Instrument for injecting a fluid into a patient and associated delivery method

Abstract

Cutlery (10; 210; 220; 230) for injecting fluid into a patient, the cutlery containing: - a needle injection device (14) comprising a needle (36) having a free end (48) adapted to be inserted into a septum (144) of an implantable chamber (18) containing a hollow base body (140), the septum (144) closing the base body (140), and the chamber comprising a conduit (146) for draining fluid from the base body (140); the needle injection device (14) comprising an intermediate tube (38); - an upstream line (13) having an upstream end (30A) intended to be connected to a liquid dispensing device (12) and a downstream end (32A), wherein the downstream end (32A) is detachably connected to the intermediate pipe (38), wherein the needle injection device (14) comprises a needle holder (34), wherein the needle holder (34) includes a core (40) which receives the needle (36) and the downstream end of the intermediate tube (38), and wherein the pressure drop through the upstream conduit (13) between its upstream end (30A) and its downstream end (32A) is higher than 25% of the total pressure drop between the upstream end (30A) of the upstream conduit (13) and the free end (48) of the needle (36) when injecting fluid via the upstream conduit (13) and the needle injection device (14), characterized in that the set includes an implantable chamber (18) containing a hollow base body (140), wherein the septum (144) closes the base body (140), and wherein the chamber has a conduit (146) for emptying fluid from the base body (140), wherein the pressure drop through the needle injection device (14) is less than four times the pressure drop through the chamber (18) when the needle (36) is inserted into the chamber (18).

Description

[0001] The present invention relates to a set for injecting fluid into a patient of the type comprising: - an implantable chamber containing a hollow base body, a septum closing the base body and a conduit for draining fluid from the base body; - a needle injection device comprising a needle with a free end intended to be inserted into the septum and an intermediate tube; - an upstream conduit comprising an upstream end intended to be connected to a liquid dispensing device and a downstream end detachably connected to the intermediate pipe.

[0002] Such a device is particularly intended for injecting fluid into a patient, for example in the field of oncology or when injecting a contrast agent into a patient in order to produce a medical image.

[0003] This image can be used for a non-invasive evaluation of the properties of the patient's vascular system, for example, to perform angiography by computed tomography, which is referred to by the English term "computer tomography" or "CT".

[0004] In this latter case, it is necessary to inject a contrast agent into the patient's vascular system very quickly and at a high throughput, which makes it possible to obtain a sufficiently high concentration to have sufficient contrast throughout the entire scan time, which is of the order of 30 to 45 seconds.

[0005] To facilitate the high-throughput injection of contrast agent into the patient's vascular system, it is known to use a device of the type mentioned above, which has a chamber implanted under the patient's skin. The chamber defines an injection point into the patient, located at a distance from the circulatory channel into which the agent is to be injected. This avoids damaging the circulatory channel by repeatedly piercing that channel.

[0006] In a known manner, such a chamber comprises a hollow body sealed by an elastic septum and a channel for draining fluid from the hollow body. The drainage channel extends from the hollow body into the vascular system to the injection point.

[0007] To inject the fluid into the patient, the physician connects the fluid delivery device's output port to the needle injection device. They then insert the device's needle through the septum into the chamber. They then trigger the fluid injection from the injection device through the injection device and into the chamber.

[0008] To ensure the introduction of fluid at very high flow rates, for example, higher than 1 ml / sec, it is necessary to significantly increase the pressure at the injection device's outlet. This outlet pressure can be higher than 18 bar, for example.

[0009] However, due to their design, the implantable chambers have a maximum working pressure that is generally much lower than the pressure of the fluid delivered by the injection device, for example, approximately 8 bar. In applications where the fluid is injected at very high flow rates, there is therefore a significant risk that the chamber will not be able to withstand the internal pressure of the fluid coming from the delivery device.

[0010] To limit this risk to the patient, the American patent application US 2009 / 0 227 951 A1 describes a device in which the needle injection device has a significant pressure drop of approximately 15 bar. Such an injection device thus guarantees patient safety by providing a high pressure drop.

