Multifluid delivery system

Abstract

A fluid delivery system is disclosed, comprising at least one first supply station supplying a first fluid and at least one second supply station supplying a second fluid different from the first fluid. The fluid delivery system further comprises a pressurizing unit for pressurizing the first and second fluids, the pressurizing unit comprising first and second pump modules, each pump module comprising a piston with a plunger defining a chamber and first and second variable volume subchambers. The fluid delivery system further comprises first and second inlet fluid circuits, first and second outlet fluid circuits, and a first recirculation fluid path fluidly communicating the first and second variable volume subchambers of the pump modules. A first actuator is further associated with the first recirculation fluid path and governs the passage of fluid bidirectionally between the first and second variable volume subchambers of the pump modules. A method of operating the fluid delivery system is also disclosed.

Description

Technical Field

[0001] The present disclosure relates to the field of fluid delivery. More specifically, the present disclosure relates to a fluid delivery system for delivering two or more fluids under predetermined and desired operating conditions. Even more specifically, the present disclosure relates to an infusion system and method for infusing at least two different medical fluids.

Background Art

[0002] The background of the present disclosure is introduced below along with a discussion of the technology relevant to its context. However, even if this discussion refers to a document, act, artifact, etc., it does not imply or mean that the discussed technology is part of the prior art or common general knowledge in the field related to the present disclosure.

[0003] Delivery systems for administering liquid compositions by injection or infusion are known in the art.

[0004] For example, the injection of fluids into patients is common in several medical procedures. For example, a contrast agent (or contrast medium), either alone or together with a saline solution, can be injected to enhance the contrast of a target (body) feature (e.g., the structure or organ of a human body) inside a patient during a scanning examination. In particular, in imaging applications (where an image representation inside a patient is created by a non-invasive method without using surgical techniques), the use of a contrast agent makes the target feature more prominent. As a result, target features that are otherwise difficult to distinguish from other neighboring features (e.g., surrounding tissue) without the contrast agent are advantageously emphasized. This significantly facilitates the work of clinicians in diagnostic applications, particularly in identifying and / or characterizing lesions and monitoring the progress and response to medical procedures. For example, iodine-based contrast agents (e.g., including iopamidol) are commonly used in computed tomography (CT) applications (e.g., angiography examinations).

[0005] Contrast agents are generally preferably injected into the patient's blood vessels using an automated injection system. The injection system pressurizes the contrast agent and injects it into the patient's vascular system or organs under predetermined injection conditions, such as a predetermined flow rate, volume, and pressure. In this method, the contrast agent can be injected in a controlled, safe, and effective manner.

[0006] Therefore, the infusion system typically includes one or more supply stations for supplying contrast agents and / or saline solutions from corresponding containers (e.g., bottles, bags, or pouches). The infusion system is further equipped with a delivery device (i.e., a combination of piping lines) that fluidly connects at least one supply station to the pressurization unit. The delivery device is located upstream of the pressurization unit and therefore does not have direct contact with the patient, and the risk of cross-contamination is virtually nonexistent or extremely low; therefore, the delivery device is generally a disposable component that is discarded periodically (e.g., every 10 or 12 hours). This means that the delivery device is not replaced when a new patient undergoes the examination and is typically left in place for multiple consecutive infusions (and thus multiple consecutive patients) until the entire predetermined time cycle intended for that delivery device has elapsed.

[0007] Power infusion systems known in the art and currently available on the market can be classified into two main groups: syringe injectors (such as Empower CTA® or Empower CTA®+ manufactured by Bracco Injeneering SA) and syringe-free injectors (such as CT Expres® manufactured by Bracco Injeneering SA).

[0008] Syringe injectors can benefit from syringe / piston technology, ensuring significantly high-pressure fluid injection as well as accuracy and precision of fluid delivery. Nevertheless, syringe injectors have several drawbacks, which mainly relate to the cumbersome procedure of handling syringes (loading and removing syringes from the injector head, filling syringes with the fluid to be injected, priming and purging syringes), the not-so-negligible cost of syringes (i.e., disposable instruments), and cumbersome waste management (i.e., the inevitable disposal of expensive contrast agents remaining in syringes that were not injected into patients and cannot be reused).

[0009] In contrast, syringe-free injectors can benefit from greater efficiency and fewer procedures. This is because the use of bottles / bags (instead of syringes) allows for the delivery of larger volumes of contrast agent to multiple patients, resulting in only one disposable line being discarded for each new patient, significantly reducing contrast agent waste and simplifying waste management. Nevertheless, the primary technology used in syringe-free injectors is the peristaltic pump—whether disposable or reusable—and this technology cannot achieve significantly higher pressures and flow rates compared to syringe injectors (especially with disposable peristaltic pumps). Furthermore, fluctuations in flow rate and / or pressure can occur during operation, which to some extent reduces the accuracy of delivery in the fluid delivery system.

[0010] Recently, certain medical procedures also require power injectors to be able to supply high-load hydraulic performance, particularly in terms of the pressure and flow rate of the fluid injected into the patient.

[0011] For example, it is becoming increasingly common for power injectors to be required to be connected to implantable devices (e.g., PICC & PORT), which are already implanted in the patient's vascular system and used to establish intravascular pathways to the patient.

[0012] A PICC is a peripherally inserted central venous catheter, typically placed in a patient's arm as an extension for intravenous passage, such as for antibiotic therapy or chemotherapy. The PICC is inserted into a peripheral vein (i.e., the cephalic vein, ulnar vein, or brachial vein) and then gradually advances through larger veins toward the heart until the tip of the catheter is stationary at the distal end of the superior vena cava, i.e., at the junction of the superior vena cava and the right atrium, while the proximal end of the PICC remains outside the body. The PICC is typically left in the patient's arm for a period ranging from 6 weeks to 1 year.

[0013] A PORT typically consists of a reservoir (portal) – equipped with a septum for needle insertion – and a catheter that enters the patient's vein from the reservoir. The reservoir is surgically inserted subcutaneously within the upper chest cavity or arm, and the catheter is inserted entirely into a vein, meaning no ends of the catheter are outside the patient's body.

[0014] Therefore, some patients who require imaging examinations (e.g., computed tomography - CT) already have PICCs and ports in appropriate locations for other purposes. Thus, multi-lobe PICCs already in appropriate locations can be advantageously used by healthcare professionals for power infusion of diagnostic and / or therapeutic drugs. However, the presence of the implanted device inevitably imposes a technical constraint on the power infusionr (especially for syringe-free power infusionrs), and even when the implanted device is sandwiched between the infusion system and the patient, the power infusionr is required to generate sufficiently high pressure and flow rate to still ensure the desired and predetermined infusion action.

[0015] WO 2016 / 033351 discloses an infusion system with a double-action infusion pump. The pump includes a cylinder and a reciprocating piston housed inside the cylinder, the reciprocating piston separating the first pump chamber of the cylinder from the second pump chamber. A reciprocating motor is connected to the reciprocating piston, and the first and second pump chambers are alternately filled and emptied by the operation of the reciprocating motor, thereby changing the speed of the reciprocation and supplying a continuous fluid discharge between the first and second pump chambers. A fluid source and a catheter are optionally connected to the double-action infusion pump. The catheter includes one or more infusion ports near the end of the catheter, the one or more infusion ports receiving and ejecting a continuous fluid discharge from the double-action infusion pump.

[0016] DE 10 2011 120 105 discloses a device having a container with an opening, in which a movable piston is arranged. A piston rod is provided in the container to slide the piston. The container is divided into chambers. A resilient sealing element is provided to close the opening of the container. Two inlet ducts are connected to the medium supply line and the chambers, respectively. Two outlet ducts are connected to the medium supply line and the chambers, respectively.

[0017] In technological fields other than medical applications, the ability to deliver compositions specifically and under predetermined conditions may also be required.

[0018] For example, adhesives are required to be delivered only when appropriate operating conditions are guaranteed, such as when a certain degree of homogeneity of the adhesive's components is achieved. Therefore, a dedicated delivery system for applying adhesives in a given environment ensures that the adhesive is delivered only when the desired homogeneity is achieved, resulting in efficient and accurate adhesive function.

[0019] For example, in the process of preparing paint compositions or coating compositions immediately before use, particularly in the automotive, aerospace, and housing equipment industries, it is necessary to ensure the desired homogeneity.

[0020] In further possible applications, the delivery system may be required to initiate the delivery of a given composition only when a threshold for its specific properties is achieved, for example, when a predetermined temperature is reached. As a result, the delivery system ensures that the temperature is effectively achieved and that proper (typically slow) heat distribution occurs within the composition.

[0021] The embodiments described above are not limited to traditional industries (such as pharmaceutical, chemical, automotive, and aerospace) where mixing or shaking steps are required before the final delivery / application step. In fact, cell / biological applications may also require that certain conditions be maintained or achieved before proceeding to subsequent steps. For example, many experiments involving cell culture media use bovine serum, which typically requires regular mixing by careful swirling before use to maintain its natural composition.

[0022] The applicant thus understands the need to advance the hydraulic behavior of fluid delivery systems, and ensures that two or more different (i.e., different) fluids are delivered at sufficient pressure (if necessary) and at sufficient velocity (if necessary), while guaranteeing high accuracy and precision during delivery.

[0023] In specific applications in the medical field, more specifically in the context of the injection or infusion of liquid drugs or diagnostically effective contrast agents into a patient's body (generally into the patient's blood vessels reaching the body part or organ of the patient being treated and / or analyzed, such as through scanning examinations like X-ray, CT, MRI, or ultrasound), the applicant understands the need to advance the hydraulic behavior of power injectors (primarily in terms of the maximum pressure and maximum flow velocity of the injected fluid) and consequently understands the need to ensure that a given injection procedure is not affected by any possible additional medical devices (e.g., PICC & PORT) already implanted in the patient's body to which the power injector needs to be connected.

[0024] Furthermore, the need to improve the hydraulic behavior of power injectors is correlated with the fact that more viscous contrast agents are becoming available on the market, and as viscosity increases in this way, the delivery performance of injectors generally decreases in terms of the maximum pressure and maximum flow velocity of the fluid being injected. To make matters worse, in certain countries, the practice of injecting fluids at room temperature, i.e., without preheating to around body temperature before injection, can sometimes adversely affect the delivery performance, although in fact, such preheating contributes favorably to reducing the viscosity of the contrast agent.

[0025] The applicant also understands the need to improve the performance of fluid delivery systems in order to deliver fluids that meet specific and predetermined fluid properties required for the proper use of the fluid. In other words, the applicant understands the need to supply fluid delivery systems that can satisfy and guarantee the delivery conditions required for the specific fluid to be delivered, and at the same time understands the need to ensure that said delivery systems are accurate, precise, effective, reliable and simple in terms of ease of use and the manufacturing process.

[0026] The applicant also understands the need to improve the delivery performance and accuracy of fluid delivery systems, which are required to deliver at least two different fluids having different characteristics / properties (i.e., contrast agents, salt solutions, and mixtures thereof of different viscosities) continuously and / or alternately. In fact, delivering at least two fluids alternately and continuously requires the step of correspondingly opening and closing different fluid paths through which the fluids flow, a step that may generate bubbles in the fluid paths due to cavitation and may also generate negative or overpressure events, which can adversely affect the flow velocity, for example, in terms of the desired flow velocity provided by the fluid delivery system and / or in terms of ensuring the regularity and continuity of the fluid flow. Furthermore, the step of alternately opening and closing different fluid paths requires that valves or clamps be operated on the high-pressure side of the fluid flow, and this embodiment is an extremely challenging and demanding requirement for the fluid delivery system to function with great accuracy and precision. [Overview of the project]

[0027] A brief summary of this disclosure is provided herein to give a basic understanding of it; however, the sole purpose of this summary is to introduce some of the concepts of this disclosure in a brief manner in preparation for the more detailed explanation below, and not to be construed as identifying or defining its essential elements.

[0028] A fluid delivery system is provided, ensuring that the fluid delivery system delivers at least two different fluids and guaranteeing that each fluid accurately and precisely achieves the desired / predetermined delivery conditions (e.g., in terms of pressure and flow rate). To this end, the applicant has found that a fluid delivery system having at least two pump modules is provided, each pump module processing at least one fluid, and at least one pump module comprising a dedicated recirculation fluid circuit (sometimes also defined in this description as a recirculation fluid path), the recirculation fluid circuit being a circuit for recirculating at least one fluid inside the corresponding pump module, the recirculation being effected when, during operation of the fluid delivery system, it is required that the at least one fluid not be delivered outside the fluid delivery system (i.e., not be discharged from the pump module and thus not be delivered by the fluid delivery system).

[0029] Therefore, one aspect of the present disclosure provides a fluid delivery system comprising: [1] At least one first supply station for supplying a first fluid and at least one second supply station for supplying a second fluid; where the second fluid is different from the first fluid; [2] A pressurization unit for pressurizing the first fluid and the second fluid, comprising: [2-1] A first pump module comprising a first chamber and a first piston received therein; where the first piston has a first plunger, the first plunger cooperating with the inner wall of the first chamber to define first and second volume-variable sub-chambers of the first chamber; and [2-2] A second pump module comprising a second chamber and a second piston received therein; where the second piston has a second plunger, the second plunger cooperating with the inner wall of the second chamber to define first and second volume-variable sub-chambers of the second chamber; [3] To supply the first fluid to the first and second volume-variable sub-chambers of the first chamber, the first inlet fluid circuit is in fluid communication with at least one first supply station and the first pump module, [4] To supply the second fluid to the first and second volume-variable sub-chambers of the second chamber, a second inlet fluid circuit that is in fluid communication with at least one second supply station and the second pump module, [5] A first recirculating fluid circuit that fluidly connects the first and second volume-variable sub-chambers of the first chamber, and [6] A first actuator for controlling the passage of fluid bidirectionally between the first and second volume-variable sub-chambers of the first chamber; Here, the first actuator is part of the first recirculating fluid circuit.

