing the operating speed of the motor-driven syringes 108a, 108b. For example, the on / off switches 138a and 138b may be variable speed buttons or slide switches that change the speed of the motors 116a and 116b, respectively, thereby changing the speed at which the plungers 112a and 112b move forward, and thus changing the discharge flow rate. The control module 136 may also include a flow rate indicator that shows the discharge flow rate. When syringes 108a and 108b are used as dispensers 102 and 104, the flow rate is directly proportional to the speed of the plungers 112a and 112b and can be directly calculated based on the dimensions of the barrels 110a and 110b of the syringes 108 and 108b.

[0056] Furthermore, the embolization system 100 may also include one-way valves 132a and 132b between the syringe outlet ports 114a and 114b and the manifold 126 to prevent backflow of fluid from one dispenser 102 or 104 to the other dispenser 102 or 104.

[0057] To monitor and control the discharge by the embolization system 100 (including automatic discharge as described herein), the system 100 includes sensors 134 for detecting fluid attributes at the location of each sensor 134 and outputting sensor signals associated with those attributes. In the example of Figure 1, the embolization system 100 includes a first sensor 134a, a second sensor 134b, a third sensor 134c, and a fourth sensor 134d. Sensors 134a to 134d may be any suitable sensors such as pressure sensors, flow sensors, or light absorption sensors. For example, sensors 134a, 134b, and 134c are pressure sensors for detecting the fluid pressure at the outlet of the first dispenser 102, the fluid pressure at the outlet of the second dispenser 104, and the fluid pressure in the manifold 126, respectively. The fourth sensor 134d is a differential pressure flow sensor for detecting the flow rate at the outlet of the manifold 126.

[0058] To control the dispensing by system 100, each of the first and second dispensers 102, 104 and sensors 134a-134d are operably connected to a controller 136. The controller 136 is an electronic controller having a microprocessor or electronic control logic (e.g., logic circuit) 138, memory 140, and software application 142. The controller 136g may also be configured to receive sensor output signals from each of the sensors 134a-134d and to use these sensor signals to monitor and control the operation of the embolization system 100. In some examples, the controller 136 can use the output signals to determine the flow rate and / or fluid pressure of the embolic particle mixture 103 dispensed by the first dispenser 102, the flow rate and / or fluid pressure of the contrast agent dispensed by the second dispenser 104, and the flow rate and / or fluid pressure of the fluid dispensed into the catheter 130. The software application 142 includes a control module 144 for controlling the operation of the embolization system 100 based on one or more sensor signals from sensors 134a to 134d. The controller 136 utilizes the control module 144 to control the operation of the first dispenser 102 and the second dispenser 104, which includes controlling the discharge flow rate, discharge pressure, the timing of the discharge on / off cycle, and / or the amount of fluid discharged during the discharge on / off cycle. The control module 144 may include a feedback control algorithm that controls the dispensing of the first dispenser 102 and the second dispenser 104 based on one or more sensor signals from sensors 134a to 134d.

[0059] The controller 136 is selectively programmable by the user to set one or more operating characteristics of the embolization system 100 during use when embolizing a target tissue area. The controller 136 includes an input device 146 that allows the user to select various operating parameters of the embolization system 100. The input device 146 may be any suitable input device such as a keyboard, touchscreen, button pad, or touchpad. As some examples, the user can set the discharge flow rate of the first dispenser 102 and / or the second dispenser 104, the discharge pressure of the first dispenser 102 and / or the second dispenser 104, the timing duration and / or switching cycle of the on / off cycle of the first dispenser 102 and / or the second dispenser 104, the cycle time between the bolus discharge of contrast agent 105 by the second dispenser 104 and the discharge of the next bolus of contrast agent 105 and / or embolic particle mixture 103, the size of the bolus of contrast agent 105 by the second dispenser 104 (e.g., discharge volume or discharge time), the total amount of embolic particle mixture 103 to be discharged (by volume, weight or other appropriate measure), the total discharge time for the embolization procedure, and so on. The software application 142 may include a number of pre-programmed discharge programs with various preset discharge parameters that the user can select. The pre-programmed discharge program can have user-selectable characteristics such as the flow rate, pressure, and total volume of the embolic particle mixture, and the injection frequency of the contrast agent 105.

[0060] The embolization system 100 may also have other sensors 134e to 134h for detecting the operating attributes of motor-driven syringes 108a and 108b and outputting respective control signals related to those operating attributes. These other sensors 134e to 134h are also operably connected to the controller 136, which is configured to receive sensor output signals from each of the sensors 134e to 134h and to use these sensor signals to monitor and control the operation of the embolization system 100. For example, sensors 134e and 134f may be torque sensors that measure the torque applied to plungers 112a and 112b, respectively. The torque applied to plungers 112a and 112b may be used by the controller 136 to indirectly determine the outlet pressures of the first dispenser 102 and the second dispenser 104. Similarly, sensors 134g and 134h may be motor current sensors that measure the current supplied to motors 118a and 118b, respectively. Furthermore, the motor current can be used indirectly to determine the operating attributes of the motor-driven syringes 108a and 108b, such as the discharge flow rates from the first dispenser 102 and the second dispenser 104, respectively. Sensors 134g and 134h may also be motion sensors configured to detect the movement (linear motion) of the plungers 112a and 112b or the rotation (rotation sensors) of the motors 118a and 118b, and they can be used to derive the discharge flow rates from the first dispenser 102 and the second dispenser 104, respectively. The control module 144, including a feedback control algorithm, can monitor and control the dispensing of the first dispenser 102 and the second dispenser 104 by utilizing the output signals from sensors 134e to 134h.

[0061] The embolization system 100 may include one or more pressure relief valves and / or regulators 148 to regulate the pressure of the fluid flow inside or out of the system. In the example in Figure 1, a pressure relief valve or regulator 148 is installed at the outlet of the manifold 126 to regulate the pressure of the fluid discharged from the embolization system 100. The pressure relief valve or regulator 148 may be installed at any one or more locations within the manifold 126, such as the outlet of the first dispenser 102, the outlet of the second dispenser 104, the outlet of the manifold 126, or within the manifold 126, to regulate the flow and pressure of the discharged fluid in or out of the system, to regulate the concentration of the fluid (e.g., the concentration of the mixture of embolic particle solution and contrast agent), and / or to promote mixing of the constituent fluids. In the case of a pressure relief valve 148, the pressure relief valve 148 also functions as a passive overpressure prevention device.

[0062] Furthermore, the embolization system 100 may also include pressure or force limiters, such as torque limiters or slip clutches, between the electric motors 118a, 118b and the couplings 120a, 120b connected to the plungers 112a, 112b, in order to prevent overpressure of the discharged fluid.