[0011] However, such an injection device must be specifically designed for high-flow injections and cannot be used for other product injections, especially those with lower flow rates where the pressure at the injection device outlet is lower. This increases the cost of the device and limits its applications.

[0012] EP 0 574 126 A1 discloses a self-priming infusion tube assembly. DE 600 28 531 T2 discloses a fluid discharge device. Wikipedia discloses the definition of the pipe friction coefficient λ at the following URL: https: / / de.wikipedia.org / w / index.php?title=Rohrreibungszahl&oldid=70124531.

[0013] It is an object of the invention to provide a cost-effective set for injecting fluid into a patient that nevertheless allows high-throughput fluid injections into a patient while ensuring patient safety.

[0014] To this end, the invention relates to a kit of the type mentioned above, characterized in that the needle injection device comprises a needle holder, in that the needle holder comprises a core which receives the needle and the downstream end of the intermediate tube, and in that the pressure drop across the upstream conduit, between its upstream end and its downstream end, is higher than 25% of the total pressure drop between the upstream end of the upstream conduit and the free end of the needle during the injection of liquid via the upstream conduit and the needle injection device, advantageously between 25% and 45% of the total pressure drop, the kit comprising an implantable chamber comprising a hollow base body, the septum closing the base body,and wherein the chamber has a conduit for emptying fluid from the base body, wherein the pressure drop through the needle injection device is less than four times the pressure drop through the chamber when the needle is inserted into the chamber.

[0015] The cutlery according to the invention may contain one or more of the following features individually or in any technically possible combination: - the pressure drop between the upstream end of the upstream line and the downstream end of the upstream line is higher than 30% of the total pressure drop between the upstream end of the upstream line and the free end of the needle and, in particular, is between 30% and 45% of the total pressure drop; - the length of the upstream pipe is greater than six times the length of the intermediate pipe; - the mean fluid passage internal diameter within the upstream conduit is less than or equal to 150% of the mean fluid passage internal diameter within the intermediate pipe; - the upstream conduit comprises an upstream tube defining a fluid circuit passage and projections for increasing the pressure drop arranged in the fluid circuit passage; and - the upstream line comprises an upstream pipe and at least one pressure drop device interposed on the upstream pipe.

[0016] The invention also relates to a method for providing a set for injecting fluid into a patient for injecting fluid into an implantable chamber arranged in the patient, the implantable chamber comprising a hollow base body, a septum closing the base body and a conduit for emptying fluid from the base body, the method being of the type comprising the following steps: - Providing a needle injection device, the needle injection device comprising a needle having a free end intended to be inserted into the septum, an intermediate tube, and a needle holder, the needle holder comprising a core receiving the needle and the downstream end of the intermediate tube; - providing an upstream conduit including an upstream end intended to be connected to a liquid dispensing device and a downstream end intended to be detachably connected to the intermediate tube, so that the pressure drop between the upstream end of the upstream conduit and the downstream end of the upstream conduit is higher than 25% of the total pressure drop between the upstream end of the upstream conduit and the free end of the needle; - Connecting the downstream end of the upstream line to the intermediate pipe, wherein the pressure drop through the needle injection device is less than four times the pressure drop through the chamber when the needle is inserted into the chamber.

[0017] The process according to the invention may include one or more of the following features individually or in all technically possible combinations: - the method further includes a step of adjusting the injection flow rate of the fluid dispensing device, prior to injecting fluid into the patient, to a value greater than or equal to 1 ml / s; and - the pressure drop between the upstream end of the upstream line and the free end of the needle is higher than ten bar.

[0018] The invention also relates to a method for injecting a liquid, advantageously a non-therapeutic liquid, in particular a diagnostic product such as a contrast agent for medical imaging, into a patient, the method being of the type comprising the following steps: - providing an upstream conduit having an upstream end and a downstream end; - connecting the upstream end of the upstream line to a fluid dispensing device and the downstream end of the upstream line to a needle injection device comprising a needle having a free end, the free end of the needle being designed to be inserted into a septum of an implantable chamber comprising a hollow base body, the septum closing the hollow base body; - Injection of fluid from the fluid delivery device via the upstream line, the needle injection device and the implantable chamber, wherein the pressure drop between the upstream end of the upstream line and the downstream end of the upstream line is greater than 25% of the pressure drop between the upstream end of the upstream line and the free end of the needle.