[0030] According to further embodiments of the present disclosure, the applicant finds to provide a fluid delivery system having at least two pump modules in order to provide a fluid delivery system that ensures the fluid delivery system delivers at least two different fluids and that each fluid accurately and precisely achieves desired / predetermined delivery conditions (e.g., in terms of pressure and flow velocity), each pump module handling at least one fluid, each pump module comprising a dedicated recirculation fluid circuit (sometimes also defined in this description as a recirculation fluid path), the recirculation fluid circuit being a circuit for recirculating the at least one fluid within the corresponding pump module, the recirculation being performed when it is required that the at least one fluid not be delivered outside the fluid delivery system (i.e., not discharged from the pump module and ultimately not delivered by the fluid delivery system) during the operation of the fluid delivery system.

[0031] Furthermore, the applicant has also found a method for operating a fluid delivery system, the fluid delivery system being a system for delivering at least a first fluid and a second fluid, the first fluid being different from the second fluid, the method comprising a step of delivering one of the first or second fluids (outside the fluid delivery system), while the other fluid is recirculated inside the fluid delivery system. With this method, the delivering step and the recirculating step are reversed as soon as it is required that the other fluid be delivered out of the fluid delivery system.

[0032] Therefore, a further aspect of this disclosure provides a method for operating a fluid delivery system, The method described above is a method for delivering at least a first fluid and a second fluid; The first fluid differs from the second fluid; The above method involves the following steps: A step of delivering the second fluid to the outside of the fluid delivery system, The step of recirculating the first fluid within the fluid delivery system, and Step of delivering the first fluid to the outside of the fluid delivery system. It is equipped with.

[0033] Another aspect of this disclosure provides a method for operating a fluid delivery system, The method described above is a method for delivering at least a first fluid and a second fluid; Here, the first fluid differs from the second fluid; The above method involves the following steps: A step of delivering the first fluid to the outside of the fluid delivery system, The step of recirculating the second fluid within the fluid delivery system, A step of delivering the second fluid to the outside of the fluid delivery system, and A step of recirculating the first fluid within the fluid delivery system; It is equipped with.

[0034] Another aspect of this disclosure provides a method for operating a fluid delivery system, The fluid delivery system comprises at least one first supply station for supplying a first fluid and at least one second supply station for supplying a second fluid; Here, the second fluid differs from the first fluid; The fluid delivery system further comprises a pressurizing unit having a first pump module and a second pump module; Here, the first and second pump modules each comprise a chamber and a piston that reciprocates within it; Here, the piston has a plunger; Here, the plunger, in cooperation with the inner wall of the chamber, defines the first and second volume-variable sub-chambers; The fluid delivery system further comprises a first (60;260) recirculation fluid path and a first actuator associated therewith for fluidly connecting the first and second volume-variable sub-chambers of the first chamber; The above method involves the following steps: A step of supplying the first fluid from the first supply station to the first and second volume-variable sub-chambers of the first chamber, A step of supplying the second fluid from the second supply station to the first and second volume-variable sub-chambers of the second chamber, A step of moving the respective pistons in the first and second chambers in the axial direction, and A step of operating the first actuator to recirculate the first fluid within the first chamber; It is equipped with.

[0035] According to further embodiments, the applicant has also found a way to operate a fluid delivery system, The method described above is a method for delivering a mixture of a first fluid and a second fluid; Here, the first fluid differs from the second fluid; The above method involves the following steps: a) A step of delivering the first fluid (outside the fluid delivery system), b) Recirculating the first fluid and the second fluid within the fluid delivery system to obtain the mixture thereof; Here, the step of recirculating the first fluid and the second fluid is preferably performed substantially simultaneously with the step of delivering the first fluid; c) A step of delivering the mixture outside the fluid delivery system, and d) Recirculating the first fluid within the fluid delivery system; Here, the step of recirculating the first fluid is preferably performed substantially simultaneously with the step of delivering the mixture; It is equipped with.

[0036] According to another embodiment, the applicant has also found a way to operate a fluid delivery system, The method described above is a method for delivering a mixture of a first fluid and a second fluid; Here, the first fluid differs from the second fluid; The above method involves the following steps: a) A step of delivering the first fluid (outside the fluid delivery system), b) Recirculating the first fluid and the second fluid within the fluid delivery system to obtain the mixture thereof; The step of recirculation is preferably carried out substantially simultaneously with the step of delivering the first fluid; and c) Step of delivering the mixture outside the fluid delivery system. It is equipped with.

[0037] More specifically, one or more aspects of this disclosure are described in an independent claim, their advantageous features are described in a dependent claim, and all expressions of such claims are incorporated herein by reference verbatim (any advantageous feature given by reference to any particular aspect shall apply mutatis mutandis to the other respective aspects).

[0038] The solutions of this disclosure, as well as any further features and benefits, are given in a purely non-restrictive manner and are best understood by referring to the following detailed description, which is read together with the accompanying drawings (hereinafter, for the sake of simplification, corresponding elements are shown by equivalent or similar references, their descriptions are not repeated, and the names of each entity are used to indicate their type or attributes in general, such as value, content, and representation). In this regard, the drawings are not necessarily drawn to scale (some details may be exaggerated and / or simplified), and unless otherwise indicated, the drawings are clearly intended to illustrate the structures and procedures conceptually depicted herein. In detail: [Brief explanation of the drawing]

[0039] [Figure 1] A schematic diagram of a fluid delivery system according to one embodiment of the present disclosure is shown, in which two pump modules are arranged in parallel. [Figure 2] A schematic diagram of another fluid delivery system of this disclosure is shown, in which two pump modules are arranged in series. [Figure 3] A schematic diagram of another configuration of the embodiment shown in Figure 2 is provided. [Figure 4] A schematic diagram of another solution to the embodiment shown in Figure 1 is presented. [Figure 5] A schematic diagram of another solution in the embodiment shown in Figure 2 is presented. [Figure 6] A schematic diagram of another solution in the embodiment shown in Figure 2 is presented. [Figure 7] A schematic diagram of another solution to the embodiment shown in Figure 1 is presented. [Figure 8] A schematic diagram of another solution in the embodiment shown in Figure 2 is presented. [Figure 9-10]Figure 2 shows a schematic diagram of the operating steps of the fluid delivery system. [Figure 11-12] Figure 5 shows a schematic diagram of the operating steps of the fluid delivery system. [Figure 13] A schematic diagram of another solution in the embodiment shown in Figure 7 is provided. [Figure 14] A schematic diagram of yet another solution of the embodiment shown in Figure 7 is provided. [Modes for carrying out the invention]

[0040] Figure 1 shows a schematic diagram of a fluid delivery system 100 according to one embodiment of the present disclosure, in which two pump modules 30, 30' are arranged in parallel. The fluid delivery system 100 is used to deliver a first fluid contained in a first supply station 10 and a second fluid contained in a second supply station 10', where the first fluid and the second fluid are different from each other.

[0041] In the case of a fluid delivery system 100 being an injection system used in the medical field, the first fluid contained in the first supply station 10 and injected into the patient's vascular system may be, for example, a contrast agent, which is administered during scanning examinations, such as CT, MRI, or ultrasound, to enhance the contrast of target (body) features (e.g., structures or organs) within the patient. In particular, in imaging applications (where the image representation of the patient's interior is created in a non-invasive manner without the use of surgical techniques), the use of a contrast agent makes the target features more prominent. As a result, target features that would be less distinguishable from other nearby features (e.g., surrounding tissues) without the contrast agent are advantageously highlighted. This significantly simplifies the work of clinicians in diagnostic applications, particularly facilitating the identification and / or characterization of lesions and monitoring the progress and response to medical procedures. For example, in CT applications, contrast agents may include iodine-based contrast agents containing diatrizoic acid, ioxaglucate, iopamidol, iohexol, ioxiran, iopromide, or iodixanol. An example of a commercial contrast agent containing iopamidol is ISOVUE®, manufactured by Bracco Diagnostics Inc.®.

[0042] According to one embodiment of the present disclosure, a fluid delivery system 100 is configured to deliver an ultrasound contrast agent (USCA) in a continuous infusion / infusion mode and / or as a bolus. In particular, the fluid delivery system 100 is used to deliver a liquid composition, the liquid composition comprising a suspension of fine particles homogeneously dispersed in a liquid carrier, preferably an aqueous liquid carrier, the fine particles comprising an enclosed pure gas or gas mixture containing at least one physiologically acceptable halogenated gas. The halogenated gas is preferably selected from CF4, C2F6, C3F8, C4F8, C4F10, C5F12, C6F14 or SF6. The gas mixture may also comprise gases such as air, oxygen, nitrogen, helium, xenon or carbon dioxide. In some cases, the fine particles (microbubbles or microballoons) comprise a mixture of nitrogen or air with at least one perfluorinated gas in a ratio varying between 1 and 99%. An example of a commercial contrast agent used in contrast-enhanced ultrasound (CEUS) applications is SonoVue® (sulfur hexafluoride microbubbles), manufactured by Bracco Suisse®.

[0043] In the medical field, the second fluid, which is contained in the second supply station 10' and injected into the patient's vascular system, may be a saline solution containing, for example, a physiological or isotonic solution (e.g., sodium chloride). Alternatively, the first fluid and / or the second fluid may be a liquid drug or medicine.

[0044] As already mentioned above, the fluid delivery system 100 of this disclosure can be used for fluid delivery in many technical fields that are not necessarily strictly related to the medical / diagnostic field. For example, the first and second fluids contained in the first and second supply stations 10, 10', respectively, may be two or more components of an adhesive, paint, coating, or substance / formulation for which delivery characteristics (e.g., temperature) need to be properly achieved / controlled.

[0045] The fluid delivery system 100 comprises a pressurizing unit 20, as disclosed in detail below in this description, which operates a first fluid and a second fluid, resulting in each fluid being delivered alternately out of the fluid delivery system (at a predetermined pressure and flow rate, determined in advance by the operator or the control unit of the fluid delivery system based on requirements designed for the use of a particular delivery) and recirculated within the fluid delivery system. The pressurizing unit 20 comprises a first pump module 30, a second pump module 30', and a drive unit M, the drive unit being associated with the two pump modules for its operation / operation. Each pump module 30, 30' comprises a chamber 31, 31', respectively, in which pistons 32, 32' are reciprocated by the drive unit M (i.e., moving back and forth - see double arrows A, A'). According to the embodiment shown in the figure, the chambers 31, 31' are represented as cylinders (e.g., like syringe barrels). However, other different configurations suited to the purpose can be similarly envisioned. Each piston 32, 32' is equipped with a piston rod 33, 33' and a plunger 34, 34', respectively, the plunger being positioned substantially perpendicular to the piston rod, and its radial expansion substantially coincides with the radial expansion of the chamber (i.e., the width of the plunger). Thus, in cooperation with the inner walls of the chambers 31, 31', each plunger 34, 34' defines a first sub-chamber 35, 35' on one side of the plunger (the left side of each plunger in the embodiment of Figure 1) and a second sub-chamber 36, 36' on the opposite side of the plunger (the right side of each plunger in the embodiment of Figure 1). During operation of the fluid delivery system 100, the pistons 32, 32' are moved back and forth (see double arrows A, A'), so that the overall volume of the first 35, 35' and second 36, 36' sub-chambers changes continuously and alternately, making these sub-chambers variable in volume. For example, when pistons 32 and 32' are moved to the right in Figure 1, the volume of the first sub-chambers 35 and 35' increases, while the volume of the second sub-chambers 36 and 36' decreases; conversely, when pistons 32 and 32' are moved to the left in Figure 1, the volume of the second sub-chambers 36 and 36' increases, while the volume of the first sub-chambers 35 and 35' decreases.According to the embodiment shown in Figure 1, the plungers 34, 34' are mounted on the shaft ends of the piston rods 33, 33' (i.e., on the shaft ends opposite to the shaft ends connected to the drive unit M). Alternatively, the plungers 34, 34' may be mounted at other positions along the longitudinal extension of the piston rods 33, 33', provided that both base walls 31a, 31b of the chamber 31 and both base walls 31a', 31b' of the chamber 31' remain sealed, allowing the piston rods 33, 33' to move axially through the base walls (i.e., through the chamber) (an embodiment not shown in the figure).

[0046] The fluid delivery system 100 of this disclosure further comprises a first inlet fluid circuit 40 and a second inlet fluid circuit 40'. In detail, the first inlet fluid circuit 40 is in fluid communication with a first supply station 10 and a first pump module 30, and similarly the second inlet fluid circuit 40' is in fluid communication with a second supply station 10' and a second pump module 30'. The first inlet fluid circuit 40 includes an inlet fluid path that supplies a first fluid (contained in the first supply station 10) to a first variable-volume sub-chamber 35 and a second variable-volume sub-chamber 36, the chambers 31 being filled with an appropriate volume of the first fluid to be delivered outside the fluid delivery system 100 (arrow B). Similarly, the second inlet fluid circuit 40' includes an inlet fluid path that supplies a second fluid (contained in the second supply station 10') to the first variable-volume sub-chamber 35' and the second variable-volume sub-chamber 36', and the chamber 31' is filled with an appropriate volume of the second fluid which is delivered outside the fluid delivery system 100 (arrow B').

[0047] More specifically, the first and second inlet fluid circuits 40, 40' include first inlet fluid paths 41, 41' that fluidize to supply stations 10, 10', and the first inlet fluid paths 41, 41' include supply station valves 11, 11', which allow the respective fluids to be discharged from the supply stations 10, 10'. The supply station valves 11, 11' are active valves operated by the fluid delivery system, which are described in detail below in this description.

[0048] Downstream of the supply station valves 11 and 11', the first and second inlet fluid circuits 40 and 40' branch into the second inlet fluid paths 42 and 42' and the third inlet fluid paths 43 and 43', respectively, which are in fluid communication with the first sub-chambers 35 and 35' and the second sub-chambers 36 and 36'. The first sub-chambers 35 and 35' are equipped with the first inlet ports 44 and 44', which connect the second inlet fluid paths 42 and 42' to the first sub-chambers 35 and 35'. Similarly, the second sub-chambers 36 and 36' are equipped with the second inlet ports 46 and 46', which connect the third inlet fluid paths 43 and 43' to the second sub-chambers 36 and 36'.