[0063] The following describes the use and operation of the embolization system 100 when performing an embolization procedure to embolict a target tissue area. The catheter 130 is inserted through an incision in the patient's body and advanced to a target location near the target tissue area to be embolized. The catheter 130 can be positioned in the patient's body before or after connecting it to the embolization system 100, but it may be preferable to position the catheter 130 before connection so that the embolization system 100 does not interfere with the operation of the catheter 130. The embolization system 100 is then connected to the catheter 130. The system 100 can also be connected to the catheter 130 via secondary fluid connections such as a rotary hemostatic valve (RHV) or a stopcock or manifold for fluid management.

[0064] Subsequently, the user can use the embolization system 100 in manual or automatic mode to embolize the target tissue area. The first dispenser 102 is filled with the embolic particle mixture 103. The embolic particle mixture 103 may contain low concentrations of embolic particles ranging from 2.0% to 0.05% by volume, or from 1.0% to 0.1% by volume. When setting the target concentration of embolic particles for the embolic particle mixture 103, there are numerous factors to consider, including the total amount of embolic particle mixture 103 used in the embolization procedure, the infusion flow rate, and the desired size and amount of embolic particles for a particular clinical scenario or a specific target area or specific tissue volume to be embolized. The range of embolic particle concentrations in the embolic particle mixture 103 disclosed herein is calculated based on the assumption that the total volume of the embolic particle mixture 103 injected is in the range of 100 to 500 cc (cubic centimeters), the cumulative injection time of the embolic particle mixture is in the range of 5 to 20 minutes, and the injection flow rate of the embolic particle mixture is in the range of 2.0 to 0.1 cc / second. Therefore, if their embolic properties deviate from the above range, the low concentration of embolic particles in the embolic particle mixture can be appropriately adjusted. The total volume of contrast agent diluted with physiological saline may be in the range of 10 to 50 cc.

[0065] The second dispenser 104 is filled with a contrast agent 105 suitable for a visualization system used to monitor the procedure. In manual mode, the user operates the first dispenser 102 and / or the second dispenser 104 as needed to dispense the desired amount of embolic particle mixture 103 and contrast agent 105, respectively. The controller 136 can be configured to provide the user with dispensing information such as the pressure, flow rate, and volume of the fluid being dispensed. The dispensing information may be displayed on a display 137 operably connected to the controller 136 (for example, the display 137 may be part of the controller 136), or provided to the user by other appropriate means, such as transmitting the dispensing information to an external device (e.g., a computing device such as a laptop or smartphone) via a communication link (e.g., a wired or wireless link such as WiFi or Bluetooth). The user can use the dispensing information to monitor and control the embolic procedure by the embolic system 100.

[0066] In one manual mode of using the embolization system 100, the user operates the manual on / off switch 138a to activate the first motor-driven syringe 108a of the first dispenser 102, thereby dispensing the embolic particle mixture 103 into the catheter 130, which is then delivered to the target area. The user can control the dispensing flow rate of the embolic particle mixture by using switch 138a or by appropriately programming the controller 136. The user intermittently operates the manual on / off switch 138b to activate the second motor-driven syringe 108b of the second dispenser 102, thereby dispensing a bolus of contrast agent 105 into the catheter 130, which is then delivered to the target area. Once the bolus of contrast agent 105 is dispensed and the bolus is expelled from the catheter at the target location, the user can track the injection of the contrast agent 105 into the target area and observe and monitor the progress of embolization in the target tissue area using a visualization system such as a fluoroscope or other appropriate X-ray system configured to detect the contrast agent and anatomical structures in the patient's body and display real-time images on a monitor. The user can temporarily stop dispensing the embolic particle mixture 103 while dispensing the bolus of contrast agent 105, and then resume dispensing the embolic particle mixture 105 to push the bolus of contrast agent 105 out of the catheter 130 into the target tissue area. Alternatively, the user can dispense the bolus of contrast agent 105 while continuously dispensing the embolic particle mixture 103.

[0067] To use the embolization system 100 in automatic mode, the user uses the input device 146 to select the desired operating parameters of the embolization system 100. Such operating parameters include the discharge flow rate of the first dispenser 102 and / or the second dispenser 104, the discharge pressure of the first dispenser 102 and / or the second dispenser 104, the on / off cycle of the first dispenser 102 and / or the second dispenser 104, the cycle time for bolus dispensing of contrast agent 105 by the second dispenser 104, the size of the bolus of contrast agent 105 by the second dispenser 104 (e.g., the amount or time to be dispensed), the total amount of embolic particle mixture 105 to be dispensed (by volume, weight or other appropriate measure), and the total dispensing time for the embolization procedure. Alternatively, the user selects a pre-programmed dispensing program and, if necessary, sets one or more of the user-selectable characteristics of the dispensing program, such as the flow rate, pressure, and total volume of the embolic particle mixture, and the injection frequency of the contrast agent 105.

[0068] The user initiates an automated embolization procedure with the embolization system 100 by entering a "start" command using the input device 146. The controller 136 automatically operates the embolization system 100 to execute a selected automated embolization dispensing program using a first dispenser 102, a second dispenser 104, sensors 134, valves, and regulators 148, all controlled by the controller 136. In a generalized example of automated embolization, the embolization system 100 activates the first dispenser 102 to dispense the embolic particle mixture 103 into the catheter 130 at a flow rate, pressure, and / or volume controlled by the controller 136, thereby injecting the embolic particle mixture 103 into the target area. This control may be achieved using a feedback control process based on sensor signals from one or more of the sensors 134a-134e. The embolization system 100 intermittently activates the second dispenser 104 to dispense a bolus of contrast agent 105 into the catheter 130, thereby injecting the contrast agent 105 into the target area. This control can also be achieved using a feedback control process based on sensor signals from one or more of the sensors 134a to 134e.

[0069] Furthermore, the embolization system 100 may be configured to emit a contrast agent signal indicating that a bolus of contrast agent 105 is about to be injected. This signal is used to inform the user or the angiography system controller that a bolus of contrast agent 105 is about to be injected, thereby allowing the angiography system to be activated manually or automatically to visualize the embolization procedure. The contrast agent signal may be an audible sound, a light indicator, or an electronic trigger. This allows the angiography system to be turned on only when necessary, in time close to the injection of the contrast agent, thereby reducing radiation exposure for the patient and the user. The controller 136 of the embolization system 100 may be configured to communicate with the angiography system to transmit a contrast agent signal to the angiography system to activate it. Once a bolus of contrast agent 105 is injected from catheter 130 at the target location, the user can use a visualization system, such as a fluoroscope or other suitable X-ray system, configured to detect the contrast agent and anatomical structures within the patient's body and display real-time images on a monitor, to track the injection of the contrast agent 105 into the target area and its propagation through the target tissue area, thereby observing and monitoring the progress of embolization in the target tissue area.