[0019] The invention will be better understood from the following description, given by way of example only, with reference to the accompanying drawings in which: - Fig. Figure 1 is a schematic sectional view of a first injection set according to the invention in use; - Fig. Figure 2 is a perspective view of an example of a needle injection device used in the kit of Fig. 1 can be used; - Fig. 3 a perspective view of the implantable chamber of the set of Fig. 1 is; - Fig. Figure 4 is a schematic view illustrating the first cutlery according to the invention; - Fig. 5 a view analogous to Fig. 4 is for a second cutlery according to the invention; - Fig. 6 a view analogous to Fig. 4 is for a third cutlery according to the invention; - Fig. Figure 7 is a partial sectional view illustrating the upstream conduit of a fourth piece of kit according to the invention; - Fig. Figure 8 is a diagram schematically illustrating the pressure drop across a tool according to the invention when injecting fluid through that tool.

[0020] In the following, the terms “upstream” and “downstream” are to be understood generally with reference to the normal flow direction of a fluid during its injection.

[0021] A first set 10 for injecting fluid into a patient 11 is shown in Fig. 3. Such a set 10 is particularly intended for injecting a fluid into the patient's vascular system at a high flow rate, for example at a flow rate of more than 1 ml / second, advantageously equal to 5 ml / second.

[0022] The injected fluid is, for example, a medication. In one variant, the injected fluid is a non-therapeutic fluid, such as a diagnostic product, in particular a contrast agent for medical imaging. The contrast agent makes it possible to create an image of the patient's vascular system, for example, using computed tomography.

[0023] The injected fluid has a viscosity preferably between 1 mPa.s and 20 mPa.s.

[0024] The set 10 comprises, from upstream to downstream, a fluid dispensing device 12 located outside the body of the patient 11, an upstream conduit 13, a needle injection device 14 intended to be inserted through the skin 16 of the patient 11, and an implantable chamber 18 according to the invention located under the skin 16 of the patient and hydraulically connected downstream to a blood circulation channel 20.

[0025] The device 12 contains a pump 22, for example, with a cylinder, which can dispense a liquid at an adjustable volumetric flow rate. The device 12 or injection device advantageously contains a member 24 for adjusting the volumetric flow rate of the pump, which can be actuated by a user.

[0026] The cylinder pump 22 of the device 12 includes an outlet attachment 26 designed to removably receive the upstream line 13.

[0027] The upstream conduit 13 includes a flexible upstream tube 28, an upstream connector 30 located at an upstream end 30A of the tube 28, and a downstream connector 32 located at a downstream end 32A of the tube 28.

[0028] The length of the upstream line is more than 1.5 m and is, for example, between 1.5 m and 2.5 m.

[0029] The fluid passage inner diameter is preferably less than 1.5 mm, as will be seen below.

[0030] The needle injection device 14 is, for example, of the type described in the applicant's French applications FR 2 869 806 A1 or FR 2 886 857 A1. It includes a needle holder 34, a needle 36 carried by the needle holder, and an intermediate tube 38 designed to connect the needle 36 to the upstream conduit.

[0031] The needle holder 34 includes a core 40 which receives the needle 36 and the downstream end of the intermediate tube 38, support ribs 42 which are intended to be placed on the patient’s skin, and in Fig. 2, an optional needle protection unit 44 which is permanently mounted on the core 40.

[0032] The core 40 is manufactured on the basis of a rigid body extending along a longitudinal axis AA'.

[0033] The support ribs 42 project transversely with respect to the axis AA' on both sides of the core 40.

[0034] The core 40 defines an inner receiving passage of an upstream portion of the needle 36 and the downstream end of the intermediate tube 38.

[0035] The needle 36 is advantageously a curved needle, called a "Huber" needle. This needle 36 includes an upstream portion 35 located within the core 40 and a downstream portion 46 projecting along an axis BB' perpendicular to the axis AA' of the core 40, for insertion into the skin 16 of the patient 11.