[0049] Upstream of the first inlet ports 44, 44', the second inlet fluid paths 42, 42' are equipped with first inlet fluid circuit valves 45, 45', which allow the respective fluids (i.e., the first fluid from the first supply station 10 and the second fluid from the second supply station 10') to flow through the second inlet fluid paths 42, 42' to the first sub-chambers 35, 35'. According to embodiments of this disclosure, the first inlet fluid circuit valves 45, 45' are check valves, i.e., one-way valves, which allow the fluid to flow through the valves in only one direction, specifically from the supply stations 10, 10' to the first sub-chambers 35, 35', and prevent the fluid from flowing back into the supply stations 10, 10'.

[0050] Similarly, upstream of the second inlet ports 46, 46', the third inlet fluid pathways 43, 43' are equipped with second inlet fluid circuit valves 47, 47', which allow the respective fluids (i.e., the first fluid from the first supply station 10 and the second fluid from the second supply station 10') to flow through the third inlet fluid pathways 43, 43' to the second sub-chambers 36, 36'. According to embodiments of this disclosure, the second inlet fluid circuit valves 47, 47' are check valves, i.e., one-way valves, which prevent backflow and allow the fluid to flow through the valves in only one direction, specifically from the supply stations 10, 10' to the second sub-chambers 36, 36', and prevent backflow of fluid to the supply stations 10, 10'.

[0051] Preferably, the inlet fluid circuit valves at the first 45, 45' and the second 47, 47' are ball check valves, in which a ball is located inside the valve body to control the fluid flow.

[0052] The fluid delivery system 100 of this disclosure further comprises a first outlet fluid circuit 50 (separated from the first inlet fluid circuit 40) and a second outlet fluid circuit 50' (separated from the second inlet fluid circuit 40'). In detail, the first outlet fluid circuit 50 is in fluid communication with the first pump module 30, and similarly, the second outlet fluid circuit 50' is in fluid communication with the second pump module 30'. Both the first and second outlet fluid circuits 50, 50' are provided with first outlet fluid paths 51, 51' and second outlet fluid paths 52, 52', allowing the fluid delivery system 100 to discharge the first fluid from chamber 31 (see arrow B) and the second fluid from chamber 31' (see arrow B'). In detail, the first sub-chambers 35, 35' are provided with first outlet ports 53, 53', and the first outlet fluid paths 51, 51' are in fluid communication with the first sub-chambers 35, 35'. Similarly, the second sub-chambers 36, 36' are equipped with second outlet ports 54, 54', and second outlet fluid paths 52, 52' are fluid-connected to the second sub-chambers 36, 36'. As will be described in detail below in this disclosure, during operation, the first 51, 51' and second 52, 52' outlet fluid paths of the outlet fluid circuits 50, 50' discharge a first fluid from either the first sub-chamber 35 or the second sub-chamber 36, and similarly discharge a second fluid from either the first sub-chamber 35' or the second sub-chamber 36'.

[0053] Downstream of the first outlet ports 53, 53', the first outlet fluid paths 51, 51' are equipped with first outlet fluid circuit valves 55, 55', which discharge the first and second fluids from the first sub-chambers 35, 35' through the first outlet fluid paths 51, 51' and from the second sub-chambers 36, 36' through the second outlet fluid paths 52, 52'. According to embodiments of the present disclosure, the first outlet fluid circuit valves 55, 55' are check valves, i.e., one-way valves, which prevent backflow and allow fluid to flow through the valves in only one direction, specifically from the first sub-chambers 35, 35' and prevent fluid from flowing back into the first sub-chambers 35, 35'.

[0054] Similarly, downstream of the second outlet ports 54, 54', the second outlet fluid paths 52, 52' are equipped with second outlet fluid circuit valves 56, 56', which discharge the first and second fluids from the second sub-chambers 36, 36' through the second outlet fluid paths 52, 52'. According to embodiments of the present disclosure, the second outlet fluid circuit valves 56, 56' are check valves, i.e., one-way valves, which allow fluid to flow through the valves in only one direction, specifically from the second sub-chambers 36, 36', and the valves prevent fluid from flowing back into the second sub-chambers 36, 36'.

[0055] Preferably, the first 55, 55' and second 56, 56' outlet fluid circuit valves are spring-loaded check valves, in which the spring component is used to assist the operation of the valve by eliminating the effect of gravity on the function of the check valve. Even more preferably, the first 55, 55' and second 56, 56' outlet fluid circuit valves are spring-loaded ball check valves.

[0056] According to the embodiment shown in Figure 1, the fluid delivery system 100 of the present disclosure further comprises a first recirculating fluid circuit 60 and a second recirculating fluid circuit 60', the recirculating fluid circuit also referred to in this description as an additional fluid circuit (i.e., an additional fluid circuit with respect to the inlet and outlet fluid circuits mentioned above). In detail, the first recirculating fluid circuit 60 fluidly connects the first and second volume-variable sub-chambers 35, 36 of the chamber 31 of the first pump module 30, the first recirculating fluid circuit 60 cooperates with a first actuator 70 (owned by the first recirculating fluid circuit 60), the actuator is for controlling the bidirectional passage of the first fluid between the first and second volume-variable sub-chambers 35, 36. Similarly, the second recirculating fluid circuit 60' fluidly connects the first and second volume-variable sub-chambers 35', 36' of the chamber 31' of the second pump module 30', and the second recirculating fluid circuit 60' cooperates with a second actuator 70' (owned by the second recirculating fluid circuit 60'), which is an actuator for controlling the bidirectional passage of the second fluid between the first and second volume-variable sub-chambers 35', 36'.

[0057] According to the embodiment shown in Figure 1, the first and second recirculating fluid circuits 60, 60' are located outside the chambers 31, 31', and the distant branches of the first and second inlet fluid circuits 40, 40' are fluidically connected upstream of the inlet ports 44, 44' and 46, 46' of the respective sub-chambers 35, 35' and 36, 36'. In detail, with respect to the first pump module 30, the first shaft end 61 of the first recirculating fluid circuit 60 is fluidically connected to the second inlet fluid path 42 of the first inlet fluid circuit 40 downstream of the first inlet fluid circuit valve 45, while the second shaft end 62 of the first recirculating fluid circuit 60 is fluidically connected to the third inlet fluid path 43 of the first inlet fluid circuit 40 downstream of the second inlet fluid circuit valve 47. Similarly, with respect to the second pump module 30', the first shaft end 61' of the second recirculating fluid circuit 60' is fluidically connected to the second inlet fluid path 42' of the second inlet fluid circuit 40' downstream of the first inlet fluid circuit valve 45', while the second shaft end 62' of the second recirculating fluid circuit 60' is fluidically connected to the third inlet fluid path 43' of the second inlet fluid circuit 40' downstream of the second inlet fluid circuit valve 47'.

[0058] The first and second actuators 70, 70' are active valves operated by the fluid delivery system 100, which will be described in detail below. Preferably, the first and second actuators 70, 70' are electromechanically driven valves that are automatically controlled and operated by the processor, i.e., control unit P, of the fluid delivery system 100. As schematically shown in the figure, the processor P controls and operates the first and second actuators 70, 70', the drive unit M, and the first and second supply station valves 11, 11'.

[0059] According to another embodiment shown in Figure 2, the fluid delivery system 100' has the two pump modules 30, 30' arranged in series, as schematically shown, rather than in parallel as shown in the embodiment of Figure 1. In this other embodiment, the two chambers 31, 31' are separated and spaced apart from each other, while a common piston rod 33 having two spaced-apart plungers 34, 34' is provided within the chambers 31, 31', thereby defining the first 35, 35' and second 36, 36' volume-variable sub-chambers, respectively. All remaining components of the other embodiment (as well as their function) are the same as the respective components of the fluid delivery system 100 shown in Figure 1, and are therefore indicated by the same reference numerals.

[0060] Another configuration relative to the embodiment in Figure 2 is schematically shown in Figure 3, in which the fluid delivery system 100'' comprises two parallel-arranged pump modules 30, 30' (similar to the embodiment in Figure 2), but the two chambers 31, 31' share a common base wall 31c. More specifically, the two chambers 31, 31' are arranged continuously along a common longitudinal axis and are adjacent to each other through the common base wall 31c. According to this embodiment, a common piston rod 33 having two spaced-apart plungers 34, 34' is provided in the chambers 31, 31', thereby defining the first 35, 35' and second 36, 36' volume-variable sub-chambers, respectively. All remaining components of this alternative embodiment (as well as their function) are the same as the respective components of the fluid delivery system 100' shown in Figure 2, and are therefore indicated by the same reference numerals.

[0061] According to another embodiment shown in Figure 4, the fluid delivery system 200 includes, for each of its pump modules 30, 30', recirculating fluid circuits 260, 260' and actuators 270, 270' located inside the respective chambers 31, 31'. In particular, the recirculating fluid circuits 260, 260' and actuators 270, 270' are integrated with the plungers 34, 34' of the pistons 32, 32', i.e., the recirculating fluid circuits and actuators are integrated inside the plunger components. More specifically, the recirculating fluid circuits 260, 260' provide fluid passages obtained inside the thickness of the plunger, ensuring fluid communication between the sub-chambers 35, 36 and 35', 36', respectively. In other words, the recirculating fluid circuits 260, 260' are ducts (through-holes) provided within the plunger, and the diameter (radial expansion) of the duct is significantly smaller than the expansion (length) of the plunger. According to the alternative embodiment shown in Figure 4, the actuators 270, 270' are located inside the recirculating fluid circuits 260, 260' and are automatically controlled and operated by the processor P of the fluid delivery system 200. Furthermore, all remaining components of this alternative embodiment (as well as their functions) are the same as the components of the fluid delivery system 100 shown in Figure 1, and are therefore indicated by the same reference numerals.

[0062] According to another embodiment shown in Figure 5, the fluid delivery system 200' combines the main technical features of the fluid delivery system 100' shown in Figure 2 with the main technical features of the fluid delivery system 200 shown in Figure 4. In detail, the fluid delivery system 200' comprises two pump modules 30, 30' arranged in series (each having spaced-apart chambers 31, 31'), and each pump module 30, 30' comprises a recirculating fluid circuit 260, 260' and actuators 270, 270', which are located inside the respective chambers 31, 31'. The configuration shown in Figure 5 can also be applied to a fluid delivery system (not shown) that combines the main technical features of the fluid delivery system 100'' shown in Figure 3 (where the two chambers 31, 31' are arranged continuously along a common longitudinal axis and adjacent to each other through a common base wall 31c) with the main technical features of the fluid delivery system 200 in Figure 5.

[0063] According to another embodiment shown in Figure 6, the first outlet fluid circuit 50 and the second outlet fluid circuit 50' of the fluid delivery system 300 have a common output for delivering the first fluid (leaving from the first pump module 30) and the second fluid (leaving from the second pump module 30') (see arrow B''). This technical solution is particularly advantageous when it is required that the first and second fluids be mixed immediately before delivery (for example, when the first and second fluids are components of a given adhesive or coating agent, and they must not be mixed beforehand, but should be mixed immediately before delivery, and in combination therewith). All remaining components of this alternative embodiment (as well as their function) are the same as the respective components of the fluid delivery system 100' shown in Figure 2, and are therefore indicated by the same reference numerals.

[0064] According to another embodiment shown in Figure 7, the pressurizing unit 20 of the fluid delivery system 400 comprises two separate drive units M and M', and each pump module 30, 30' is operated by its own dedicated drive unit (i.e., drive unit M acts on the piston 32 of the first pump module 30, and drive unit M' acts on the piston 32' of the second pump module 30'). The operation of the fluid delivery system according to this embodiment is particularly efficient in terms of controlling the fluid flow and as well as precisely delivering the desired volume of fluid. In fact, a fluid delivery system with a single drive unit needs to discharge the changing volume of the sub-chambers in the two chambers 31, 31' at the same flow velocity. In some applications, this configuration is difficult to control and manage, for example, when it is desired to mix two fluids (a first fluid processed by a first pump module 30 and a second fluid processed by a second pump module 30', the first fluid being different from the second fluid), and this is particularly difficult when a mixing ratio other than 50 / 50% (i.e., 50% of the first fluid and 50% of the second fluid) is required. For example, if it is required that the fluid be delivered by the fluid delivery system 400 at a mixing ratio of 30 / 70% (i.e., a mixture of 30% of the first fluid and 70% of the second fluid), the actuators 70, 70' of the first and second recirculating fluid circuits 60, 60' can be closed, and the speeds of the pistons 32, 32' can be set to different values ​​from each other in order to properly achieve the desired 30 / 70% mixing ratio (this is actually possible because each piston is operated independently by a separate, independent drive unit). It can be emphasized that even in embodiments of the fluid delivery system comprising two separate drive units, it is particularly advantageous to provide each of the two pump modules with its own recirculation fluid circuit, because the circuit ensures that each single fluid is properly and continuously recirculated within its respective pump module (i.e., the first fluid is continuously recirculated within the first pump module 30, and the second fluid is continuously recirculated within the second pump module 30'), and the predetermined recirculation contributes to keeping the fluid before delivery (i.e., each single fluid) moving, and thus continuing to be mixed and shaken.

[0065] According to another embodiment shown in Figure 8, the fluid delivery system 500 includes a first additional supply station 510 that is in fluid communication with the first pump module 30. Similarly, compared to the embodiment shown in Figure 2, the first inlet fluid circuit 40 includes an additional first inlet fluid path 541 that fluidly connects the first additional supply station 510 to a second inlet fluid path 42 of the first inlet fluid circuit 40. Furthermore, the additional first inlet fluid path 541 includes an additional supply station valve 511 that allows fluid to be discharged from the first additional supply station 510. The additional supply station valve 511 is an active valve operated by the fluid delivery system 500, which will be described in detail below.

[0066] In a further embodiment (not shown in the figure), the fluid delivery system 500 comprises a second additional supply station that is in fluid communication with a second pump module 30'.

[0067] In further embodiments (not shown in the figures), a first additional supply station 510 in fluid communication with the first pump module 30 and / or a second additional supply station in fluid communication with the second pump module 30' may be provided in any of the disclosed embodiments of the fluid delivery system according to this disclosure (e.g., fluid delivery system 100 in Figure 1, fluid delivery system 100'' in Figure 3, fluid delivery system 200 in Figure 4, fluid delivery system 200' in Figure 5, and fluid delivery system 300 in Figure 6).