[0070] Referring to Figures 2 and 3, two different control schemes for dispensing the embolic particle mixture and contrast agent are shown. Figure 2 is a chart showing a pressure-balancing scheme in which the dispensing / injection pressure is controlled and the flow rate is determined by the controlled dispensing / injection pressure. The pressure-balancing scheme can be used to ensure that a safe pressure is always maintained for the fluid being injected into specific anatomical structures in the target region. As shown in Figure 2, in the pressure-balancing scheme, the dispensing of the embolic particle mixture 103 by the first dispenser 102 is paused during the bolus dispensing of the contrast agent 105 by the second dispenser 104. This keeps the injection pressure at the outlet of the manifold 126 substantially constant, and the pressure rise during the bolus injection of the contrast agent 105 can be kept to a minimum. The embolic system 100 may be configured to operate using the pressure-balancing scheme by using a pressure relief valve and / or regulator 148 to maintain a set dispensing / injection pressure, and / or by configuring the controller 136 to control the dispensing. For example, the pressure relief valve and / or regulator 148 can be set to control the discharge pressure, and / or the controller 136 can control the operating force of the motor-driven syringes 108a and 108b, such as by controlling the current of the motors 134h and 134g, so that the first dispenser 102 and the second dispenser 104 can obtain a desired discharge pressure.

[0071] In contrast, Figure 3 is a chart showing a flow balance method in which the discharge / injection flow rate is controlled and the pressure is determined by the discharge / injection flow rate. This method is considered preferable to ensure the desired flow rate of the embolic particle mixture 103 (or, assuming that the concentration of the embolic particle mixture 103 is relatively constant, the discharge rate of embolic particles proportional to that flow rate) during embolization using the embolization system 100. As shown in Figure 3, in the flow balance method, in order to maintain the set flow rate of the embolic particle mixture, the discharge of the embolic particle mixture 103 by the first dispenser 102 is continuously performed even during the bolus discharge of the contrast agent 105 by the second dispenser 104. As a result, as also shown in Figure 3, the injection pressure at the outlet of the manifold 126 increases during the bolus injection of the contrast agent 105. The embolization system 100 can be configured to operate in a flow-balancing manner by configuring the controller 136 to control the discharge flow rates of the first dispenser 102 and the second dispenser 104, for example by controlling the speed at which each motor-driven syringe 108a, 108b is operated, i.e., the speed at which the plungers 112a, 112b advance (which may be proportional to the speed of each motor 134g, 134h).

[0072] Referring to Figure 4, another example of the embolization system 200 is disclosed. This embolization system 200 is the same as the embolization system 100, except that the first dispenser 102 and the second dispenser 104 are motor-driven syringes 108a and 108b, but instead are a first pressurized dispenser 202a and a second pressurized dispenser 202b. Each of the first and second pressurized dispensers 202a and 202b comprises a pressure chamber 110a and 110b and a pressure source 204a and 204b. The pressure sources 204a and 204b may be a gas source (e.g., hospital compressed air), a fluid pump, or a pressure canister / container / chamber / bag for pressurizing the pressure chambers 110a and 110b. As shown in Figure 4, the pressure sources 204a and 204b may be located on the embolization system 200. Alternatively, the pressure sources 204a, 204b may be located outside the embolization system 200, in which case the embolization system 100 has fittings for connecting the external pressure sources 204a, 204b to the system 100. Pressure relief valves 206a, 206b and / or regulators can be used to control the pressure provided by the pressure sources 206a, 206b and pressurize the pressure chambers 110a, 110b.

[0073] Furthermore, the first and second pressurized dispensers 202a and 202b each include a first discharge valve 208a and a second discharge valve 208b at their respective outlets 114a and 114b. The first and second discharge valves 208a and 208b are operably connected to a controller 136 so that the controller can open and close the discharge valves 208a and 208b to discharge the respective fluids from the pressurized dispensers 202a and 202b. The first and second pressurized dispensers 202a and 202b operate to discharge the embolic particle mixture 103 and the contrast agent 105, respectively. Specifically, after pressurizing chambers 110a and 110b, the respective discharge valves 208a and 208b are opened to discharge a pressurized stream of the embolic particle mixture 103 and contrast agent 105, and then the respective discharge valves 208a and 208b are closed to stop the discharge.

[0074] Monitoring and control of the embolization system 200 are the same as those described for the embolization system 100, except that dispensing is performed by controlling the first and second pressurized dispensers 202a and 202b instead of the motor-driven syringes 108a and 108b. Similarly, the method of use and operation of the embolization system 200 when performing an embolization procedure to embolize a target tissue area are the same as those of the embolization system 100, except that dispensing is performed by controlling the operation of the first and second pressurized dispensers 202a and 202b instead of the motor-driven syringes 108a and 108b.

[0075] Referring to Figure 5, another example of the embolization system 300 is disclosed. This embolization system 300 is very similar to the embolization system 100, but differs in that it is configured to separately dispense embolic particles 302 (dispersed in a carrier fluid containing a high concentration of embolic particles 302) and a delivery medium 304, and to mix the embolic particles and the delivery medium to prepare and dispense an embolic particle mixture 103. This is similar to the configuration in the embolization system 100 described herein, in which the first dispenser 102 comprises a first sub-dispenser for dispensing embolic particles and a second sub-dispenser for dispensing the delivery medium, and the embolic particles and the delivery medium are mixed to produce an embolic particle mixture dispensed by the first dispenser 102. This allows the embolization system 300 to vary the concentration of the embolic particle mixture, and also allows the user to selectively control the concentration of the embolic particle mixture. Figure 5 is a partial view of the embolization system 300 and does not show all the details of the operating mechanisms of the first sub-dispenser 306, the second sub-dispenser 308 and the second dispenser 104, nor does it show the manual on / off switches 138a, 138b or the controller 136. It will be understood that the operating mechanisms of the first sub-dispenser 306, the second sub-dispenser 308 and the second dispenser 104 may be identical or similar to the operating mechanisms of the embolization system 100 (i.e., motor-driven syringes 108a, 108b) and / or the embolization system 200 (i.e., pressurized dispensers 202a, 202b) described herein. Furthermore, it will be understood that the embolization system 300 includes the same or similar manual on / off switches 138a, 138b and controller 136 as those in the embolization systems 100 and 200, and that these elements function as described herein.