[0036] The downstream portion 46 of the needle 36 has a free beveled end 48 to facilitate penetration of the needle 36 through the skin 16 and its introduction into the chamber 18.

[0037] The intermediate tube 38 is permanently secured in the needle holder 34. It extends between an upstream end 50A, which is provided with a connector 50, and a downstream end 52, which is permanently connected to the upstream portion 35 of the needle 36 in the core 40.

[0038] The intermediate tube 38 is advantageously provided with a closure member formed by a clamp 54 which can interrupt or reduce the amount of fluid flowing through the intermediate tube 38.

[0039] The Fig. The needle protection unit 44 shown in Figure 2 is optional. This needle protection unit 44 is described in detail in French application FR 2 886 857 A1. It includes a base 56 pivoted around the core 40 and a hollow pusher 58 slidably mounted in the base 56 to receive the downstream portion 46 of the needle 36 during its withdrawal.

[0040] As described in detail in FR 2 886 857 A1, the base 56 and the pusher 58 are pivotable about the axis CC' between a lying product injection configuration in the patient, which is Fig. 2, and an upright configuration of withdrawing the needle into the hollow pusher 58.

[0041] According to the invention, the upstream line 13 and the needle injection device 14 are dimensioned such that the pressure drop ΔPa through the upstream line 13 between the upstream end 30A and the downstream end 32B of the upstream line 13 is higher than 25% of the total pressure drop ΔPb through the upstream line 13 and the needle injection device 14 between the upstream end 30A of the upstream line 13 and the free end 48 of the needle.

[0042] For example, if the pressure delivered by the pump of the device 12 is higher than 16 bar, with a fluid flow rate delivered by the pump of more than 5 ml / sec, the pressure drop ΔPa through the upstream line 13 is higher than 4 bar, with a total pressure drop ΔPb through the upstream line 13 and the needle injection device 14 higher than 12 bar.

[0043] Advantageously, the pressure drop ΔPa through the line 13 is between 25% and 60% of the total pressure drop ΔPb through the line 13 and the needle injection device 14, and in particular between 25% and 45%, advantageously between 30% and 45%, of this total pressure drop.

[0044] For this purpose, in a first embodiment, which is shown schematically in Fig. 4, the fluid passage inner diameter D1 through the upstream pipe 28 is less than or equal to 150%, in particular less than 100%, of the fluid passage inner diameter D2 through the intermediate pipe 38.

[0045] For example, if the fluid passage diameter D2 of the intermediate tube 38 is between 1 mm and 1.5 mm, the fluid passage inner diameter D1 of the tube 28 is between 1.5 mm and 1.3 mm.

[0046] As will be seen below, this pressure drop within the upstream line 13 ensures that the fluid pressure in the chamber 18 is lower than a given safety value when the needle 36 is inserted into the chamber 18, despite the large internal cross-section of the intermediate tube 38 and despite the relatively weak pressure drop across the needle 36.

[0047] In addition, the pressure drop through the needle injection device 14 is less than three times, in particular four times, the pressure drop through the chamber 18 when the needle 36 is inserted into the chamber.

[0048] In addition, the pressure drop between the upstream end 30A of the upstream line 13 and the free end 48 of the needle 36 is higher than four times the pressure drop through the chamber 18.

[0049] To measure these pressure drops, the following method can be used: either by simulating fluid flow or by simulating an in vitro injection by placing pressure sensors at appropriate locations. The fluid used to measure the pressure drop has a viscosity equal to 10 mPa.s.

[0050] As through the Fig. 1 to 3, the chamber 18 has a base body 140 which defines an internal volume 142 for receiving liquid, a septum 144 closing the internal volume 142 and intended to be pierced by the needle 36, and a line or channel 146 for emptying the liquid from the internal volume 142 to the circulation channel of the blood 20.

[0051] The base body 140 includes an inner container 150 having a central axis DD' and an outer peripheral housing 152, which in this example is snapped onto the inner container 150.

[0052] In this example, the container 150 includes a metallic tray 154 for holding liquid, a lower insert 156 mounted around the tray 154, and a retaining ring 158 of the septum 144 disposed above the tray 154. In one variation, the tray 154, insert 156, and retaining ring 158 are made from a single piece.