[0068] In the first embodiment, an additional supply station fluidically connected to a given pump module contains the same fluid as that stored in the supply station of the pump module. Therefore, it is envisioned that this additional supply station may be equipped with a fluid source to provide the fluid delivery system with a backup solution in case the supply station fails, or to increase the autonomy of the fluid delivery system, as well as to ensure the continuity of fluid delivery when the supply station runs out of fluid.

[0069] In a second embodiment, an additional supply station, fluidically connected to a given pump module, contains a fluid different from the fluid contained in the supply station of the pump module. For example, the fluid contained in the supply station is a high-concentration contrast agent (e.g., ISOVUE®-370), while the fluid contained in the additional supply station is a saline solution. This solution is particularly advantageous because, by appropriately mixing the high-concentration contrast agent with the saline solution, the fluid delivery system can deliver large quantities of contrast agents at different concentrations starting from a single type of high-concentration contrast agent. The mixing step to ensure that the delivered contrast agent reaches a desired concentration for a given patient and / or for a given medical (diagnostic or therapeutic) application is described in detail below.

[0070] The operation of the delivery system according to this disclosure will be described below with respect to some of the embodiments described above, and with respect to applications related to the medical field, more specifically to applications related to the alternating or simultaneous injection of contrast agents and saline solutions for diagnostic purposes. However, as already mentioned above in this disclosure, the delivery system according to this disclosure may also be used in other areas of technology unrelated to medical / healthcare applications. Furthermore, the general operating principles—described below with respect to some embodiments of the delivery system according to this disclosure—are applicable to the majority of embodiments shown in the figures disclosed and / or related to this disclosure.

[0071] As a first example of how to operate the delivery system according to this disclosure, see Figures 9 and 10, which use the delivery system 100' according to the embodiment shown in Figure 2 as an example.

[0072] Supply station 10 contains a first fluid (not shown), such as a contrast agent, which is required to be injected into the patient by delivery system 100' (see arrow B), while supply station 10' contains a second fluid (not shown), such as a saline solution, which is required to be injected into the patient by delivery system 100' (see arrow B'). Typically, the first fluid exiting to B and the second fluid exiting to B' are transported to the patient through a common tube (patient line – not shown), which is mechanically and fluidly connected to a catheter and / or needle leading into the patient's vascular system.

[0073] As an initial initiation step, the delivery method according to this disclosure comprises the steps of filling the first and second sub-chambers 35, 36 of the first pump module 30 with the first fluid, and similarly filling the first and second sub-chambers 35', 36' of the second pump module 30' with the second fluid. To perform the filling step, the processor P opens the supply station valves 11, 11', closes the actuators 70, 70' of the first and second recirculation fluid circuits 60, 60', and acts on a drive unit M to reciprocate a common piston 32 inside the chambers 31, 31', thereby allowing the first and second fluids to exit the supply stations 10, 10', respectively, and flow through the first inlet fluid circuit 40 and the second inlet fluid circuit 40'. In detail, as soon as the piston 32 moves axially in the first direction (e.g., arrow C in Figure 9), the axial movement of the piston increases the volume of the first sub-chamber (e.g., sub-chambers 35, 35') and creates negative pressure within it. Therefore, each fluid can flow through the first 41, 41' and second 42, 42' inlet fluid paths of the first and second inlet fluid circuits 40, 40', that is, through the corresponding first inlet fluid circuit valves (e.g., first inlet fluid circuit valves 45, 45'), so that the fluid enters and fills the first sub-chamber. At the same time, the air contained inside the second sub-chamber (e.g., sub-chambers 36, 36') is primed away from the fluid delivery system through the venting means of the second inlet fluid circuit valve on the opposite side (e.g., second inlet fluid circuit valves 47, 47') as the volume of the sub-chamber decreases due to the axial movement of the piston (arrow C). In fact, the air contained in the first sub-chambers 35, 35' is generally forced out of the sub-chamber through the first inlet port 44, 44', then through the second inlet fluid paths 42, 42', and finally through the first inlet fluid circuit valves 45, 45'.Next, in order to fill the second sub-chamber with the respective fluids and prime the first sub-chamber (i.e., expel air from it), the processor P operates the drive unit M to reverse the movement of the piston, so that the piston moves axially in the second direction opposite to the first direction (e.g., arrow D in Figure 10). During the filling and priming steps, while the piston is moving, the actuators 70, 70' maintain their closure, so the axial movement of the piston (arrow D) increases the volume of the second sub-chamber (e.g., sub-chambers 36, 36') and creates negative pressure within it. Thus the first and second fluids can flow through the first 41, 41' and third 43, 43' inlet fluid paths of the first and second inlet fluid circuits 40, 40', respectively, that is, through the corresponding second inlet fluid circuit valves (e.g., second fluid circuit valves 47, 47'), and so the fluids enter and fill the second sub-chamber. Simultaneously, the air still contained within the first sub-chamber (e.g., sub-chambers 35, 35') is primed from the fluid delivery system through the venting means of the corresponding first inlet fluid circuit valve (e.g., first inlet fluid circuit valves 45, 45') as the volume of the sub-chamber decreases due to the axial movement of the piston (arrow D). In fact, the air contained within the second sub-chambers 36, 36' is generally forced out of the sub-chamber through the second inlet ports 46, 46', then through the third inlet fluid path 43, 43', and finally through the second inlet fluid circuit valves 47, 47'. During the priming step, some amounts of the first and second fluids are released from the fluid delivery system through the first 50 and second 50' outlet fluid circuits, allowing for proper priming of the first 50 and second 50' outlet fluid circuits as well.

[0074] Alternatively, air priming of the fluid delivery system is performed by a dedicated venting means (not shown in the figure) separate from the fluid circuit valves. According to another embodiment, the dedicated venting means is associated with each valve of the fluid delivery system. According to yet another embodiment, the dedicated venting means is associated with the actuators 70, 70' of the first and second recirculating fluid circuits 60, 60'.

[0075] As soon as chambers 31 and 31' are filled with the first and second fluids respectively and the priming of the fluid delivery system is complete, processor P closes the supply station valves 11 and 11' and opens the actuators 70 and 70' of the first and second recirculating fluid circuits 60 and 60', while the drive unit M remains operating, thereby continuing to move the piston 32 axially within chambers 31 and 31' (arrows C and D). Alternatively, processor P opens the actuators 70 and 70' of the first and second recirculating fluid circuits 60 and 60', while maintaining the supply station valves 11 and 11' in an open working state while the two fluids are being recirculated within their respective chambers 31 and 31'.

[0076] By maintaining the actuators 70, 70' of the first and second recirculating fluid circuits 60, 60' in an open working state, the fluid delivery system 100' is prevented from delivering the first and second fluids to its outside. In fact, thanks to the open working state of actuators 70, 70' and the axial movement of piston 32, the first fluid is continuously recirculated in the first chamber 31 through the first recirculating fluid circuit 60, while the second fluid is continuously recirculated in the second chamber 31' through the second recirculating fluid circuit 60'. In detail, when piston 32 moves in the first direction (for example, arrow C in Figure 9), the first fluid contained in the second sub-chamber 36 is pushed out through its second inlet port 46 and then enters the first sub-chamber 35 at the first inlet port 44 through the first recirculating fluid circuit 60 and the first actuator 70. At the same time, the second fluid contained in the second sub-chamber 36' is pushed out through its second inlet port 46', and then enters the first sub-chamber 35' through the first inlet port 44' via the second recirculation fluid circuit 60' and the second actuator 70'.

[0077] Subsequently, when the piston 32 reaches its first end, i.e., when the plunger 34 completes its axial movement in the first direction (rightward in Figure 9 - see arrow C) and reaches the vicinity of the base wall 31a of the chamber 31, and at the same time the plunger 34' reaches the vicinity of the base wall 31a' of the chamber 31', the processor P acts the drive unit M to reverse the axial movement of the piston (leftward in Figure 10 - see arrow D). Similar to the first stroke of the piston described above, the first fluid contained in the first sub-chamber 35 is pushed out through its first inlet port 44 and then enters the second sub-chamber 36 at the second inlet port 46 through the first recirculation fluid circuit 60 and the first actuator 70. At the same time, the second fluid contained in the first sub-chamber 35' is pushed out through its first inlet port 44' and then enters the second sub-chamber 36' at the second inlet port 46' through the second recirculation fluid circuit 60' and the second actuator 70'.

[0078] Then, as soon as the piston 32 reaches its second end, i.e., the plungers 34, 34' complete their axial movement in the second direction (leftward in Figure 10 - see arrow D) and reach the vicinity of the base walls 31b, 31b' of the respective chambers 31, 31' (resulting in the first sub-chambers 35, 35' containing substantially less volume of fluid each, while the second sub-chambers 36, 36' contain larger volume of fluid each), the processor P acts the drive unit M to reverse the axial movement of the piston again (rightward in Figure 9 - see arrow C), thereby starting a new filling / discharging cycle for the chambers 31, 31' of the fluid delivery system 100'. Of course, any number of cycles can be prepared according to the requirements of the specific fluid to be delivered and the requirements of the specific application in which the fluid delivery system is implemented. As already mentioned above, the first recirculation step, which recirculates the two fluids within each chamber, is particularly advantageous because it allows the two fluids to continue moving within the fluid delivery system, thereby ensuring proper and homogeneous shaking of each individual fluid before delivery.

[0079] It must be noted that the fluid contained in the second sub-chambers 36, 36' and pushed out by the plungers 34, 34' cannot flow back into the supply stations 10, 10', nor can it pass through the second outlet fluid paths 52, 52' of the first and second outlet fluid circuits 50, 50'. In fact, it is desirable that the supply station valves 11, 11' be closed, and furthermore, both the first 45, 45' and second 47, 47' inlet fluid circuit valves are one-way valves, allowing fluid to flow from the supply stations 10, 10' to their respective chambers 31, 31', but not the other way around, thereby preventing the fluid released from the first 35, 35' and second 36, 36' sub-chambers from flowing back through the first 41, 41' and second 42, 42' inlet fluid paths of the first and second inlet fluid circuits 40, 40'. Furthermore, the first 55, 55' and second 56, 56' outlet fluid circuit valves open automatically only when the fluid discharged from the first 35, 35' and second 36, 36' sub-chambers is at a sufficiently high pressure to overcome the internal elasticity of the valves (preferably the first and second outlet fluid circuit valves are spring-loaded ball check valves). Therefore, when the actuators 70, 70' are open, the fluid discharged from the first 35, 35' and second 36, 36' sub-chambers does not have enough force to overcome the internal elasticity of the first 55, 55' and second 56, 56' outlet fluid circuit valves, and thus the fluid is not delivered to the outside of the fluid delivery system 100' but is recirculated within each sub-chamber.

[0080] As is evident from the above, the fluid delivery system of the present disclosure enables the continuous and predetermined movement (e.g., in terms of volume, piston movement speed) of one or both fluids before they leave the fluid delivery system. As already stated above, this aspect of the present disclosure is particularly advantageous when certain properties of a fluid (e.g., homogeneity of composition, temperature, viscosity, mixing, fluidity) are required to be achieved and / or maintained before fluid delivery begins. In fact, the fluid delivery system according to the present disclosure enables the fluid introduced into the first 31 and second 31' chambers to be continuously recirculated by alternating filling and releasing between the first 35, 35' and second 36, 36' sub-chambers when the fluid delivery system 100' is not delivering, i.e., when no fluid is leaving the fluid delivery system. Thanks to the recirculation fluid circuits of the first 60 and second 60' and the associated actuators of the first 70 and second 70', the recirculation and redistribution of the fluid between the two sub-chambers contributes to balancing the pressure within them. This embodiment is particularly advantageous because it allows the system to be operated under limited (low) pressure, at least in the initial stages before the delivery system has delivered fluid out of the system, thereby limiting the technical constraints required for implementation if the system is required to be operated under high pressure.

[0081] As soon as recirculation is complete (for example, when the desired homogeneity of one or both fluids is successfully achieved and at some point it is required that the delivery of the first and / or second fluids be initiated), processor P causes the first or second actuator 70, 70' to act appropriately to close it and to stop the step of recirculating at least one of the first and second fluids.

[0082] For example, if it is requested that a first fluid contained within the supply station 10 be delivered first, the processor P closes the first actuator 70 of the first recirculating fluid circuit 60, while the second actuator 70' of the second recirculating fluid circuit 60' remains open, resulting in the delivery of the first fluid (arrow B) while the second fluid continues to recirculate within its respective chamber 31'. This is, for example, the case where, at a predetermined time in an infusion / infusion process performed on a given patient undergoing an examination procedure (e.g., a CT diagnostic examination), the fluid delivery system 100' is requested to deliver only the first fluid (e.g., contrast agent) contained within the supply station 10, while the recirculation of the second fluid (e.g., a saline solution) is taking place (i.e., the second fluid is not delivered out of the fluid delivery system at that moment).

[0083] Therefore, the delivery method according to this disclosure comprises the step of initiating the delivery of the first fluid contained in the first chamber 31 (i.e., delivery to the outside of the fluid delivery system). To perform the above step, as described above, the processor P closes the first actuator 70 of the first recirculating fluid circuit 60 and opens the first supply station valve 11. The first supply station valve 11 remains open during the delivery of the first fluid (the fluid leaving the fluid delivery system—see arrow B). This is important because refilling the sub-chambers 35, 36 of the first chamber 31 with fresh first fluid is crucial to avoid fluid perturbations that could disrupt the precise function of the piston and, consequently, the precise function of the entire fluid delivery system. By closing the first actuator 70, the first fluid is prevented from flowing through the first recirculation fluid circuit 60 (while, as already mentioned above, the first and second inlet fluid circuit valves 45 and 47 prevent the first fluid from flowing back into the first supply station 10). By pushing the first plunger 34 in the first direction (arrow C in Figure 9) and then in the second opposite direction (arrow D in Figure 10), the first fluid is able to exit the second outlet port 54 and the first outlet port 53 of the first chamber 31, respectively. Therefore, when the first fluid is pushed to pass through the second outlet port 54 (arrow C), the first fluid flows into the second outlet fluid path 52 of the first outlet fluid circuit 50 and then through the second outlet fluid circuit valve 56. This is because, at this stage of the procedure, the first actuator 70 is closed, and the fluid pressure is sufficiently high to overcome the internal elasticity of the second outlet fluid circuit valve 56. Similarly, when the first fluid is pushed to pass through the first outlet port 53 (arrow D), the first fluid flows into the first outlet fluid path 51 of the first outlet fluid circuit 50 and then through the first outlet fluid circuit valve 55. This is because, at this stage of the procedure, the first actuator 70 is closed, and the fluid pressure is high enough to overcome the internal elasticity of the first outlet fluid circuit valve 55. As a result, the first fluid is finally delivered by successively releasing fluid from the first and second sub-chambers 35, 36 of the first chamber 31 (arrow B).In fact, since the first and second outlet fluid circuit valves 55 and 56 are one-way valves, the first fluid cannot flow back through the pressurized path and is thus forcibly delivered (arrow B).