[0076] As shown in Figure 5, the embolization system 300 includes a first sub-dispenser 306 for dispensing embolic particles 306. The combination of the first sub-dispenser 306 and the second sub-dispenser 308 can be considered as the first dispenser 102 of the embolization system 300. The embolization system 300 also includes additional sensors 134 for the first and second sub-dispensers 306, 308, which can detect fluid attributes at their respective locations and output sensor signals related to those attributes. Similarly, the additional sensors 134 are also operably connected to the controller 136. A manual on / off switch 138 may include a switch 138 for activating the first sub-dispenser 306 and a switch for activating the second sub-dispenser 308, so that the user can manually change the concentration of embolic particles 304 in the embolic particle mixture 103 using these switches. Alternatively, both the first sub-dispenser 306 and the second sub-dispenser 308 may be operated by a single manual switch 138a, in which case the flow rates of the first sub-dispenser 306 and the second sub-dispenser 308 can be controlled by the controller 136 to achieve a selected concentration. For example, the user can use the input device 146 to select a concentration (constant or variable concentration, as described herein), and the controller 136 can control the respective dispensing flow rates of the first sub-dispenser 306 and the second sub-dispenser 308 to achieve the selected concentration.

[0077] The embolization system 300 also includes a mixer 310 connected to and fluidly communicating with the outlet 128 of the manifold 126. The mixer 310 may be any suitable mixer configured to mix the embolization particles 302 with the delivery medium 304 and output the embolization particle mixture 103 through the outlet 312 of the mixer 310. The mixer 310 may be a passive mixer such as a flow-induced mixer, a static mixer or a vortex mixer, or an active mixer such as a mixer with a movable mixing element, a mixer with a non-movable mixing element such as an acoustic transducer, or a mixer with a mechanical wave transmitter.

[0078] The monitoring and control of the embolization system 300 is the same as described for the embolization system 100, except that it adds the function of separately dispensing embolic particles 306 from a first sub-dispenser 306 and delivery medium 304 from a second sub-dispenser 308, mixing the dispensed embolic particles 306 and delivery medium 304 to produce an embolic particle mixture 103, and dispensing it from the mixer into the catheter 130. For this reason, the controller 136 and software application 142 are also configured to change the concentration of the embolic particle mixture, allowing the user to selectively control the concentration of the embolic particle mixture. For example, the controller 136 and software application 142 are configured so that the user can use the input device 146 to select a constant concentration or a variable concentration selected by the user as the concentration of the embolic particle mixture 103. The flow rate of the mixed embolic particle mixture 103 may also be selected by the user or set in a pre-programmed dispensing program. For example, the controller 136 and software application 142 may include a preset program that changes the concentration during the embolization procedure, which may be set to gradually increase or decrease the concentration over a period of the embolization procedure, or to use a constant concentration over a period of the embolization procedure. The change in concentration may be made within a user-selectable concentration range that defines minimum and maximum concentrations, or within a flow rate range that defines minimum and maximum values ​​for the number of embolic particles discharged (i.e., the number of embolic particles per unit time). The controller 136 can determine the concentration and flow rate of the discharged embolic particle mixture 103 to achieve a programmed flow rate for the number of embolic particles.

[0079] Similarly, the method of use and operation of the embolization system 300 when performing an embolization procedure to embolize a target tissue area is substantially the same as that of the embolization system 100, except that the embolization particles 302 and the delivery medium 304 are dispensed separately by the first sub-dispenser 306 and the second sub-dispenser 308, and they are mixed in the mixer 310 to produce an embolization particle mixture 103, which is then dispensed from the mixer into the catheter 130, and the embolization system can change the concentration of embolization particles 302 in the embolization particle mixture 103 during the procedure. The catheter 130 is inserted and positioned at a target location near the target tissue area to be embolized, as described for the embolization system 100. The first sub-dispenser 306 is filled with embolic particles 302, the second sub-dispenser 308 is filled with a delivery medium 304 such as saline, water and / or medication, and the second dispenser 104 is filled with a contrast agent 105 suitable for a visualization system used to monitor the procedure. The user can then use the embolization system 300 in manual or automatic mode to embolize the target tissue area.

[0080] In manual mode, the user can operate the first sub-dispenser 306 and the second sub-dispenser 308 as needed to dispense embolic particles 302 and delivery medium 304 in selected relative amounts, thereby dispensing an embolic particle mixture 103 of a selected concentration. For example, by dispensing and mixing embolic particles 302 and delivery medium 304 in predetermined relative amounts, a low-concentration embolic particle mixture 103 can be produced in which the embolic particle concentration in the embolic particle mixture 103 is in the range of 2.0% to 0.05% by volume, or in the range of 1.0% to 0.1% by volume. The user can intermittently operate the second dispenser 104 to intermittently dispense boluses of contrast agent 105. The controller 136 may be configured to provide the user with dispensing information such as the pressure, flow rate, and volume of the dispensing fluid. Discharge information can be displayed on a display 137 operably connected to the controller 136 (for example, the display 137 may be part of the controller 136), or provided to the user by other appropriate means, such as transmitting the discharge information to an external device (e.g., a computing device such as a laptop or smartphone) via a communication link (e.g., a wired or wireless link such as WiFi or Bluetooth). The user can use the discharge information to monitor and control the embolization procedure using the embolization system 100.

[0081] In an example of manual mode using the embolization system 300, the user operates a manual on / off switch 138a to activate the first sub-dispenser 306, thereby dispensing embolic particles 302, and the second sub-dispenser 308, thereby dispensing the delivery medium 304. These are mixed in the mixer 310 to produce an embolic particle mixture 103, which is then dispensed into the catheter 130 and delivered to the target area by the catheter 130. The user can select the concentration of the embolic particle mixture 103 using the controller 136, which then controls the relative amounts of embolic particles 302 dispensed by the first sub-dispenser 306 and the delivery medium 304 dispensed by the second sub-dispenser 308 to obtain the selected concentration. The controller 136 generates a selected concentration by controlling the relative flow rates of embolic particles 302 dispensed by the first sub-dispenser 306 and the delivery medium 304 dispensed by the second sub-dispenser 308. The user operates a manual on / off switch 138a to simultaneously activate the dispensing of embolic particles 302 by the first sub-dispenser 306 and the dispensing of delivery medium 304 by the second sub-dispenser 308. The embolic particles 302 and delivery medium 304 flow through the manifold 126 and are mixed in the mixer 310 to produce an embolic particle mixture 103 of the selected concentration. The embolic particle mixture 310 is injected into the catheter 130, flows through the catheter 130, and is dispensed from the distal end of the catheter 130 into the target tissue area. Alternatively, the user can manually operate both the first sub-dispenser 306 and the second sub-dispenser 304 separately to manually control the relative amounts of embolic particles 302 and delivery medium 304, thereby producing an embolic particle mixture 103 of a manually controlled concentration. In this case, the manual on / off switch 138a may include separate switches for the first sub-dispenser 306 and the second sub-dispenser 308. The user can control the discharge flow rate of the embolic particle mixture 103 by using switch 138a or by appropriately programming the controller 136.