[0053] The tub 154 is formed, for example, from titanium. It has a bottom 160 that defines the bottom of the interior volume 142 and partially that of the chamber 18, and a substantially cylindrical side wall 162 that laterally defines the interior volume 142.

[0054] The side wall 162 has an annular shoulder 164 for supporting the septum 144, which extends along its upper edge.

[0055] The insert 156 extends around the side wall 162 of the tub 154 under the annular shoulder 164.

[0056] The retaining ring 158 extends opposite the annular shoulder 164 and defines an upper clamping surface of the septum 144.

[0057] The internal volume 142 is defined between the side wall 162 and the bottom of the tub 154. The internal volume 142 opens upwardly via an upper main opening 168, which accommodates the septum 144. It opens laterally through the side wall 162 of the tub via a radial opening 170 for product discharge. The radial opening 170 has a smaller cross-section than the cross-section of the main opening 168.

[0058] The insert 156 defines a radial passage through which the conduit 146 extends.

[0059] The peripheral housing 152 is made of plastic, such as polyoxymethylene or POM. It extends around the insert 156 and the retaining ring 158 to hold the retaining ring 158 and the insert 156 in position on the tray 154.

[0060] The peripheral housing 152 has a lower surface 172 flush with the bottom 160 of the container 150 and a concave upper surface 174 that converges from top to bottom from the retaining ring 158 to a peripheral edge 176 of the peripheral housing 152 located in the region of the lower surface 172.

[0061] The peripheral housing 152 has a peripheral lip 178 substantially parallel to the lower surface 172 which engages the retaining ring 158 around the main opening 168.

[0062] The peripheral edge 176 defines the outer contour of the chamber 18. In this example, this contour has a substantially triangular shape.

[0063] The peripheral housing 152 also defines through openings 180 for the passage of a suture material and a radial opening 182 for the passage of the conduit 146.

[0064] The through-holes 180 connect the upper surface 174 to the lower surface 172 near the peripheral edge 176, substantially parallel to the axis D-D'. They are angularly distributed around the axis DD'. The radial opening 182 opens opposite the opening 170, which it extends radially with respect to the axis DD'.

[0065] The septum 144, for example, is made of a soft plastic such as silicone. It has a central region 184 that closes the main opening 168 and a peripheral region 186 that is clamped between the annular shoulder 164 and the lower surface 166 of the retaining ring 158. The main region 184 has a greater height than the peripheral region.

[0066] The septum 144 tightly seals the inner volume 142 from the outside.

[0067] The line 146 includes a rigid connection 188, a flexible tube 190 and a clamping ring 192 for crimping the flexible tube 190 onto the rigid connection 188.

[0068] It projects radially relative to the base body 140 through the radial opening 182 and beyond this radial opening 182.

[0069] The rigid connector 188 is formed by a hollow rod 194 mounted on the side wall 162 of the container around the opening 170. The hollow rod 194 projects radially from the base body 140 through the radial opening 182.

[0070] The tube 190 is made of soft plastic. It has a greater length than the maximum transverse dimension of the base body 140, for example, at least twice this maximum dimension.

[0071] The tube 190 extends between an upstream end 196 which is press-fitted around the free end of the rigid connector 188 and a free downstream end 198 which is intended to be inserted into the blood circulation channel 20.

[0072] The clamping ring 192 is press-fitted into the radial opening 182 to compress the flexible tube 190 against the hollow rod 194. It projects radially beyond the base body 140 for a length less than that of the tube 190, for example, at least twice that of the tube 190.

[0073] The operation of the first cutlery 10 according to the invention will now be described.

[0074] First, the implantable chamber 18 is surgically placed beneath the skin 16 of the patient 11. To this end, the chamber 18 is placed against the patient's tissue and held in place by suturing it through the through-holes 180. The septum 144 is then positioned adjacent to the skin 16 to conveniently receive the needle 36 of the needle injection device 14.

[0075] The elastic tube 190 is extended in the patient's body to position its free end 198 in the patient's vascular system, for example, in a blood circulation channel 20.

[0076] Then the patient's skin 16 is placed back on so that the chamber 18 is partially or completely covered by the skin 16.