[0084] It can be noted that the delivery method according to this disclosure does not necessarily require the sub-chambers 35, 36 to be completely filled with the first fluid, or that the sub-chambers to be completely discharged of the first fluid. In other words, it is not necessary for the first plunger 34 to reach the base walls 31a, 31b of the first chamber 31 during the forward and backward axial movement. This means that the delivery method according to this disclosure may include a step of partially filling / discharging the first fluid into / from each sub-chamber of the first chamber, especially when a limited (typically small) volume of the first fluid is required to be delivered in a single pass (i.e., the first plunger moves in a single translation without backward movement). Of course, this embodiment described above can also be applied to the sub-chambers 35', 36' of the second chamber 31'.

[0085] As mentioned above, during the step of delivering the first fluid (arrow B), the first supply station valve 11 remains open so that the new first fluid can alternately enter the two sub-chambers of the first chamber, and no undesirable perturbation effects occur while the piston moves axially within the first chamber 31. It should be noted that the new first fluid entering the system during the delivery step does not pass through the first actuator 70 and the first recirculation fluid circuit 60, and therefore the new first fluid is not delivered directly. In fact, the new first fluid enters the sub-chamber, which is under-pressurized, while the first fluid delivered by the system is the fluid that was contained in the pressurized sub-chamber. Therefore, before delivery, the new first fluid is continuously moving and mixing within each sub-chamber thanks to the axial movement of the piston, thereby ensuring that the desired delivery conditions are achieved before it finally leaves the system.

[0086] As already mentioned above, the applicant has found that recirculation of the first fluid within the first chamber 31 by flowing the first fluid through the first recirculation fluid circuit 60 and the first actuator 70 associated therewith significantly reduces or even completely eliminates the risk of pressure pulsation when the first fluid is being delivered, particularly at the start of the fluid delivery procedure. In fact, the fluid delivery system according to the present disclosure can adequately control the pressure drop or pressure spike that occurs when the piston 32 begins to move, thanks to the presence of the first recirculation fluid circuit 60 and the first actuator 70. In fact, according to the present disclosure, the fluid delivery system begins delivery of the first fluid (outside the fluid delivery system—arrow B) when recirculation of the first fluid within the first chamber 31 has already begun, and therefore delivery begins when the piston is already moving within the first chamber 31. What this obviously means is that the start of fluid delivery is not simultaneous with the start of piston movement, because the delivery of the first fluid begins when the piston is already moving axially within the first chamber 31 so that the step of recirculation of the first fluid can be carried out.

[0087] Furthermore, as already mentioned above, the applicant also found that recirculation of the first fluid within the first chamber 31 by flowing the first fluid through the first recirculating fluid circuit 60 and the associated first actuator 70 significantly reduces or even eliminates the delay time of the fluid delivery system. The delay time is the technical time that the fluid delivery system inevitably requires to prepare for fluid delivery. In fact, as soon as the processor P instructs the drive unit M to supply current, the current typically increases the electromagnetic field, which activates the rotor magnets that generate torque on the gears, thereby causing the piston to begin moving. When the piston begins to move, the fluid pressure begins to rise and requires even more time to reach and overcome the pressure thresholds set in the first and second outlet fluid circuit valves 55, 56. The sum of all these times is called the "delay time," which is so significant that it inevitably causes a delay in the delivery of fluid out of the fluid delivery system. Thanks to the presence of the first recirculating fluid circuit 60 and the associated first actuator 70, the fluid delivery system 100' of the present disclosure is able to overcome or reduce the delay time because the piston 32 begins moving well in advance of fluid delivery to recirculate the first fluid within the first chamber 31. Therefore, as soon as the processor P closes the first actuator 70 to initiate the delivery of the first fluid (arrow B), the fluid pressure rises rapidly and quickly overcomes the pressure thresholds set in the first and second outlet fluid circuit valves 55, 56. As a result, the system delivers the first fluid immediately after the processor P commands the start of delivery.

[0088] Immediately upon request to terminate the delivery of the first fluid (e.g., contrast agent) contained in the first supply station 10 and to begin the delivery of the second fluid (e.g., saline solution) contained in the second supply station 10', the processor P opens the first actuator 70 of the first recirculating fluid circuit 60 and closes the second actuator 70' of the second recirculating fluid circuit 60', thereby enabling the delivery of the second fluid (arrow B'), while the first fluid is recirculated within each chamber 31.

[0089] Therefore, the delivery method according to this disclosure further comprises the step of initiating the delivery of the second fluid contained in the first chamber 31' (i.e., delivery to the outside of the fluid delivery system). To perform the above step, as described above, the processor P closes the second actuator 70' of the second recirculating fluid circuit 60' and opens the second supply station valve 11'. The second supply station valve 11' remains open during the delivery of the second fluid (the fluid leaving the fluid delivery system—see arrow B'). This is important because refilling the sub-chambers 35', 36' of the second chamber 31' with new second fluid is crucial to avoid fluid perturbations that could disrupt the precise function of the piston and, consequently, the precise function of the entire fluid delivery system. By closing the second actuator 70', the second fluid is prevented from flowing through the second recirculation fluid circuit 60' (while, as already mentioned above, the first and second inlet fluid circuit valves 45' and 47' prevent the second fluid from flowing back into the second supply station 10'). By pushing the second plunger 34' in the first direction (arrow C in Figure 9) and the second opposite direction (arrow D in Figure 10), the second fluid is able to exit from the second outlet port 54' and the first outlet port 53' of the second chamber 31', respectively. Therefore, when the second fluid is pushed to pass through the second outlet port 54' (arrow C), the second fluid flows into the second outlet fluid path 52' of the second outlet fluid circuit 50' and then through the second outlet fluid circuit valve 56'. This is because, at this stage of the procedure, the second actuator 70' is closed, and the fluid pressure is sufficiently high to overcome the internal elasticity of the second outlet fluid circuit valve 56'. Similarly, when the second fluid is pushed to pass through the first outlet port 53' (arrow D), the second fluid flows into the first outlet fluid path 51' of the second outlet fluid circuit 50' and then passes through the first outlet fluid circuit valve 55'. This is because, at this stage of the procedure, the second actuator 70' is closed, and the fluid pressure is high enough to overcome the internal elasticity of the first outlet fluid circuit valve 55'.As a result, the second fluid is finally delivered by continuously releasing fluid from the first and second sub-chambers 35' and 36' of the second chamber 31' (arrow B'). In fact, since the first and second outlet fluid circuit valves 55' and 56' are one-way valves, the second fluid cannot flow back through the pressurized path and is thus forcibly delivered (arrow B').

[0090] The operation of another delivery system 200' shown in Figure 5 is disclosed below in detail with reference to Figures 11 and 12, and the operation is substantially the same as each step of the method disclosed above with respect to the fluid delivery system 100' in Figure 2.

[0091] As an initial initiation step, the delivery method according to this disclosure comprises the steps of filling the first and second sub-chambers 35, 36 of the first pump module 30 with the first fluid, and similarly filling the first and second sub-chambers 35', 36' of the second pump module 30' with the second fluid. To perform the filling step, the processor P opens the first and second supply station valves 11, 11', closes the first and second actuators 270, 270' of the first and second recirculation fluid circuits 260, 260', and acts on a drive unit M to move a common piston 32 inside the first and second chambers 31, 31', thereby allowing the first and second fluids to exit the first and second supply stations 10, 10', respectively, and flow through the first and second inlet fluid circuits 40, 40'. In detail, as soon as the piston 32 moves axially in the first direction (e.g., arrow C in Figure 11), the axial movement of the piston increases the volume of the first sub-chamber (e.g., sub-chambers 35, 35') and creates negative pressure within it. Thus, each fluid can flow through the first 41, 41' and second 42, 42' inlet fluid paths of the first and second inlet fluid circuits 40, 40', i.e., through the corresponding first inlet fluid circuit valves (e.g., first inlet fluid circuit valves 45, 45'), so that the fluid enters and fills the first sub-chambers 35, 35'. At the same time, the air contained inside the second sub-chamber (e.g., sub-chambers 36, 36') is primed from the fluid delivery system through the venting means of the second inlet fluid circuit valve on the opposite side (e.g., second inlet fluid circuit valves 47, 47') as the volume of the sub-chamber decreases due to the axial movement of the piston (arrow C). In fact, the air contained in the second sub-chambers 36, 36' is generally forced out of the sub-chambers through the second inlet ports 46, 46', then through the third inlet fluid path 43, 43', and finally through the second inlet fluid circuit valves 47, 47'.Next, in order to fill the second sub-chamber with the respective fluid and prime the first sub-chamber (i.e., expel air from it), the processor P operates the drive unit M to reverse the movement of the piston, so that the piston moves axially in the second direction opposite to the first direction (e.g., arrow D in Figure 12). During the filling and priming steps, while the piston is moving, the first and second actuators 270, 270' remain closed, so the axial movement of the piston (arrow D) increases the volume of the second sub-chamber (e.g., sub-chambers 36, 36') and creates negative pressure within it. Therefore, the first and second fluids can flow through the first 41, 41' and third 43, 43' inlet fluid paths of the first and second inlet fluid circuits 40, 40', respectively, that is, through the corresponding second inlet fluid circuit valves (e.g., second fluid circuit valves 47, 47'), and thus the fluids enter and fill the second sub-chambers 36, 36'. Simultaneously, the air still contained within the first sub-chambers (e.g., sub-chambers 35, 35') is primed from the delivery system through the venting means of the corresponding first inlet fluid circuit valves (e.g., first inlet fluid circuit valves 45, 45') as the volume of the sub-chambers decreases due to the axial movement of the piston (arrow D). In fact, the air contained in the first sub-chambers 35, 35' is generally forced out of the sub-chambers through the first inlet ports 44, 44', then through the second inlet fluid paths 42, 42', and finally through the first inlet fluid circuit valves 45, 45'. During the priming step, some amounts of the first and second fluids may also be primed from the delivery system through the first and second outlet fluid circuits 50, 50'.

[0092] Alternatively, air priming of the fluid delivery system is performed by a dedicated venting means (not shown in the figure) separate from the fluid circuit valves. According to another embodiment, the dedicated venting means is associated with each valve of the fluid delivery system. According to yet another embodiment, the dedicated venting means is associated with the actuators 270, 270' of the first and second recirculating fluid circuits 260, 260'.

[0093] As soon as chambers 31 and 31' are filled with the first and second fluids, respectively, and the priming of the delivery system is complete, processor P closes the first and second supply station valves 11 and 11' and opens the first and second actuators 270 and 270' of the first and second recirculation fluid circuits 260 and 260', while drive unit M remains operating, thereby continuing to move piston 32 axially within the first and second chambers 31 and 31' (arrows C and D). Alternatively, processor P opens the first and second actuators 270 and 270' of the first and second recirculation fluid circuits 260 and 260', while maintaining the first and second supply station valves 11 and 11' in an open working state while the two fluids are being recirculated within their respective chambers 31 and 31'.

[0094] The first actuator 270 is designed so that when the piston 32 moves in the first direction (see arrow C in Figure 11), the first fluid moves in the second direction, i.e., the opposite direction to the first direction (see arrow E in Figure 11), (flowing through the first recirculating fluid circuit 260). Therefore, the movement of the plunger 34 in the first direction results in an increase in the volume of the first sub-chamber 35 and a corresponding decrease in the volume of the second sub-chamber 36, while the first fluid, which was initially contained in the second sub-chamber 36, enters the first sub-chamber 35 by passing through the first recirculating fluid circuit 260 and the associated first actuator 270.

[0095] Similarly, the second actuator 270' is designed so that when the piston 32 moves in the first direction (see arrow C in Figure 11), the second fluid moves in the second direction, i.e., the opposite direction to the first direction (see arrow E' in Figure 11), by flowing through the second recirculating fluid circuit 260'. Thus, the movement of the plunger 34' in the first direction results in an increase in the volume of the first sub-chamber 35' and a corresponding decrease in the volume of the second sub-chamber 36', while the second fluid initially contained in the second sub-chamber 36' enters the first sub-chamber 35' by passing through the second recirculating fluid circuit 260' and its associated second actuator 270'.

[0096] By maintaining the first and second actuators 270, 270' of the first and second recirculating fluid circuits 260, 260' in an open working state, the fluid delivery system 200' is prevented from delivering the first and second fluids to its outside. In fact, thanks to the open working state of the first and second actuators 270, 270' and the axial movement of the piston 32, the first fluid is continuously recirculated in the first chamber 31 through the first recirculating fluid circuit 260, while the second fluid is continuously recirculated in the second chamber 31' through the second recirculating fluid circuit 260'. In detail, when the piston 32 moves in the first direction (for example, arrow C in Figure 11), the first fluid, which was contained in the second sub-chamber 36, is pushed out through the first recirculating fluid circuit 260 and the first actuator 270 into the first sub-chamber 35. Simultaneously, the second fluid contained in the second sub-chamber 36' is pushed out through the second recirculating fluid circuit 260' and the second actuator 270' into the first sub-chamber 35'.