[0082] The user intermittently operates the manual on / off switch 138b to activate the second dispenser 104, thereby discharging a bolus of contrast agent 105 into the catheter 130, which is then delivered to the target area by the catheter 130. Once the bolus of contrast agent 105 has been dispensed and the bolus has been removed from the catheter at the target location, the user can track the injection of the contrast agent 105 into the target area and observe and monitor the progress of embolization in the target tissue area using a visualization system such as a fluoroscope or other appropriate X-ray system configured to detect the contrast agent and anatomical structures in the patient's body and generate real-time images displayed on a monitor. The user can temporarily stop discharging the embolic particle mixture 103 while discharging the bolus of contrast agent 105, and then resume discharging the embolic particle mixture 103 (or delivery medium 304 only) to push the bolus of contrast agent 105 out of the catheter 130 into the target tissue area. Alternatively, the user can continuously dispense the embolic particle mixture 103 while simultaneously dispensing a bolus of contrast agent 105.

[0083] In another embodiment, the sub-dispenser operating mode can also be applied to the contrast agent 105. The system 100 is configured to allow the user to select a set concentration of the contrast agent 105, and is configured to dispense the contrast agent 105 from a second dispenser 104 and simultaneously dispense the delivery medium 304 from a second sub-dispenser 308, mix them in a mixer 310 to produce a contrast agent of the set concentration, and then dispense the contrast agent into the catheter 130 by the system 100.

[0084] To use the embolization system 300 in automatic mode, the user uses the input device 146 to select the desired operating parameters of the embolization system 300. Such operating parameters include the discharge flow rate of the first dispenser 102 and / or the second dispenser 104, the discharge pressure of the first sub-dispenser 306, the second sub-dispenser 308 and / or the second dispenser 104, the on / off cycle of the discharge of the embolic particle mixture 103 by the first sub-dispenser 306 and the second sub-dispenser 308 and / or the discharge of the contrast agent 105 by the second dispenser 104, and the cycle of the discharge of the bolus of the contrast agent 105 and / or the discharge of the embolic particle mixture 103 by the second dispenser 104. This includes the timing period and / or cycle rate of the on / off cycles of the first dispenser 102 and / or the second dispenser 104, the cycle time between the bolus dispensing of contrast agent 105 by the second dispenser 104 and the next bolus dispensing of contrast agent 105 and / or the dispensing of embolic particle mixture 103), the size of the bolus of contrast agent 105 by the second dispenser 104 (e.g., the amount or time to be dispensed), the total amount of embolic particle mixture 105 to be dispensed (by volume, weight or other appropriate measure), and the total dispensing time for the embolization procedure. Alternatively, the user may select a pre-programmed dispensing program and, if necessary, set one or more of the user-selectable characteristics of the dispensing program, such as the flow rate, pressure, total volume of embolic particle mixture, and the injection frequency of contrast agent 105.

[0085] Subsequently, the user initiates the automated embolization procedure in the embolization system 300 by entering a "start" command using the input device 146. The controller 136 automatically operates the embolization system 300 to execute a selected automated embolization dispensing program using the first sub-dispenser 306, the second sub-dispenser 308, the second dispenser 104, the sensor 134, the valves, and the regulator 148, all controlled by the controller 136. In a generalized example of automated embolization, the embolization system 300 activates the first sub-dispenser 306 to dispense embolic particles 302 and simultaneously activates the second sub-dispenser 308 to dispense the delivery medium 304. The controller 136 controls the relative flow rates of the embolic particles 302 dispensed by the first sub-dispenser 306 and the delivery medium 304 dispensed by the second dispenser 308 to control the concentration of the embolic particle mixture, producing a concentration selected by the user or a concentration set by a pre-programmed dispensing program. The embolic particles 302 and delivery medium 304 flow through the manifold 126 and are mixed in the mixer 310 to produce an embolic particle mixture 103 of a selected concentration. The embolic particle mixture 310 is injected into the catheter 130, flows through the catheter 130, and is discharged from the distal end of the catheter 130 into the target tissue region. The flow rate, pressure, and / or volume of the discharged embolic particle mixture 103 are controlled by the controller 136, which may be performed using a feedback control process based on sensor signals from one or more of the sensors 134a-134e. The embolic system 300 intermittently activates a second dispenser 104 to discharge a bolus of contrast agent 105 into the catheter 130 and inject the contrast agent 105 into the target region. This control may also be performed using a feedback control process based on sensor signals from one or more of the sensors 134a-134e.

[0086] Once a bolus of contrast agent 105 is injected from catheter 130 at the target location, the user can track the injection of contrast agent 105 into the target area and observe and monitor the progress of embolization in the target tissue area using a visualization system such as a fluoroscope or other appropriate X-ray system configured to detect the contrast agent and anatomical structures within the patient's body and generate real-time images displayed on a monitor.

[0087] Referring to Figures 6 and 7, two different control schemes are shown for dispensing the embolic particle mixture 103 and contrast agent 105 using the embolic system 300. The control schemes shown in Figures 6 and 7 are similar to those shown in Figures 2 and 3, except that the control schemes in Figures 6 and 7 are for the embolic system 300 which has separate dispensers for the embolic particles 302 and the delivery medium 304. Figure 6 is a chart showing a pressure-balancing scheme in which the dispensing / injection pressure is controlled and the flow rate is determined by the controlled dispensing / injection pressure. The pressure-balancing scheme can be used to ensure that a safe pressure is always maintained for the fluid being injected into a specific anatomical structure in the target region. As shown in Figure 6, in the pressure-balancing scheme, the dispensing of the embolic particles 302 by the first sub-dispenser 306 and the dispensing of the delivery medium 304 by the second sub-dispenser 308 (i.e., the dispensing of the embolic particle mixture 103) are paused during the bolus dispensing of the contrast agent 105 by the second dispenser 104. This ensures that the injection pressure in the mixer 310 remains substantially constant, potentially limiting the pressure increase even during bolus injection of contrast agent 105. The embolization system 300 may be configured to operate using a pressure balancing scheme by using a pressure relief valve and / or regulator 148 to maintain a set discharge / injection pressure, and / or by configuring the controller 136 to control discharge. For example, the pressure relief valve and / or regulator 148 may be configured to control the discharge pressure, and / or the controller 136 may control the operating force of the motor-driven syringe 108 (if dispensers 104, 306, and 308 are motor-driven syringes) by controlling the current of the motor 134, for example, so that the desired discharge pressure is obtained by the first sub-dispenser 306, the second sub-dispenser 308, and the second dispenser 104.