[0077] When a fluid injection is to be performed into the patient, the physician first performs an X-ray of the patient to indicate the exact position of the chamber 18 and to determine its characteristics, in particular the injection flow rate or the maximum pressure.

[0078] He then sets the flow rate adjustment device 24 to a flow rate lower than or equal to the maximum flow rate allowed by the chamber 18.

[0079] The physician then selects an upstream line 13 and a needle injection device 14 as defined above.

[0080] The physician connects the upstream connector 30, located at the upstream end 30A of the upstream line 13, to the output attachment 26 of the device 12.

[0081] He then connects the intermediate pipe 38 to the upstream line 13 by mounting the connector 50 located at the upstream end 50A of the intermediate pipe 38 onto the downstream connector 32 located at the downstream end 32B of the upstream pipe 28.

[0082] The presence of the upstream line 13, which is selected so that the pressure drop ΔPa through this line 13 is higher than at least 25% of the total pressure drop ΔPb through the line 13 and the needle injection device 14, guarantees that the total pressure drop ΔPb is sufficiently large to ensure patient safety, in particular by preventing the pressure in the chamber from exceeding the maximum pressure Ps that this chamber can withstand at high injection flow rates.

[0083] This guarantee is maintained even if the needle injection device 14 is not specifically designed for high-throughput injections. This allows for the use of a standardized needle injection device at a lower cost.

[0084] The physician then inserts the needle 36 through the skin 16 of the patient 11 and through the septum 144 by grasping the needle holder 34 to guide the free end 48 of the needle 36 into the internal volume 142.

[0085] A continuous fluid path is then established from the device 12 through the outlet cap 26, the upstream tube 28, the intermediate tube 38, the needle 36, the internal volume 142, the orifice 170 and the downstream channel defined in the conduit 146 to a free end 198 of the tube 190.

[0086] The doctor can then safely inject fluid into the patient, especially at a high flow rate of more than 1 ml / s, especially higher than 4 ml / s.

[0087] As through Fig. As illustrated in Figure 8, although the injection pressure P1 at the outlet of the device 12 is higher than four times the maximum pressure Ps tolerated by the chamber, the upstream line 13 is designed to significantly reduce the pressure P2 at its outlet.

[0088] This ensures that the pressure P3 in the chamber 18 at the free end 48 of the needle 36 is substantially lower than the maximum pressure Ps, even if the needle injection device 14 has a small pressure drop.

[0089] The needle injection device 14 can therefore be used not only in high pressure applications with an upstream line 13 that guarantees patient safety, but also in applications with much lower injection pressures without an upstream line 13 or with an upstream line with a low pressure drop.

[0090] The cost of the needle injection device 14, and thus of the set 10, can be reduced accordingly, since a standard needle injection device can be manufactured for both the high-pressure and low-pressure applications.

[0091] In the case of an injection at a pressure of approximately 0.1 bar relative to the outlet of the device 12, the flow rate through the chamber 18 can be higher than 0.5 ml / s. Despite the low inlet pressure, this flow rate is, for example, higher than 0.6 ml / s.

[0092] The second injection set 210, which is Fig. 5, the fluid passage inner diameter D1 of the upstream pipe 28 is not necessarily less than 150% of the fluid passage inner diameter D2 of the intermediate pipe 38.

[0093] In contrast, the length L1 of the upstream pipe 28 is increased and is chosen to be greater than, for example, at least six times the length L2 of the intermediate pipe 38.

[0094] In the third kit 220 according to the invention, the upstream line 13 is provided with an intermediate element 222, formed for example by a filter, which makes it possible to increase its pressure drop so that the pressure drop through the upstream line 13 is higher than 25% of the pressure drop through the upstream line 13 and the needle injection device 14.

[0095] For this purpose, the pressure drop through filter 222, for example, is higher than 2.5 bar.

[0096] The operation of the third cutlery 220 according to the invention is analogous to that of the first cutlery 10.

[0097] The upstream pipe 28 of a fourth piece of equipment 230 according to the invention is in Fig. 7. Unlike the upstream tube 28 of the first set 10, this tube is provided with elements 232 projecting into the inner passage defined by the upstream tube 28 so that the pressure drop through the upstream line 13 is higher than 25% of the pressure drop through the upstream line 13 and the needle injection device 14.