[0097] Subsequently, when the piston 32 reaches its first end, i.e., when the plunger 34 completes its axial movement in the first direction (rightward in Figure 11 - see arrow C) and reaches the vicinity of the base wall 31a of the first chamber 31, and at the same time the plunger 34' reaches the vicinity of the base wall 31a' of the second chamber 31', the processor P acts the drive unit M to reverse the axial movement of the piston (leftward in Figure 12 - see arrow D). Similar to the first stroke of the piston described above, the first fluid contained in the first sub-chamber 35 is pushed out through the first recirculating fluid circuit 260 and the first actuator 270 into the second sub-chamber 36 (see arrow F in Figure 12). At the same time, the second fluid contained in the first sub-chamber 35' is pushed out through the second recirculating fluid circuit 260' and the second actuator 270' into the second sub-chamber 36' (see arrow F' in Figure 12).

[0098] Then, as soon as the piston 32 reaches its second end, i.e., the plungers 34, 34' complete their axial movement in the second direction (leftward in Figure 12 - see arrow D) and reach the vicinity of the base walls 31b, 31b' of the first and second chambers 31, 31' respectively (resulting in the first sub-chambers 35, 35' containing substantially less volume of fluid each, while the second sub-chambers 36, 36' contain larger volume of fluid each), the processor P acts the drive unit M to reverse the axial movement of the piston again (rightward in Figure 11 - see arrow C), thereby starting a new filling / discharging cycle for the first and second chambers 31, 31' of the fluid delivery system 200'. Of course, any number of cycles can be prepared according to the requirements of the specific fluid to be delivered and the requirements of the specific application in which the delivery system is implemented. As already mentioned above, the first recirculation step, which recirculates the two fluids within each chamber, is particularly advantageous because it allows the two fluids to continue moving within the fluid delivery system, thereby ensuring proper and homogeneous shaking of each individual fluid before delivery.

[0099] As soon as recirculation is complete (for example, when the desired homogeneity of one or both fluids is successfully achieved and at some point it is required that the delivery of the first and / or second fluids be initiated), processor P causes the first or second actuator 270, 270' to act appropriately to close it and to stop the step of recirculating at least one of the first and second fluids.

[0100] For example, if it is requested that only the first fluid contained within the supply station 10 be delivered, the processor P closes the first actuator 270 of the first recirculating fluid circuit 260, while the second actuator 270' of the second recirculating fluid circuit 260' remains open, allowing the first fluid to be delivered (arrow B) while the second fluid continues to recirculate within its respective second chamber 31'. This is, for example, the case where, at a predetermined time in an infusion / infusion procedure performed on a given patient undergoing a medical examination (e.g., a CT scan), the delivery system 200' is requested to deliver only the first fluid (e.g., contrast agent) contained within the supply station 10, while the second fluid (e.g., a saline solution) is being recirculated (i.e., the second fluid is not delivered out of the fluid delivery system at that moment).

[0101] Therefore, the delivery method according to this disclosure comprises the step of initiating the delivery of the first fluid contained in the first chamber 31 (i.e., delivery to the outside of the fluid delivery system). To perform the step, as described above, the processor P closes the first actuator 270 of the first recirculating fluid circuit 260 and opens the first supply station valve 11. The first supply station valve 11 remains open during the delivery of the first fluid (the fluid leaving the delivery system—see arrow B). This is important because refilling the sub-chambers 35, 36 of the first chamber 31 with fresh first fluid is crucial to avoid fluid perturbations that could disrupt the precise function of the piston and, consequently, the precise function of the entire delivery system. By closing the first actuator 270, the first fluid is prevented from flowing through the first recirculation fluid circuit 260 (while, as already mentioned above, the first and second inlet fluid circuit valves 45 and 47 prevent the first fluid from flowing back to the first supply station 10). By pushing the first plunger 34 in the first direction (arrow C in Figure 11) and the second opposite direction (arrow D in Figure 12), the first fluid can exit the second outlet port 54 and the first outlet port 53 of the first chamber 31, respectively. Therefore, when the first fluid is pushed to pass through the second outlet port 54 (arrow C), the first fluid flows into the second outlet fluid path 52 of the first outlet fluid circuit 50 and then through the second outlet fluid circuit valve 56. This is because, at this stage of the procedure, the first actuator 270 is closed, and the fluid pressure is sufficiently high to overcome the internal elasticity of the second outlet fluid circuit valve 56. Similarly, when the first fluid is pushed to pass through the first outlet port 53 (arrow D), the first fluid flows into the first outlet fluid path 51 of the first outlet fluid circuit 50 and then through the first outlet fluid circuit valve 55. This is because, at this stage of the procedure, the first actuator 270 is closed, and the fluid pressure is high enough to overcome the internal elasticity of the first outlet fluid circuit valve 55. As a result, the first fluid is finally delivered by successively releasing fluid from the first and second sub-chambers 35, 36 of the first chamber 31 (arrow B).In fact, since the first and second outlet fluid circuit valves 55 and 56 are one-way valves, the first fluid cannot flow back through the pressurized path and is thus forcibly delivered (arrow B).

[0102] Similarly, as soon as it is requested to terminate the delivery of the first fluid (e.g., contrast agent) contained in the first supply station 10 and to begin the delivery of the second fluid (e.g., saline solution) contained in the second supply station 10', the processor P opens the first actuator 270 of the first recirculating fluid circuit 260 and closes the second actuator 270' of the second recirculating fluid circuit 260', thereby enabling the delivery of the second fluid (arrow B'), while the first fluid is recirculated within each of the first chambers 31.

[0103] Therefore, the delivery method according to this disclosure further comprises the step of initiating the delivery of the second fluid contained in the first chamber 31' (i.e., delivery to the outside of the fluid delivery system). To perform the above step, as described above, the processor P closes the second actuator 270' of the second recirculating fluid circuit 260' and opens the second supply station valve 11'. The second supply station valve 11' remains open during the delivery of the second fluid (the fluid leaving the fluid delivery system—see arrow B'). This is because refilling the sub-chambers 35', 36' of the second chamber 31' with new second fluid is important to avoid fluid perturbations that could disrupt the precise function of the piston and, consequently, the precise function of the entire delivery system. By closing the second actuator 270', the second fluid is prevented from flowing through the second recirculation fluid circuit 260' (while, as already mentioned above, the first and second inlet fluid circuit valves 45' and 47' prevent the second fluid from flowing back into the second supply station 10'). By pushing the second plunger 34' in the first direction (arrow C in Figure 11) and the second opposite direction (arrow D in Figure 12), the second fluid is allowed to exit from the second outlet port 54' and the first outlet port 53' of the second chamber 31', respectively. Therefore, when the second fluid is pushed to pass through the second outlet port 54' (arrow C), the second fluid flows into the second outlet fluid path 52' of the second outlet fluid circuit 50' and then through the second outlet fluid circuit valve 56'. This is because, at this stage of the procedure, the second actuator 270' is closed, so the fluid pressure is sufficiently high to overcome the internal elasticity of the second outlet fluid circuit valve 56'. Similarly, when the second fluid is pushed to pass through the first outlet port 53' (arrow D), the second fluid flows into the first outlet fluid path 51' of the second outlet fluid circuit 50' and then passes through the first outlet fluid circuit valve 55'. This is because, at this stage of the procedure, the second actuator 270' is closed, so the fluid pressure is high enough to overcome the internal elasticity of the first outlet fluid circuit valve 55'.As a result, the second fluid is finally delivered by continuously releasing fluid from the first and second sub-chambers 35' and 36' of the second chamber 31' (arrow B'). In fact, since the first and second outlet fluid circuit valves 55' and 56' are one-way valves, the second fluid cannot flow back through the pressurized path and is thus forcibly delivered (arrow B').

[0104] In this disclosure, the steps of mixing two different fluids and subsequently delivering the resulting mixture of the two fluids will be described below with reference to the fluid delivery system shown herein in Figures 8 and 13.

[0105] Therefore, according to the embodiment of Figure 8, a first fluid (for example, a contrast agent when the fluid delivery system 500 is applied in the medical field) is contained in the first supply station 10, while a second fluid (for example, a saline solution when the fluid delivery system 500 is applied in the medical field) is contained in the second supply station 10' and an additional first supply station 510, wherein the first fluid is different from the second fluid.

[0106] Let's assume that the fluid delivery system 500 defines a delivery protocol (infusion protocol) which requires the delivery of, for example, a first predetermined volume of a second fluid, followed by a second predetermined volume of a mixture of the first and second fluids, and finally a third predetermined volume of the second fluid, thereby administering it to a predetermined patient.

[0107] With respect to the second chamber 31', since only the second fluid is contained therein, the steps of priming and filling the second chamber 31' are carried out in the same manner as the respective steps disclosed above with respect to the embodiments of Figures 9 and 10.

[0108] With respect to the first chamber 31, the filling step is performed by introducing a certain amount of the first fluid into the second sub-chamber 36 and a certain amount of the second fluid into the first sub-chamber 35. This is achieved by opening the first supply station valve 11 and the additional supply station valve 511, while initially keeping the first actuator 70 in a closed working state. Thus, thanks to the forward and backward translational movement of the piston 32 (common to both the first and second chambers 31, 31'), a negative pressure is generated in either the first or second sub-chamber 35, 36, thereby allowing the respective fluids to enter their respective sub-chambers, and priming of the first inlet fluid circuit 40, the first and second sub-chambers 35, 36, and the first outlet fluid circuit 50 is also made possible as already disclosed above in this description. As soon as the desired amounts of the first and second fluids have entered the first chamber 31, the processor P closes the first supply station valve 11 and the additional supply station valve 511 and opens the first actuator 70. Therefore, the recirculation of the first fluid from the second sub-chamber 36 to the first sub-chamber 35 can occur in the same way as the recirculation of the second fluid from the first sub-chamber 35 to the second sub-chamber 36 (by the reverse movement of the piston 32), thereby mixing the first fluid with the second fluid and finally obtaining the desired delivered mixture.

[0109] As already noted above, according to this embodiment, a high-concentration contrast agent (e.g., ISOVUE®-370) can be used as the first fluid and a saline solution as the second fluid, and by appropriately mixing the high-concentration contrast agent with the saline solution, the fluid delivery system can consequently supply large quantities of contrast agents of different concentrations starting from a single type of high-concentration contrast agent. This represents a very advantageous feature of the present disclosure because the processor P can be programmed to calculate the volumes of the first and second fluids, and the fluids need to be mixed to obtain a mixture of desired concentrations that best suit the particular patient being treated (e.g., taking into account the patient's age, weight, sex, race, clinical condition, etc.) and the particular examination being performed (type of scanning examination, body part to be examined, etc.).

[0110] Following the example delivery protocol described above, immediately after the filling and priming steps are completed, the step of delivering the second fluid (e.g., a salt solution in the given example) is performed by closing the second actuator 70', thereby interrupting the recirculation of the second fluid within the second chamber 31'. Simultaneously with the step of delivering the second fluid, the step of mixing the first and second fluids within the first chamber 31 is performed as described above by opening the first actuator 70 of the first recirculation fluid circuit 60. As soon as the requested first volume of the second fluid is delivered out of the fluid delivery system 500 (arrow B'), the processor P is activated so that the second actuator 70' of the second recirculation fluid circuit 60' reaches the open working state, thereby enabling the recirculation of the second fluid within the second chamber 31' and interrupting the delivery of the second fluid out of the delivery system 500. Meanwhile, processor P closes the first actuator 70 to stop the recirculation of the mixed first and second fluids within the first chamber 31, thereby allowing the resulting mixture (at the desired contrast agent concentration) to be delivered out of the fluid delivery system 500 (arrow B). Thereafter, as soon as the requested second volume of the desired mixture is delivered, processor P opens the first actuator 70 to allow the mixed first and second fluids to recirculate within the first chamber 31, and processor P also closes the second actuator 70' to allow the final third volume of the second fluid to be delivered according to the exemplified delivery protocol described above.

[0111] According to another embodiment shown in Figure 13, a first fluid (for example, a contrast agent when the fluid delivery system 400' is applied in the medical field) is contained in a first supply station 10, while a second fluid (for example, a saline solution when the fluid delivery system 400' is applied in the medical field) is contained in a second supply station 10' and an additional first supply station 410, wherein the first fluid is different from the second fluid.

[0112] As shown above with respect to the embodiment in Figure 8, let us assume that the fluid delivery system 400' is required to deliver, for example, a first volume of a second fluid, followed by a second volume of a mixture of the first and second fluids, and finally a third volume of the second fluid.

[0113] With respect to the second chamber 31', since only the second fluid is contained therein, the steps of priming and filling the second chamber 31' are carried out in the same manner as the respective steps disclosed above with respect to the embodiments of Figures 9 and 10.

[0114] With respect to the first chamber 31, the filling step is performed by introducing a predetermined amount of the first fluid into the second sub-chamber 36 and a predetermined amount of the second fluid into the first sub-chamber 35. This is achieved by opening the first supply station valve 11 and the additional supply station valve 411, while initially keeping the first actuator 70 in a closed working state. Thus, thanks to the forward and backward translational movement of the piston 32, a negative pressure is generated in either the first or second sub-chambers 35, 36, thereby allowing the respective fluids to enter their respective sub-chambers, and also enabling priming of the first inlet fluid circuit 40, the first and second sub-chambers 35, 36, and the first outlet fluid circuit 50. As soon as the desired amounts of the first and second fluids have entered the first chamber 31, the processor P closes the first supply station valve 11 and the additional supply station valve 511 and opens the first actuator 70. Therefore, the recirculation of the first fluid from the second sub-chamber 36 to the first sub-chamber 35 can occur in the same way as the recirculation of the second fluid from the first sub-chamber 35 to the second sub-chamber 36 (by the reverse movement of the piston 32), thereby mixing the first and second fluids and finally obtaining the desired delivered mixture.

[0115] Following the example delivery protocol described above, immediately after the filling and priming steps are completed, the step of delivering the second fluid (a saline solution in a given example) is performed by closing the second actuator 70', thereby interrupting the recirculation of the second fluid within the second chamber 31'. Preferably, simultaneously with the step of delivering the second fluid, the step of mixing the first and second fluids within the first chamber 31 is performed as described above by opening the first actuator 70 of the first recirculation fluid circuit 60'. As soon as the requested first volume of the second fluid is delivered out of the fluid delivery system 400' (arrow B'), the processor P is activated so that the second actuator 70' of the second recirculation fluid circuit 60' reaches the open working state, thereby enabling the recirculation of the second fluid within the second chamber 31' and interrupting the delivery of the second fluid out of the delivery system 400'. Meanwhile, processor P closes the first actuator 70 to stop the recirculation of the mixed first and second fluids within the first chamber 31, thereby allowing the resulting mixture (at the desired contrast agent concentration) to be delivered out of the fluid delivery system 400' (arrow B). Thereafter, as soon as the requested second volume of the desired mixture is delivered, processor P opens the first actuator 70 to allow the mixed first and second fluids to recirculate within the first chamber 31, and processor P also closes the second actuator 70' so that the final third volume of the second fluid can be delivered according to the exemplified delivery protocol described above.