[0088] In contrast to the pressure-balancing method, Figure 7 is a chart showing the flow-balancing method, in which the discharge / injection flow rate is controlled and the pressure is determined by the controlled discharge / injection flow rate. This method is considered preferable to ensure the desired flow rate of the embolic particle mixture 103 (or, assuming that the concentration of the embolic particle mixture 103 is relatively constant, the discharge rate of embolic particles proportional to that flow rate) during embolization using the embolization system 300. As shown in Figure 7, in the flow-balancing method, in order to maintain the set flow rate of the embolic particle mixture 103, the discharge of embolic particles 302 by the first sub-dispenser 306 continues even during the bolus discharge of contrast agent 105 by the second dispenser 104 (while the discharge of delivery medium 304 by the second sub-dispenser 308 is temporarily paused). As a result, as also shown in Figure 7, the injection pressure at the outlet of the manifold 126 increases during the bolus injection of contrast agent 105. The embolization system 300 can be configured to operate in a flow-balancing manner by configuring the controller 136 to control the discharge flow rates of the first sub-dispenser 306, the second sub-dispenser 308, and the second dispenser 104, for example by controlling the speed at which each of the first and second sub-dispensers 306, 308, and the second dispenser 104 is activated, or by controlling the discharge flow rate in other ways.

[0089] The embolization system 300 may also be configured to have the dispenser configuration of the embolization system 200 shown in Figure 4. In such an embolization system, the first and second sub-dispensers 306, 308 and the second dispenser 104 consist of pressurized dispensers identical or similar to the pressurized dispenser 200 described herein and shown in Figure 4. The embolization system similarly includes a pressure source 204 and a dispensing valve 208 for each of the first and second sub-dispensers 306, 308 and the second dispenser 104. The method of use and operation of the embolization system 300 having pressurized dispensers is the same as described for the embolization system 300, except that dispensing is performed by controlling the pressurized dispenser 202 instead of the motor-driven syringe 108. Similarly, the method of use and operation of the embolization system 300 having a pressurized dispenser when performing an embolization procedure to embolict a target tissue area is the same as that of the embolization system 300, except that dispensing is performed by controlling the operation of the pressurized dispenser 202.

[0090] Next, with reference to Figures 8 and 9, a flow rectifier 400 for use with any of the embolization systems described herein (including embolization systems 100, 200, 300 and variations of the disclosure) will be described. As shown in Figure 8, the embolic particles 302 in the embolic particle mixture 103 may aggregate and occlude at physical obstacles or fault sites in the flow path, such as tapered outlets or vascular bifurcations. Such aggregation and occlusion can also reduce the effectiveness of embolization because the distribution of embolic particles 302 in the embolic particle mixture 103 is disordered and non-uniform, making them more likely to aggregate and occlude when encountering obstacles or fault sites.

[0091] To prevent such aggregation and blockage, the embolization systems disclosed herein may include a flow rectifier 400 that adjusts the flow patterns of the embolus particles 302 and the delivery medium 304, and combines the two flows to "mix" the embolus particles 302 and the delivery medium 304 in a regular and specific arrangement. As shown in Figure 9, the flow rectifier 400 has a first channel 410 (inner tube 410) located in the center of the device and a second channel 412 (outer tube 412) having an annular cross-section surrounding the first channel, with the first channel 410 and the second channel 412 being coaxially arranged. The first channel 410 has a first inlet 402 that is connected to the outlet of a first sub-dispenser 306 and is in fluid communication with this outlet. The first channel 410 has a tapered first outlet 414 located in the center of a tapered second outlet 416 of the second channel 412.

[0092] The first channel 410 is configured to rectify the flow of embolic particles 302 as they flow through the first channel 412, thereby generating a more uniform pattern and stable flow rate of embolic particles 302 at the first outlet 414. The uniform pattern may be a state in which the embolic particles 302 are arranged in a single line, or it may be a flow in which the number of embolic particles 302 present across the diameter of the outlet 414 is extremely small (for example, less than 5, or less than 10, or less than 20).

[0093] The second flow path 410 is configured to rectify the flow of the delivery medium 304 into a uniform laminar flow pattern at the second outlet 416. Thus, the rectified flow of embolic particles 302 and the rectified flow of the delivery medium 304 merge at the first outlet 414 and the second outlet 416, respectively, to generate a flow of embolic particle mixture 103 having a structure in which a sheath flow 420 of the delivery medium 304 surrounds a uniform and aligned flow of embolic particles 302 420. The sheath flow 420 surrounding the embolic particles 302 can be formed in a two-dimensional (2D), three-dimensional (3D), or cylindrically symmetrical form, depending on the configuration of the flow rectifier 400. The configuration in which a cylindrical sheath flow 420 surrounds the central flow of the embolic particle flow 420 of embolic particles 302 prevents the embolic particles 302, which are rectified in a single-row arrangement or low-particle-number profile, from coming into contact with the surrounding walls, tubular members, or catheters. This reduces the turbulence caused by the injection of the unrectified embolic particle mixture 103, preventing or reducing the occurrence of random bolus blockages formed by flow circulation and turbulence. Furthermore, the rectification and alignment of the embolic particles 302 by the flow rectifier 400 allows for the application of passive or active measurements to predict or count the number of embolic particles 302 discharged. This counting result is used by the controller 136 to control the discharge of the embolic particle mixture 103, resulting in more predictable therapeutic control. Such organized / rectified laminar flow not only reduces turbulence due to uncontrolled mixing but also provides a uniform distribution over the delivery of embolic particles 302 along the flow field or pressure gradient.

[0094] The flow rectifier 400 is not limited to the example shown in Figure 9, and may be other types of suitable flow rectifiers, such as a rectifier that utilizes a microchannel, fluid tip, microgroove, or microstructure to provide a uniform distribution of embolic particles 302 in the flow of the discharged embolic particle mixture 103. A fluid tip or fluid microchannel may also be used to fill the dispenser of the embolization system and mix and prepare the embolic particles 302, embolic particle mixture 103, and / or contrast agent 105 before connecting the embolization system to a catheter for use in embolization procedures.