[0098] In Fig. In the example shown in Figure 7, the projecting elements 232 are formed by protrusions projecting radially to the axis of the tube 28.

[0099] The operation of the fourth cutlery 230 according to the invention is also analogous to that of the first cutlery 10.

[0100] As described above, pressure drops can be clearly measured by simulating fluid flow or in vitro injection by placing pressure sensors at appropriate locations. In the former case, software programs such as FLUENT, COMSOL, or CODE SATURNE can be used. In the case of in vitro injection simulations, the fluid flow rate can also be set to 5 ml / s and the viscosity to 10 mPa.s.

[0101] Another way to determine pressure drops can be to use Poiseuille's law, which defines the pressure drop produced by laminar flow in a pipe as a function of diameter, length, fluid flow rate, and viscosity.

[0102] As stated above, the fluid flow rate is fixed at 5 ml / s and the viscosity is chosen at 10 mPa.s.

[0103] Particular embodiments of the invention will now be described. Example 1 :

[0104] A needle injection device 14 of the type Polyperf Safe® 603011, distributed by PEROUSE MEDICAL, is used. This needle injection device 14 includes a needle 36 and an intermediate tube 38. The pressure drop measured by this needle injection device between the free end 48 of the needle and the upstream end of the intermediate tube 38 is 3.32 bar.

[0105] To obtain an upstream line 13 having a pressure drop between its upstream end 30A and its downstream end 32B of greater than 25% of the total pressure drop between the upstream end 30A of the upstream line 13 and the free end of the needle 36, the upstream line 13 has a fluid passage inner diameter of 2.2 mm and a length of 127 cm. In this case, the pressure drop generated by the upstream line 13 is 1.1 bar. This represents approximately 25% of the total pressure drop. Example 2 :

[0106] In this example, a needle injection device 14 of the type Polyperf Safe® 601509, marketed by PEROUSE MEDICAL, is used. This needle injection device 14 has a pressure drop of 3.95 bar. In this case, the upstream line 13 has a diameter of 2.2 mm and a length of 151 cm. With this length, the upstream line 13 generates a pressure drop of 1.31 bar, which is essentially equal to 25% of the total pressure drop. Example 3 :

[0107] The needle injection device 14 is a Polyperf Safe® 601507, distributed by PEROUSE MEDICAL. This needle injection device 14 has a pressure drop of 3.90 bar. The upstream line 13 is then selected with a fluid passage inner diameter of 1.5 mm and a length of 134 cm, creating a pressure drop of 1.30 bar. Example 4 :

[0108] The same needle injection device 14 as in Example 1 is used. The upstream line 13 has a fluid passage inner diameter of 1.2 mm and a length of 139 cm. The pressure drop through the upstream line 13 between its upstream end and its downstream end is substantially equal to 13.7 bar, i.e., 80% of the total pressure drop between the upstream end 30A of the upstream line 13 and the free end 48 of the needle 36. Example 5 :

[0109] The same needle injection device 14 as in Example 2 is used. An upstream line 13 with a fluid passage inner diameter of 1.2 mm and a length of 133 cm is used. The pressure drop through the upstream line 13 is substantially equal to 13.0 bar, which represents 76% of the total pressure drop between the upstream end 30A of the upstream line 13 and the free end 48 of the needle 36. Example 6 :

[0110] The same needle injection device 14 as in Example 3 is used. The upstream line 13 has a diameter of 0.8 mm and a length of 110 cm, creating a pressure drop of 13.1 bar. This pressure drop represents approximately 77% of the total pressure drop between the upstream end 30A of the upstream line 13 and the free end 48 of the needle 36.

[0111] These above examples illustrate the fact that the necessary parameters to obtain a set according to the invention in which the pressure drop through the upstream conduit between its upstream end and its downstream end is higher than 25% of the total pressure drop between the upstream end of the upstream conduit and the free end of the needle can be determined depending on the needle injection device 14 considered.