[0116] According to a further embodiment shown in Figure 14, the fluid delivery system 400'' is substantially the same as the fluid delivery system 400 in Figure 7, except that a second recirculation fluid circuit is not assumed. In fact, if the second fluid contained in the second supply station 10' is not required to be recirculated within the second chamber 31', because, for example, a predetermined homogeneity of the second fluid (for example, if the second fluid is a saline solution) does not need to be maintained or achieved, the fluid delivery system 400'' is equipped with two separate, independent drive units M, M', so that the delivery of the second fluid (arrow B') is performed by the processor P starting the drive unit M' (and thus by moving the second piston 32') at the very predetermined moment when the second fluid is required to be delivered. In other words, according to this embodiment, the second chamber 31' of the second pump module 30' can be filled and discharged without any need for recirculation of the second fluid within the second chamber 31'.

[0117] [Modification form] To satisfy local and specific requirements, many logical and / or physical modifications and changes can be applied to the present disclosure by those skilled in the art. More specifically, although the present disclosure is described in some features relating to one or more embodiments, it should be understood that many omissions, substitutions, and changes are possible in form and detail, as with other embodiments. In particular, different embodiments of the present disclosure may be implemented without certain details (such as numerical values) that would give a closer understanding, as revealed in the above description. Conversely, well-known features may be omitted or simplified so as not to obscure the description with unnecessary details. Furthermore, each particular element and / or step of a method described relating to any embodiment of the present disclosure is expressly intended to be incorporated into any other embodiment as a general design choice. In any case, any numerical value should be read modified (if not already done) with the term "about," and any numerical range should be intended to expressly specify any numerical value that can take place on the continuum within that range (including the endpoints). Furthermore, ordinal numbers or other modifiers are used simply as labels to distinguish elements with the same name and do not imply any priority, priority, or order by themselves.The terms “include,” “comprise,” “have,” “contain,” and “involve” (and any of these forms) should be intended to have an unrestricted, non-exclusive meaning (i.e., not limited to the listed items); the terms “based on,” “dependent on,” “according to,” and “function of” (and any of these forms) should be intended to have a non-exclusive relationship (i.e., may involve further variables); the term “a / an” should be intended to mean one or more (unless explicitly indicated otherwise); and the term “means for” (or any of the means-plus-function forms) should be intended to mean any structure adapted or configured to perform the function in question.

[0118] As disclosed above, the actuators and supply station valves of the recirculating fluid circuit are active components controlled by the processor P, while the remaining valves of the fluid delivery system are check valves that do not need to be actuated by the processor P. In a further embodiment (not shown in the figures), to enhance the safety and reliability of the fluid delivery system of this disclosure, all valves of the fluid delivery system are active mechanical valves or active mechanical clamps controlled by the processor P. In detail, the active mechanical valve / clamp is a mechanical gate that opens and closes the fluid path by acting radially on its outer surface.

[0119] According to one embodiment of the present invention (not shown in the figures), the volume of the supply station is significantly larger than the volume of the chamber of the fluid delivery system. This embodiment is particularly advantageous because it ensures that multiple deliveries (e.g., injections or infusions) can be performed without requiring frequent replacement of the fluid container, thereby advantageously minimizing the overall size of the fluid delivery system, and thus ensuring greater flexibility, easier handling, (if necessary) portability, and lower cost.

[0120] In a further embodiment, a method for operating a fluid delivery system of the present disclosure comprises the steps of calculating the amount (volume) of fluid to be delivered for a given application, and then moving a piston axially to define a sub-chamber such that the volume of the sub-chamber is substantially equal to the calculated volume of fluid to be delivered. This embodiment is particularly important when a small amount of fluid needs to be delivered (i.e., less than the chamber volume of the fluid delivery system), and therefore it is desirable to deliver such a small amount while the piston is moving axially in only one direction, thereby avoiding reverse movement of the piston and the resulting perturbation / delay of delivery.

[0121] Alternatively, the calculation step may not be performed by the control unit of the fluid delivery system. Instead, the volume to be delivered is calculated offline and subsequently provided to the processor as input delivery data. Therefore, immediately before the delivery step begins, the piston is moved axially to define a sub-chamber having a volume corresponding to the calculated volume.

[0122] In other applications (not shown in the figures), the delivery system of the present disclosure may be used to deliver not necessarily at least one and a second fluid, but two or more fluids or mixtures thereof. In fact, the delivery system may be used to administer the fluids, thereby creating customized preparations for any particular need. For example, when the delivery system of the present disclosure is used in the medical field, two or more liquid drugs can be appropriately administered and sequentially collected in a suitable storage container (e.g., a pouch) that is advantageously customized for a given patient, thereby reducing or even avoiding the waste of valuable and expensive substances. As stated above, the delivery station may have different appropriate volumes as well as the chambers of each pump module (and thus each sub-chamber), and the delivery / administration / collection of different fluids may be controlled (by appropriately programming the processor P) according to the actual needs of each particular case. Customizing the infusion, or customizing a given preparation to be administered sequentially (e.g., filling a pouch for subsequent intravenous administration), or even customizing the concentration of a given contrast agent to be injected are all advantageous aspects that make the delivery system of the present disclosure extremely versatile and valuable.

[0123] The delivery system of this disclosure further enables the alternating delivery (or injection) of a first fluid and a second fluid in very small and separate volumes by rapidly switching between two pump modules (for example, by the processor P continuously activating / deactivating the first and second actuators of the first and second recirculating fluid circuits). In other words, thanks to the delivery system of this disclosure, the contrast agent and saline solution can be rapidly and repeatedly administered (i.e., injected) to the patient, and as a result, mixing of the contrast agent and saline solution is achieved inside the patient's organs, for example, inside the heart. This particular injection phase (known as Diluject® or Rapid Phasing, and a specific technical feature of the CT Expres® automated syringe-free injector manufactured by Bracco Injeneering SA) can be performed with improved efficiency and reliability by using the delivery system of this disclosure.