[0095] Next, referring to Figure 10, the distal end of an embolization system 500 is shown, which has different catheters for dispensing the embolic particle mixture 103 and the contrast agent 105. The embolization system 500 is configured similarly to any of the embolization systems 100, 200, 300 and any of the variations of the disclosure, except that system 500 has a first catheter 502 for dispensing the embolic particle mixture 103 and a second catheter 504 for dispensing the contrast agent 105. The embolization system 500 may include a catheter hub 506 and first and second fittings 510, 512 for connecting and sealing the first catheter 502 and the second catheter 504 to the first and second dispensers 120, 104 in a coaxial configuration. For example, the catheter hub 506 may be a rotary hemostatic valve (RHV) or a Touhy-Borst connector. In the illustrated embodiment, the first catheter 502 is a microcatheter and the second catheter 504 is a guide catheter, and they are configured such that the first catheter 502 is insertable into the lumen of the second catheter 504 and the first catheter 502 and the second catheter 504 are coaxially arranged. The first connector 510 is located at the distal end of the first fluid conduit 514, which is in fluid communication with the first dispenser 102. The first connector 510 is configured to be attached to the proximal end of the first catheter 502. The second connector 512 is located at the distal end of the second fluid conduit 516, which is in fluid communication with the second dispenser. The second connector 512 is configured to be attached to the first coupling 518 of the catheter hub 506. The catheter hub 506 has a second coupling 520 configured to be attached to the proximal end of the second catheter 504. The catheter hub 506 also has a compression joint 524 configured to receive the first catheter 502 and form a fluid-tight seal around the first catheter 502. The first catheter 502 is inserted through the compression joint 524 and into the lumen of the second catheter 504, thereby forming an annular channel 522 between the first catheter 502 and the second catheter 504.The catheter hub 506 has a fluid channel 526 that fluidly connects a second fluid conduit 516 to an annular channel 522. The first catheter 502 is connected to a first dispenser and is in fluid communication with the first dispenser, and the second catheter 504 is connected to a second dispenser 102 via the annular channel 522 and is in fluid communication with the second dispenser. As a result, the first dispenser 102 can dispense an embolic particle mixture 103 through the lumen of the first catheter 502, and the second dispenser 104 can dispense a contrast agent via the annular channel 522, which can be supplied from their respective outlets located at the distal ends of the first and second catheters 502 and 504. The embolic system 500 may have any of the features and embodiments described herein for the embolic systems 100, 200, and 300.

[0096] The method of use and operation of the embolization system 500 when performing an embolization procedure to embolize a target tissue area is substantially the same as that of the respective embolization systems 100, 200, and 300, except for the arrangement and function of the first catheter 502 and the second catheter 504. In one method, the second catheter 504 is used like a guide catheter 504 and is inserted into the vascular system as described herein and advanced to a target position near the target tissue area to be embolized. The second catheter 504 is connected to the catheter hub 506 by connecting its proximal end to the second coupling 520 of the catheter hub 506. The first catheter 502 is then inserted into the lumen of the second catheter 504 via the compression joint 524 of the catheter hub 506 and advanced through the lumen of the second catheter 504 to the target position. Alternatively, the first catheter 502 may be inserted first and advanced to the target position and used like a guidewire. Subsequently, with the first catheter 502 in the lumen of the second catheter 504, the second catheter 504 is advanced over the first catheter 502. The proximal end of the second catheter 504 is connected to the second coupling 520 of the catheter hub 506 before or after the second catheter 504 is advanced over the first catheter 502 and reaches the target position. Then, the first joint 510 is connected to the proximal end of the first catheter 502, and the second joint 512 is connected to the first coupling of the catheter hub 506, thereby connecting the embolization system 500 to the first and second catheters 502 and 504.

[0097] Subsequently, the embolization system 500 is operated in manual mode, automatic mode, or any other suitable manner, as described above for each embolization system 100, 200, and 300.

[0098] Various aspects of this disclosure will be described below with reference to the drawings. Note that the drawings are not drawn to scale, and elements having similar structure or function are represented by the same reference numerals throughout the drawings. Also note that the drawings are intended solely to facilitate explanation and are not intended to be an exhaustive description of this disclosure or to limit its scope, and the scope of this disclosure is defined solely by the appended claims and their equivalents. Furthermore, each illustrated aspect does not necessarily have all the features or advantages of the aspects described herein. Features or advantages described in relation to a particular aspect of this disclosure are not necessarily limited to that aspect and may be implemented in conjunction with any other aspect, even if not so illustrated.

Claims

1. A system for discharging embolic particles into a catheter to deliver them into the patient's body in order to embolize a target area, A first dispenser for dispensing an embolic particle mixture containing a mixture of embolic particles and a delivery medium into a catheter, the first dispenser being electronically controllable to automatically control the dispensing of the embolic particle mixture, A second dispenser for dispensing contrast agent into a catheter, the second dispenser being electronically controllable to automatically control the dispensing of the contrast agent, A system comprising a controller operably connected to the first dispenser and the second dispenser, the controller configured to automatically control the first dispenser and the second dispenser in order to controllably dispense an embolic mixture from the first dispenser and controllably dispense a contrast agent from the second dispenser.

2. In the system described in claim 1, A system characterized in that the first dispenser includes a first power injector configured to controllably discharge a pressurized flow of an embolic particle mixture from the first dispenser, and the second dispenser includes a second power injector configured to controllably discharge a pressurized flow of a contrast agent from the second dispenser.

3. In the system described in claim 2, A system characterized in that the first dispenser includes a first power-driven syringe, and the second power-driven injector includes a second power-driven syringe.

4. In the system described in claim 1, The first dispenser includes a first sub-dispenser for discharging embolic particles into the mixer and a second sub-dispenser for discharging a delivery medium into the mixer. The system further comprises a mixer that is in fluid communication with the first sub-dispenser and the second sub-dispenser, wherein the mixer is configured to mix embolic particles and a delivery medium to output an embolic particle mixture.

5. In the system described in claim 4, A system characterized in that the first sub-dispenser includes a first powered injector configured to controllably discharge a pressurized flow of embolic particles into the mixer, the second sub-dispenser includes a second powered injector configured to controllably discharge a pressurized flow of a delivery medium into the mixer, and the second dispenser includes a third motor-driven injector configured to controllably discharge a pressurized flow of contrast agent from the second dispenser.

6. In the system described in claim 1, The system is characterized in that the controller is selectively programmable to control the characteristics of either the discharge of the embolic particle mixture by the first dispenser or the discharge of the contrast agent by the second dispenser.

7. In the system described in claim 6, A system characterized in that the characteristics of the discharge from the first dispenser and the second dispenser are at least one of the following: discharge flow rate, discharge pressure, and discharge volume.

8. In the system described in claim 6, The system further comprises a first sensor operably connected to the controller, configured to detect the attributes of dispensing by at least one of the first dispenser and the second dispenser, and to output a first sensor signal related to the attributes, The system is characterized in that the controller is configured to control dispensing by at least one of the first dispenser and the second dispenser using a feedback control process using the first sensor signal.

9. In the system described in claim 8, The first sensor includes one of a flow sensor, a pressure sensor, a force sensor, a torque sensor, and a current sensor. The attribute of the discharge is one of the injection flow rate and injection pressure of the discharge into the catheter by at least one of the first dispenser and the second dispenser, and the controller controls at least one of the first dispenser and the second dispenser using the feedback control process to achieve predetermined characteristics of the discharge into the catheter. A system characterized in that the predetermined characteristics of discharge into the catheter include one or more of the flow rate, pressure, and concentration of the discharged embolic particle mixture or contrast agent.

10. In the system according to any one of claims 1 to 9, The aforementioned controller A step of discharging an embolic particle mixture at a predetermined flow rate controlled by the controller, A system characterized by being configured to automatically perform a process including the step of intermittently discharging a bolus of contrast agent at a predetermined flow rate controlled by the controller.