Claims

[1] Set (10; 210; 220 ; 230) for injecting fluid into a patient, the set containing: - a needle injection device (14) comprising a needle (36) having a free end (48) adapted to be inserted into a septum (144) of an implantable chamber (18) containing a hollow base body (140), the septum (144) closing the base body (140), and the chamber containing a conduit (146) for draining fluid from the base body (140); the needle injection device (14) comprising an intermediate tube (38); - an upstream line (13) having an upstream end (30A) intended to be connected to a liquid dispensing device (12) and a downstream end (32A), wherein the downstream end (32A) is detachably connected to the intermediate pipe (38), wherein the needle injection device (14) comprises a needle holder (34), wherein the needle holder (34) includes a core (40) which receives the needle (36) and the downstream end of the intermediate tube (38), and wherein the pressure drop through the upstream line (13) between its upstream end (30A) and its downstream end (32A) is higher than 25% of the total pressure drop between the upstream end (30A) of the upstream line (13) and the free end (48) of the needle (36) when injecting liquid via the upstream line (13) and the needle injection device (14), characterized bythat the instrument contains an implantable chamber (18) containing a hollow base body (140), wherein the septum (144) closes the base body (140), and wherein the chamber has a conduit (146) for emptying fluid from the base body (140), wherein the pressure drop through the needle injection device (14) is less than four times the pressure drop through the chamber (18) when the needle (36) is inserted into the chamber (18). [2] Cutlery (10; 210; 220; 230) according to claim 1, characterized by that the pressure drop between the upstream end (30A) of the upstream line (13) and the downstream end (32A) of the upstream line (13) is higher than 30% of the total pressure drop between the upstream end (30A) of the upstream line (13) and the free end (48) of the needle (36), and in particular is between 30% and 45% of the total pressure drop. [3] Cutlery (210) according to one of the preceding claims, characterized by that the length of the upstream line (13) is greater than six times the length of the intermediate pipe (38). [4] Cutlery (10) according to one of the preceding claims, characterized by that the mean fluid passage inner diameter within the upstream conduit (13) is less than or equal to 150% of the mean fluid passage inner diameter within the intermediate pipe (38). [5] Cutlery (230) according to one of the preceding claims, characterized by in that the upstream conduit (13) comprises an upstream tube defining a fluid circuit passage and projections (232) for increasing the pressure drop arranged in the fluid circuit passage. [6] Cutlery (220) according to one of the preceding claims, characterized byin that the upstream line (13) comprises an upstream pipe (28) and at least one pressure drop member (222) interposed on the upstream pipe (28). [7] A method of providing a set (10; 210; 220; 230) for injecting fluid into a patient, for injecting fluid into an implantable chamber (18), the implantable chamber (18) comprising a hollow base body (140), a septum (144) closing the base body (140) and a conduit (146) for emptying fluid from the base body (140), the method being of the type comprising the following steps: - Providing a needle injection device (14), the needle injection device (14) comprising a needle (36) having a free end (48) intended to be inserted into the septum (144), an intermediate tube (38) and a needle holder (34), the needle holder (34) including a core (40) receiving the needle (36) and the downstream end of the intermediate tube (38); - providing an upstream line (13) having an upstream end (30A) intended to be connected to a device (12) for dispensing liquid and a downstream end (32A) intended to be removably connected to the intermediate tube (38) so that the pressure drop between the upstream end (30A) of the upstream line (13) and the downstream end (32A) of the upstream line (13) is greater than 25% of the total pressure drop between the upstream end (30A) of the upstream line (13) and the free end (48) of the needle (36); - connecting the downstream end (32A) of the upstream line (13) to the intermediate tube (38), wherein the pressure drop through the needle injection device (14) is less than four times the pressure drop through the chamber (18) when the needle (36) is inserted into the chamber (18). [8] Method according to claim 7, characterized by that it further comprises a step of adjusting the injection flow rate of the liquid dispensing device (12) to a value greater than or equal to 1 ml / s before injecting liquid into the patient. [9] Method according to one of claims 7 or 8, characterized by that the pressure drop between the upstream end (30A) of the upstream line (13) and the free end (48) of the needle (36) is higher than ten bar.

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