[0124] The following are preferred aspects and embodiments of the present disclosure. 1. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500), [1] at least one first supply station (10) for supplying the first fluid and at least one second supply station (10') for supplying the second fluid; Here, the second fluid is different from the first fluid; [2] Pressurizing unit (20) for pressurizing the first fluid and the second fluid, comprising the following: [2-1] A first pump module (30) comprising a first chamber (31) and a first piston (32) housed therein; Here, the first piston has a first plunger (34), which, in cooperation with the inner wall of the first chamber (31), defines the first (35) and second (36) volume-variable sub-chambers of the first chamber (31); and [2-2] A second pump module (30') comprising a second chamber (31') and a second piston (32') housed therein; Here, the second piston has a second plunger (34'), which, in cooperation with the inner wall of the second chamber (31'), defines the first (35') and second (36') volume-variable sub-chambers of the second chamber (31'); [3] A first inlet fluid circuit (40) that is in fluid communication with at least one first supply station (10) and the first pump module (30) in order to supply the first fluid to the first (35) and second (36) volume variable sub-chambers of the first chamber (31), [4] A second inlet fluid circuit (40') in fluid communication with at least one second supply station (10') and the second pump module (30') to supply the second fluid to the first (35') and second (36') volume variable sub-chambers of the second chamber (31'), [5] A first recirculating fluid circuit (60;260) that fluidly connects the first (35) and second (36) volume variable subchambers of the first chamber (31), and [6] A first actuator (70;270) for controlling the passage of fluid bidirectionally between the first (35) and second (36) volume-variable sub-chambers of the first chamber (31); Here, the first actuator (70;270) is part of the first recirculating fluid circuit (60); A fluid delivery system equipped with the following features. 2. A fluid delivery system (100;100';100'';200;200';300;400;400';500) as described in Embodiment 1, The second chamber (31') further comprises a second recirculating fluid circuit (60'; 260') that fluidly connects the first (35') and second (36') volume-variable sub-chambers of the second chamber (31'). A fluid delivery system characterized by the following features. 3. A fluid delivery system (100;100';100'';200;200';300;400;400';500) as described in Embodiment 2, The second chamber (31') further comprises a second actuator (70'; 270') for controlling the passage of the fluid bidirectionally between the first (35') and second (36') volume-variable sub-chambers; Here, the second actuator (70';270') is part of the second recirculating fluid circuit (60';260'); A fluid delivery system characterized by the following features. 4. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in any of Embodiments 1 to 3, The pressurizing unit (20) further comprises at least one drive unit (M;M') for causing the first (32) and second (32') pistons to reciprocate (A;A';C;D) within the first (31) and second (31') chambers, respectively. A fluid delivery system characterized by the following features. 5. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in any of Embodiments 1 to 4, The first chamber (31) further comprises a first outlet fluid circuit (50) in fluid communication with the first pump module (30) for discharging the first fluid from either of the first (35) or second (36) volume-variable sub-chambers; Here, the first outlet fluid circuit (50) is separated from the first inlet fluid circuit (40); A fluid delivery system characterized by the following features. 6. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in any of Embodiments 1 to 5, The second chamber (31') further comprises a second outlet fluid circuit (50') in fluid communication with the second pump module (30') for discharging the second fluid from either of the first (35') or second (36') volumetric sub-chambers; Here, the second outlet fluid circuit (50') is separated from the second inlet fluid circuit (40'); A fluid delivery system characterized by the following features. 7. A fluid delivery system (100;200;400;400';400'') as described in any of Embodiments 1 to 6, The first pump module (30) and the second pump module (30') are arranged in parallel. A fluid delivery system characterized by the following features. 8. A fluid delivery system (100;200) as described in Embodiment 7, The first piston (32) and the second piston (32') are separate and associated with a common single drive unit (M). A fluid delivery system characterized by the following features. 9. A fluid delivery system (400;400';400'') as described in Embodiment 7, The first piston (32) and the second piston (32') are separated and associated with the first (M) and second (M') drive units, respectively. A fluid delivery system characterized by the following features. 10. A fluid delivery system (100'; 100''; 200'; 300; 500) as described in any of Embodiments 1 to 6, The first pump module (30) and the second pump module (30') are arranged in series. A fluid delivery system characterized by the following features. 11. A fluid delivery system (100';100'';200';300;500) as described in Embodiment 10, The first piston (32) and the second piston (32') define a common piston that moves axially within the first (31) and second (31') chambers (A; A'; C; D). A fluid delivery system characterized by the following features. 12. A fluid delivery system (100'; 100''; 200'; 300; 500) as described in Embodiment 11, The first (34) and second (34') plungers are spaced apart along the common piston (32), Each plunger reciprocates within its corresponding chamber (31, 31'). A fluid delivery system characterized by the following features. 13. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in any of Embodiments 1 to 12, The first (40) and second (40') inlet fluid circuits are provided with a first inlet fluid path (41; 41'); Here, the first inlet fluid path is in fluid communication with the at least one first (10) and the at least one second (10') supply station; Here, the first inlet fluid path (41;41') is equipped with a supply station valve (11;11'); A fluid delivery system characterized by the following features. 14. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in Embodiment 13, Downstream of the supply station valve (11;11'), the first (40) and second (40') inlet fluid circuits comprise a second inlet fluid path (42;42') and a third inlet fluid path (43;43'); Here, the second and third inlet fluid paths are in fluid communication with the first volume-variable sub-chamber (35;35') and the second volume-variable sub-chamber (36;36'), respectively; Here, the second inlet fluid path (42;42') is equipped with a first inlet fluid circuit valve (45;45'); and Here, the third inlet fluid path (43) is equipped with a second inlet fluid circuit valve (47; 47'); A fluid delivery system characterized by the following features. 15. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in Embodiments 5 and 6, The first (50) and second (50') outlet fluid circuits comprise a first outlet fluid path (51; 51') and a second outlet fluid path (52; 52'); Here, the first and second outlet fluid paths are in fluid communication with the first volume-variable sub-chamber (35;35') and the second volume-variable sub-chamber (36;36'), respectively; Here, the first outlet fluid path (51;51') is equipped with a first outlet fluid circuit valve (55;55'); and Here, the second outlet fluid path (52; 52') is equipped with a second outlet fluid circuit valve (56; 56'); A fluid delivery system characterized by the following features. 16. A fluid delivery system (100;100';100'';300;400;400';500) as described in Embodiments 2 and 3, The first (60) and second (60') recirculation fluid circuits and the associated first (70) and second (70') actuators are located outside the first (31) and second (31') chambers, respectively. A fluid delivery system characterized by the following features. 17. A fluid delivery system (100;100';100'';300;400;400';500) as described in Embodiment 16, The first (60) and second (60') recirculation fluid circuits are fluidly connected to the second inlet fluid path (42;42') downstream of the first inlet fluid circuit valve (45;45') and to the third inlet fluid circuit (43;43') downstream of the second inlet fluid circuit valve (47;47'). A fluid delivery system characterized by the following features. 18. A fluid delivery system (200;200') as described in Embodiments 2 and 3, The first (260) and second (260') recirculating fluid circuits and the first (270) and second (270') actuators are housed inside the first (31) and second (31') chambers, respectively, and are integrated with the first (34) and second (34') plungers of the first (32) and second (32') pistons, respectively. A fluid delivery system characterized by the following features. 19. A fluid delivery system (200;200') as described in Embodiment 18, The first (260) and second (260') recirculating fluid circuits each comprise fluid passages obtained within the thickness of the first (34) and second (34') plungers; Here, the fluid passage is a passage for ensuring fluid communication between the first (35;35') and second (36;36') volume-variable sub-chambers; A fluid delivery system characterized by the following features. 20. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in Embodiment 1, The system further comprises a processor (P) for controlling and operating the first actuator (70;270). A fluid delivery system characterized by the following features. 21. A fluid delivery system (100;100';100'';200;200';300;400;400';500) as described in Embodiment 3, The system further comprises a processor (P) for controlling and operating the second actuator (70';270'). A fluid delivery system characterized by the following features. 22. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) described in Embodiment 13, The system further comprises a processor (P) for controlling and operating the supply station valves (11;11'). A fluid delivery system characterized by the following features. 23. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in Embodiment 4, The system further comprises a processor (P) for controlling and operating at least one of the drive units (M;M'). A fluid delivery system characterized by the following features. 24. A fluid delivery system (400'; 500') described in any of Embodiments 1 to 23, Further equipped with additional supply stations (410; 510) A fluid delivery system characterized by the following features. 25. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in Embodiments 20-22, The first (70;270) and second (70';270') actuators and the supply station valve (11;11') are active valves that are operated by the processor (P). A fluid delivery system characterized by the following features. 26. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) described in Embodiment 20, All valves (70;70';270;270';11;11';45;45';47;47';55;55';56;56') in the fluid delivery system are active mechanical clamps that are operated by the control unit (P). A fluid delivery system characterized by the following features. 27. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in any of Embodiments 1 to 26, The volumes of the first (10) and second (10') supply stations are significantly larger than the volumes of the first (31) and second (31') chambers of the fluid delivery system. A fluid delivery system characterized by the following features. 28. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) as described in any of Embodiments 1 to 27, The fluid delivery system is an injection system, and the first and second fluids are medical fluids selected from liquid drugs, pharmaceuticals, diagnostically effective contrast agents, saline solutions, or mixtures thereof. A fluid delivery system characterized by the following features. 29. A method for operating a fluid delivery system (100;100';100'';200;200';300;400;400';400'';500), The method described above is a method for delivering at least a first fluid and a second fluid; The first fluid differs from the second fluid; The above method involves the following steps: A step of delivering the second fluid to the outside of the fluid delivery system, The step of recirculating the first fluid within the fluid delivery system, and A step of delivering the first fluid to the outside of the fluid delivery system; A method for providing this. 30. A method of performing the operation described in Embodiment 29, The step of delivering the second fluid outside the fluid delivery system is performed simultaneously with the step of recirculating the first fluid inside the fluid delivery system. A method characterized by the following: 31. A method of performing the operations described in Embodiments 29 and 30, The step of delivering the first fluid outside the fluid delivery system is performed after the step of delivering the second fluid outside the fluid delivery system has been stopped. A method characterized by the following: 32. A method for operating a fluid delivery system (100;100';100'';200;200';300;400;400';500), The method described above is a method for delivering at least a first fluid and a second fluid; Here, the first fluid differs from the second fluid; The above method involves the following steps: A step of delivering the first fluid to the outside of the fluid delivery system, The step of recirculating the second fluid within the fluid delivery system, A step of delivering the second fluid to the outside of the fluid delivery system, and A step of recirculating the first fluid within the fluid delivery system; A method for providing this. 33. A method of performing the operation described in Embodiment 32, The step of recirculating the second fluid within the fluid delivery system is performed substantially simultaneously with the step of delivering the first fluid outside the fluid delivery system. A method characterized by the following: 34. A method of performing the operations described in Embodiments 32 and 33, The step of recirculating the first fluid within the fluid delivery system is performed substantially simultaneously with the step of delivering the second fluid outside the fluid delivery system. A method characterized by the following: 35. A method of performing an operation as described in any of embodiments 32 to 34, The step of delivering the first fluid outside the fluid delivery system is performed alternately with the step of delivering the second fluid outside the fluid delivery system. A method characterized by the following: 36. A method for operating a fluid delivery system (100;100';100'';200;200';300;400;400';400'';500), The fluid delivery system comprises at least one first supply station (10) for supplying a first fluid and at least one second supply station (10') for supplying a second fluid; Here, the second fluid differs from the first fluid; The fluid delivery system (100;100';100'';200;200';300;400;400';500) further comprises a pressurizing unit (20) having a first pump module (30) and a second pump module (30'); Here, the first and second pump modules each comprise a chamber (31;31') and a reciprocating piston (32;32') (A;A';C;D) within it; Here, the piston (32;32') has a plunger (34;34'); Here, the plunger, in cooperation with the inner wall of the chamber (31;31'), defines the first (35;35') and second (36;36') volume-variable sub-chambers; The fluid delivery system (100;100';100'';200;200';300;400;400';500) further comprises a first (60;260) recirculation fluid path and associated first actuators (70;270) for fluidly connecting the first (35) and second (36) volume-variable sub-chambers of the first (31) chamber; The above method involves the following steps: A step of supplying the first fluid from the first supply station (10) to the first (35) and second (36) volume-variable sub-chambers of the first chamber (31), A step of supplying the second fluid from the second supply station (10') to the first (35') and second (36') volume-variable sub-chambers of the second chamber (31'), The step of moving each of the pistons (32;32') in the first (31) and second (31') chambers in the axial direction (A;A';C;D), and A step of operating the first actuator (70;270) to recirculate the first fluid within the first chamber (31); A method for providing this. 37. A method of operation as described in Embodiment 31, The method further comprises the steps of delivering the first fluid outside the delivery system and delivering the second fluid outside the delivery system; Here, the delivery steps are performed alternately; method. 38. A method of performing the operation described in Embodiment 36, The fluid delivery system (100;100';100'';200;200';300;400;400';500) further comprises a second (60';260') recirculation fluid path and associated second actuator (70';270') for fluidly connecting the first (35') and second (36') volume variable sub-chambers of the second (31') chamber, The method further comprises the step of operating the second actuator (70'; 270') to recirculate the second fluid within the second chamber (31'). method. 39. A method of performing the operations described in Embodiments 37 and 38, The step of delivering the first fluid to the outside of the delivery system is performed simultaneously with the step of recirculating the second fluid. method. 40. A method of performing the operations described in Embodiments 37 and 38, The step of delivering the second fluid outside the delivery system is performed simultaneously with the step of recirculating the first fluid. method. 41. A method of operation described in any of embodiments 38 to 40, The recirculation step is performed by flowing the first fluid and the second fluid through the first (60;260) and second (60';260') recirculation fluid paths, respectively; Here, the steps are performed while moving each piston (32;32') multiple times in the axial direction within the first (31) and second (31') chambers (A;A';C;D); method. 42. A method of operation as described in Embodiment 37, The step of recirculating the first fluid is repeated continuously until the step of delivering the second fluid outside the fluid delivery system is completed. method. 43. A method of operation as described in Embodiment 38, The step of recirculating the second fluid is repeated continuously until the step of delivering the first fluid out of the fluid delivery system is completed. method. 44. A method of operation as described in Embodiment 36, The fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) further comprises a valve (11) associated with the first supply station (10); The pressurizing unit (20) further comprises at least one drive unit (M; M'); The step of supplying the first fluid comprises filling the first chamber (31) with the first fluid; The step of filling the first chamber (31) is as follows: The step of opening the valve (11) associated with the first supply station (10), The step of closing the first actuator (70;270) of the first recirculating fluid path (60;260), and A step of operating the drive unit (M) to reciprocate the piston (32) within the first chamber (31); How to prepare even more. 45. A method of operation as described in Embodiment 38, The fluid delivery system (100;100';100'';200;200';300;400;400';500) further comprises a valve (11') associated with the second supply station (10'); The pressurizing unit (20) further comprises at least one drive unit (M; M'); The step of supplying the second fluid comprises filling the second chamber (31') with the second fluid; The step of filling the second chamber (31') is as follows: The step of opening the valve (11') associated with the second supply station (10'), The step of closing the second actuator (70';270') of the second recirculating fluid path (60';260'), and A step of operating the drive unit (M;M') to reciprocate the piston (32') within the second chamber (31'); How to prepare even more. 46. ​​A method of operation as described in Embodiments 44 and 45, The step further comprises priming the outside of the fluid delivery system with air; Here, the priming step is performed simultaneously with the step of filling the first (31) and second (31') chambers; method. 47. A method of performing an operation as described in any of Embodiments 36 to 46, The following steps: A step of calculating the volume of the first fluid and the volume of the second fluid to be delivered for a predetermined application, and Step (A;A';C;D) involves moving each of the pistons (32;32') axially to define the volume of the sub-chamber (35;36;35';36') to be substantially equal to the calculated volumes of the first and second fluids to be delivered. How to prepare even more. 48. A method of operation as described in Embodiment 31, The following steps: A step of supplying the volume of a first fluid and the volume of a second fluid to be delivered for a predetermined application as input delivery data, and Step (A;A';C;D) involves moving each of the pistons (32;32') axially to define the volume of the sub-chamber (35;36;35';36') to be substantially equal to the calculated volumes of the first and second fluids to be delivered. How to prepare even more. 49. A method for operating a fluid delivery system (400'; 400''; 500), The method described above is a method for delivering a mixture of a first fluid and a second fluid; Here, the first fluid differs from the second fluid; The above method involves the following steps: A step of delivering the first fluid to the outside of the fluid delivery system, The step of recirculating the first fluid and the second fluid within the fluid delivery system to create a mixture thereof, and A step of delivering the mixture to the outside of the fluid delivery system; A method for providing this. 50. A method for operating the fluid delivery system (400'; 500) described in Embodiment 49, The system further comprises the step of recirculating the first fluid within the fluid delivery system. A method characterized by the following: 51. A method for operating the fluid delivery system described in Embodiment 49, The step of recirculating the first fluid and the second fluid within the fluid delivery system is performed substantially simultaneously with the first step of delivering the first fluid outside the fluid delivery system. A method characterized by the following: 52. A method for operating the fluid delivery system described in Embodiment 50, The step of recirculating the first fluid within the fluid delivery system is performed substantially simultaneously with the step of delivering the mixture outside the fluid delivery system. A method characterized by the following: 53. A method for operating the fluid delivery system described in Embodiment 49, The step of delivering the first fluid outside the fluid delivery system is performed alternately with the step of delivering the second fluid outside the fluid delivery system. A method characterized by the following:

Claims

1. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500), [1] at least one first supply station (10) for supplying the first fluid and at least one second supply station (10') for supplying the second fluid; Here, the second fluid is different from the first fluid; [2] A pressurizing unit (20) for pressurizing the first fluid and the second fluid, comprising the following: [2-1] A first pump module (30) comprising a first chamber (31) and a first piston (32) housed therein; Here, the first piston has a first plunger (34), which, in cooperation with the inner wall of the first chamber (31), defines the first (35) and second (36) volume-variable sub-chambers of the first chamber (31); and [2-2] A second pump module (30') comprising a second chamber (31') and a second piston (32') housed therein; Here, the second piston has a second plunger (34'), which, in cooperation with the inner wall of the second chamber (31'), defines the first (35') and second (36') volume-variable sub-chambers of the second chamber (31'); [3] A first inlet fluid circuit (40) that is in fluid communication with at least one first supply station (10) and the first pump module (30) in order to supply the first fluid to the first (35) and second (36) volume variable sub-chambers of the first chamber (31), [4] To supply the second fluid to the first (35') and second (36') volume-variable sub-chambers of the second chamber (31'), a second inlet fluid circuit (40') is in fluid communication with at least one second supply station (10') and the second pump module (30'), [5] A first recirculating fluid circuit (60;260) that fluidly connects the first (35) and second (36) volume variable sub-chambers of the first chamber (31), and [6] A first actuator (70;270) for controlling the passage of fluid bidirectionally between the first (35) and second (36) volume-variable sub-chambers of the first chamber (31); Here, the first actuator (70;270) is part of the first recirculating fluid circuit (60); A fluid delivery system equipped with the following features.

2. A fluid delivery system (100;100';100'';200;200';300;400;400';500) according to claim 1, The second chamber (31') further comprises a second recirculating fluid circuit (60'; 260') that fluidly connects the first (35') and second (36') volume-variable sub-chambers of the second chamber (31'). A fluid delivery system characterized by the following features.

3. A fluid delivery system (100;100';100'';200;200';300;400;400';500) according to claim 2, The second chamber (31') further comprises a second actuator (70'; 270') for controlling the passage of the fluid bidirectionally between the first (35') and second (36') volume-variable sub-chambers; Here, the second actuator (70';270') is part of the second recirculating fluid circuit (60';260'); A fluid delivery system characterized by the following features.

4. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) according to any one of claims 1 to 3, The pressurizing unit (20) further comprises at least one drive unit (M;M') for causing the first (32) and second (32') pistons to reciprocate (A;A';C;D) within the first (31) and second (31') chambers, respectively. A fluid delivery system characterized by the following features.

5. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) according to any one of claims 1 to 4, The first chamber (31) further comprises a first outlet fluid circuit (50) in fluid communication with the first pump module (30) for discharging the first fluid from either of the first (35) or second (36) volume-variable sub-chambers; Here, the first outlet fluid circuit (50) is separated from the first inlet fluid circuit (40); A fluid delivery system characterized by the following features.

6. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) according to any one of claims 1 to 5, The second chamber (31') further comprises a second outlet fluid circuit (50') in fluid communication with the second pump module (30') for discharging the second fluid from either of the first (35') or second (36') volume-variable sub-chambers; Here, the second outlet fluid circuit (50') is separated from the second inlet fluid circuit (40'); A fluid delivery system characterized by the following features.

7. A fluid delivery system (100;100';100'';300;400;400';500) according to claims 2 and 3, The first (60) and second (60') recirculation fluid circuits and the associated first (70) and second (70') actuators are located outside the first (31) and second (31') chambers, respectively. A fluid delivery system characterized by the following features.

8. A fluid delivery system (200;200') according to claims 2 and 3, The first (260) and second (260') recirculating fluid circuits and the first (270) and second (270') actuators are housed inside the first (31) and second (31') chambers, respectively, and are integrated with the first (34) and second (34') plungers of the first (32) and second (32') pistons, respectively. A fluid delivery system characterized by the following features.

9. A fluid delivery system (100;100';100'';200;200';300;400;400';400'';500) according to any one of claims 1 to 8, The fluid delivery system is an injection system, and the first and second fluids are medical fluids selected from liquid drugs, pharmaceuticals, diagnostically effective contrast agents, saline solutions, or mixtures thereof. A fluid delivery system characterized by the following features.

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