11. In the system according to any one of claims 1 to 10, The system further comprises a flow rectifier, the flow rectifier having an inlet connected to the outlet of the manifold and in fluid communication with the outlet of the manifold, and a rectifier outlet, the flow rectifier being configured to adjust the flow pattern of the embolic particle mixture as the embolic particle mixture flows through the flow rectifier to generate a more uniform flow of embolic particles in the delivery medium.

12. In the system according to claim 11, The system is characterized in that the flow rectifier is configured to generate a laminar flow of the embolic particle mixture, and the embolic particles are aligned near the centerline of the flow of the embolic particle mixture at the outlet of the rectifier.

13. In the system according to any one of claims 1 to 12, The system further comprises a manifold that is in fluid communication with both the first dispenser and the second dispenser, wherein the first dispenser and the second dispenser discharge into the manifold, and the manifold has an outlet for discharge from the manifold.

14. In the system according to any one of claims 1 to 13, A first catheter that is in fluid communication with the first dispenser, The present invention further comprises a second catheter that is in fluid communication with the second dispenser, A system characterized in that the first catheter is insertable into the lumen of the second catheter, the first dispenser is configured to dispense an embolic particle mixture into the first catheter, and the second catheter is configured to dispense a contrast agent into an annular channel formed between the first catheter and the second catheter.

15. In the system described in claim 14, To fluidly connect the first dispenser to the first catheter, a first joint is provided for connection to the proximal end of the first catheter, The second dispenser further comprises a second fitting for connecting to a catheter hub in order to fluidly connect the second dispenser to the annular flow path, The catheter hub comprises a first coupling for connection to the second joint, a second coupling for connection to the proximal end of the second catheter, and a compression joint for receiving the first catheter and forming a fluid-tight seal around the first catheter. The system is characterized in that the catheter hub includes a fluid channel that fluidly connects the first coupling to the annular channel.

16. In the system according to any one of claims 1 to 15, The system is characterized in that the embolic particle mixture contains embolic particles at a low concentration in the range of 2.0 to 0.05% by volume.

17. In the system according to any one of claims 1 to 16, The system is characterized in that the controller is configured to be triggered by manual input from a user to activate the second dispenser and dispense the contrast agent.

18. In the system according to any one of claims 1 to 16, The system is characterized in that the controller is configured to automatically start the dispensing of contrast agent by the second dispenser.

19. A method for embolizing a target tissue region within the body, A step of injecting a contrast agent-free embolic particle mixture into a target tissue area via a catheter, wherein the embolic particle mixture comprises a mixture of embolic particles and a delivery medium, and the injection of the embolic particle mixture is automatically controlled by a controller. A method comprising the steps of intermittently injecting a bolus of contrast agent into a target vessel via a catheter in order to monitor the progression of embolization in a target tissue region on a visualization system, wherein the injection of the contrast agent is automatically controlled by the controller.

20. In the method according to claim 19, A method characterized in that the injection of an embolic particle mixture is temporarily suspended while a bolus of contrast agent is injected.

21. In the method according to claim 19 or 20, The method is characterized in that the embolic particle mixture is a pre-mixture of embolic particles and a delivery medium placed in the first dispenser.

22. In the method according to any one of claims 19 to 21, A method characterized in that the embolic particle mixture is dispensed into the catheter by a first dispenser configured to dispense the embolic particle mixture into the catheter, and the contrast agent is dispensed into the catheter by a second dispenser configured to dispense the contrast agent into the catheter.

23. In the method of claim 22, A method characterized in that the first dispenser includes a first power injector configured to controllably discharge a pressurized flow of an embolic particle mixture, and the second dispenser includes a second power injector configured to controllably discharge a pressurized flow of a contrast agent.

24. In the method according to claim 23, A method characterized in that the first dispenser includes a first power-driven syringe, and the second power-driven injector includes a second power-driven syringe.

25. In the method according to claim 19 or 20, The method is characterized in that the first dispenser includes a first sub-dispenser for discharging embolic particles into a mixer and a second sub-dispenser for discharging a delivery medium into the mixer, and the mixer is configured to mix the embolic particles and the delivery medium and output the embolic particle mixture into the catheter.

26. In the method of claim 25, A method characterized in that the second dispenser is configured to dispense a contrast agent into the mixer, and while the second dispenser dispenses the contrast agent into the mixer, the second sub-dispenser dispenses a delivery medium into the mixer to generate a contrast agent mixture.

27. In the method of claim 25, A method characterized in that the first sub-dispenser includes a first powered injector configured to controllably discharge a pressurized flow of embolic particles into the mixer, the second sub-dispenser includes a second powered injector configured to controllably discharge a pressurized flow of a delivery medium into the mixer, and the second dispenser includes a third motor-driven injector configured to controllably discharge a pressurized flow of contrast agent from the second dispenser.

28. In the method according to any one of claims 22 to 27, The method is characterized in that the first dispenser is an automatic controller configured to controllably dispense an embolic particle mixture into the catheter, and the second dispenser is an automatic dispenser configured to controllably dispense a contrast agent into the catheter.

29. In the method of claim 28, The method is characterized in that the controller is triggered by manual input from a user to activate the second dispenser and dispense contrast agent into the catheter.

30. In the method of claim 28, A method characterized in that the controller automatically starts the dispensing of contrast agent by the second dispenser.

31. In the method according to any one of claims 28 to 30, The controller is programmable to control the characteristics of the discharge of the embolic particle mixture by the first dispenser and the discharge of the contrast agent by the second dispenser. A method characterized in that the characteristics of the discharge from the first dispenser and the second dispenser are at least one of the following: discharge flow rate, discharge pressure, and discharge volume.

32. In the method according to claim 31, The controller receives a first sensor signal from a first sensor relating to the attributes of dispensing by the first and second dispensers, The controller further includes the step of controlling the dispensing by the first dispenser and the second dispenser based on the first sensor signal using a feedback control process, A method characterized in that the first sensor includes one of a flow sensor, a pressure sensor, a force sensor, a torque sensor, and a current sensor.

33. In the method according to claim 32, A method characterized in that the attribute of the discharge is one of the injection flow rate and injection pressure of the discharge into the catheter by the first dispenser and the second dispenser, and the controller controls the first dispenser and the second dispenser using the feedback control process to achieve predetermined characteristics of the discharge into the catheter.

34. In the method according to claim 33, A method characterized in that the predetermined characteristics of discharge into the catheter include one or more of the flow rate, pressure, and concentration of the discharged embolic particle mixture or contrast agent.

35. In the method according to any one of claims 19 to 34, The method is characterized in that the embolic particle mixture contains embolic particles at a low concentration in the range of 2.0 to 0.05% by volume.

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